Change search
Refine search result
1234 1 - 50 of 179
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1. Alaerts, Maaike
    et al.
    Ceulemans, Shana
    Forero, Diego
    Moens, Lotte N.
    De Zutter, Sonia
    Heyrman, Lien
    Lenaerts, An-Sofie Lenaerts
    Norrback, Karl-Fredrik
    Umeå universitet.
    Goossens, Dirk
    De Rijk, Peter
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Adolfsson, Rolf
    Umeå universitet.
    Del-Favero, Jurgen
    Detailed analysis of the serotonin transporter gene (SLC6A4) shows no association with bipolar disorder in the Northern Swedish population2009In: American Journal of Medical Genetics Part B: Neuropsychiatric Genetics, ISSN 1552-4841, Vol. 150B, no 4, p. 585-592Article in journal (Refereed)
    Abstract [en]

    Through active reuptake of serotonin into presynaptic neurons, the serotonin transporter (5-HTT) plays an important role in regulating serotonin concentrations in the brain, and it is the site of binding for tricyclic antidepressants and selective serotonin reuptake inhibitors (SSRIs). Therefore it has been hypothesized that this transporter is involved in the etiology of bipolar (BP) disorder. Inconsistent association study results for the SLC6A4 gene encoding 5-HTT reported in literature emphasize the need for more systematic and detailed analyses of this candidate gene. We performed an extensive analysis of SLC6A4 on DNA of 254 BPI patients and 364 control individuals from a Northern Swedish isolated population. This analysis consisted of a HapMap LD-based association study including three widely investigated polymorphisms (5-HTTVNTR, 5-HTTLPR, and rs3813034), a copy-number variation (CNV) analysis and a mutation analysis of the complete coding sequence and the 3'-UTR of SLC6A4. No single marker showed statistically significant association with BPI, nor did any of the haplotypes. In the mutation analysis 13 novel variants were detected, including 2 amino acid substitutions M389V and 1587L, but these are probably not implicated in risk for BP. No deletions or duplications were detected in the CNV analysis. We conclude that variation in the SLC6A4 gene or its regulatory regions does not contribute to the susceptibility for BP disorder in the Northern Swedish population.

  • 2. Alaerts, Maaike
    et al.
    Ceulemans, Shana
    Forero, Diego
    Moens, Lotte N.
    De Zutter, Sonia
    Heyrman, Lien
    Lenaerts, An-Sofie
    Norrback, Karl-Fredrik
    De Rijk, Peter
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Goossens, Dirk
    Adolfsson, Rolf
    Del-Favero, Jurgen
    Support for NRG1 as a Susceptibility Factor for Schizophrenia in a Northern Swedish Isolated Population2009In: Archives of General Psychiatry, ISSN 0003-990X, E-ISSN 1538-3636, Vol. 66, no 8, p. 828-837Article in journal (Refereed)
    Abstract [en]

    Context: Neuregulin 1 (NRG1), a growth factor involved in neurodevelopment, myelination, neurotransmitter receptor expression, and synaptic plasticity, first joined the list of candidate genes for schizophrenia when a 7-marker haplotype at the 5' end of the gene (Hap(ICE)) was shown to be associated with the disorder in the Icelandic population. Since then, more genetic and functional evidence has emerged, which supports a role for NRG1 in the development of schizophrenia.

    Objective: To determine the contribution of NRG1 to susceptibility for schizophrenia in a northern Swedish isolated population.

    Design: Detailed linkage disequilibrium (LD)-based patient- control association study. This is the first study to type and analyze the 7 Hap(ICE) markers and a set of 32 HapMap tagging single-nucleotide polymorphisms (SNPs) that represents variants with a minor allele frequency of at least 1% and fully characterizes the LD structure of the 5' part of NRG1.

    Setting: Outpatient and inpatient hospitals.

    Participants: A total of 486 unrelated patients with schizophrenia and 514 unrelated control individuals recruited from a northern Swedish isolated population.

    Main Outcome Measures: Association between markers and disease.

    Results: Analysis of the Hap(ICE) markers showed the association of a 7-marker and 2-microsatellite haplotype, different from the haplotypes associated in the Icelandic population and overrepresented in northern Swedish control individuals. Subsequently, a more detailed analysis that included all 37 genotyped SNPs was performed by investigating haplotypic association, dependent and independent of LD block structure. We found significant association with 5 SNPs located in the second intron of NRG1 (.007 <= P <= .04). Also, 2-, 3-, and 4-SNP windows that comprise these SNPs were associated (P < 3 x 10(-4)). One protective haplotype (0% vs 1.8%; P < 5 x 10(-5)) and 1 disease risk-causing haplotype (40.4% vs 34.9%, P=.02) were defined.

    Conclusion: The NRG1 gene contributes to the susceptibility for schizophrenia in the northern Swedish population.

  • 3.
    Andreasson, Anna Nixon
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet.
    Szulkin, Robert
    Undén, Anna-Lena
    von Essen, Jan
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Lekander, Mats
    Stockholm University, Faculty of Social Sciences, Stress Research Institute. Karolinska Institutet.
    Inflammation and positive affect are associated with subjective health in women of the general population2013In: Journal of Health Psychology, ISSN 1359-1053, E-ISSN 1461-7277, Vol. 18, no 3, p. 311-320Article in journal (Refereed)
    Abstract [en]

    Poor subjective health has been associated with higher levels of inflammatory cytokines. We investigated whether such an association would apply to women of the general population. Levels of cytokines, affect and subjective health were assessed in 347 women of the general population aged 45 to 90 years. Higher levels of interleukin-6 were associated with poor subjective health, especially in participants over 65 years of age. Positive affect was a more robust determinant of subjective health than negative affect. The presence of low-grade inflammation and absence of positive affect, rather than presence of negative affect, may be important determinants of subjective health.

  • 4. Athanasiu, Lavinia
    et al.
    Giddaluru, Sudheer
    Fernandes, Carla
    Christoforou, Andrea
    Reinvang, Ivar
    Lundervold, Astri J.
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Aging Research Center (ARC), (together with KI). Umeå University, Sweden.
    Kauppi, Karolina
    Adolfsson, Rolf
    Eriksson, Elias
    Sundet, Kjetil
    Djurovic, Srdjan
    Espeseth, Thomas
    Nyberg, Lars
    Steen, Vidar M.
    Andreassen, Ole A.
    Le Hellard, Stephanie
    A genetic association study of CSMD1 and CSMD2 with cognitive function2017In: Brain, behavior, and immunity, ISSN 0889-1591, E-ISSN 1090-2139, Vol. 61, p. 209-216Article in journal (Refereed)
    Abstract [en]

    The complement cascade plays a role in synaptic pruning and synaptic plasticity, which seem to be involved in cognitive functions and psychiatric disorders. Genetic variants in the closely related CSMD1 and CSMD2 genes, which are implicated in complement regulation, are associated with schizophrenia. Since patients with schizophrenia often show cognitive impairments, we tested whether variants in CSMD1 and CSMD2 are also associated with cognitive functions per se. We took a discovery-replication approach, using well-characterized Scandinavian cohorts. A total of 1637 SNPs in CSMD1 and 206 SNPs in CSMD2 were tested for association with cognitive functions in the NCNG sample (Norwegian Cognitive NeuroGenetics; n = 670). Replication testing of SNPs with p-value < 0.001 (7 in CSMD1 and 3 in CSMD2) was carried out in the TOP sample (Thematically Organized Psychosis; n =1025) and the BETULA sample (Betula Longitudinal Study on aging, memory and dementia; n = 1742). Finally, we conducted a meta-analysis of these SNPs using all three samples. The previously identified schizophrenia marker in CSMD1 (SNP rs10503253) was also included. The strongest association was observed between the CSMDI SNP rs2740931 and performance in immediate episodic memory (p-value = 5 Chi 10(-6), minor allele A, MAF 0.48-0.49, negative direction of effect). This association reached the study-wide significance level (p <= 1.2 Chi 10(-5)). SNP rs10503253 was not significantly associated with cognitive functions in our samples. In conclusion, we studied n = 3437 individuals and found evidence that a variant in CSMD1 is associated with cognitive function. Additional studies of larger samples with cognitive phenotypes will be needed to further clarify the role of CSMD1 in cognitive phenotypes in health and disease.

  • 5. Backeström, Anna
    et al.
    Eriksson, Sture
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Olsson, Tommy
    Rolandsson, Olov
    Glucose but not insulin or insulin resistance is associated with memory performance in middle-aged non-diabetic women: a cross sectional study2015In: Diabetology and Metabolic Syndrome, ISSN 1758-5996, E-ISSN 1758-5996, Vol. 7, article id 20Article in journal (Refereed)
    Abstract [en]

    Background: Elevated concentrations of plasma glucose appear to play a role in memory impairment, and it has been suggested that insulin might also have a negative effect on cognitive function. Our aim was to study whether glucose, insulin or insulin resistance are associated with episodic or semantic memory in a non-diabetic and non-demented population. Methods: We linked and matched two population-based data sets identifying 291 participants (127 men and 164 women, mean age of 50.7 +/- 8.0 years). Episodic and semantic memory functions were tested, and fasting plasma insulin, fasting plasma glucose, and 2-hour glucose were analysed along with other potential influencing factors on memory function. Since men and women display different results on memory functions they were analysed separately. Insulin resistance was calculated using the HOMA-IR method. Results: A higher fasting plasma glucose concentration was associated with lower episodic memory in women (r = -0.08, 95% CI -0.14; -0.01), but not in men. Plasma insulin levels and insulin resistance were not associated with episodic or semantic memory in women or in men after adjustments for age, fasting glucose, 2-hour glucose, BMI, education, smoking, cardiovascular disease, hypertension, cholesterol, and physical activity. Conclusions: This indicates that fasting glucose but not insulin, might have impact on episodic memory in middle-aged women.

