Imaginative elaboration in agenesis of the corpus callosum: topic modeling and perplexity.

OBJECTIVE: Previous studies have found deficits in imaginative elaboration and social inference to be associated with agenesis of the corpus callosum (ACC; Renteria-Vasquez et al., 2022; Turk et al., 2009). In the current study, Thematic Apperception Test (TAT) responses from a neurotypical control group and a group of individuals with ACC were used to further study the capacity for imaginative elaboration and story coherence. METHOD: Topic modeling was employed utilizing Latent Diritchlet Allocation to characterize the narrative responses to the pictures used in the TAT. A measure of the difference between models (perplexity) was used to compare the topics of the responses of individual participants to the common core model derived from the responses of the control group. Story coherence was tested using sentence-to-sentence Latent Semantic Analysis. RESULTS: Group differences in perplexity were statistically significant overall, and for each card individually (p < .001). There were no differences between the groups in story coherence. CONCLUSIONS: TAT narratives from persons with ACC were normally coherent, but more conventional (i.e., more similar to the core text) compared to those of neurotypical controls. Individuals with ACC can make conventional social inferences about socially ambiguous stimuli, but are restricted in their imaginative elaborations, resulting in less topical variability (lower perplexity values) compared to neurotypical controls.

Smartphone-based gaze estimation for in-home autism research.

Atypical gaze patterns are a promising biomarker of autism spectrum disorder. To measure gaze accurately, however, it typically requires highly controlled studies in the laboratory using specialized equipment that is often expensive, thereby limiting the scalability of these approaches. Here we test whether a recently developed smartphone-based gaze estimation method could overcome such limitations and take advantage of the ubiquity of smartphones. As a proof-of-principle, we measured gaze while a small sample of well-assessed autistic participants and controls watched videos on a smartphone, both in the laboratory (with lab personnel) and in remote home settings (alone). We demonstrate that gaze data can be efficiently collected, in-home and longitudinally by participants themselves, with sufficiently high accuracy (gaze estimation error below 1° visual angle on average) for quantitative, feature-based analysis. Using this approach, we show that autistic individuals have reduced gaze time on human faces and longer gaze time on non-social features in the background, thereby reproducing established findings in autism using just smartphones and no additional hardware. Our approach provides a foundation for scaling future research with larger and more representative participant groups at vastly reduced cost, also enabling better inclusion of underserved communities.

Comprehensive Social Trait Judgments From Faces in Autism Spectrum Disorder.

Processing social information from faces is difficult for individuals with autism spectrum disorder (ASD). However, it remains unclear whether individuals with ASD make high-level social trait judgments from faces in the same way as neurotypical individuals. Here, we comprehensively addressed this question using naturalistic face images and representatively sampled traits. Despite similar underlying dimensional structures across traits, online adult participants with self-reported ASD showed different judgments and reduced specificity within each trait compared with neurotypical individuals. Deep neural networks revealed that these group differences were driven by specific types of faces and differential utilization of features within a face. Our results were replicated in well-characterized in-lab participants and partially generalized to more controlled face images (a preregistered study). By investigating social trait judgments in a broader population, including individuals with neurodevelopmental variations, we found important theoretical implications for the fundamental dimensions, variations, and potential behavioral consequences of social cognition.

Neural signatures of social inferences predict the number of real-life social contacts and autism severity.

We regularly infer other people's thoughts and feelings from observing their actions, but how this ability contributes to successful social behavior and interactions remains unknown. We show that neural activation patterns during social inferences obtained in the laboratory predict the number of social contacts in the real world, as measured by the social network index, in three neurotypical samples (total n = 126) and one sample of autistic adults (n = 23). We also show that brain patterns during social inference generalize across individuals in these groups. Cross-validated associations between brain activations and social inference localize selectively to the right posterior superior temporal sulcus and were specific for social, but not nonsocial, inference. Activation within this same brain region also predicts autism-like trait scores from questionnaires and autism symptom severity. Thus, neural activations produced while thinking about other people's mental states predict variance in multiple indices of social functioning in the real world.

Alcohol, cannabis, and nicotine use have distinct associations with COVID-19 pandemic-related experiences: An exploratory Bayesian network analysis across two timepoints.

