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Publications (7 of 7) Show all publications
Liljefors, J., Almeida, R., Rane, G., Lundström, J. N., Herman, P. & Lundqvist, M. (2024). Distinct functions for beta and alpha bursts in gating of human working memory. Nature Communications, 15(1), Article ID 8950.
Open this publication in new window or tab >>Distinct functions for beta and alpha bursts in gating of human working memory
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2024 (English)In: Nature Communications, E-ISSN 2041-1723, Vol. 15, no 1, article id 8950Article in journal (Refereed) Published
Abstract [en]

Multiple neural mechanisms underlying gating to working memory have been proposed with divergent results obtained in human and animal studies. Previous findings from non-human primates suggest prefrontal beta frequency bursts as a correlate of transient inhibition during selective encoding. Human studies instead suggest a similar role for sensory alpha power fluctuations. To cast light on these discrepancies we employed a sequential working memory task with distractors for human participants. In particular, we examined their whole-brain electrophysiological activity in both alpha and beta bands with the same single-trial burst analysis earlier performed on non-human primates. Our results reconcile earlier findings by demonstrating that both alpha and beta bursts in humans correlate with the filtering and control of memory items, but with region and task-specific differences between the two rhythms. Occipital beta burst patterns were selectively modulated during the transition from sensory processing to memory retention whereas prefrontal and parietal beta bursts tracked sequence order and were proactively upregulated prior to upcoming target encoding. Occipital alpha bursts instead increased during the actual presentation of unwanted sensory stimuli. Source reconstruction additionally suggested the involvement of striatal and thalamic alpha and beta. Thus, specific whole-brain burst patterns correlate with different aspects of working memory control.

National Category
Neurosciences
Identifiers
urn:nbn:se:su:diva-236923 (URN)10.1038/s41467-024-53257-7 (DOI)001338950000037 ()39419974 (PubMedID)2-s2.0-85206680358 (Scopus ID)
Available from: 2024-12-09 Created: 2024-12-09 Last updated: 2024-12-09Bibliographically approved
Pierzchajlo, S., Jernsäther, T., Fontana, L., Almeida, R. & Olofsson, J. K. (2024). Olfactory Categorization is Shaped by a Transmodal Cortical Network for Evaluating Perceptual Predictions. Journal of Neuroscience, 44(22), Article ID e1232232024.
Open this publication in new window or tab >>Olfactory Categorization is Shaped by a Transmodal Cortical Network for Evaluating Perceptual Predictions
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2024 (English)In: Journal of Neuroscience, ISSN 0270-6474, E-ISSN 1529-2401, Vol. 44, no 22, article id e1232232024Article in journal (Refereed) Published
Abstract [en]

Creating and evaluating predictions are considered important features in sensory perception. Little is known about processing differences between the senses and their cortical substrates. Here, we tested the hypothesis that olfaction, the sense of smell, would be highly dependent on (nonolfactory) object-predictive cues and involve distinct cortical processing features. We developed a novel paradigm to compare prediction error processing across senses. Participants listened to spoken word cues (e.g., “lilac”) and determined whether target stimuli (odors or pictures) matched the word cue or not. In two behavioral experiments (total n = 113; 72 female), the disparity between congruent and incongruent response times was exaggerated for olfactory relative to visual targets, indicating a greater dependency on predictive verbal cues to process olfactory targets. A preregistered fMRI study (n = 30; 19 female) revealed the anterior cingulate cortex (a region central for error detection) being more activated by incongruent olfactory targets, indicating a role for olfactory predictive error processing. Additionally, both the primary olfactory and visual cortices were significantly activated for incongruent olfactory targets, suggesting olfactory prediction errors are dependent on cross-sensory processing resources, whereas visual prediction errors are not. We propose that olfaction is characterized by a strong dependency on predictive (nonolfactory) cues and that odors are evaluated in the context of such predictions by a designated transmodal cortical network. Our results indicate differences in how predictive cues are used by different senses in rapid decision-making.