  • 6.
    Ballesteros, Soledad
    et al.
    Universidad Nacional de Educacin a Distancia, Madrid, Spain.
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Lemaire, Patrick
    Aix-en-Provence, University of Provence, France.
    Ageing, cognition, and neuroscience: An introduction2009In: European Journal of Cognitive Psychology, ISSN 0954-1446, E-ISSN 1464-0635, Vol. 21, no 2-3, p. 161-175Article, review/survey (Refereed)
    Abstract [en]

    The main goal of this special issue is to report new cognitive data in normal and pathological ageing that are related to neural data at different levels. Ageing is a universal complex process that profoundly affects mind and brain of all individuals. A number of psychological theories and theoretical approaches see ageing as a set of gains and losses. Cognitive research has relied upon behavioural measures of cognitive performance. We summarise briefly the large variety of topics dealt with in the articles that compose this special issue. This is organised in four main domains: (1) processing speed, inhibition, and executive processes in normal and pathological ageing; (2) implicit learning and memory in normal ageing; (3) cognitive flexibility and episodic memory; and (4) processing emotional information in the old age.

  • 7. Bergdahl, Jan
    et al.
    Larsson, Anne
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Åhlström, Katrina Riklund
    Nyberg, Lars
    Treatment of chronic stress in employees: Subjective, cognitive, and neural correlates.2005In: Scandinavian Journal of Psychology, ISSN 0036-5564, Vol. 46, no 5, p. 395-402Article in journal (Refereed)
    Abstract [en]

    This study reports the effect of an affect-focused intervention program, the Affect School (AS), on stress, psychological symptoms, cognitive functioning and neural activity. Fifty employees in social service and education, with high levels of chronic stress, were randomly divided into a treatment (N=27) and control (N=23) group. Complete sets of data were available in 20 participants in the treatment group and in 17 in the control group. The Percieved Stress Questionnaire assessed stress and the Symptom Chech List-90 psychological symptoms before and after the treatment. Episodic-memory functioning under focussed and divided attention conditions was also assessed. Prior and after the AS, seven participants in the treatment group were studied with fMRI during episodic memory processing. After the AS there was a reduction in stress and psychological symptoms for the treatment group but not in the control group. The controls showed a reduction in episodic memory functioning whereas the performance of the treatment group remained intact. The fMRI scanning indicated a qualitative change in the neural network subserving episodic memory. These preliminary results suggest that the AS is effective on individuals with high stress.

  • 8. Bergdahl, Maud
    et al.
    Bergdahl, Jan
    Nyberg, Lars
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Difference in apolipoprotein E type 4 allele (APOE ɛ4) among dentate and edentulous subjects2008In: Gerodontology, ISSN 0734-0664, E-ISSN 1741-2358, Vol. 25, no 3, p. 179-186Article in journal (Refereed)
    Abstract [en]

    Objectives: To evaluate the frequency of apolipoprotein (APOE) alleles and determine whether APOE type 4 allele (ɛ4) was associated with edentulousness even when certain factors were controlled.

    Background: The APOE are important in lipid homeostasis, and APOE ɛ4 has been found in many diseases and to have a negative impact on longevity. Tooth loss is more common in ill aged subjects with low income and education.

    Materials and methods: In a population-based study involving 1860 subjects between 35 and 85 years 1321 dentate (mean age = 54; 54% women, 46% men) and 539 edentulous (mean age = 72; 62% women, 38% men) subjects were studied. Logistic regression was performed with dentate/edentulous as dependent variables and years of education, socio-economic status, social network, stress level, handicap from birth, 23 various diseases and APOE ɛ4 as covariates. Thereafter, APOE ɛ4 frequencies were studied in 342 dentate and 336 edentulous subjects 50–85 years of age. The subjects were matched with regard to age, gender, years of education, living condition, stress level, handicap from birth and 23 various diseases.

    Results: APOE allele frequency in the total group was ɛ2 = 7.8%, ɛ3 = 76.4% and ɛ4 = 15.8%. Age, living condition, years of education and APOE ɛ4 were significant covariates in edentulous subjects (p ≤ 0.001). APOE ɛ4 in the matched groups revealed significant differences between the dentate group and the edentulous group (χ2 = 5.68; p = 0.017). There was no group effect (F(29,648) = 0.849; p < 0.696; Wilks' lambda = 0.963). In the dentate group, the frequencies of APOE were: ɛ2 = 8.8%, ɛ3 = 77.9% and ɛ4 = 13.3%. Corresponding frequencies of APOE in the edentulous group were: ɛ2 = 6.6%, ɛ3 = 75.4% and ɛ4 = 18.0%.

    Conclusion: Despite matching both groups with regard to different background factors, the edentulous group had a higher frequency of APOE ɛ4 than the dentate group. Thus, genetic factors might contribute to greater risk in developing complex oral diseases leading to tooth loss or just be an indication that the subjects in our study carrying APOE ɛ4 are more fragile.

  • 9. Bergdahl, Maud
    et al.
    Habib, Reza
    Bergdahl, Jan
    Nyberg, Lars
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Natural teeth and preserved cognitive function in humans.2007In: Scandinavian Journal of Psychology, Vol. 48, p. 557-565Article in journal (Refereed)
    Abstract [en]

    A number of neurobiological, psychological and social factors may account for cognitive impairment. In animal studies a relation between dental status and cognitive performance has been found. It is unclear whether such a relation exists for humans, even though many older adults have poor oral health. In a large-scale population-based study involving individuals between the ages 35 to 90 years, 1366 subjects with natural teeth (55% women, 45% men; age M=56.3) and 510 edentulous subjects (61% women, 39% men; age M=73.4) were compared regarding their performance on twelve cognitive tests. In a subsequent analysis, cognitive performance was examined while the natural teeth group (N=239; 51% women, 49% men; age M=69.2) and the edentulous group (N=216; 54% women, 46% men; age M=68.8) were matched with regard to age, gender, years of education, MMSE, stress level and various diseases. The natural teeth group had a lower mean age, more formal education, reported less back pain, and performed significantly higher on several cognitive tests. After matching the groups, the natural teeth group performed significantly higher on multiple cognitive tests. The results suggest that functional natural teeth relate to relatively preserved cognitive functioning in older age, which underlines the necessity of adequate dental care in the elderly.

  • 10. Bergman, Olle
    et al.
    Westberg, Lars
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Adolfsson, Rolf
    Eriksson, Elias
    Preliminary evidence that polymorphisms in dopamine-related transcription factors LMX1A, LMX1B and PITX3 are associated with schizophrenia2010In: Progress in Neuro-psychopharmacology and Biological Psychiatry, ISSN 0278-5846, E-ISSN 1878-4216, Vol. 34, no 6, p. 1094-1097Article, review/survey (Refereed)
    Abstract [en]

    The early development of dopaminergic pathways has been attributed importance for the aetiology of schizophrenia. Several transcription factors are involved in the survival and maturation of dopamine neurons, including LMX1A, LMX1B and PITX3. The possibility that polymorphisms in these genes may influence the development and/or the maintenance of dopaminergic neurons prompted us to investigate if five single nucleotide polymorphisms (SNPs) previously linked to Parkinson's disease are associated with this disorder. Preliminary evidence that genetic variation in LMX1A (rs6668493, rs4657411), LMX1B (rs10987386) and PITX3 (rs4919621) may increase the risk of developing schizophrenia is presented.

  • 11. Ceulemans, Shana
    et al.
    De Zutter, Sonia
    Heyrman, Lien
    Norrback, Karl-Fredrik
    Nordin, Annelie
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Adolfsson, Rolf
    Del-Favero, Jurgen
    Claes, Stephan
    Evidence for the involvement of the glucocorticoid receptor gene in bipolar disorder in an isolated northern Swedish population2011In: Bipolar Disorders, ISSN 1398-5647, E-ISSN 1399-5618, Vol. 13, no 7-8, p. 614-623Article in journal (Refereed)
    Abstract [en]

    Objectives: Dysfunction of the hypothalamus-pituitary-adrenal (HPA) axis is one of the most consistent findings in the pathophysiology of mood disorders. The potential role of genes related to HPA axis function has been investigated extensively in major depression. However, in bipolar disorder (BPD) such studies are scarce. We performed a systematic HapMap-based association study of six genes crucial for HPA axis function in relation to BPD. Methods: Haplotype tagging single nucleotide polymorphisms (htSNPs) were selected in order to identify all haplotypes with a frequency of more than 1% in the genes encoding the glucocorticoid receptor (GR), mineralocorticoid receptor (MR), corticotrophin releasing hormone receptor 1 (CRH-R1) and 2 (CRH-R2), CRH binding protein (CRH-BP), and FK binding protein 5 (FKBP5). This resulted in a total selection of 225 SNPs that were genotyped and analyzed in 309 BPD patients and 364 matched control individuals all originating from an isolated northern Swedish population. Results: Consistent evidence for an association with BPD was found for NR3C1, the gene encoding GR. Almost all SNPs in two adjacent haplotype blocks contributed to the positive signal, comprised of significant single marker, sliding window, and haplotype-specific p-values. All these results point to a moderately frequent (10–15%) susceptibility haplotype covering the entire coding region and 3? untranslated region (UTR) of NR3C1. Conclusions: This study contributes to the growing evidence for a role of the glucocorticoid receptor gene (NR3C1) in vulnerability to mood disorders, and BPD in particular, and warrants further in vitro investigation of the at-risk haplotypes with respect to disease etiology. However, this association might be restricted to this specific population, as it is observed in a rather small sample from an isolated population without replication, and data from large meta-analyses for genome-wide association studies in BPD do not show the GR as a very strong candidate.