BACKGROUND: Substance use trends during the COVID-19 pandemic have been extensively documented. However, relatively less is known about the associations between pandemic-related experiences and substance use. METHOD: In July 2020 and January 2021, a broad U.S. community sample (N = 1123) completed online assessments of past month alcohol, cannabis, and nicotine use and the 92-item Epidemic-Pandemic Impacts Inventory, a multidimensional measure of pandemic-related experiences. We examined links between substance use frequency, and pandemic impact on emotional, physical, economic, and other key domains, using Bayesian Gaussian graphical networks in which edges represent significant associations between variables (referred to as nodes). Bayesian network comparison approaches were used to assess the evidence of stability (or change) in associations between the two timepoints. RESULTS: After controlling for all other nodes in the network, multiple significant edges connecting substance use nodes and pandemic-experience nodes were observed across both time points, including positive- (r range 0.07-0.23) and negative-associations (r range -0.25 to -0.11). Alcohol was positively associated with social and emotional pandemic impacts and negatively associated with economic impacts. Nicotine was positively associated with economic impact and negatively associated with social impact. Cannabis was positively associated with emotional impact. Network comparison suggested these associations were stable across the two timepoints. CONCLUSION: Alcohol, nicotine, and cannabis use had unique associations to a few specific domains among a broad range of pandemic-related experiences. Given the cross-sectional nature of these analyses with observational data, further investigation is needed to identify potential causal links.

Verbal problem-solving in agenesis of the corpus callosum: Analysis using semantic similarity.

OBJECTIVE: Previous studies demonstrated that individuals with agenesis of the corpus callosum (AgCC) experience difficulties in novel and complex problem-solving. The present study investigated verbal problem-solving, deductive reasoning, and semantic inference in AgCC. METHOD: Capacity for semantic inference was tested in 25 individuals with AgCC and normal-range intelligence compared to 29 neurotypical controls. The Word Context Test (WCT) of Delis-Kaplan Executive Function System was used, employing a novel method of analysis (semantic similarity) to detect trial-by-trial progress toward a solution. RESULTS: With respect to the typical WCT scores, persons with AgCC had fewer total consecutive correct responses. In addition, semantic similarity to the correct word was significantly lower overall in persons with AgCC than in controls. CONCLUSION: These findings indicated that individuals with AgCC who have intelligence in the normal range are less able at the WCT taking all trials into account, although they often solve the problem eventually. This outcome is consistent with previous research indicating that callosal absence in AgCC results in a restricted imagination for possibilities, limiting their problem-solving and inferential capacities. The results also highlight the usefulness of semantic similarity as a means of scoring the WCT. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

COVID-Dynamic: A large-scale longitudinal study of socioemotional and behavioral change across the pandemic.

The COVID-19 pandemic has caused enormous societal upheaval globally. In the US, beyond the devastating toll on life and health, it triggered an economic shock unseen since the great depression and laid bare preexisting societal inequities. The full impacts of these personal, social, economic, and public-health challenges will not be known for years. To minimize societal costs and ensure future preparedness, it is critical to record the psychological and social experiences of individuals during such periods of high societal volatility. Here, we introduce, describe, and assess the COVID-Dynamic dataset, a within-participant longitudinal study conducted from April 2020 through January 2021, that captures the COVID-19 pandemic experiences of >1000 US residents. Each of 16 timepoints combines standard psychological assessments with novel surveys of emotion, social/political/moral attitudes, COVID-19-related behaviors, tasks assessing implicit attitudes and social decision-making, and external data to contextualize participants' responses. This dataset is a resource for researchers interested in COVID-19-specific questions and basic psychological phenomena, as well as clinicians and policy-makers looking to mitigate the effects of future calamities.

Posttraumatic stress disorder symptom trajectories in a 16-month COVID-19 pandemic period.

