Biology subjects

Wöstmann, M.

Publications and source records attributed to Wöstmann, M..

4 recordsLinked to original sources

bioRxiv2025

Temporal contrast enhancement generalizes across pain and auditory modalities

Temporal contrast enhancement (TCE), also termed offset analgesia, describes a temporal filtering mechanism whereby a small decrease in stimulus intensity produces a disproportionately large reduction in perceived pain. Although TCE is considered a robust marker of endogenous pain modulation, its underlying mechanisms remain unresolved. It is unclear whether TCE reflects a nociceptive-specific modulatory process or a supramodal temporal filtering mechanism that generalizes to non-painful but aversive sensory stimulation. In this study, healthy and pain-free participants were enrolled in two experiments: a behavioral study (n=33) or a neurophysiological study (n=29). Continuous pain-ratings, electroencephalography (EEG) and pupillometry data were collected. A conventional TCE paradigm was applied using either noxious heat delivered via a thermal contact stimulator or unpleasant auditory stimulation delivered through over-ear headphones. Both noxious heat and unpleasant sounds induced behavioral TCE-effects (p<0.01), indicating a supramodal mechanism with modality-specific temporal dynamics, which was further supported by the absence of a significant correlation of TCE-effects across modalities (p>0.05). In the second experiment, noxious heat - but not unpleasant sound - resulted in decreased power of neural alpha oscillations ([~]10 Hz, p<0.05) and increased pupil size (p<0.05) potentially indicating bottom-up modulation of the autonomic nervous system and a release of neural inhibition, respectively. However, subjectively experienced TCE-effects were not reflected in neurophysiological correlates. These findings support the view of TCE as a supramodal temporal filtering mechanism characterized by modality-specific temporal dynamics, for which no corresponding signatures are found in EEG or pupillometry.

neuroscience↗

bioRxiv2022

Slow neural oscillations explain temporal fluctuations in distractibility

Human environments comprise various sources of distraction, which often occur unexpectedly in time. The proneness to distraction (i.e., distractibility) is posited to be independent of attentional sampling of targets, but its temporal dynamics and neurobiological basis are largely unknown. Brain oscillations in the theta band (3 - 8 Hz) have been associated with fluctuating neural excitability, which is hypothesised here to explain rhythmic modulation of distractibility. In a pitch discrimination task (N = 30) with unexpected auditory distractors, we show that distractor-evoked neural responses in the electroencephalogram and perceptual susceptibility to distraction were co-modulated and cycled approximately 3 - 5 times per second. Pre-distractor neural phase in left inferior frontal and insular cortex regions explained fluctuating distractibility. Thus, human distractibility is not constant but fluctuates on a subsecond timescale. Furthermore, slow neural oscillations subserve the behavioural consequences of a hitherto largely unexplained but ever-increasing phenomenon in modern environments - distraction by unexpected sound.

neuroscience↗

bioRxiv2018

Irrelevant speech disrupts memory more when spoken by a familiar talker

When listening, familiarity with an attended talkers voice improves speech comprehension. Here, we instead investigated the effect of familiarity with a distracting talker. In an irrelevant-speech task, we assessed listeners working memory for the serial order of spoken digits when a task-irrelevant, distracting sentence was produced by either a familiar or an unfamiliar talker (with rare omissions of the task-irrelevant sentence). We tested two groups of listeners using the same experimental procedure. The first group were undergraduate psychology students (N=66) who had attended an introductory statistics course. Critically, each student had been taught by one of two course instructors, whose voices served as familiar and unfamiliar task-irrelevant talkers. The second group of listeners were family members and friends (N=20) who had known either one of the two talkers for more than ten years. Students, but not family members and friends, made more errors when the task-irrelevant talker was familiar versus unfamiliar. Interestingly, the effect of talker familiarity was not modulated by the presence of task-irrelevant speech: students experienced stronger working-memory disruption by a familiar talker irrespective of whether they heard a task-irrelevant sentence during memory retention or merely expected it. While previous work has shown that familiarity with an attended talker benefits speech comprehension, our findings indicate that familiarity with an ignored talker deteriorates working memory for target speech. The absence of this effect in family members and friends suggests that the degree of familiarity modulates memory disruption.

neuroscience↗

bioRxiv2017

Opposite effects of lateralised transcranial alpha versus gamma stimulation on spatial attention

Spatial attention relatively increases the power of neural 10-Hz alpha oscillations in the hemisphere ipsilateral to attention. The functional roles of lateralised oscillations for attention are unclear. Here, 20 human participants performed a dichotic listening task under continuous transcranial alternating current stimulation (tACS) at alpha (10 Hz, vs sham) or gamma (47 Hz, vs sham) frequency, targeting left temporo-parietal cortex. Participants attended to four spoken numbers presented to one ear, while ignoring numbers on the other ear. As predicted, we found that alpha-tACS contralateral to the attended ear decreased recall of attended targets. Notably, gamma-tACS reversed the effect. Results provide a proof of concept that externally amplified oscillations can enhance spatial attention and facilitate attentional selection of speech. Furthermore, opposite effects of alpha versus gamma oscillations support the view that, across modalities, states of high alpha are incommensurate with active neural processing as reflected by states of high gamma.

neuroscience↗