  • 12. Danielsson, Henrik
    et al.
    Henry, Lucy
    Rönnberg, Jerker
    Nilsson, Lars-Goran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Executive functions in individuals with intellectual disability2010In: Research in Developmental Disabilities, ISSN 0891-4222, E-ISSN 1873-3379, Vol. 31, no 6, p. 1299-1304Article in journal (Refereed)
    Abstract [en]

    The aim of the present study was to investigate executive functions in adults with intellectual disability, and compare them to a closely matched control group longitudinally for 5 years. In the Betula database, a group of adults with intellectual disability (ID, n = 46) was defined from measures of verbal and non-verbal IQ. A control group, with two people for every person with intellectual disability (n = 92), was chosen by matching on the following criterion in order of priority: IQ higher than 85, age, sex, sample, level of education, and years of education. Three types of tasks of executive functions were included on two occasions, with 5 years between testing sessions: The Tower of Hanoi,. executively loaded dual task versions of word recall, and verbal fluency. Adults with ID showed significant impairments on verbal fluency and on the executively loaded dual task word recall task (at encoding but not at recall). There were no group differences on the Tower of Hanoi. No significant differences between the two test occasions were found. The results are interpreted in terms of individuals with ID having problems with speed of accessing lexical items and difficulties with working memory-related executive control at encoding, which includes shifting between tasks. There are, however, not necessarily problems with inhibition. The dual task results additionally imply that the adults with intellectual disability were more sensitive to strategy interruptions at encoding, but that dividing attention at recall did not have such detrimental effects.

  • 13. de Frias, Cindy
    et al.
    Lövdén, Martin
    Lindenberger, Ulman
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Revisiting the dedifferebtion hypothesis with longitudinal multi-cohort data2007In: Intelligence, Vol. 35, p. 381-392Article in journal (Refereed)
    Abstract [en]

    The present longitudinal multi-cohort study examines whether interindividual variability in cognitive performance and change increases in old age, and whether associations among developments of different cognitive functions increase with adult age. Multivariate multiple-group latent growth modeling was applied to data from narrow cohorts separated by five years of age. Tests assessing episodic recall, semantic knowledge, semantic fluency, and visuospatial ability were administered to 1000 non-demented adults (initially aged 35–80 years), participating in the Betula Project at three occasions over a 10-year period. Greater interindividual differences in change were noted in older age groups. Age-related increases in correlations among performance scores were noted for different cognitive measures beginning in old age, but not earlier. Our study supports a dynamic view of dedifferentiation of cognitive aging.

  • 14.
    de Frias, Cindy M.
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Annerbrink, Kristina
    Westberg, Lars
    Eriksson, Elias
    Adolfsson, Rolf
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Catechol O-Methyltransferase Val¹-sup-5-sup-8 Met Polymorphism is Associated with Cognitive Performance in Nondemented Adults.2005In: Journal of Cognitive Neuroscience, ISSN 0898-929X, Vol. 17, no 7, p. 1018-1025Article in journal (Refereed)
    Abstract [en]

    The catechol O-methyltransferase (COMT) gene is essential in the metabolic degradation of dopamine in the prefrontal cortex. In the present study, we examined the effect of a Val¹-sup-5-sup-8Met polymorphism in the COMT gene on individual differences and changes in cognition (executive functions and visuospatial ability) in adulthood and old age. The participants were 292 nondemented men (initially aged 35-85 years) from a random sample of the population (i.e., the Betula study) tested at two occasions with a 5-year interval. Confirmatory factor analyses were used to test the underlying structure of three indicators of executive functions (verbal fluency, working memory, and Tower of Hanoi). Associations between COMT, age, executive functioning, and visuospatial (block design) tasks were examined using repeated-measures analyses of variance. Carriers of the Val allele (with higher enzyme activity) compared with carriers of the Met/Met genotype (with low enzyme activity) performed worse on executive functioning and visuospatial tasks. Individuals with the /Val genotype declined in executive functioning over the 5-year period, whereas carriers of the Met allele remained stable in performance. An Age × COMT interaction for visuospatial ability located the effect for middle-aged men only. This COMT polymorphism is a plausible candidate gene for executive functioning and fluid intelligence in nondemented middle-aged and older adults.

  • 15.
    de Frias, Cindy M.
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Bunce, David
    Wahlin, Åke
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Adolfsson, Rolf
    Sleegers, Kristel
    Cruts, Marc
    Van Broeckhoven, Christine
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Cholesterol and triglycerides moderate the effect of apolipoprotein E on memory functioning in older adults.2007In: Journal of Gerontology: Psychological Sciences, ISSN 1079-5014, Vol. 62B, no 2, p. P112-P118Article in journal (Refereed)
    Abstract [en]

    We used data from the Betula Study to examine associations between total cholesterol, triglycerides, and apolipoprotein E on 10-year changes in cognitive performance. Tests assessing episodic memory (recall and recognition), semantic memory (knowledge and fluency), and visuospatial ability (block design) were administered to 524 nondemented adults (initial age of 55-80 years); multilevel modeling was applied to the data. Higher triglyceride levels were associated with a decline in verbal knowledge. Lipid levels moderated the influence of apolipoprotein E on episodic memory, such that among epsilon 4 allele carriers, decline in recognition was noted for individuals with higher cholesterol levels. Cholesterol and triglyceride levels are pharmacologically modifiable risk factors that account for variation In normal cognitive aging.

  • 16.
    de Frias, Cindy M.
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Marklund, Petter
    Eriksson, Elias
    Larsson, Anne
    Öman, Lena
    Annerbrink, Kristina
    Bäckman, Lars
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Nyberg, Lars
    Influence of COMT Gene Polymorphism on fMRI-assessed Sustained and Transient Activity during a Working Memory Task2010In: Journal of cognitive neuroscience, ISSN 0898-929X, E-ISSN 1530-8898, Vol. 22, no 7, p. 1614-1622Article in journal (Refereed)
    Abstract [en]

    The catechol O-methyltransferase (COMT) gene-encoding an enzyme that is essential for the degradation of dopamine (DA) in prefrontal cortex (PFC)-contains a single nucleotide polymorphism (val/met) important for cognition. According to the tonic-phasic hypothesis, individuals carrying the low-enzyme- activity allele (met) are characterized by enhanced tonic DA activity in PFC, promoting sustained cognitive representations in working memory. Val carriers have reduced tonic but enhanced phasic dopaminergic activity in subcortical regions, enhancing cognitive flexibility. We tested the tonic-phasic DA hypothesis by dissociating sustained and transient brain activity during performance on a 2-back working memory test using mixed blocked/event-related functional magnetic resonance imaging. Participants were men recruited from a random sample of the population (the Betula study) and consisted of 11 met/met and 11 val/val carriers aged 50 to 65 years, matched on age, education, and cognitive performance. There were no differences in 2-back performance between genotype groups. Met carriers displayed a greater transient medial temporal lobe response in the updating phase of working memory, whereas val carriers showed a greater sustained PFC activation in the maintenance phase. These results support the tonic-phasic theory of DA function in elucidating the specific phenotypic influence of the COMT val(158)met polymorphism on different components of working memory.

  • 17. de Frias, Cindy
    et al.
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Herlitz, Agneta
    Sex differences in cognition are stable over a 10-year period in adulthood and old age.2006In: Aging, Neuropsychology and Cognition, ISSN 1382-5585, Vol. 13, no 3-4, p. 574-587Article in journal (Refereed)
    Abstract [en]

    Sex differences in declarative memory and visuospacial ability are robust in cross-sectional studies. The present longitudinal study examined whether sex differences in cognition were present over a 10-year period, and whether age modified the magnitude of sex differences. Tests assessing episodic and semantic memory, and visuospatial ability were administered to 625 nondemented adults (initially aged 35-80 years), participating in the population based Betula study at two follow-up occasions. There was stability of sex differences across five age groups and over a 10-year period. Women performed at a higher level than men on episodic recall, face and verbal recognition, and semantic fluency, whereas men performed better than women on a task assessing visuospatial ability. Sex differences in cognitive functions are stable over a 10-year period and from 35 to 90 years of age. Decreasing levels of estrogen in women and sex differences in age-related cortical atrophy do not seem to influence cognitive sex differences.