COVID-19 pandemic presents an unheralded opportunity to better understand trajectories of posttraumatic stress disorder (PTSD) symptoms across a prolonged period of social disruption and stress. We tracked PTSD symptoms among trauma-exposed individuals in the United States and sought to identify population-based variability in PTSD symptom trajectories and understand what, if any, early pandemic experiences predicted membership in one trajectory versus others. As part of a longitudinal study of U.S. residents during the pandemic, participants who reported at least one potentially traumatic experience in their lifetime (N = 1,206) at Wave 1 (April 2020) were included in the current study. PTSD symptoms were assessed using the PCL-5 at four time points extending to July 2021. Latent growth mixture modeling was used to identify heterogeneous symptom trajectories. Trajectory membership was regressed on experiences from the early stage of the pandemic as measured using the Epidemic-Pandemic Impacts Inventory in a model that controlled for variables with documented associations to PTSD trajectories, including age, sex, income, and trauma history. Four trajectories were identified, categorized as resilient (73.0%), recurring (13.3%), recovering (8.3%), and chronic (5.5%). Emotional and physical health problems and positive changes associated with the early phase of the pandemic were each significant predictors of trajectory membership over and above all other variables in the model. Predictors primarily differentiated the resilient trajectory from each of the other three trajectories. Distinct PTSD symptom trajectories during the COVID-19 pandemic suggest a need for targeted efforts to help individuals at most risk for ongoing distress.

Dissociable brain structural asymmetry patterns reveal unique phenome-wide profiles.

Broca reported ~150 years ago that particular lesions of the left hemisphere impair speech. Since then, other brain regions have been reported to show lateralized structure and function. Yet, studies of brain asymmetry have limited their focus to pairwise comparisons between homologous regions. Here, we characterized separable whole-brain asymmetry patterns in grey and white matter structure from n = 37,441 UK Biobank participants. By pooling information on left-right shifts underlying whole-brain structure, we deconvolved signatures of brain asymmetry that are spatially distributed rather than locally constrained. Classically asymmetric regions turned out to belong to more than one asymmetry pattern. Instead of a single dominant signature, we discovered complementary asymmetry patterns that contributed similarly to whole-brain asymmetry at the population level. These asymmetry patterns were associated with unique collections of phenotypes, ranging from early lifestyle factors to demographic status to mental health indicators.

Atypical gaze patterns in autistic adults are heterogeneous across but reliable within individuals.

BACKGROUND: Across behavioral studies, autistic individuals show greater variability than typically developing individuals. However, it remains unknown to what extent this variability arises from heterogeneity across individuals, or from unreliability within individuals. Here, we focus on eye tracking, which provides rich dependent measures that have been used extensively in studies of autism. Autistic individuals have an atypical gaze onto both static visual images and dynamic videos that could be leveraged for diagnostic purposes if the above open question could be addressed. METHODS: We tested three competing hypotheses: (1) that gaze patterns of autistic individuals are less reliable or noisier than those of controls, (2) that atypical gaze patterns are individually reliable but heterogeneous across autistic individuals, or (3) that atypical gaze patterns are individually reliable and also homogeneous among autistic individuals. We collected desktop-based eye tracking data from two different full-length television sitcom episodes, at two independent sites (Caltech and Indiana University), in a total of over 150 adult participants (N = 48 autistic individuals with IQ in the normal range, 105 controls) and quantified gaze onto features of the videos using automated computer vision-based feature extraction. RESULTS: We found support for the second of these hypotheses. Autistic people and controls showed equivalently reliable gaze onto specific features of videos, such as faces, so much so that individuals could be identified significantly above chance using a fingerprinting approach from video epochs as short as 2 min. However, classification of participants into diagnostic groups based on their eye tracking data failed to produce clear group classifications, due to heterogeneity in the autistic group. LIMITATIONS: Three limitations are the relatively small sample size, assessment across only two videos (from the same television series), and the absence of other dependent measures (e.g., neuroimaging or genetics) that might have revealed individual-level variability that was not evident with eye tracking. Future studies should expand to larger samples across longer longitudinal epochs, an aim that is now becoming feasible with Internet- and phone-based eye tracking. CONCLUSIONS: These findings pave the way for the investigation of autism subtypes, and for elucidating the specific visual features that best discriminate gaze patterns-directions that will also combine with and inform neuroimaging and genetic studies of this complex disorder.

