| 1. |
- Guath, Mona, et al.
(författare)
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Pupillary response in reward processing in adults with major depressive disorder in remission
- 2023
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Ingår i: Journal of the International Neuropsychological Society. - : Cambridge University Press. - 1355-6177 .- 1469-7661. ; 29:3, s. 306-315
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Tidskriftsartikel (refereegranskat)abstract
- Objective:Major depressive disorder (MDD) is associated with impaired reward processing and reward learning. The literature is inconclusive regarding whether these impairments persist after remission. The current study examined reward processing during a probabilistic learning task in individuals in remission from MDD (n = 19) and never depressed healthy controls (n = 31) matched for age and sex. The outcome measures were pupil dilation (an indirect index of noradrenergic activity and arousal) and computational modeling parameters.Method:Participants completed two versions (facial/nonfacial feedback) of probabilistic reward learning task with changing contingencies. Pupil dilation was measured with a corneal reflection eye tracker. The hypotheses and analysis plan were preregistered.Result:Healthy controls had larger pupil dilation following losses than gains (p <.001), whereas no significant difference between outcomes was found in individuals with a history of MDD, resulting in an interaction between group and outcome (beta = 0.81, SE = 0.34, t = 2.37, p = .018). The rMDD group also achieved lower mean score at the last trial (t[46.77] = 2.12, p = .040) as well as a smaller proportion of correct choices (t[46.70] = 2.09, p = .041) compared with healthy controls.Conclusion:Impaired reward processing may persist after remission from MDD and could constitute a latent risk factor for relapse. Measuring pupil dilation in a reward learning task is a promising method for identifying reward processing abnormalities linked to MDD. The task is simple and noninvasive, which makes it feasible for clinical research.
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| 2. |
- Kleberg, Johan L., et al.
(författare)
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No transfer of arousal from other’s eyes in Williams syndrome
- 2023
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Typically developing humans automatically synchronize their arousal levels, resulting in pupillary contagion, or spontaneous adaptation of pupil size to that of others. This phenomenon emerges in infancy and is believed to facilitate social interaction. Williams syndrome (WS) is a genetic condition characterized by a hyper-social personality and social interaction challenges. Pupillary contagion was examined in individuals with WS (n = 44), age-parallel-matched typically developing children and adults (n = 65), and infants (n = 79). Bayesian statistics were used. As a group, people with WS did not show pupillary contagion (Bayes factors supporting the null: 25–50) whereas control groups did. This suggests a very early emerging atypical developmental trajectory. In WS, higher pupillary contagion was associated with lower autistic symptoms of social communication. Diminished synchronization of arousal may explain why individuals with WS have social challenges, whereas synchronization of arousal is not a necessary correlate of high social motivation.
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| 3. |
- Kleberg, Johan L., et al.
(författare)
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Social feedback enhances learning in Williams syndrome
- 2023
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Williams syndrome (WS) is a rare genetic condition characterized by high social interest and approach motivation as well as intellectual disability and anxiety. Despite the fact that social stimuli are believed to have an increased intrinsic reward value in WS, it is not known whether this translates to learning and decision making. Genes homozygously deleted in WS are linked to sociability in the general population, making it a potential model condition for understanding the social brain. Probabilistic reinforcement learning was studied with either social or non-social rewards for correct choices. Social feedback improved learning in individuals with Williams syndrome but not in typically developing controls or individuals with other intellectual disabilities. Computational modeling indicated that these efects on social feedback were mediated by a shift towards higher weight given to rewards relative to punishments and increased choice consistency. We conclude that reward learning in WS is characterized by high volatility and a tendency to learn how to avoid punishment rather than how to gain rewards. Social feedback can partly normalize this pattern and promote adaptive reward learning.
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| 4. |
- Lundin Kleberg, Johan, et al.
(författare)
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Williams syndrome : reduced orienting to other's eyes in a hypersocial phenotype
- 2023
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Ingår i: Journal of autism and developmental disorders. - : Springer Nature. - 0162-3257 .- 1573-3432. ; 53:7, s. 2786-2797
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Tidskriftsartikel (refereegranskat)abstract
- Williams syndrome (WS) is a rare genetic condition associated with high sociability, intellectual disability, and social cognitive challenges. Attention to others' eyes is crucial for social understanding. Orienting to, and from other’s eyes was studied in WS (n = 37, mean age = 23, age range 9–53). The WS group was compared to a typically developing comparison participants (n = 167) in stratified age groups from infancy to adulthood. Typically developing children and adults were quicker and more likely to orient to eyes than the mouth. This bias was absent in WS. The WS group had reduced peak saccadic velocities, indicating hypo-arousal. The current study indicates reduced orienting to others’ eyes in WS, which may affect social interaction skills.