  • 18.
    Del Missier, Fabio
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Cognitive psychology. University of Trieste, Italy.
    Hansson, Patrik
    Parker, Andrew M.
    Bruine de Bruin, Wändi
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Cognitive psychology. Stockholm University, Faculty of Social Sciences, Aging Research Center (ARC), (together with KI).
    Mäntylä, Timo
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Cognitive psychology.
    Unraveling the Aging Skein: Disentangling Sensory and Cognitive Predictors of Age-related Differences in Decision Making2017In: Journal of Behavioral Decision Making, ISSN 0894-3257, E-ISSN 1099-0771, Vol. 30, no 1, p. 123-139Article in journal (Refereed)
    Abstract [en]

    Age-related differences in sensory functioning, processing speed, and working memory have been identified as three significant predictors of the age-related performance decline observed in complex cognitive tasks. Yet, the assessment of their relative predictive capacity and interrelations is still an open issue in decision making and cognitive aging research. Indeed, no previous investigation has examined the relationships of all these three predictors with decision making. In an individual-differences study, we therefore disentangled the relative contribution of sensory functioning, processing speed, and working memory to the prediction of the age-related decline in cognitively demanding judgment and decision-making tasks. Structural equation modeling showed that the age-related decline in working memory plays an important predictive role, even when controlling for sensory functioning, processing speed, and education. Implications for research on decision making and cognitive aging are discussed.

  • 19. Del Missier, Fabio
    et al.
    Mäntylä, Timo
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Cognitive psychology.
    Hansson, Patrik
    Bruine de Bruin, Wändi
    Parker, Andrew M.
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Cognitive psychology.
    Predictors of Decision Making Across the Adult Life-Span: An Individual-Differences Study2016Conference paper (Other academic)
    Abstract [en]

    Age-related decline in complex cognitive tasks has been explained by changes in sensory functioning, processing speed, and working memory. However, there is still no agreement on the relative importance of these factors, and their relative role in decision making has not been investigated. In an individual-difference study on a population-based Swedish sample of adults (N = 563, age range 30-89), we disentangled the contribution of sensory decline, processing speed, and working memory measures to age-related changes in three cognitively-demanding decision-making tasks of the Adult Decision-Making Competence Battery (Resistance to Framing, Applying Decision Rules, Under/Overconfidence). Structural equation modeling showed that working memory is a significant predictor even when the influence of sensory variables, processing speed, and education (as a control for cohort effects) is taken into account. Moreover, the effects of sensory functioning and processing speed on decision making were mediated by working memory. These findings indicate that the age-related decline in complex decision-making tasks may not be entirely explained by changes in lower-level processes, highlighting the functional role of working memory processes.

  • 20.
    Del Missier, Fabio
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Mäntylä, Timo
    Stockholm University, Faculty of Social Sciences, Department of Psychology. Stockholm Brain Inst, Stockholm, Sweden.
    Hansson, Patrik
    de Bruin, Wändi Bruine
    Parker, Andrew M.
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    The Multifold Relationship Between Memory and Decision Making: An Individual-Differences Study2013In: Journal of Experimental Psychology. Learning, Memory and Cognition, ISSN 0278-7393, E-ISSN 1939-1285, Vol. 39, no 5, p. 1344-1364Article in journal (Refereed)
    Abstract [en]

    Several judgment and decision-making tasks are assumed to involve memory functions, but significant knowledge gaps on the memory processes underlying these tasks remain. In a study on 568 adults between 25 and 80 years of age, hypotheses were tested on the specific relationships between individual differences in working memory, episodic memory, and semantic memory, respectively, and 6 main components of decision-making competence, In line with the hypotheses, working memory was positively related with the more cognitively demanding tasks (Resistance to Framing, Applying Decision Rules, and Under/Overconfidence), whereas episodic memory was positively associated with a more experience-based judgment task (Recognizing Social Norms). Furthermore, semantic memory was positively related with 2 more knowledge-based decision-making tasks (Consistency in Risk Perception and Resistance to Sunk Costs). Finally, the age-related decline observed in some of the decision-making tasks was (partially or totally) mediated by the age-related decline in working memory or episodic memory. These findings are discussed in relation to the functional roles fulfilled by different memory processes in judgment and decision-making tasks.

  • 21. Duarte Fernandes, Carla Patricia
    et al.
    Tjelta Westlye, Lars
    Giddaluru, Sudheer
    Christoforou, Andrea
    Kauppi, Karolina
    Adolfsson, Rolf
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Nyberg, Lars
    Johansen Lundervold, Astri
    Reinvang, Ivar
    Steen, Vidar Martin
    Le Hellard, Stephanie
    Espeseth, Thomas
    Lack of association of the rs1344706 ZNF804A variant with cognitive functions and DTI indices of white matter microstructure in two independent healthy populations2014In: Psychiatry Research: Neuroimaging, ISSN 0925-4927, E-ISSN 1872-7506, Vol. 222, no 1-2, p. 60-66Article in journal (Refereed)
    Abstract [en]

    The rs1344706 single nucleotide polymorphism with in intron 2 of the ZNF804A gene is strongly associated with schizophrenia and bipolar disorder. This variant has also been associated in some studies with a range of cognitive and neuro imaging phenotypes, but several studies have reported no effect on the same phenotypes in other samples. Here, we genotyped 670 healthy adult Norwegian subjects and 1753 healthy adult Swedish subjects for rs1344706, and tested for associations with cognitive phenotypes including general intellectual abilities, memory functions and cognitive inhibition. We also tested whether rs1344706 is associated with white matter microstructural properties using diffusion tensor imaging (DTI) data from 250 to 340 of the Norwegian and Swedish subjects, respectively. Whole-brain voxel-wise statistical modeling of the effect of the ZNF804A variant on two DTI indices, fractional anisotropy (FA) and radial diffusivity (RD), was performed using tract-based spatial statistics (TBSS), and commonly reported effect sizes were calculated within several large-scale white matter pathways based on neuroanatomic atlases. No significant associations were found between rs1344706 and the cognitive traits or white matter microstructure. We conclude that the rs1344706 SNP has no significant effect on these phenotypes in our two reasonably powered samples.

  • 22.
    Ekström, Ingrid
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Perception and psychophysics.
    Sjölund, Sara
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Perception and psychophysics.
    Nordin, Steven
    Nordin Adolfsson, Annelie
    Adolfsson, Rolf
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Cognitive psychology.
    Larsson, Maria
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Perception and psychophysics.
    Olofsson, Jonas K.
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Perception and psychophysics. Swedish Collegium for Advanced Study, Sweden.
    Smell Loss Predicts Mortality Risk Regardless of Dementia Conversion2017In: Journal of The American Geriatrics Society, ISSN 0002-8614, E-ISSN 1532-5415, Vol. 65, no 6, p. 1238-1243Article in journal (Refereed)
    Abstract [en]

    Objectives

    To determine whether dementia could explain the association between poor olfactory performance and mortality risk within a decade-long follow-up period.

    Design

    Prospective cohort study.

    Setting

    Betula Study, Umeå, Sweden.

    Participants

    A population-based sample of adult participants without dementia at baseline aged 40 to 90 (N = 1,774).

    Measurements

    Olfactory performance using the Scandinavian Odor-Identification Test (SOIT) and self-reported olfactory function; several social, cognitive, and medical risk factors at baseline; and incident dementia during the following decade.

    Results

    Within the 10-year follow-up, 411 of 1,774 (23.2%) participants had died. In a Cox model, the association between higher SOIT score and lower mortality was significant (hazard ratio (HR) = 0.74 per point interval, 95% confidence interval (CI) = 0.71-0.77, P < .001). The effect was attenuated, but remained significant, after controlling for age, sex, education, and health-related and cognitive variables (HR = 0.92, 95% CI = 0.87-0.97, P = .001). The association between SOIT score and mortality was retained after controlling for dementia conversion before death (HR = 0.92, 95% CI = 0.87-0.97, P = .001). Similar results were obtained for self-reported olfactory dysfunction.

    Conclusion

    Poor odor identification and poor self-reported olfactory function are associated with greater likelihood of future mortality. Dementia does not attenuate the association between olfactory loss and mortality, suggesting that olfactory loss might mark deteriorating health, irrespective of dementia.

  • 23. Eriksson Sörman, Daniel
    et al.
    Sundström, Anna
    Rönnlund, Michael
    Adolfsson, Rolf
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Leisure Activity in Old Age and Risk of Dementia: A 15-Year Prospective Study2014In: The journals of gerontology. Series B, Psychological sciences and social sciences, ISSN 1079-5014, E-ISSN 1758-5368, Vol. 69, no 4, p. 493-501Article in journal (Refereed)
    Abstract [en]

    Objectives. The aim of this study was to investigate whether leisure activity is associated with incident dementia in an older sample. Method. We examined a sample of 1,475 elderly (>= 65 years) who were dementia free at baseline over a follow-up period of up to 15 years. In addition to analyses involving the total time period, separate analyses of three time periods were performed, 1-5, 6-10, and 11-15 years, following baseline measurement of leisure activity. Results. After controlling for a variety of potential confounders, analyses of data for the total time period revealed that higher levels of Total activity and Social activity, but not Mental activity, were associated with decreased risk of dementia. However, analyses of the separate time periods showed that this association was only significant in the first time period, 1-5 years after baseline. Discussion. The results from this study provide little support for the hypothesis that frequent engagement in leisure activities among elderly serve to protect against dementia diseases across a longer time frame. The finding of a relationship for the first time period, 1-5 years after baseline, could indicate short-term protective effects but could also reflect reverse causality.