Caltech Conte Center, a multimodal data resource for exploring social cognition and decision-making.

This data release of 117 healthy community-dwelling adults provides multimodal high-quality neuroimaging and behavioral data for the investigation of brain-behavior relationships. We provide structural MRI, resting-state functional MRI, movie functional MRI, together with questionnaire-based and task-based psychological variables; many of the participants have multiple datasets from retesting over the course of several years. Our dataset is distinguished by utilizing open-source data formats and processing tools (BIDS, FreeSurfer, fMRIPrep, MRIQC), providing data that is thoroughly quality checked, preprocessed to various extents and available in multiple anatomical spaces. A customizable denoising pipeline is provided as open-source code that includes tools for the generation of functional connectivity matrices and initialization of individual difference analyses. Behavioral data include a comprehensive set of psychological assessments on gold-standard instruments encompassing cognitive function, mood and personality, together with exploratory factor analyses. The dataset provides an in-depth, multimodal resource for investigating associations between individual differences, brain structure and function, with a focus on the domains of social cognition and decision-making.

Social Inferences in Agenesis of the Corpus Callosum and Autism: Semantic Analysis and Topic Modeling.

Impoverished capacity for social inference is one of several symptoms that are common to both agenesis of the corpus callosum (AgCC) and Autism Spectrum Disorder (ASD). This research compared the ability of 14 adults with AgCC, 13 high-functioning adults with ASD and 14 neurotypical controls to accurately attribute social meaning to the interactions of animated triangles. Descriptions of the animations were analyzed in three ways: subjective ratings, Linguistic Inquiry and Word Count, and topic modeling (Latent Dirichlet Allocation). Although subjective ratings indicated that all groups made similar inferences from the animations, the index of perplexity (atypicality of topic) generated from topic modeling revealed that inferences from individuals with AgCC or ASD displayed significantly less social imagination than those of controls.

Knowledge gaps for functional outcomes after multilobar resective and disconnective pediatric epilepsy surgery: Conference Proceedings of the Patient-Centered Stakeholder Meeting 2019.

For children with medication-resistant epilepsy who undergo multilobar or hemispheric surgery, the goal of achieving seizure freedom is met with a variety of potential functional consequences, both favorable and unfavorable. However, there is a paucity of literature that comprehensively addresses the cognitive, medical, behavioral, orthopedic, and sensory outcomes across the lifespan following large epilepsy surgeries in childhood, leaving all stakeholders underinformed with regard to counseling and expectations. Through collaboration between clinicians, researchers, and patient/caregiver stakeholders, the "Functional Impacts of Large Resective or Disconnective Pediatric Epilepsy Surgery: Identifying Gaps and Setting PCOR Priorities" meeting was convened on July 18, 2019, to identify gaps in knowledge and inform various patient-centered research initiatives. Clinicians and researchers with content expertise presented the best available data in each functional domain which is summarized here. As a result of the meeting, the top three consensus priorities included research focused on postoperative: (1) hydrocephalus; (2) mental health issues; and (3) literacy and other educational outcomes. The proceedings of this meeting mark the first time research on functional outcomes after resective and disconnective pediatric epilepsy surgery has been codified and shared among multidisciplinary stakeholders. This joint initiative promotes continued collaboration in the field and ensures that advancements align with actual patient and family needs and experiences. Collaboration around common objectives will lead to better informed counseling around postoperative expectations and management for children undergoing epilepsy surgery.

Reorganization of the Social Brain in Individuals with Only One Intact Cerebral Hemisphere.