Keywords
multimodal, predictive coding, sensory integration
National Category
Neurosciences
Research subject
Psychology
Identifiers
urn:nbn:se:su:diva-235777 (URN)10.1523/JNEUROSCI.1232-23.2024 (DOI)001251866300011 ()38561229 (PubMedID)2-s2.0-85194950048 (Scopus ID)
Available from: 2024-11-25 Created: 2024-11-25 Last updated: 2025-08-25Bibliographically approved
Lebedev, A. V., Acar, K., Garzón, B., Almeida, R., Råback, J., Åberg, A., . . . Petrovic, P. (2021). Psychedelic drug use and schizotypy in young adults. Scientific Reports, 11(1), Article ID 15058.
Open this publication in new window or tab >>Psychedelic drug use and schizotypy in young adults
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2021 (English)In: Scientific Reports, E-ISSN 2045-2322, Vol. 11, no 1, article id 15058Article in journal (Refereed) Published
Abstract [en]

Despite recently resurrected scientific interest in classical psychedelics, few studies have focused on potential harms associated with abuse of these substances. In particular, the link between psychedelic use and psychotic symptoms has been debated while no conclusive evidence has been presented. Here, we studied an adult population (n=1032) with a special focus on young (18-35 years) and healthy individuals (n=701) to evaluate the association of psychedelic drug use with schizotypy and evidence integration impairment typically observed in psychosis-spectrum disorders. Experimental behavioural testing was performed in a subsample of the subjects (n=39). We observed higher schizotypy scores in psychedelic users in the total sample. However, the effect size was notably small and only marginally significant when considering young and healthy subjects (Cohen's d=0.13). Controlling for concomitant drug use, none of our analyses found significant associations between psychedelic use and schizotypal traits. Results from experimental testing showed that total exposure to psychedelics (frequency and temporal proximity of use) was associated with better evidence integration (Cohen's d=0.13) and a higher sensitivity of fear responses (Cohen's d=1.05) to the effects instructed knowledge in a reversal aversive learning task modelled computationally with skin conductance response and pupillometry. This effect was present even when controlling for demographics and concomitant drug use. On a group level, however, only difference in sensitivity of fear responses to instructed knowledge reached statistical significance. Taken together, our findings suggest that psychedelic drug use is only weakly associated with psychosis-like symptoms, which, in turn, is to a large extent explained by psychiatric comorbidities and use of other psychoactive substances. Our results also suggest that psychedelics may have an effect on flexibility of evidence integration and aversive learning processes, that may be linked to recently suggested therapeutic effects of psychedelic drugs in non-psychotic psychiatric populations.

National Category
Psychiatry
Identifiers
urn:nbn:se:su:diva-197118 (URN)10.1038/s41598-021-94421-z (DOI)000679382900008 ()34301969 (PubMedID)
Available from: 2021-09-28 Created: 2021-09-28 Last updated: 2022-09-15Bibliographically approved
Löwing, K., Holmström, L., Almeida, R. & Eliasson, A.-C. (2020). Do Infants at Risk of Developing Cerebral Palsy or Other Neurodevelopmental Disorders Learn What They Practice?. Journal of Clinical Medicine, 9(7), Article ID 2041.
Open this publication in new window or tab >>Do Infants at Risk of Developing Cerebral Palsy or Other Neurodevelopmental Disorders Learn What They Practice?
2020 (English)In: Journal of Clinical Medicine, E-ISSN 2077-0383, Vol. 9, no 7, article id 2041Article in journal (Refereed) Published
Abstract [en]

Through secondary analyses of the Small Step. Randomized Control Trial, we tested the hypothesis that children at risk of developing cerebral palsy (CP) or other neurodevelopmental disorders would learn what they practice, i.e., that they would have a more rapid development within the specifically trained foci (hand use or mobility) of each time period compared to the development rate within the foci not trained at that time. Nineteen infants (6.3 (1.62) months corrected age) included in the Small Step program were assessed at six time points during the intervention. For statistical analysis, general and mixed linear models were used, and the independent variables were the Peabody Developmental Motor scale (stationary, locomotion, grasping and visuomotor sub scales), the Gross Motor Function Measure-66 and the Hand Assessment for Infants. Outcomes related to gross motor function improved significantly more after mobility training than after hand use training, while fine motor function was improved to the same extent following both training types. Significantly higher improvements after the first training period were seen in one out of three outcome measures in both gross and fine motor assessments. The improvements observed were all independent of diagnosis at two years. The concept “you learn what you practice” was most clearly confirmed in the case of gross motor development.

