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  • 1.
    Alemán Bañón, José
    et al.
    Stockholms universitet, Humanistiska fakulteten, Institutionen för svenska och flerspråkighet, Centrum för tvåspråkighetsforskning.
    Martin, Clara
    Anticipating information structure: An event-related potentials study of focus assignment via the it-cleft2019Ingår i: Neuropsychologia, ISSN 0028-3932, E-ISSN 1873-3514, Vol. 134, artikel-id 107203Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The present study uses event-related potentials to investigate the role of prediction in the processing of information structure, a domain of language that belongs to the level of the discourse. Twenty-three native speakers of English read short contexts including three Noun Phrases (NPs) (e.g., Either an adviser or an agent can be helpful to a banker), followed by a wh-question that established the discourse role of each referent (In your opinion, which of the two should a banker hire?). The NP that the question was about (banker) was the Topic, and the two NPs that could fill the slot opened by the wh-question (adviser, agent) were the Focus NPs. The participants’ brain activity was recorded with EEG while they read the responses to the wh-questions, which differed along two dimensions: (1) the availability of the it-cleft construction (In my opinion, [it is] an agent…), a Focus-devoted device that makes Focus assignment predictable in the response; and (2) the discourse role of the target noun (Focus, Topic), which corresponds to the first referent in the response (In my opinion, [it is] an agent/a banker…). Crucially, we manipulated the phonological properties of the Focus and Topic nouns such that, if the Topic noun began with a consonant (e.g., a banker), both nouns that could fill the slot opened by the wh-question began with a vowel (e.g., an agent, an adviser) (counterbalanced in the overall design). This allowed us to measure effects of prediction at the prenominal article, before the integration of semantic and discourse information took place. The analyses on prenominal articles revealed an N400 effect for articles that were unexpected based on the phonological properties of the Focus nouns, but only in the conditions with the it-cleft. This effect emerged between 250 and 400 ms, with a frontal bias. The analyses on the noun revealed that violations of information structure (i.e., cases where the it-cleft was followed by the Topic noun) yielded a broadly distributed P600 effect, relative to appropriately clefted (i.e., focused) nouns. A similar (but numerically less robust) effect emerged for Topic relative to Focus NPs in the conditions without the it-cleft, suggesting that, in the absence of a constraining cue, comprehenders still assigned Focus to the first referent in the response. Overall, these results suggest that, when reading answers to wh-questions, comprehenders use information structure constraints (i.e., prior context + the it-cleft) to anticipate the form that the response should take (i.e., how information should be packaged).

  • 2.
    Arshamian, Artin
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Psykologiska institutionen.
    Iannilli, Emilia
    Gerber, Johannes C.
    Willander, Johan
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Psykologiska institutionen.
    Persson, Jonas
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Psykologiska institutionen.
    Seo, Han-Seok
    Hummel, Thomas
    Larsson, Maria
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Psykologiska institutionen.
    The functional neuroanatomy of odor evoked autobiographical memories cued by odors and words2013Ingår i: Neuropsychologia, ISSN 0028-3932, E-ISSN 1873-3514, Vol. 51, nr 1, s. 123-131Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Behavioral evidence indicates that odor evoked autobiographical memories (OEAMs) are older, more emotional, less thought of and induce stronger time traveling characteristics than autobiographical memories (AMs) evoked by other modalities. The main aim of this study was to explore the neural correlates of AMs evoked by odors as a function of retrieval cue. Participants were screened for specific OEAMs and later presented with the odor cue and its verbal referent in an fMRI paradigm. Because the same OEAM was retrieved across both cue formats (odor and word), potential cue dependent brain activations were investigated. The overall results showed that odor and word cued OEAMs activated regions typically associated with recollection of autobiographical information. Although no odors were presented, a verbal cuing of the OEAMs activated areas associated with olfactory perception (e.g., piriform cortex). However, relative to word cuing, an odor cuing of OEAMs resulted in more activity in MTL regions such as the parahippocampus, and areas involved in visual vividness (e.g., occipital gyrus and precuneus). Furthermore, odor cues activated areas related to emotional processing, such as limbic and tempopolar regions significantly more. In contrast, word cues relative to odor cues recruited a more widespread and bilateral prefrontal activity. Hippocampus activity did not vary as function of the remoteness of the memory, but recollection of OEAMs from the 1st vs the 2nd decade of life showed specific activation in the right OFC, whereas the 2nd reflected a higher activation in the left inferior frontal gyrus.