Social cognition and emotion are ubiquitous human processes that recruit a reliable set of brain networks in healthy individuals. These brain networks typically comprise midline (e.g., medial prefrontal cortex) as well as lateral regions of the brain including homotopic regions in both hemispheres (e.g., left and right temporo-parietal junction). Yet the necessary roles of these networks, and the broader roles of the left and right cerebral hemispheres in socioemotional functioning, remains debated. Here, we investigated these questions in four rare adults whose right (three cases) or left (one case) cerebral hemisphere had been surgically removed (to a large extent) to treat epilepsy. We studied four closely matched healthy comparison participants, and also compared the patient findings to data from a previously published larger healthy comparison sample (n = 33). Participants completed standardized socioemotional and cognitive assessments to investigate social cognition. Functional magnetic resonance imaging (fMRI) data were obtained during passive viewing of a short, animated movie that distinctively recruits two social brain networks: one engaged when thinking about other agents' internal mental states (e.g., beliefs, desires, emotions; so-called Theory of Mind or ToM network), and the second engaged when thinking about bodily states (e.g., pain, hunger; so-called PAIN network). Behavioral assessments demonstrated remarkably intact general cognitive functioning in all individuals with hemispherectomy. Social-emotional functioning was somewhat variable in the hemispherectomy participants, but strikingly, none of these individuals had consistently impaired social-emotional processing and none of the assessment scores were consistent with a psychiatric disorder. Using inter-region correlation analyses, we also found surprisingly typical ToM and PAIN networks, as well as typical differentiation of the two networks (in the intact hemisphere of patients with either right or left hemispherectomy), based on idiosyncratic reorganization of cortical activation. The findings argue that compensatory brain networks can process social and emotional information following hemispherectomy across different age levels (from 3 months to 20 years old), and suggest that social brain networks typically distributed across midline and lateral brain regions in this domain can be reorganized, to a substantial degree.

Single-neuron correlate of epilepsy-related cognitive deficits in visual recognition memory in right mesial temporal lobe.

OBJECTIVE: Impaired memory is a common comorbidity of refractory temporal lobe epilepsy (TLE) and often perceived by patients as more problematic than the seizures themselves. The objective of this study is to understand what the relationship of these behavioral impairments is to the underlying pathophysiology, as there are currently no treatments for these deficits, and it remains unknown what circuits are affected. METHODS: We recorded single neurons in the medial temporal lobes (MTLs) of 62 patients (37 with refractory TLE) who performed a visual recognition memory task to characterize the relationship between behavior, tuning, and anatomical location of memory selective and visually selective neurons. RESULTS: Subjects with a seizure onset zone (SOZ) in the right but not left MTL demonstrated impaired ability to recollect as indicated by the degree of asymmetry of the receiver operating characteristic curve. Of the 1973 recorded neurons, 159 were memory selective (MS) and 366 were visually selective (VS) category cells. The responses of MS neurons located within right but not left MTL SOZs were impaired during high-confidence retrieval trials, mirroring the behavioral deficit seen both in our task and in standardized neuropsychological tests. In contrast, responses of VS neurons were unimpaired in both left and right MTL SOZs. Our findings show that neuronal dysfunction within SOZs in the MTL was specific to a functional cell type and behavior, whereas other cell types respond normally even within the SOZ. We show behavioral metrics that detect right MTL SOZ-related deficits and identify a neuronal correlate of this impairment. SIGNIFICANCE: Together, these findings show that single-cell responses can be used to assess the causal effects of local circuit disruption by an SOZ in the MTL, and establish a neural correlate of cognitive impairment due to epilepsy that can be used as a biomarker to assess the efficacy of novel treatments.

Alexithymia and somatization in agenesis of the corpus callosum.

Deficient communication between the cerebral hemispheres is one of several prevailing neurobiological explanations for alexithymia and has been strongly supported by research on patients with commissurotomy. We examined self-reported symptoms of alexithymia in adults with agenesis of the corpus callosum (AgCC), a condition characterized by more subtle reductions in interhemispheric transfer than in commissurotomy. Sixteen adults with AgCC and full-scale intelligence quotient >80 were compared with 15 neurotypical controls group-matched for age and intelligence score. The AgCC group endorsed greater difficulty identifying and describing feelings and more vague physical symptoms than controls but similar levels of emotional experience and emotional coping. This finding of impaired emotional interpretation with intact emotional experience is consistent with findings in callosotomy patients, implicating the critical role of the corpus callosum in cognitive dimensions of emotion processing. Further study of alexithymia in AgCC using task-based measures may help clarify the nature of this relationship.

How representative are neuroimaging samples? Large-scale evidence for trait anxiety differences between fMRI and behaviour-only research participants.