Keywords
early intervention, cerebral palsy, development, other neurological disorder, gross motor function, upper limb function
National Category
Pediatrics
Identifiers
urn:nbn:se:su:diva-185641 (URN)10.3390/jcm9072041 (DOI)000557072800001 ()32610634 (PubMedID)
Available from: 2020-10-28 Created: 2020-10-28 Last updated: 2022-02-25Bibliographically approved
Namaganda, L. H., Almeida, R., Kajungu, D., Wabwire-Mangen, F., Peterson, S., Andrews, C., . . . Forssberg, H. (2020). Excessive premature mortality among children with cerebral palsy in rural Uganda: A longitudinal, population-based study. PLOS ONE, 15(12), Article ID e0243948.
Open this publication in new window or tab >>Excessive premature mortality among children with cerebral palsy in rural Uganda: A longitudinal, population-based study
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2020 (English)In: PLOS ONE, E-ISSN 1932-6203, Vol. 15, no 12, article id e0243948Article in journal (Refereed) Published
Abstract [en]

Background

Studies from high-income countries reported reduced life expectancy in children with cerebral palsy (CP), while no population-based study has evaluated mortality of children with CP in sub-Saharan Africa. This study aimed to estimate the mortality rate (MR) of children with CP in a rural region of Uganda and identify risk factors and causes of death (CODs).

Methods and findings

This population-based, longitudinal cohort study was based on data from Iganga-Mayuge Health and Demographic Surveillance System in eastern Uganda. We identified 97 children (aged 2-17 years) with CP in 2015, whom we followed to 2019. They were compared with an age-matched cohort from the general population (n = 41 319). MRs, MR ratios (MRRs), hazard ratios (HRs), and immediate CODs were determined. MR was 3952 per 100 000 person years (95% CI 2212-6519) in children with CP and 137 per 100 000 person years (95% CI 117-159) in the general population. Standardized MRR was 25 center dot 3 in the CP cohort, compared with the general population. In children with CP, risk of death was higher in those with severe gross motor impairments than in those with milder impairments (HR 6 center dot 8; p = 0 center dot 007) and in those with severe malnutrition than in those less malnourished (HR = 3 center dot 7; p = 0 center dot 052). MR was higher in females in the CP cohort, with a higher MRR in females (53 center dot 0; 95% CI 26 center dot 4-106 center dot 3) than in males (16 center dot 3; 95% CI 7 center dot 2-37 center dot 2). Age had no significant effect on MR in the CP cohort, but MRR was higher at 10-18 years (39 center dot 6; 95% CI 14 center dot 2-110 center dot 0) than at 2-6 years (21 center dot 0; 95% CI 10 center dot 2-43 center dot 2). Anaemia, malaria, and other infections were the most common CODs in the CP cohort.

Conclusions

Risk of premature death was excessively high in children with CP in rural sub-Saharan Africa, especially in those with severe motor impairments or malnutrition. While global childhood mortality has significantly decreased during recent decades, this observed excessive mortality is a hidden humanitarian crisis that needs to be addressed.