  • 24. Forero, Diego A.
    et al.
    Herteleer, Liesbet
    De Zutter, Sonia
    Norrback, Karl-Fredrik
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Cognitive psychology.
    Adolfsson, Rolf
    Callaerts, Patrick
    Del-Favero, Jurgen
    A network of synaptic genes associated with schizophrenia and bipolar disorder2016In: Schizophrenia Research, ISSN 0920-9964, E-ISSN 1573-2509, Vol. 172, no 1-3, p. 68-74Article in journal (Refereed)
    Abstract [en]

    Identification of novel candidate genes for schizophrenia (SZ) and bipolar disorder (BP), two psychiatric disorders with large epidemiological impacts, is a key research area in neurosciences and psychiatric genetics. Previous evidence from genome-wide studies suggests an important role for genes involved in synaptic plasticity in the risk for SZ and BP. We used a convergent genomics approach, combining different lines of biological evidence, to identify genes involved in the cAMP/PKA/CREB functional pathway that could be novel candidates for BP and SZ: CREB1, CREM, GRIN2C, NPY2R, NF1, PPP3CB and PRKAR1A. These 7 genes were analyzed in a HapMap based association study comprising 48 common SNPs in 486 SZ, 351 BP patients and 514 control individuals recruited from an isolated population in Northern Sweden. Genetic analysis showed significant allelic associations of SNPs in PRKAR1A with SZ and of PPP3CB and PRKAR1A with BP. Our results highlight the feasibility and the importance of convergent genomic data analysis for the identification of candidate genes and our data provide support for the role of common inherited variants in synaptic genes and their involvement in the etiology of BP and SZ.

  • 25. Habib, Reza
    et al.
    Nyberg, Lars
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Cognitive and non-cognitive factors contributing to the longitudinal identification of successful older adults in the Betula study.2007In: Aging, Neuropsychology and Cognition., Vol. 14, p. 257-273Article in journal (Refereed)
    Abstract [en]

    Studies of successful aging have typically defined elderly who fall in the upper end of a distribution of test scores as successful. A different definition of successful aging requires that older adults fall at or above the mean level of younger adults and maintain this level over time. Here we examined this definition of successful aging in a sample of 1463 individuals between 50 to 85 years of age. Based on principal coordinate analysis of cognitive and non-cognitive variables, we identified a group of 55 (8.3%) 70-85 years olds that were high functioning. This group of elderly showed elevated performance on a range of cognitive tasks. Non-cognitive factors that characterized this group included education and subjective health. The participants were re-tested 5 years later and the same type of analysis was repeated. Of the remaining individuals who initially were classified as high functioning, 18 (35%) remained high functioning and thus met the definition for successful aging. Years of education was a significant predictor of who remained successful over time.

  • 26. Hansson, Patrik
    et al.
    Rönnlund, Michael
    Juslin, Peter
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Adult age differences in the realism of confidence judgments: Overconfidence, format dependence, and cognitive predictors2008In: Psychology and Aging, ISSN 0882-7974, E-ISSN 1939-1498, Vol. 23, no 3, p. 531-544Article in journal (Refereed)
    Abstract [en]

    Realistic confidence judgments are essential to everyday functioning, but few studies have addressed the issue of age differences in overconfidence. Therefore, the authors examined this issue with probability judgment and intuitive confidence intervals in a sample of 122 healthy adults (ages: 35-40, 55-60, 70-75 years). In line with predictions based on the naïve sampling model (P. Juslin, A. Winman, & P. Hansson, 2007), substantial format dependence was observed, with extreme overconfidence when confidence was expressed as an intuitive confidence interval but not when confidence was expressed as a probability judgment. Moreover, an age-related increase in overconfidence was selectively observed when confidence was expressed as intuitive confidence intervals. Structural equation modeling indicated that the age-related increases in overconfidence were mediated by a general cognitive ability factor that may reflect executive processes. Finally, the results indicated that part of the negative influence of increased age on general ability may be compensated for by an age-related increase in domain-relevant knowledge.

  • 27. Hansson, Patrik
    et al.
    Sunnegårdh-Grönberg, Karin
    Bergdahl, Jan
    Bergdahl, Maud
    Nyberg, Lars
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology. Stockholm Brain Institute.
    Relationship between natural teeth and memory in a healthy elderly population2013In: European Journal of Oral Sciences, ISSN 0909-8836, E-ISSN 1600-0722, Vol. 121, no 4, p. 333-340Article in journal (Refereed)
    Abstract [en]

    The relationship between mastication and cognitive function remains unclear, but both animal and experimental human studies suggest a possible causal relationship. In the present study it was hypothesized that natural teeth are of importance for hippocampus-based cognitive processes, such as episodic long-term memory. A population-based sample of 273 participants (55-80yr of age; 145 women) was investigated in a cross-sectional study. The participants underwent health assessment, completed a battery of cognitive tests, and took part in an extensive clinical oral examination. The number of natural teeth contributed uniquely and significantly to explaining variance (3-4%) in performance on measures of episodic memory and semantic memory over and above individual differences in age, years of education, gender, occupation, living conditions, and medical history. The number of natural teeth did not have an influence on the performance of measures of working memory, visuospatial ability, or processing speed. Within the limitations of the current study, a small, but significant, relationship between episodic memory and number of natural teeth is evident.

  • 28.
    Hedner, Margareta
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Perception and psychophysics.
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Cognitive psychology.
    Olofsson, Jonas K.
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Perception and psychophysics.
    Bergman, Olle
    Department of Pharmacology, Göteborg University, Göteborg, Sweden.
    Eriksson, Elias
    Department of Pharmacology, Göteborg University, Göteborg, Sweden.
    Nyberg, Lars
    Department of Radiation Sciences and Integrative Medical Biology, Umeå, Sweden.
    Larsson, Maria
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Perception and psychophysics.
    Age-Related Olfactory Decline is Associated with the BDNF Val66met Polymorphism: Evidence from a Population-Based Study2010In: Frontiers in Aging Neuroscience, ISSN 1663-4365, Vol. 2, no 7, p. 24-Article in journal (Refereed)
    Abstract [en]

    The present study investigates the effect of the brain-derived neurotrophic factor (BDNF) val66met polymorphism on change in olfactory function in a large scale, longitudinal population-based sample (n = 836). The subjects were tested on a 13 item force-choice odor identification test on two test occasions over a 5-year-interval. Sex, education, health-related factors, and semantic ability were controlled for in the statistical analyses. Results showed an interaction effect of age and BDNF val66met on olfactory change, such that the magnitude of olfactory decline in the older age cohort (70–90years old at baseline) was larger for the val homozygote carriers than for the met carriers. The older met carriers did not display larger age-related decline in olfactory function compared to the younger group. The BDNF val66met polymorphism did not affect the rate of decline in the younger age cohort (45–65years). The findings are discussed in the light of the proposed roles of BDNF in neural development and maintenance.

  • 29. Holmgren, Sara
    et al.
    Molander, Bo
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Episodic memory in adult age and effects of sibship size and birth order: Longitudinal data2007In: Journal of Adult Development, ISSN 1068-0667, Vol. 14, no 1/2, p. 37-46Article in journal (Refereed)
    Abstract [en]

    This study examined the effects of sibship size and birth order on episodic memory performance in adulthood and old age. Participants were 1,141 healthy individuals aged 35-80 years, who took part in a longitudinal project on age, health, and memory. Episodic memory measurements over a 5-year interval included tests of recognition (recognition of faces, family names, first names, and nouns) and tests of recall (free recall of sentences, free recall and cued recall of nouns, and recall of activities). Results showed significant effects for both recall and recognition, that is, the smaller the sibship size is for an individual and the earlier born, the better memory performance. These results demonstrate that the effects of sibship size and birth order previously shown in children and adolescents (Belmont and Marolla, Science 182:1096-1101, 1973; Zajonc and Markus, Psych Rev 82:74-88, 1975; Zajonc, Am Psychol 56:490-496, 2001) are robust over time and hold over a large adult range.

  • 30. Holmgren, Sara
    et al.
    Molander, Bo
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Intelligence and executive functioning in adult age: Effects of sibship size and birth order.2006In: European Journal of Cognitive Psychology, ISSN 0954-1446, Vol. 18, no 1, p. 138-158Article in journal (Refereed)
    Abstract [en]

    A study on inttelligence (i.e., block design and word comprehension) and executive functioning (i.e., working memory and verbal fluency) as related to family size and birth order was performed in middle-aged, young-old, and old-old adults. Previous studies and theories on the structural issues of family environment and its relationship to intelligence was the point of departure of this research. Using data from healthy participants, aged 35-85 years, in the Betula project (Nilsson et al., 1997, 2004), this study revealed that effects of sibship size and birth order, previously demonstrated in children, remain in adult age. Working memory was the most sensitive of the four tests used for revealing effects of the sibship size and birth order. Implications for the relationship between executive functioning and intelligence, and implications for the confluence and resource dilution models (Blake, 1981; Downey, 2001; Zajonc, 1976) are discussed.

