Biology subjects

Schröger, E.

Publications and source records attributed to Schröger, E..

3 recordsLinked to original sources

bioRxiv2025

Lesions in the cerebellum impact cross-modal temporal predictions

The cerebellum (CE) supports the encoding of the precise sensory event timing and the generation of temporal predictions. Here we investigated whether focal CE lesions impact temporal predictions in a cross-modal context. Individuals with CE lesion (n=9) and healthy-matched controls (HC) were presented with visuo-auditory stimulus pairs, presented in a temporally regular (predictable) or irregular (unpredictable) manner while EEG was recorded. We hypothesized cross-modal temporal predictions to be mediated by pre-stimulus cerebello-cortical beta-band (12-25Hz) activity. In turn, we expected HC, but not CE patients, to show a modulation of pre-stimulus beta power as a function of temporal prediction. HC showed greater pre-stimulus beta-band suppression in anticipation of sound onsets, and stronger post-stimulus delta- and theta-band (1-4Hz; 4-8Hz) power in the predictable than the unpredictable condition. Furthermore, they displayed a significant modulation of pre-stimulus delta-beta cross-frequency coupling as a function of temporal prediction. These effects were not observed in the CE group. Results confirm that cerebellar lesions impair the generation of temporal predictions in cross-modal (visuo-auditory) stimulus processing, extending the role of cerebellar predictive timing from sensorimotor to motor-independent cross-modal perception.

neuroscience↗

bioRxiv2023

Neural signatures of automatic repetition detection in temporally regular and jittered acoustic sequences

Detection of repeating patterns within continuous sound streams is crucial for efficient auditory perception. Previous studies demonstrated a remarkable sensitivity of the human auditory system to periodic repetitions in randomly generated sounds. Automatic repetition detection was reflected in different EEG markers, including sustained activity, neural synchronisation, and event-related responses to pattern occurrences. The current study investigated how listeners attention and the temporal regularity of a sound modulate repetition perception, and how this influence is reflected in different EEG markers that were previously suggested to subserve dissociable functions. We reanalysed data of a previous study in which listeners were presented with random acoustic sequences with and without repetitions of a certain sound segment. Repeating patterns occurred either regularly or with a temporal jitter within the sequences, and participants attention was directed either towards or away from the auditory stimulation. Across both regular and jittered sequences during both attention and in-attention, pattern repetitions led to increased sustained activity throughout the sequence, evoked a characteristic positivity-negativity complex in the event-related potential, and enhanced inter-trial phase coherence of low-frequency oscillatory activity time-locked to repeating pattern onsets. While regularity only had a minor (if any) influence, attention significantly strengthened pattern repetition perception, which was consistently reflected in all three EEG markers. These findings suggest that the detection of pattern repetitions within continuous sounds relies on a flexible mechanism that is robust against in-attention and temporal irregularity, both of which typically occur in naturalistic listening situations. Yet, attention to the auditory input can enhance processing of repeating patterns and improve repetition detection.

neuroscience↗

bioRxiv2018

Emotion lies in the eye of the listener: emotional arousal to novel sounds is reflected in the sympathetic contribution to the pupil dilation response and the P3

Novel sounds in the auditory oddball paradigm elicit a biphasic dilation of the pupil (PDR) and P3a as well as novelty P3 event-related potentials (ERPs). The biphasic PDR has been hypothesized to reflect the relaxation of the iris sphincter muscle due to parasympathetic inhibition and the constriction of the iris dilator muscle due to sympathetic activation. We measured the PDR and the P3 to neutral and to emotionally arousing negative novels in dark and moderate lighting conditions. By means of principal component analysis (PCA) of the PDR data we extracted two components: the early one was absent in darkness and, thus, presumably reflects parasympathetic inhibition, whereas the late component occurred in darkness and light and presumably reflects sympathetic activation. Importantly, only this sympathetic late component was enhanced for emotionally arousing (as compared to neutral) sounds supporting the hypothesis that emotional arousal specifically activates the sympathetic nervous system. In the ERPs we observed P3a and novelty P3 in response to novel sounds. Both components were enhanced for emotionally arousing (as compared to neutral) novels. Our results demonstrate that sympathetic and parasympathetic contributions to the PDR can be separated and link emotional arousal to sympathetic nervous system activation.\n\nHighlightsO_LIPDR and ERP effects of novel emotional and neutral oddball sounds were studied.\nC_LIO_LIParasympathetic and sympathetic contributions to the PDR were dissociated by PCA.\nC_LIO_LIThe parasympathetic PDR component was absent in darkness.\nC_LIO_LIEmotional arousal enhanced the sympathetic contribution to the PDR and the P3 ERP.\nC_LIO_LIEffects of emotional arousal are mediated by the sympathetic pathway.\nC_LI

neuroscience↗