  • 3.
    Bellander, Martin
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI).
    Brehmer, Yvonne
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI).
    Westerberg, Helena
    Karlsson, Sari
    Fürth, Daniel
    Bergman, Olle
    Eriksson, Elias
    Bäckman, Lars
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI).
    Preliminary evidence that allelic variation in the LMX1A gene influences training-related working memory improvement2011Ingår i: Neuropsychologia, ISSN 0028-3932, E-ISSN 1873-3514, Vol. 49, nr 7, s. 1938-42Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    LMX1A is a transcription factor involved in the development of dopamine (DA)-producing neurons in midbrain. Previous research has shown that allelic variations in three LMX1A single nucleotide polymorphisms (SNPs) were related to risk of Parkinson's disease (PD), suggesting that these SNPs may influence the number of mesencephalic DA neurons. Prompted by the established link between striatal DA functions and working memory (WM) performance, we examined two of these SNPs in relation to the ability to benefit from 4 weeks of WM training. One SNP (rs4657412) was strongly associated with the magnitude of training-related gains in verbal WM. The allele linked to larger gains has previously been suggested to be associated with higher dopaminergic nerve cell density. No differential gains of either SNP were observed for spatial WM, and the genotype groups were also indistinguishable in tests of attention, interference control, episodic memory, perceptual speed, and reasoning for both SNPs. This pattern of data is in agreement with previous findings from our group, suggesting that cognitive effects of DA-related genes may be more easily detected in a training context than for single-assessment performance scores.

  • 4. Boraxbekk, C. J.
    et al.
    Hagkvist, Filip
    Lindner, Philip
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Psykologiska institutionen, Klinisk psykologi. Umeå University, Sweden; Karolinska Institutet, Sweden.
    Motor and mental training in older people: Transfer, interference, and associated functional neural responses2016Ingår i: Neuropsychologia, ISSN 0028-3932, E-ISSN 1873-3514, Vol. 89, s. 371-377Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Learning new motor skills may become more difficult with advanced age. In the present study, we randomized 56 older individuals, including 30 women (mean age 70.6 years), to 6 weeks of motor training, mental (motor imagery) training, or a combination of motor and mental training of a finger tapping sequence. Performance improvements and post-training functional magnetic resonance imaging (fMRI) were used to investigate performance gains and associated underlying neural processes. Motor only training and a combination of motor and mental training improved performance in the trained task more than mental-only training. The fMRI data showed that motor training was associated with a representation in the premotor cortex and mental training with a representation in the secondary visual cortex. Combining motor and mental training resulted in both premotor and visual cortex representations. During fMRI scanning, reduced performance was observed in the combined motor and mental training group, possibly indicating interference between the two training methods. We concluded that motor and motor imagery training in older individuals is associated with different functional brain responses. Furthermore, adding mental training to motor training did not result in additional performance gains compared to motor-only training and combining training methods may result in interference between representations, reducing performance.

  • 5.
    Freidle, Malin
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI).
    Nilsson, Jonna
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI).
    Lebedev, Alexander
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI). Karolinska Institutet, Sweden.
    Lövdén, Martin
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI).
    No evidence for any effect of multiple sessions of frontal transcranial direct stimulation on mood in healthy older adults2020Ingår i: Neuropsychologia, ISSN 0028-3932, E-ISSN 1873-3514, Vol. 137, artikel-id 107325Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The dorsolateral prefrontal cortex (DLPFC) is part of a network important for emotional regulation and the possibility of modulating activity in this region with transcranial direct current stimulation (TDCS) to change mood has gained great interest, particularly for application in clinical populations. Whilst results in major depressive disorder have been promising, less is known about the effects of TDCS on mood in non-clinical populations. We hypothesized that multiple sessions of anodal TDCS applied over the left DLPFC would enhance mood, primarily as measured by the Profile of Mood States questionnaire, in healthy older adults. In addition, in an exploratory analysis, we examined the potentially moderating role of working memory training. Working memory, just like emotional regulation, taxes the DLPFC, which suggests that engaging in a working memory task whilst receiving TDCS may have a different effect on activity in this region and consequently mood. A total of 123 participants between 65 and 75 years of age were randomly assigned to receive either 20 sessions of TDCS, with or without working memory training, or 20 sessions sham stimulation, with or without working memory training. We found no support for enhancement of mood due to TDCS in healthy older adults, with or without cognitive training and conclude that the TDCS protocol used is unlikely to improve mood in non-depressed older individuals.