  • 31.
    Josefsson, Maria
    et al.
    Umeå universitet.
    de Luna, Xavier
    Umeå universitet.
    Pudas, Sara
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Nyberg, Lars
    Umeå universitet.
    Genetic and Lifestyle Predictors of 15-Year Longitudinal Change in Episodic Memory2012In: Journal of The American Geriatrics Society, ISSN 0002-8614, E-ISSN 1532-5415, Vol. 60, no 12, p. 2308-2312Article in journal (Refereed)
    Abstract [en]

    Objectives: To reveal distinct longitudinal trajectories in episodic memory over 15 years and to identify demographic, lifestyle, health-related, and genetic predictors of stability or decline. Design: Prospective cohort study. Setting: The Betula Project, Umeå, Sweden. Participants: One thousand nine hundred fifty-four healthy participants aged 35 to 85 at baseline. Measurements: Memory was assessed according to validated episodic memory tasks in participants from a large population-based sample. Data were analyzed using a random-effects pattern-mixture model that considered the effect of attrition over two to four longitudinal sessions. Logistic regression was used to determine significant predictors of stability or decline relative to average change in episodic memory. Results: Of 1,558 participants with two or more test sessions, 18% were classified as maintainers and 13% as decliners, and 68% showed age-typical average change. More educated and more physically active participants, women, and those living with someone were more likely to be classified as maintainers, as were carriers of the met allele of the catechol-O-methyltransferase gene. Less educated participants, those not active in the labor force, and men were more likely to be classified as decliners, and the apolipoprotein E &#603;4 allele was more frequent in decliners. Conclusion: Quantitative, attrition-corrected assessment of longitudinal changes in memory can reveal substantial heterogeneity in aging trajectories, and genetic and lifestyle factors predict such heterogeneity.

  • 32. Kask, Kristiina
    et al.
    Bäckström, Torbjörn
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Sundström-Poromaa, Inger
    Allopregnanolone impairs episodic memory in healthy women2008In: Psychopharmacology, ISSN 0033-3158, E-ISSN 1432-2072, Vol. 199, no 2, p. 161-168Article in journal (Refereed)
    Abstract [en]

    Allopregnanolone is an endogenous neuroactive steroid that, through its binding to the γ-aminobutyric acid (GABA) A receptor, has GABA-active properties. Animal studies indicate that allopregnanolone administration results in diminished learning and memory impairment. The aim of the current study was to investigate the effect of intravenously administered allopregnanolone on episodic memory, semantic memory, and working memory in healthy women. Twenty-eight healthy women were included in the study. The participants were scheduled for the memory tests twice in the follicular phase. During the test sessions, an intravenous allopregnanolone and placebo infusion were administered in a double-blinded, randomized order at intervals of 48 h. Before and 10 min after the allopregnanolone/placebo injections, memory tasks were performed. The study demonstrated that allopregnanolone impaired episodic memory in healthy women. There was a significant difference between pre- and postallopregnanolone injection episodic memory scores (p < 0.05), whereas there was no change in episodic memory performance following the placebo injections. There was also a significant difference between allopregnanolone and placebo postinjection episodic memory scores (p < 0.05). There were no effects of allopregnanolone on the semantic memory task or working memory task. Intravenous allopregnanolone impairs episodic memory in healthy women, but there is a high degree of individual variability.

  • 33. Kauppi, Karolina
    et al.
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Adolfsson, Rolf
    Eriksson, Elias
    Nyberg, Lars
    KIBRA Polymorphism Is Related to Enhanced Memory and Elevated Hippocampal Processing2011In: Journal of Neuroscience, ISSN 0270-6474, E-ISSN 1529-2401, Vol. 31, no 40, p. 14218-14222Article in journal (Refereed)
    Abstract [en]

    Several studies have linked the KIBRA rs17070145 T polymorphism to superior episodic memory in healthy humans. One study investigated the effect of KIBRA on brain activation patterns (Papassotiropoulos et al., 2006) and observed increased hippocampal activation in noncarriers of the T allele during retrieval. Noncarriers were interpreted to need more hippocampal activation to reach the same performance level as T carriers. Using large behavioral (N = 2230) and fMRI (N = 83) samples, we replicated the KIBRA effect on episodic memory performance, but found increased hippocampal activation in T carriers during episodic retrieval. There was no evidence of compensatory brain activation in noncarriers within the hippocampal region. In the main fMRI sample, T carriers performed better than noncarriers during scanning but, importantly, the difference in hippocampus activation remained after post hoc matching according to performance, sex, and age (N = 64). These findings link enhanced memory performance in KIBRA T allele carriers to elevated hippocampal functioning, rather than to neural compensation in noncarriers.

  • 34. Kauppi, Karolina
    et al.
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Adolfsson, Rolf
    Lundquist, Anders
    Eriksson, Elias
    Nyberg, Lars
    Decreased medial temporal lobe activation in BDNF 66Met allele carriers during memory encoding2013In: Neuropsychologia, ISSN 0028-3932, E-ISSN 1873-3514, Vol. 51, no 12, p. 2462-2468Article in journal (Refereed)
    Abstract [en]

    The Met allele of the Brain-derived neurotrophic factor (BDNF) Val66Met polymorphism has been associated with impaired activity-dependent secretion of BDNF protein and decreased memory performance. Results from imaging studies relating Val66Met to brain activation during memory processing have been inconsistent, with reports of both increased and decreased activation in the Medial Temporal Lobe (MTL) in Met carriers relative to Val homozygotes. Here, we extensively studied BDNF Val66Met in relation to brain activation and white matter integrity as well as memory performance in a large imaging (n=194) and behavioral (n=2229) sample, respectively. Functional magnetic resonance imaging (fMRI) was used to investigate MTL activation in healthy participants in the age of 55–75 years during a face-name episodic encoding and retrieval task. White matter integrity was measured using diffusion tensor imaging.

    BDNF Met allele carriers had significantly decreased activation in the MTL during encoding processes, but not during retrieval processes. In contrast to previous proposals, the effect was not modulated by age and the polymorphism was not related to white matter integrity. Met carriers had lower memory performance than Val homozygotes, but differences were subtle and not significant. In conclusion, the BDNF Met allele has a negative influence on MTL functioning, preferentially during encoding processes, which might translate into impaired episodic memory function.

  • 35.
    Kauppi, Karolina
    et al.
    Umeå university.
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Adolfsson, Rolf
    Ume university.
    Nyberg, Lars
    Umeå university.
    Combined gene effects on hippocampal mnemonic processing: A large-scale imaging-genetics study of APOE, BDNF, KIBRA, and CLSTN22013In: Cognitive Neuroscience Society: 2013 Annual Meeting Program. A Supplement of the Journal of Cognitive Neuroscience, 2013, p. 140-141Conference paper (Other academic)
  • 36. Kauppi, Karolina
    et al.
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology. Stockholm Brain Institute, Sweden.
    Persson, Jonas
    Stockholm University, Faculty of Social Sciences, Aging Research Center (ARC), (together with KI).
    Nyberg, Lars
    Additive genetic effect of APOE and BDNF on hippocampus activity2014In: NeuroImage, ISSN 1053-8119, E-ISSN 1095-9572, Vol. 89, p. 306-313Article in journal (Refereed)
    Abstract [en]

    Human memory is a highly heritable polygenic trait with complex inheritance patterns. To study the genetics of memory and memory-related diseases, hippocampal functioning has served as an intermediate phenotype. The importance of investigating gene-gene effects on complex phenotypes has been emphasized, but most imaging studies still focus on single polymorphisms. APOE epsilon 4 and BDNF Met, two of the most studied gene variants for variability in memory performance and neuropsychiatric disorders, have both separately been related to poorer episodic memory and altered hippocampal functioning. Here, we investigated the combined effect of APOE and BDNF on hippocampal activation (N = 151). No non-additive interaction effects were seen. Instead, the results revealed decreased activation in bilateral hippocampus and parahippocampus as a function of the number of APOE e4 and.BDNE Met alleles present (neither, one, or both). The combined effect was stronger than either of the individual effects, and both gene variables explained significant proportions of variance in BOLD signal change. Thus, there was an additive gene-gene effect of APOE and BDNF on medial temporal lobe (MTL) activation, showing that a larger proportion of variance in brain activation attributed to genetics can be explained by considering more than one gene variant This effect might be relevant for the understanding of normal variability in memory function as well as memory-related disorders associated with APOE and BDNF.

  • 37. Kompus, Kristiina
    et al.
    Westerhausen, Rene
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Hugdahl, Kenneth
    Jongstra, Susan
    Berglund, Alexander
    Arver, Stefan
    Savic, Ivanka
    Deficits in inhibitory executive functions in Klinefelter (47, XXY) syndrome2011In: Psychiatry Research, ISSN 0165-1781, E-ISSN 1872-7123, Vol. 189, no 1, p. 135-140Article in journal (Refereed)
    Abstract [en]

    Klinefelter syndrome (47, XXY) is a sex chromosome aneuploidy associated with mild deficits in cognitive and language functions. Dysfunctions have also been reported in performance of tasks which examine executive functions. However, it is unclear whether the impaired performance is caused or accentuated by problems with semantic processing and information processing speed. In the present study we used an experimental task which is relatively insensitive to these confounding factors. We examined inhibitory executive functions in a group of XXY males compared with male (XY) and female (XX) controls, using a dichotic listening speech sound task with instructions to focus attention on either the right or the left ear stimulus. With this task, inhibitory executive functions can be assessed separately from language, processing speed, and attention orientation abilities. We found that XXY males showed a selective deficit in inhibitory executive functions compared to both control groups, whereas attentional orientation was not impaired. The present findings suggest that executive dysfunctions associated to Klinefelter syndrome can be selectively identified, and are particularly accentuated in the inhibitory sub-component. Such improved understanding of the nature of executive dysfunctions in XXY males may aid the development of specific neuropsychological rehabilitation strategies.