Over the past three decades, functional magnetic resonance imaging (fMRI) has become crucial to study how cognitive processes are implemented in the human brain. However, the question of whether participants recruited into fMRI studies differ from participants recruited into other study contexts has received little to no attention. This is particularly pertinent when effects fail to generalize across study contexts: for example, a behavioural effect discovered in a non-imaging context not replicating in a neuroimaging environment. Here, we tested the hypothesis, motivated by preliminary findings (N = 272), that fMRI participants differ from behaviour-only participants on one fundamental individual difference variable: trait anxiety. Analysing trait anxiety scores and possible confounding variables from healthy volunteers across multiple institutions (N = 3317), we found robust support for lower trait anxiety in fMRI study participants, consistent with a sampling or self-selection bias. The bias was larger in studies that relied on phone screening (compared with full in-person psychiatric screening), recruited at least partly from convenience samples (compared with community samples), and in pharmacology studies. Our findings highlight the need for surveying trait anxiety at recruitment and for appropriate screening procedures or sampling strategies to mitigate this bias.

Everyday Executive Function and Self-Awareness in Agenesis of the Corpus Callosum.

OBJECTIVE: Agenesis of the corpus callosum (AgCC) is associated with a range of cognitive deficits, including mild to moderate problems in higher order executive functions evident in neuropsychological assessments. Previous research has also suggested a lack of self-awareness in persons with AgCC. METHOD: We investigated daily executive functioning and self-awareness in 36 individuals with AgCC by analyzing self-ratings on the Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A), as well as ratings on the same instrument from close relatives. Discrepancies between self- and informant-ratings were compared to the normative sample and exploratory analyses examined possible moderating effects of participant and informant characteristics. RESULTS: Significant deficiencies were found in the Behavioral Regulation and Metacognitive indices for both the self and informant results, with elevated frequency of metacognition scores in the borderline to clinical range. Informants also endorsed elevated frequency of borderline to clinically significant behavioral regulation scores. The proportion of AgCC participants whose self-ratings indicated less metacognitive impairment than informant-ratings was greater than in the normative sample. Self-ratings of behavioral regulation impairment decreased with age and informant-ratings of metacognition were higher in males than females. CONCLUSIONS: These findings provide evidence that individuals with AgCC experience mild to moderate executive functioning problems in everyday behavior which are observed by others. Results also suggest a lack of self-understanding or insight into the severity of these problems in the individuals with AgCC, particularly with respect to their metacognitive functioning.

Appreciation of Social Norms in Agenesis of the Corpus Callosum.

OBJECTIVE: Anecdotal reports regarding high-functioning adults with agenesis of the corpus callosum (AgCC) suggest that they often lack psychosocial insight. We attempted to determine whether adults with AgCC are able to correctly identify appropriate behaviors within social contexts using the Social Norms Questionnaire. METHOD: The Social Norms Questionnaire measures knowledge of norms and judgments of what is appropriate to do in particular contexts. It was administered online to individuals with AgCC and control participants. RESULTS: Individuals with AgCC scored significantly lower in understanding social norms than controls, tending to over-adhere to social norms significantly more than controls. There was no significant difference regarding breaking of social norms. CONCLUSION: Results suggest that adults with AgCC have deficient judgment regarding the nuances of appropriate behaviors in social contexts. They adhere to social norms concretely, lacking the ability to integrate context in social scenarios to make appropriately nuanced judgments.

Personality beyond taxonomy.

Human and animal behaviour exhibits complex but regular patterns over time, often referred to as expressions of personality. Yet it remains unclear what personality really is: is it just the behavioural patterns themselves, something in the brain, in the genes or perhaps all of these? Here we offer a set of causal hypotheses about the role of personality, integrating psychological and neuroscientific approaches to personality in a testable framework. These hypotheses clarify the causal and constitutive relations that personality has with genes, environment, brain, mind and behaviour, and we suggest specific experiments that can adjudicate amongst the different hypotheses. We focus on a set of models that propose that personality is instantiated in the brain, distally caused by genes and environment and, in turn, causing the overt behaviours from which it is often inferred. We argue that articulating and testing such models will be essential in a mature science of personality.