National Category
Pediatrics
Identifiers
urn:nbn:se:su:diva-190098 (URN)10.1371/journal.pone.0243948 (DOI)000603612300027 ()33373366 (PubMedID)
Available from: 2021-02-10 Created: 2021-02-10 Last updated: 2022-02-25Bibliographically approved
Vestberg, T., Jafari, R., Almeida, R., Maurex, L., Ingvar, M. & Petrovic, P. (2020). Level of play and coach-rated game intelligence are related to performance on design fluency in elite soccer players. Scientific Reports, 10(1), Article ID 9852.
Open this publication in new window or tab >>Level of play and coach-rated game intelligence are related to performance on design fluency in elite soccer players
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2020 (English)In: Scientific Reports, E-ISSN 2045-2322, Vol. 10, no 1, article id 9852Article in journal (Refereed) Published
Abstract [en]

Executive brain functions are innate mechanisms for regulating behavior. While the impact of suboptimal executive functions has been characterized in patients, their contribution to individual success has not been elucidated. We set out to understand how executive functions relate to successful human behavior by examining their relation to game intelligence in sport - the ability to read a game and quickly adapt the behavior. In elite soccer players (n = 51), those playing in national teams (national team players) significantly outperformed those only playing at premier league level (premier league players) in Design Fluency (DF), a complex visuo-spatial executive function test that includes measures of creativity and cognitive flexibility. Their result showed a moderate correlation with coach rated game intelligence, remained also when correcting for low level cognitive capacity and was most evident when considering cognitive flexibility. DF capacity also correlated with number of assists made during the season but not with number of made goals during the same period, linking the fast planning of several steps in DF to fast planning of several steps in the soccer game. Altogether, our data suggests that DF capacity relates to success in soccer both on a subjective and on an objective level.

National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:su:diva-184582 (URN)10.1038/s41598-020-66180-w (DOI)000546568400001 ()32587269 (PubMedID)
Available from: 2020-09-10 Created: 2020-09-10 Last updated: 2025-02-11Bibliographically approved
Holmström, L., Eliasson, A.-C., Almeida, R., Furmark, C., Weiland, A.-L., Tedroff, K. & Löwing, K. (2019). Efficacy of the Small Step Program in a Randomized Controlled Trial for Infants under 12 Months Old at Risk of Cerebral Palsy (CP) and Other Neurological Disorders. Journal of Clinical Medicine, 8(7), Article ID 1016.
Open this publication in new window or tab >>Efficacy of the Small Step Program in a Randomized Controlled Trial for Infants under 12 Months Old at Risk of Cerebral Palsy (CP) and Other Neurological Disorders
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2019 (English)In: Journal of Clinical Medicine, E-ISSN 2077-0383, Vol. 8, no 7, article id 1016Article in journal (Refereed) Published
Abstract [en]

The objective was to evaluate the effects of the Small Step Program on general development in children at risk of cerebral palsy (CP) or other neurodevelopmental disorders. A randomized controlled trial compared Small Step with Standard Care in infants recruited at 4-9 months of corrected age (CA). The 35-week intervention targeted mobility, hand use, and communication during distinct periods. The Peabody Developmental Motor Scales(2ed) (PDMS-2) was the primary outcome measure. For statistical analysis, a general linear model used PDMS-2 as the main outcome variable, together with a set of independent variables. Thirty-nine infants were randomized to Small Step (n = 19, age 6.3 months CA (1.62 SD)) or Standard Care (n = 20, age 6.7 months CA (1.96 SD)). Administering PDMS-2 at end of treatment identified no group effect, but an interaction between group and PDMS-2 at baseline was found (p < 0.02). Development was associated with baseline assessments in the Standard Care group, while infants in the Small Step group developed independent of the baseline level, implying that Small Step helped the most affected children to catch up by the end of treatment. This result was sustained at 2 years of age for PDMS-2 and the PEDI mobility scale.

Keywords
early intervention, cerebral palsy, development, other neurological disorder, gross motor function, upper limb function, communication
National Category
Neurosciences Pediatrics
Identifiers
urn:nbn:se:su:diva-173052 (URN)10.3390/jcm8071016 (DOI)000479003300101 ()31336705 (PubMedID)
Available from: 2019-09-23 Created: 2019-09-23 Last updated: 2022-03-23Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-9559-9903

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