  • 38.
    Kormi-Nouri, Reza
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Moniri, Sadegheh
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Episodic and semantic memory in bilingual and monolingual children2003In: Scandinavian Journal of Psychology, ISSN 0036-5564, Vol. 44, no 1, p. 47-54Article in journal (Refereed)
    Abstract [en]

    Although bilinguality has been reported to confer advantages upon children with respect to various cognitive abilities, much less is known about the relation between memory and bilinguality. In this study, 60 (30 girls and 30 boys) bilingual and 60 (30 girls and 30 boys) monolingual children in three age groups (mean ages 8.5, 10.5 and 12.5 years) were compared on episodic memory and semantic memory tasks. Episodic memory was assessed using subject-performed tasks children learned subject-performed tasks (with real or imaginary objects) and verbal task, with retrieval by both free recall and cued recall. Semantic memory was assessed by word fluency tests. Positive effects of bilingualism were found on both episodic memory and semantic memory tasks at all age levels. These findings suggest that bilingual children integrate and/or organize the information of two languages, and so bilingualism creates advantages in terms of cognitive abilities (including memory). Some sex differences were also found in episodic memory but not in semantic memory. This episodic memory difference was found with younger children.

    Key words: “bilingualism”, “episodic memory”, “semantic memory”, “action memory”, “verbal memory”, “children”

  • 39.
    Kormi-Nouri, Reza
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Ohta, Nobuo
    The novelty effect: Support for the Novelty-Encoding Hypothesis.2005In: Scandinavian Journal of Psychology, ISSN 0036-5564, Vol. 46, no 2, p. 133-143Article in journal (Refereed)
    Abstract [en]

    In two experiments, we examined the "Novelty-Encoding Hypothesis" proposed by Tulving and Kroll (1995), suggesting that the encoding of online information into long-term memory is influenced by its novelty and that novelty increases recognition performance. In Phase 1 (familiarization phase), subjects participated in a standard memory experiment in which different types of materials (verbs and nouns) were studied under different encoding conditions (enactment and non-enactment) and were tested by an expected recognition test. In Phase 2 (critical phase), subjects evaluated the materials (both familiar materials which were encoded earlier in Phase 1, and novel materials which were not presented earlier in Phase 1) in a frequency judgment task and were given an unexpected recognition test. The results of both experiments showed that novel items were recognized better than familiar items. This result held true for both hit rates--false alarms and hit rates. The novelty effect was observed for different subjects (Swedish and Japanese), different materials (verbs and nouns; high frequency and low frequency), and different types of encoding in Phase 1 (enactment and non-enactment). These findings provide support for the "Novelty-Encoding Hypothesis" stating that the effect is based on the encoding of target items at the time of the critical study (Phase 2). A comparison between the present experiments and the Tulving and Kroll (1995), Dobbins, Kroll, Yonelinas & Liu (1998) and Greene (1999) studies suggests that the novelty effect is more pronounced under incidental encoding than under intentional encoding.

  • 40. Kormi-Nouri, Reza
    et al.
    Shojaei, Razie-Sadat
    Moniri, Sadegheh
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Gholami, Ali-Reza
    Moradi, Ali-Reza
    Akbari-Zardkhaneh, Saeed
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    The effect of childhood bilingualism on episodic and semantic memory tasks2008In: Scandinavian Journal of Psychology, ISSN 0036-5564, E-ISSN 1467-9450, Vol. 49, no 2, p. 93-109Article in journal (Refereed)
    Abstract [en]

    Kormi-Nouri, Moniri and Nilsson (2003) demonstrated that Swedish-Persian bilingual children recalled at a higher level than Swedish monolingual children, when they were tested using Swedish materials. The present study was designed to examine the bilingual advantage of children who use different languages in their everyday life but have the same cultural background and live in their communities in the same way as monolingual children. In four experiments, 488 monolingual and bilingual children were compared with regard to episodic and semantic memory tasks. In experiments 1 and 2 there were 144 boys and 144 girls in three school groups (aged 9-10 years, 13-14 years and 16-17 years) and in three language groups (Persian monolingual, Turkish-Persian bilingual, and Kurdish-Persian bilingual). In experiments 3 and 4, there were 200 male students in two school groups (aged 9-10 years and 16-17 years) and in two language groups (Persian monolingual and Turkish-Persian bilingual). In the episodic memory task, children learned sentences (experiments 1-3) and words (Experiment 4). Letter and category fluency tests were used as measures of semantic memory. To change cognitive demands in memory tasks, in Experiment 1, the integration of nouns and verbs within sentences was manipulated by the level of association between verb and noun in each sentence. At retrieval, a recognition test was used. In experiments 2 and 3, the organization between sentences was manipulated at encoding in Experiment 2 and at both encoding and retrieval in Experiment 3 through the use of categories among the objects. At retrieval, free recall or cued recall tests were employed. In Experiment 4, the bilingual children were tested with regard to both their first and their second language. In all four experiments, a positive effect of bilingualism was found on episodic and semantic memory tasks; the effect was more pronounced for older than younger children. The bilingual advantage was not affected by changing cognitive demands or by using first/second language in memory tasks. The present findings support the cross-language interactivity hypothesis of bilingual advantage.

  • 41.
    Kubik, Veit
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Jönsson, Fredrik U.
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Knopf, Monika
    Two effects, one explanation: a study on the effects of intended and actual enactment2012In: International Journal of Psychology, ISSN 0020-7594, E-ISSN 1464-066X, Vol. 47, no Supplement 1, p. 562-562Article in journal (Other academic)
    Abstract [en]

    Motor-function encoding action phrases, facilitates recollection more than verbal encoding (enactment effect, c.f. Nilsson, 2000). Further, if the phrases are intended to be recalled via motor-function encoding it also leads to higher memory accessibility, referred to as the intention-superiority effect (Goschke & Kuhl, 1993) or the intended enactment effect (Freeman & Ellis, 2003), depending on whether the same process or different processes are assumed to underlie both effects. In three experiments, both effects were studied as a function of list length (18, 30, 60, or 90 items), retrieval measures (free recall, cued recall and recognition). Additionally, different moderator variables for these effects were investigated (familiarity, degree of motor involvement of the action phrases, individual differences in action orientation). Similar effects of intended and actual enactment were found for memory accuracy and accessibility (i.e., response latencies), but the effects were moderated by the nature of the action phrase and action orientation. State-oriented individuals and highly motoric action phrases showed a pronounced (intended) enactment effect. The results, at least partially, support a common explanation for both effects.

  • 42.
    Kubik, Veit
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Olofsson, Jonas
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Jönsson, Fredrik
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Putting Action Memory to the Test: Testing Affects Restudy but not Forgetting of Action EventsManuscript (preprint) (Other academic)
  • 43.
    Kubik, Veit
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Olofsson, Jonas
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Jönsson, Fredrik
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Testing Effects on Subsequent Re-Encoding and Forgetting of Action PhrasesManuscript (preprint) (Other academic)
  • 44.
    Kubik, Veit
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Psychology. Stockholm Brain Institute, Sweden.
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Aging Research Center (ARC), (together with KI). Stockholm Brain Institute, Sweden; Umeå University, Sweden.
    Olofsson, Jonas K.
    Stockholm University, Faculty of Social Sciences, Department of Psychology. Stockholm Brain Institute, Sweden; Swedish Collegium of Advanced Study, Sweden.
    Jönsson, Fredrik U.
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Effects of testing on subsequent re-encoding and long-term forgetting of action-relevant materials: On the influence of recall type2015In: Scandinavian Journal of Psychology, ISSN 0036-5564, E-ISSN 1467-9450, Vol. 56, no 5, p. 475-481Article in journal (Refereed)
    Abstract [en]

    Testing one's memory of previously studied information reduces the rate of forgetting, compared to restudy. However, little is known about how this direct testing effect applies to action phrases (e.g., wash the car) - a learning material relevant to everyday memory. As action phrases consist of two different components, a verb (e.g., wash) and a noun (e.g., car), testing can either be implemented as noun-cued recall of verbs or verb-cued recall of nouns, which may differently affect later memory performance. In the present study, we investigated the effect of testing for these two recall types, using verbally encoded action phrases as learning materials. Results showed that repeated study-test practice, compared to repeated study-restudy practice, decreased the forgetting rate across 1 week to a similar degree for both noun-cued and verb-cued recall types. However, noun-cued recall of verbs initiated more new subsequent learning during the first restudy, compared to verb-cued recall of nouns. The study provides evidence that testing has benefits on both subsequent restudy and long-term retention of action-relevant materials, but that these benefits are differently expressed with testing via noun-cued versus verb-cued recall.