  • 6. Johansson, Jarkko
    et al.
    Salami, Alireza
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI). Umeå University, Sweden.
    Lundquist, Anders
    Wåhlin, Anders
    Andersson, Micael
    Nyberg, Lars
    Longitudinal evidence that reduced hemispheric encoding/retrieval asymmetry predicts episodic-memory impairment in aging2020Ingår i: Neuropsychologia, ISSN 0028-3932, E-ISSN 1873-3514, Vol. 137, artikel-id 107329Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The HERA (Hemispheric Encoding/Retrieval Asymmetry) model captures hemispheric lateralization of prefrontal cortex (PFC) brain activity during memory encoding and retrieval. Reduced HERA has been observed in cross-sectional aging studies, but there is no longitudinal evidence, to our knowledge, on age-related changes in HERA and whether maintained or reduced HERA relates to well-preserved memory functioning. In the present study we set out to explore HERA in a longitudinal neuroimaging sample from the Betula study [3 Waves over 10 years; Wave-1: n = 363, W2: n = 227, W3: n = 101]. We used fMRI data from a face-name paired-associates task to derive a HERA index. In support of the HERA model, the mean HERA index was positive across the three imaging waves. The longitudinal age-HERA relationship was highly significant (p < 10(-11)), with a HERA decline occurring after age 60. The age-related HERA decline was associated with episodic memory decline (p < 0.05). Taken together, the findings provide large-scale support for the HERA model, and suggest that reduced HERA in the PFC reflects pathological memory aging possibly related to impaired ability to bias mnemonic processing according to the appropriate encoding or retrieval state.

  • 7. Kauppi, Karolina
    et al.
    Nilsson, Lars-Göran
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Psykologiska institutionen.
    Adolfsson, Rolf
    Lundquist, Anders
    Eriksson, Elias
    Nyberg, Lars
    Decreased medial temporal lobe activation in BDNF 66Met allele carriers during memory encoding2013Ingår i: Neuropsychologia, ISSN 0028-3932, E-ISSN 1873-3514, Vol. 51, nr 12, s. 2462-2468Artikel i tidskrift (Refereegranskat)
    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.

  • 8.
    Lövdén, Martin
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI).
    Bodammer, Nils Christian
    Kühn, Simone
    Kaufmann, Jörn
    Schütze, Hartmut
    Tempelmann, Claus
    Heinze, Hans-Jochen
    Düzel, Emrah
    Schmiedek, Florian
    Lindenberger, Ulman
    Experience-dependent plasticity of white-matter microstructure extends into old age2010Ingår i: Neuropsychologia, ISSN 0028-3932, E-ISSN 1873-3514, Vol. 48, nr 13, s. 3878-3883Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Experience-dependent alterations in the human brain's white-matter microstructure occur in early adulthood, but it is unknown whether such plasticity extends throughout life. We used cognitive training, diffusion-tensor imaging (DTI), and structural MRI to investigate plasticity of the white-matter tracts that connect the left and right hemisphere of the frontal lobes. Over a period of about 180 days, 20 younger adults and 12 older adults trained for a total of one hundred and one 1-h sessions on a set of three working memory, three episodic memory, and six perceptual speed tasks. Control groups were assessed at pre- and post-test. Training affected several DTI metrics and increased the area of the anterior part of the corpus callosum. These alterations were of similar magnitude in younger and older adults. The findings indicate that experience-dependent plasticity of white-matter microstructure extends into old age and that disruptions of structural interhemispheric connectivity in old age, which are pronounced in aging, are modifiable by experience and amenable to treatment.

  • 9.
    Olofsson, Jonas K.
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Psykologiska institutionen, Perception och psykofysik. Swedish Collegium for Advanced Study, Sweden.
    Josefsson, Maria
    Ekström, Ingrid
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Psykologiska institutionen, Perception och psykofysik.
    Wilson, Donald
    Nyberg, Lars
    Nordin, Steven
    Nordin Adolfsson, Annelie
    Adolfsson, Rolf
    Nilsson, Lars-Göran
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Psykologiska institutionen, Kognitiv psykologi.
    Larsson, Maria
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Psykologiska institutionen, Perception och psykofysik.
    Long-term episodic memory decline is associated with olfactory deficits only in carriers of ApoE-є42016Ingår i: Neuropsychologia, ISSN 0028-3932, E-ISSN 1873-3514, Vol. 85, s. 1-9Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The ɛ4 allele of the Apolipoprotein E gene is a genetic risk factor for late-onset dementia of the Alzheimers' type (DAT), which is characterized by loss of both episodic memoryand olfactory functions. Little is known about the possible role of ɛ4 in the association between ongoing episodic memory decline and olfactory deficits in the general population, but such information is relevant in determining the relevance of olfaction as a marker of DAT risk. The present study was based on a large, population-based sample (n=1087, aged 45–90 years, of which 324 were ɛ4-carriers). Episodic memory change rates were established using data collected every 5 years for a 10–20 year interval leading up to an olfactory assessment using the Scandinavian Odor Identification Test at the last wave of data collection. Participants were classified according to whether or not their episodic memory ability declined more rapidly than the age-typical norm (by >1SD). Our main result is that only in ɛ4-carriers was episodic memory decline associated with odor identification impairment. In individuals without ɛ4, odor identification was unrelated to episodic memory decline status. Follow-up analyses indicated that this moderation by ɛ4 was due to the olfactory nature of the identification test, and that the effect was not caused by 63 individuals with dementia. Our results suggest that the ɛ4 determines the functional association between ongoing episodic memory decline and olfaction. These findings are consistent with the notion that ɛ4-carriers with DAT, compared to non-carriers, display a cortical atrophy pattern that is more focused on mediotemporal lobe regions supporting olfactory and episodic memory functions. Olfactory and memory assessments might provide complementary information on mediotemporal atrophy prior to clinical dementia onset, but the ɛ4 should be considered when using olfactory assessment as an early-stage indicator.

  • 10.
    Pantzar, Alexandra
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI).
    Laukka, Erika J.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI).
    Atti, Anna Rita
    Papenberg, Göran
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI). Max Planck Society, Germany.
    Keller, Lina
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI). Karolinska Institutet, Sweden.
    Graff, Caroline
    Fratiglioni, Laura
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI). Stockholm Gerontology Research Center, Sweden.
    Bäckman, Lars
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI). Stockholm Gerontology Research Center, Sweden.
    Interactive effects of KIBRA and CLSTN2 polymorphisms on episodic memory in old-age unipolar depression2014Ingår i: Neuropsychologia, ISSN 0028-3932, E-ISSN 1873-3514, Vol. 62, s. 137-142Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The KIBRA (rs17070145) C-allele and the CLSTN2 (rs6439886) T-allele have both been associated with poorer episodic memory performance. Given that episodic memory is affected in depression, we hypothesized that the combination of these risk alleles would be particularly detrimental to episodic memory performance in depressed persons. In the population-based SNAC-K study, 2170 participants (>= 60 years) without dementia (DSM-IV criteria) and antidepressant pharmacotherapy were clinically examined and diagnosed following ICD-10 criteria for unipolar depression, and genotyped for KIBRA and CLSTN2. Participants were categorized according to unipolar depression status (yes, no) and genotype combinations (KIBRA: CC, any T; CLSTN2: TT, any C). Critically, a three-way interaction effect showed that the CC/TT genotype combination was associated with poorer episodic recall and recognition performance only in depressed elderly persons, with depressed CC/TT carriers consistently performing at the lowest level. This finding supports the view that effects of genetic polymorphisms on cognitive functioning may be most easily disclosed at suboptimal levels of cognitive ability, such as in old-age depression.