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| 5. |
- Willfors, Charlotte
(författare)
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Identification of biobehavioral markers of neurodevelopmental disorders in twins
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD) are complex neurodevelopmental disorders (NDD), heterogeneous in phenotypes and etiology. The exact mechanisms driving the phenotypes are still largely unknown. The overall aim of this thesis is to find new leads for ASD and ADHD etiology, focusing on environmental factors through the examination of discordant twins. For this purpose, two ASD enriched and well characterized twin cohorts were investigated; the Roots of Autism and ADHD Twin Study of Sweden (RATSS) and the Californian Autism Twin Study (CATS). In study I, we are discussing the background the aims and the rationale for the RATSS program. In study II, the association between ASD and IQ is examined. There is a robust and negative phenotypic correlation between IQ and ASD, categorical as well as dimensional, underpinned by genetic and non-shared environmental (NSE) factors. The role of non-shared environment in ASD, focusing on early medical events, is explored in Study III. There is an association between the total load of early medical events and ASD, both categorically as well as dimensionally defined. The association is particularly driven by behavioral dysregulation in infants (feeding and sleeping problems, excessive crying and worriedness) as a function of NSE factors. In study IV, we test the hypothesis of a link between ASD and pre- and postnatal dysregulation of metals. ASD cases demonstrate higher lead levels during a period of 20 weeks before and 30 weeks after birth, lower manganese levels 17 weeks prenatally to 30 weeks postnatally, and a reduction in zinc 10 weeks prenatally to five weeks postnatally. In study V we study executive functioning as a behavioral marker of ADHD. There is a link between ADHD on one hand, and foresighted planning and inhibitory control on the other hand, mediated by NSE factors. In summary, the findings support ASD to be continuously distributed in the population with clinical phenotypes being the extremes of these continuums. They point to a cumulative multifactor threshold model, including both genetic and NSE components in the etiology of ASD. More specifically, the results support that systemic pre- and postnatal elemental dysregulation increase ASD risk, and an association between early medical events and ASD risk. The findings also indicate low IQ to be a behavioral marker for ASD, and poor executive functioning to be a behavioral marker for ADHD. Both these association are underpinned by NSE factors.
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| 6. |
- Willfors, Charlotte, et al.
(författare)
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On the role of non-shared environment for executive functioning in ADHD : a twin-differences design study
- 2014
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Ingår i: International Journal of Developmental Disabilities. - Stockholm : Karolinska Institutet, Dept of Medical Epidemiology and Biostatistics. - 2047-3877. ; 60:3, s. 163-173
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: The study of differences between monozygotic (MZ) twin pairs with respect to ADHD may provide novel leads to disentangle the environmental contribution driving its phenotypes. Objectives: To examine non-shared environmental influences on executive function in dimensionally defined ADHD. Methods: This study included 27 MZ twin pairs (7 female) aged 11–20 years being moderately to substantially discordant for ADHD traits as assessed by the Attention Problem (AP) scale of the Child Behavior Checklist/Adult Behavior Checklist. The twins completed the Wisconsin Card Sorting Test (WCST) for cognitive flexibility and the Tower Test (TT) for foresighted planning. Two statistical approaches were used to analyze the data. First, correlations between ADHD trait intra-pair differences and WCST and TT scores were calculated. Second, the significance of those intra-pair differences on WCST and TT, using ADHD as categorical variable in clinically discordant pairs, was tested. Results: Both analysing strategies revealed a link between ADHD on one hand, and foresighted planning and inhibitory control on the other hand mediated by non-shared environmental factors. The first statistical approach yielded positive correlations between intra-pairs differences on the AP scale and intra-pair differences on two subscales of the TT: total rule violation (rs = 0·41) and rule-violation-per-item-ratio (rs = 0·38). Findings in categorically discordant pairs were consistent, showing within-pair differences on the same subtests (z-1·63, P = 0·05, one-tailed and z = −1·60, P = 0·05, one-tailed). Conclusions: Findings confirm previous research suggesting ADHD to be a quantitative extreme on a continuum with executive functions being a cognitive marker of ADHD traits. Non-shared environmental factors appear to influence planning skills and inhibitory control.
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| 7. |
- Zander, Eric, et al.
(författare)
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The Interrater Reliability of the Autism Diagnostic Interview-Revised (ADI-R) in Clinical Settings
- 2017
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Ingår i: Psychopathology. - : S. Karger AG. - 0254-4962 .- 1423-033X. ; 50:3, s. 219-227
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Tidskriftsartikel (refereegranskat)abstract
- Background: The Autism Diagnostic Interview-Revised (ADI-R) is considered a first choice assessment tool in autism spectrum disorder. Nevertheless, despite its wide use in psychiatric practice and recommendations by various clinical guidelines, its interrater reliability has predominantly been confirmed in research settings by specially trained, research reliability interviewers. The reliability of ADI-R assessments among clinicians has not yet been established. Therefore, this study examined the spontaneous interrater reliability of the ADI-R in a naturalistic clinical multicenter setting. Sampling and Methods: Ten video-recorded ADI-R administrations were rated by 5 different raters each from a pool of 11 raters affiliated to 8 different clinical sites. Results: The interrater reliability for the 12 diagnostic criteria operationalizing autism spectrum disorders according to DSM-IV/ICD-10 in the ADI-R algorithms ranged between G(q,k) (analogous to intraclass correlations) = 0.96 and 0.99 for reciprocal social interaction, 0.96 and 1.00 for communication, and 0.91 and 0.97 for repetitive and restricted behavior. Reliability of diagnostic classification was KCohen 0.83. Conclusions: The findings endorse the psychometric properties of ADI-R in terms of interrater reliability previously reported from research settings and support their generalization to common clinical settings. Limitations of this study include an unbalanced sample composition.
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