Biology subjects

Peterburs, J.

Publications and source records attributed to Peterburs, J..

3 recordsLinked to original sources

bioRxiv2024

Specific amygdala and hippocampal subfield volumes in social anxiety disorder and their relation to clinical characteristics; an international mega-analysis

Social anxiety disorder (SAD) has been associated with alterations in amygdala and hippocampal volume but there is mixed evidence for the direction of volumetric alterations. Additionally, little is known about the involvement of the distinct subfields in the pathophysiology of SAD. Volumetric data from a large multi-centre sample of 107 adult individuals with SAD and 140 healthy controls (HCs) was segmented using FreeSurfer to produce 9 amygdala and 12 hippocampal subfield volumes. Volumes were compared between groups using linear mixed-effects models adjusted for age, age-squared, sex, site and whole amygdala and hippocampal volumes. Subgroup analyses examined subfield volumes in relation to comorbid anxiety disorder, and comorbid major depressive disorder (MDD), psychotropic medication status, and symptom severity. In the full sample, SAD was associated with smaller amygdala volumes in the basal (d=-0.32, pFDR=0.022), accessory basal (d=- 0.42, pFDR=0.005) and corticoamygdaloid transition area (d=-0.37, pFDR=0.014), and larger hippocampal volume in the CA3 (d=0.34, pFDR=0.024), CA4 (d=0.44, pFDR=0.007), dentate gyrus (d=0.35, pFDR=0.022) and molecular layer (d=0.28, pFDR= 0.033), compared to HCs. SAD without comorbid anxiety, in addition, demonstrated smaller lateral amygdala (d=-0.30, pFDR=0.037) and hippocampal amygdala transition area (d=-0.33, pFDR=0.027) relative to HCs. In SAD without comorbid MDD, only the smaller accessory basal amygdala remained significant (d=-0.41, pFDR=0.017). No association was found between subfield volume and medication status or symptom severity. In conclusion, we observed distinct patterns of volumetric differences across specific amygdala and hippocampal subfields, regions that are associated with sensory information processing, threat evaluation and fear generalization. These findings suggest a possible disruption in information flow between the amygdala and hippocampal formation for fear processing in SAD.

neuroscience↗

bioRxiv2022

Walk the Plank! Using mobile EEG to investigate emotional lateralization of immersive fear in virtual reality

1.Most studies on emotion processing rely on the presentation of emotional images or films. However, this methodology lacks ecological validity, limiting the extent to which findings can generalize to emotion processing in the wild. More realistic paradigms using Virtual Reality (VR) may be better suited to investigate authentic emotional states and their neuronal correlates. This preregistered study examines the neuronal underpinnings of naturalistic fear, measured using mobile electroencephalography (EEG). Seventy-five healthy participants entered a simulation in which they walked across a virtual plank which extended from the side of a skyscraper - either 80 stories up (the negative condition) or at street level (the neutral condition). Subjective ratings showed that the negative condition induced feelings of fear and presence. Following the VR experience, subjects passively viewed negative and neutral images from the International Affective Picture system (IAPS) outside of VR. We compared frontal alpha asymmetry between the plank and IAPS task and across valence of the conditions. Asymmetry indices (AI) in the plank task revealed greater right-hemispheric lateralization during the negative VR condition, relative to the neutral VR condition and to IAPS viewing. Within the IAPS task, no significant asymmetries were detected, though AIs in the VR task and in the IAPS task were negatively correlated suggesting that stronger right-hemispheric activation in the VR task was associated with stronger left-hemispheric activation during the IAPS task. In summary, our findings indicate that immersive technologies such as VR can advance emotion research by providing more ecologically valid ways to induce emotion.

neuroscience↗

bioRxiv2019

Reward Prediction Error Signaling during Reinforcement Learning in Social Anxiety Disorder is altered by Social Observation

BACKGROUNDDysfunctional expectations of impending social or performance outcomes are core features of Social Anxiety Disorder (SAD) but often lack formal definition in clinical research. Reinforcement learning (RL) models offer a framework to define changes in outcome expectations in a formal way by computing the prediction error (PE). This study quantifies the updating of expectations by PEs in SAD and investigates alterations in RL regions associated with PE signaling.\n\nMETHOD48 adult participants (24 diagnosed with SAD and 24 age-, gender-, and education- matched healthy controls (HC)) underwent event-related functional magnetic resonance imaging while learning from probabilistic feedback. Crucially, both groups completed two parallel versions of the task: one in which they learned under scrutiny (social observation) and one in which they learned without being overtly evaluated (non-social control condition).\n\nRESULTSCoupling to prediction errors in SAD was elevated in dorsomedial prefrontal cortex (DMPFC) when learning under observation. These findings provide the first evidence that PE signaling during social performance situations in SAD is associated with hypersensitive response signatures in DMPFC, a brain region associated with using others value standards as a proxy for ones own value standards. Dynamic Causal Modelling further revealed that RPE-modulated connectivity from ventral pallidum to DMPFC during observation was reduced in SAD.\n\nCONCLUSIONSThe present results corroborate a crucial role of DMPFC in SAD, which corresponds to dysfunctional expectations about others alleged performance standards that play a prominent role in current models of the disorder.

neuroscience↗