  • 11. Papenberg, Goran
    et al.
    Bäckman, Lars
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI).
    Chicherio, Christian
    Nagel, Irene E
    Heekeren, Hauke R
    Lindenberger, Ulman
    Li, Shu-Chen
    Higher intraindividual variability is associated with more forgetting and dedifferentiated memory functions in old age2011Ingår i: Neuropsychologia, ISSN 0028-3932, E-ISSN 1873-3514, Vol. 49, nr 7, s. 1879-1888Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Intraindividual trial-to-trial reaction time (RT) variability is commonly found to be higher in clinical populations or life periods that are associated with impaired cognition. In the present study, higher within-person trial-to-trial RT variability in a perceptual speed task is related to more forgetting and dedifferentiation of memory functions in older adults (aged 60-71 years). More specifically, our study showed that individuals in a high-variability group (n=175) forgot more memory scenes over a 1-week retention interval than individuals in the low-variability group (n=174). In contrast, slower RT speed was associated with poorer episodic memory in general, but unrelated to the amount of forgetting. Moreover, results from multiple group latent factor analyses showed that episodic memory and working memory functions were more highly correlated in the high-variability (r=.63) than in the low-variability (r=.25) group. Given that deficits in dopamine (DA) modulation may underlie increases in RT variability, the present findings are in line with (i) recent animal studies implicating DA in long-term episodic memory consolidation and (ii) neurocomputational work linking DA modulation of performance variability to dedifferentiation of cognitive functions in old age.

  • 12.
    Persson, Jonas
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Psykologiska institutionen.
    Lind, J.
    Larsson, A.
    Ingvar, Martin
    Sleegers, K.
    Van Broeckhoven, C.
    Adolfsson, R.
    Nilsson, Lars-Göran
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Psykologiska institutionen.
    Nyberg, Lars
    Altered deactivation in individuals with genetic risk for Alzheimer's disease2008Ingår i: Neuropsychologia, ISSN 0028-3932, E-ISSN 1873-3514, Vol. 46, nr 6, s. 1679-1687Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Regions that show task-induced deactivations may be part of a default-mode network related to processes that are more engaged during passive than active task conditions. Alteration of task-induced deactivations with age and dementia is indicated by atypical engagement of default-mode network regions. Genetic studies show a relation between the apolipoprotein E4 (<i>APOE4</i>) allele and the common form of Alzheimer’s disease (AD), and altered functional brain activation has been observed in non-demented <i>APOE4</i> carriers compared to non-carriers. Here we investigate the hypothesis of altered default-mode network brain responses in individuals with genetic risk for AD. Functional MRI was used to assess task-induced deactivation in 60 subjects of which 30 carried at least one copy of the <i>APOE4</i> allele, and 30 non-carriers. Subjects were scanned while performing a semantic categorization task shown to promote episodic memory encoding. The results show patterns of deactivation consistent with the default-mode network. We also found reduced deactivation in non-demented <i>APOE4</i> carriers compared to non-carriers, suggesting alterations in the default-mode network in the absence of dementia. These results implicate possibilities for investigatin altered properties of task-induced deactivations in individuals with genetic risk for AD, and may prove useful for pre-clinical identification of individuals susceptible to memory problems and AD.

  • 13. Preuschhof, Claudia
    et al.
    Heekeren, Hauke R
    Li, Shu-Chen
    Sander, Thomas
    Lindenberger, Ulman
    Bäckman, Lars
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI).
    KIBRA and CLSTN2 polymorphisms exert interactive effects on human episodic memory2010Ingår i: Neuropsychologia, ISSN 0028-3932, E-ISSN 1873-3514, Vol. 48, nr 2, s. 402-408Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Individual differences in episodic memory are highly heritable. Several studies have linked a polymorphism in the gene encoding the KIBRA protein to episodic memory performance. Results regarding CLSTN2, the gene encoding the synaptic protein calsyntenin 2, have been less consistent, possibly pointing to interactions with other genes. Given that both KIBRA and CLSTN2 are expressed in the medial temporal lobe and have been linked to synaptic plasticity, we investigated whether KIBRA and CLSTN2 interactively modulate episodic memory performance (n=383). We replicated the beneficial effect of the KIBRA T-allele on episodic memory, and discovered that this effect increases with the associative demands of the memory task. Importantly, the memory-enhancing effect of the KIBRA T-allele was boosted by the presence of the CLSTN2 C-allele, which positively affected memory performance in some previous studies. In contrast, the presence of CLSTN2 C-allele led to reduced performance in subjects homozygous for the KIBRA C-allele. Overall, these findings suggest that KIBRA and CLSTN2 interactively modulate episodic memory performance, and underscore the need for delineating the interactive effects of multiple genes on brain and behavior.