  • 45.
    Kubik, Veit
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Cognitive psychology.
    Olofsson, Jonas K.
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Perception and psychophysics. Swedish Collegium of Advanced Study, Sweden.
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Aging Research Center (ARC), (together with KI). Stockholm Brain Institute, Stockholm; Umeå University, Sweden.
    Jönsson, Fredrik U.
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Cognitive psychology.
    Putting action memory to the test: Testing affects subsequent restudy but not long-term forgetting of action events2016In: Journal of Cognitive Psychology, ISSN 2044-5911, E-ISSN 2044-592X, Vol. 28, no 2, p. 209-219Article in journal (Refereed)
    Abstract [en]

    Testing memory typically enhances subsequent re-encoding of information (“indirect” testing effect) and, as compared to restudy, it also benefits later long-term retention (“direct” testing effect). We investigated the effect of testing on subsequent restudy and 1-week retention of action events (e.g. “water the plant”). In addition, we investigated if the type of recall practice (noun-cued vs. verb-cued) moderates these testing benefits. The results showed an indirect testing effect that increased following noun-cued recall of verbs as compared to verb-cued recall of nouns. In contrast, a direct testing effect on the forgetting rate of performed actions was not reliably observed, neither for noun- nor verb-cued recall. Thus, to the extent that this study successfully dissociated direct and indirect testing-based enhancements, they seem to be differentially effective for performed actions, and may rely on partially different mechanisms.

  • 46.
    Kubik, Veit
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Psychology. Stockholm Brain Institute, Sweden.
    Söderlund, Hedvig
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology. Stockholm Brain Institute, Sweden.
    Jönsson, Fredrik U.
    Stockholm University, Faculty of Social Sciences, Department of Psychology. Stockholm Brain Institute, Sweden.
    Individual and Combined Effects of Enactment and Testing on Memory for Action Phrases2014In: Experimental psychology (Göttingen), ISSN 1618-3169, E-ISSN 2190-5142, Vol. 61, no 5, p. 347-355Article in journal (Refereed)
    Abstract [en]

    We investigated the individual and combined effects of enactment and testing on memory for action phrases to address whether bothstudy techniques commonly promote item-specific processing. Participants (N = 112) were divided into four groups (n = 28). They eitherexclusively studied 36 action phrases (e.g., ‘‘lift the glass’’) or both studied and cued-recalled them in four trials. During study trials participantsencoded the action phrases either by motorically performing them, or by reading them aloud, and they took final verb-cued recall tests over 18-min and 1-week retention intervals. A testing effect was demonstrated for action phrases, however, only when they were verbally encoded, andnot when they were enacted. Similarly, enactive (relative to verbal) encoding reduced the rate of forgetting, but only when the action phraseswere exclusively studied, and not when they were also tested. These less-than-additive effects of enactment and testing on the rate of forgetting,as well as on long-term retention, support the notion that both study techniques effectively promote item-specific processing that can only bemarginally increased further by combining them.

  • 47.
    Lansner, Anders
    et al.
    Stockholm University, Faculty of Science, Numerical Analysis and Computer Science (NADA). Royal Institute of Technology, Sweden.
    Marklund, Petter
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Sikström, Sverker
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Reactivation in Working Memory: An Attractor Network Model of Free Recall2013In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, no 8, article id e73776Article in journal (Refereed)
    Abstract [en]

    The dynamic nature of human working memory, the general-purpose system for processing continuous input, while keeping no longer externally available information active in the background, is well captured in immediate free recall of supraspan word-lists. Free recall tasks produce several benchmark memory phenomena, like the U-shaped serial position curve, reflecting enhanced memory for early and late list items. To account for empirical data, including primacy and recency as well as contiguity effects, we propose here a neurobiologically based neural network model that unifies short- and long-term forms of memory and challenges both the standard view of working memory as persistent activity and dual-store accounts of free recall. Rapidly expressed and volatile synaptic plasticity, modulated intrinsic excitability, and spike-frequency adaptation are suggested as key cellular mechanisms underlying working memory encoding, reactivation and recall. Recent findings on the synaptic and molecular mechanisms behind early LTP and on spiking activity during delayed-match-to-sample tasks support this view.

  • 48.
    Larsson, Maria
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Perception and psychophysics.
    Ekström, Ingrid
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Perception and psychophysics.
    Sjölund, Sara
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Perception and psychophysics.
    Nordin, Steven
    Nordin Adolfsson, Annelie
    Adolfsson, Rolf
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Cognitive psychology.
    Olofsson, Jonas K.
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Perception and psychophysics. Swedish Collegium for Advanced Study, Sweden.
    Loss of Olfactory Function Predicts Mortality Irrespective of Dementia Conversion: 10-year follow-up of an age-varied sample2016In: Chemical Senses, ISSN 0379-864X, E-ISSN 1464-3553, Vol. 41, no 9, p. e111-e288Article in journal (Refereed)
    Abstract [en]

    The objective of this study was to examine the association between performance in odor identification and future mortality in a community cohort of adults aged between 40 and 90 years. We assessed olfactory performance with a 13-item-version of the Scandinavian Odor Identification Test (SOIT). The results showed that during follow-up (mean=9.4 years, standard deviation=2.23), 411 of 1774 (23.2%) participants died. In a Cox model, the association between higher SOIT score and mortality was highly significant (hazard ratio [HR]=0.74, per point interval, 95% confidence interval [CI]=0.71–0.77, p<0.001). The effect was attenuated, but remained significant after controlling for age, sex, education, and health and cognitive variables that were also associated with an increased risk of mortality (HR=0.92, 95% CI=0.87–0.97, p=0.001). Controlling for dementia conversion prior to death did not attenuate the association between SOIT score and mortality (HR=0.92, 95% CI=0.87–0.97, p=0.001). Similar results were obtained for olfactory sensitivity as assessed by self-report. Overall, the present findings show that poor odor identification performance is associated with an increased likelihood of future mortality in middle-aged and older adults, after controlling for social, cognitive, and medical risk factors. Most importantly, controlling for the development of dementia did not attenuate the association between odor identification and mortality, suggesting that olfactory decline might mark deteriorating health also irrespective of dementia.

  • 49. Launer, L J
    et al.
    Berger, K
    Breteler, M M B
    Dufoil, C
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Regional variability in the prevalence of cerebral white matter lesions: An MRI study in 9 European countries (CASCADE).2006In: Neuroepidemiology, ISSN 0251-5350, Vol. 26, no 1, p. 23-29Article in journal (Refereed)
    Abstract [en]

    White matter lesions (WML) on MRI of the brain are common in both demented and nondemented older persons. They may be due to ischemic events and are associated with cognitive and physical impairments. It is not known whether the prevalence of these WML in the general population differs across European countries in a pattern similar to that seen for coronary heart disease. Here we report the prevalence of WML in 1,805 men and women drawn from population-based samples of 65- to 75-yearolds in ten European cohorts. Data were collected using standardized methods as a part of the multicenter study CASCADE (Cardiovascular Determinants of Dementia). Centers were grouped by region: south (Italy, Spain, France), north (Netherlands, UK, Sweden), and central (Austria, Germany, Poland). In this 10-year age stratum, 92% of the sample had some lesions, and the prevalence increased with age. The prevalence of WML was highest in the southern region, even after adjusting for differences in demographic and selected cardiovascular risk factors. Brain aging leading to disabilities will increase in the future. As a means of hypothesis generation and for health planning, further research on the geographic distribution of WML may lead to the identification of new risk factors for these lesions.

  • 50.
    Lekander, Mats
    et al.
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Von Essen, Jan
    Schultzberg, Marianne
    Andreasson, Anna Nixon
    Stockholm University, Faculty of Social Sciences, Stress Research Institute.
    Garlind, Anita
    Hansson, Lars-Olof
    Nilsson, Lars-Göran
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Cytokines and memory across the mature life span of women2011In: Scandinavian Journal of Psychology, ISSN 0036-5564, E-ISSN 1467-9450, Vol. 52, no 3, p. 229-235Article in journal (Refereed)
    Abstract [en]

    Increasing evidence suggests a role of the immune system in modulation of cognition, but details on affected memory systems are largely lacking. We therefore aimed to study the relation between selected cytokines and subsets of memory, and the impact of age in these relations. From a random population-based sample (the Betula Prospective Cohort Study), 298 women (age 45-90) were studied in terms of episodic recall and recognition, semantic fluency and knowledge, and prospective memory. Circulating cytokines of relevance for cognition and aging were measured with ELISA. Levels of interleukin (IL)-6 and sIL-2R were significantly and negatively associated with most cognitive variables, while the opposite was true for IL-1 beta. Age shared substantial variance with both cytokines and memory, and turned most correlations non-significant when controlled for together with education, BMI and presence of disease. Interactions between age and cytokines were further analyzed in multiple regressions. For IL-6, significant negative interactions with age were found for semantic fluency (p < 0.05) and prospective memory (p < 0.01), and for sIL-2R in predicting semantic knowledge (p < 0.05), indicating an increased negative impact of these cytokines on memory with increasing age. In conclusion, the study indicates a relation between cytokines and memory that appears to be largely mediated by age, and supports the suggestion that cytokine dysregulation with higher age may interact with cognitive aging.

1234 1 - 50 of 179
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf