Biology subjects

Kalisch, R.

Publications and source records attributed to Kalisch, R..

6 recordsLinked to original sources

bioRxiv2026

Cross-Modal Organization of Facial and Vocal Behavior Revealed by Coordination Metrics Derived from Temporal Alignment

Facial and vocal behaviors jointly convey affective and communicative information, yet their cross-modal organization remains difficult to characterize quantitatively. We propose a framework for characterizing facial-vocal organization by aligning facial and vocal dynamics using canonical time warping. Multivariate facial action unit trajectories and vocal prosodic trajectories were extracted from recordings of spontaneous speech and aligned in a shared latent space. From the alignment process, we derived three cross-modal coordination metrics: "scaling factor", reflecting the relative scaling between modalities; "time shift ratio", reflecting the frequency of temporal shifts; and "time shift magnitude", reflecting their size. We evaluated these metrics in verbally fluent adults with autism spectrum disorder (ASD; N = 35) and controls (N = 44). The proposed metrics did not differ significantly between diagnostic groups but showed associations with individual differences in communication and anxiety. Scaling factor was linked to trait anxiety in ASD, whereas time shift ratio was associated with communication characteristics across participants. The proposed metrics also showed little association with conventional vocal pitch variability, suggesting that they capture aspects of expressive organization not reflected by vocal variability alone. Our findings support alignment-derived metrics as a complementary approach for characterizing individual variability in facial-vocal expressive behavior.

neuroscience↗

bioRxiv2025

A ventral striatal learning signal reflecting individual differences in the success of fear extinction

Individual differences in fear extinction learning are centrally involved in anxiety vulnerability. We here investigate individual extinction differences using a model-free, data-driven approach, by applying Latent Class Growth Modeling (LCGM) to four in-house data sets from altogether N=234 healthy male participants. This revealed two distinct trajectory classes: fast extinguishers and slow extinguishers. This pattern was replicated in two independent public data sets (total N=275, female and male). In a subset of the in-house samples with functional magnetic resonance imaging (fMRI) data (n=122 males), we investigated the neural correlates of class membership, focusing on the ventral striatum (VS), a key area previously implicated in encoding extinction prediction errors (EPE). We found that fast extinguishers exhibited VS activity at the time of unconditioned stimulus omission early in extinction, consistent with an EPE signal, whereas this signal only appeared late in extinction in slow extinguishers. These findings suggest that extinction success is shaped by how the VS learns safety.

neuroscience↗

bioRxiv2022

Arousal defines the conditions for facilitation by L-DOPA of extinction consolidation and associated prefrontal activity

Even after successful extinction, conditioned fear can return. Strengthening the consolidation of the fear-inhibitory safety memory formed during extinction is one way to counteract return of fear. In this preregistered direct replication study in male participants, we confirm that spontaneous post-extinction reactivations of a neural activation pattern evoked in the ventromedial prefrontal cortex (vmPFC) during extinction predict extinction memory retrieval 24 h later. We do not confirm that L-DOPA administration after extinction enhances retrieval and that this is mediated by enhancement of the number of vmPFC reactivations. However, additional non-preregistered analyses reveal a beneficial effect of L-DOPA on extinction retrieval when controlling for the trait-like stable baseline levels of salivary alpha-amylase enzymatic activity (trait sAA) levels that participants show on the three experimental days. Further, trait sAA negatively predicts retrieval, and this effect is rescued by L-DOPA treatment. Our results suggest that individuals with high basal levels of sympathetic nervous system (SNS) activity may have poor extinction and that L-DOPA may be selectively beneficial for these individuals, which holds potential for clinical applications.

neuroscience↗

bioRxiv2020

Reconceptualising resilience within a translational framework is supported by unique and brain-region specific transcriptional signatures in mice

Chronic social defeat (CSD) in mice has been increasingly employed in experimental resilience research. Particularly, the degree of CSD-induced social avoidance is used to classify animals into resilient (socially non-avoidant) versus susceptible (avoidant). In-spired by human data pointing to threat-safety discrimination and responsiveness to extinction training of aversive memories as characteristics of resilient individuals, we here describe a translationally informed stratification which identified three phenotypic subgroups of mice following CSD: the Discriminating-avoiders, characterised by successful social threat-safety discrimination and successful extinction of social avoidance; the Indis-criminate-avoiders, showing aversive response generalisation, and the Non-avoiders (absence of social avoidance) displaying impaired conditioned learning. Furthermore, and supporting the biological validity of our approach, we uncovered subgroup-specific transcriptional signatures in classical fear conditioning and anxiety-related brain regions. Our reconceptualisation of resilience in mice refines the currently used dichotomous classification and contributes to advancing future translational approaches.

neuroscience↗

bioRxiv2018

A Combined Behavioral and Neuroimaging Battery to Test Positive Appraisal Style Theory of Resilience in Longitudinal Studies

Resilience is the maintenance or rapid recovery of mental health during and after stressor exposure. It is becoming increasingly clear that resilience results from a complex and dynamic process of adaptation to stressors involving the biological, psychological and social levels. Positive appraisal style theory of resilience (PASTOR) claims that the common final pathway to maintained mental health lies in the non-negative (non-catastrophizing, non-pessimistic) appraisal of potential stressors, permitting the organism to fine-tune stress responses to optimal levels, thus avoiding unnecessary stress, inefficient deployment of resources and concomitant deleterious allostatic load effects. Successful adaptation consists in developing or strengthening a positive appraisal style. Another key element of PASTOR is that a positive appraisal style is strongly determined by the efficacy and efficiency of the neural and cognitive processes that underlie positive stressor appraisal. We here present a combined behavioral and functional magnetic resonance imaging (fMRI) battery designed to assess such processes repeatedly in longitudinal settings. The battery includes tests of stress reactivity and recovery, reward sensitivity, safety learning and memory in the context of fear conditioning and extinction, volitional situation-focused reappraisal, volitional self-focused reappraisal, and emotional interference inhibition, along with structural MRI and resting-state MRI scans. A detailed description of the battery methods is provided. The feasibility of the battery was successfully tested in N=55 healthy subjects; group results of the individual tasks largely replicate existing literature.

neuroscience↗

bioRxiv2018

Excitability regulation in the dorsomedial prefrontal cortex during sustained instructed fear responses: a TMS-EEG study

BackgroundThreat detection is essential for protecting individuals from precarious situations. Early studies suggested a network of amygdala, limbic regions and dorsomedial prefrontal cortex (dmPFC) involved in fear processing. Excitability regulation in the dmPFC might be crucial for physiological fear processing, while an abnormal excitability pattern could lead to mental illness. Non-invasive paradigms to measure excitability regulation during fear processing in humans are missing.\n\nMethodsWe adapted an experimental approach of excitability characterization using electroencephalography (EEG) recordings and transcranial magnetic stimulation (TMS) over the dmPFC during an instructed fear paradigm to dynamically dissect its role in fear processing. Event-related (ERP) and TMS-evoked potentials (TEP) were analyzed to trace dmPFC excitability in healthy young volunteers (n = 40, age = 27.6 {+/-} 5.7 years, 22 females). Moreover, we linked the excitability regulation patterns to individual structural MRI-derived properties of gray matter microstructural integrity of the fear network.\n\nResultsAn increased cortical excitability was demonstrated in the threat (T) condition in comparison to no-threat (NT) as showed by increased amplitude of evoked potentials. Furthermore, TMS over the dmPFC induced markedly increased evoked responses during T condition in relation to NT. Moreover, we found that the structural integrity of the dmPFC and the amygdala predict excitability regulation patterns as measured by ERP and TEP during fear processing.\n\nConclusionsWe describe the dynamic range of excitability regulation in dmPFC during fear processing. The applied paradigm can be used to non-invasively track response abnormalities to threat stimuli in healthy subjects or patients with mental disorders.

neuroscience↗