  • 14.
    Rönnlund, Michael
    et al.
    Umeå universitet.
    Nilsson, Lars-Göran
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Psykologiska institutionen. Stockholm Brain Institute, Stockholm, Sweden.
    Flynn effects on sub-factors of episodic and semantic memory: Parallel gains over time and the same set of determining factors2009Ingår i: Neuropsychologia, ISSN 0028-3932, E-ISSN 1873-3514, Vol. 47, nr 11, s. 2174-2180Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The study examined the extent to which time-related gains in cognitive performance, so-called Flynn effects, generalize across sub-factors of episodic memory (recall and recognition) and semantic memory (knowledge and fluency). We conducted time-sequential analyses of data drawn from the Betula prospective cohort study, involving four age-matched samples (35–80 years; N = 2996) tested on the same battery of memory tasks on either of four occasions (1989, 1995, 1999, and 2004). The results demonstrate substantial time-related improvements on recall and recognition as well as on fluency and knowledge, with a trend of larger gains on semantic as compared with episodic memory [Rönnlund, M., & Nilsson, L. -G. (2008). The magnitude, generality, and determinants of Flynn effects on forms of declarative memory: Time-sequential analyses of data from a Swedish cohort study. Intelligence], but highly similar gains across the sub-factors. Finally, the association with markers of environmental change was similar, with evidence that historical increases in quantity of schooling was a main driving force behind the gains, both on the episodic and semantic sub-factors. The results obtained are discussed in terms of brain regions involved.

  • 15. Ziaei, Maryam
    et al.
    Persson, Jonas
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI).
    Bonyadi, Mohammad Reza
    Reutens, David C.
    Ebner, Natalie C.
    Amygdala functional network during recognition of own-age vs. other-age faces in younger and older adults2019Ingår i: Neuropsychologia, ISSN 0028-3932, E-ISSN 1873-3514, Vol. 129, s. 10-20Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Facial cues, such as a person's age, provide important information for social interactions. Processing such facial cues can be affected by observer bias. However, there is currently no consensus regarding how the brain is processing facial cues related to age, and if facial age processing changes as a function of the age of the observer (i.e., own-age bias). The primary study aim was to investigate functional networks involved in processing own-age vs. other-age faces among younger and older adults and determine how emotional expression of the face modulates own-age vs. other-age face processing. The secondary study aim was to examine the relation between higher social cognitive processes (i.e., empathy) and modulation of brain activity by facial age and emotional expression. During functional magnetic resonance imaging (fMRI) younger and older participants were asked to recognize happy, angry, and neutral expressions in own-age and other-age faces. Functional connectivity analyses with the amygdala as seed showed that for own-age faces both age groups recruited a network of regions including the anterior cingulate and anterior insula that was involved in empathy and detection of salient information. Brain-behavior analyses furthermore showed that empathic responses in younger, but not in older, participants were positively correlated with engagement of the medial prefrontal cortex during processing of angry own-age faces. These findings identify the neurobehavioral correlates of facial age processing, and its modulation by emotion expression, and directly link facial cue processing to higher-order social cognitive functioning.

  • 16. Ziaei, Maryam
    et al.
    Salami, Alireza
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI). Umeå University, Sweden.
    Persson, Jonas
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI).
    Age-related alterations in functional connectivity patterns during working memory encoding of emotional items2017Ingår i: Neuropsychologia, ISSN 0028-3932, E-ISSN 1873-3514, Vol. 94, s. 1-12Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Previous findings indicate age-related differences in frontal-amygdala connectivity during emotional processing. However, direct evidence for age differences in brain functional activation and connectivity during emotional processing and concomitant behavioral implications is lacking. In the present study, we examined the impact of aging on the neural signature of selective attention to emotional information during working memory (WM) encoding. Participants completed an emotional WM task in which they were asked to attend to emotional targets and ignore irrelevant distractors. Despite an overall reduction in accuracy for older relative to younger adults, no behavioral age effect was observed as a function of emotional valence. The functional connectivity patterns of left ventrolateral prefrontal cortex showed that younger adults recruited one network for encoding of both positive and negative emotional targets and this network contributed to higher memory accuracy in this cohort. Older adults, on the other hand, engaged two distinct networks for encoding of positive and negative targets. The functional connectivity analysis using left amygdala further demonstrated that older adults recruited one single network during encoding of positive as well as negative targets whereas younger adults recruited this network only for encoding of negative items. The engagement of amygdala functional network also contributed to higher memory performance and faster response times in older adults. Our findings provide novel insights into the differential roles of functional brain networks connected to the medial PFC and amygdala during encoding of emotionally-valenced items with advancing age.

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