Biology subjects

Woestmann, M.

Publications and source records attributed to Woestmann, M..

17 recordsLinked to original sources

bioRxiv2026

Variability of Head Motion Reveals Development of Spatial Attention

Selective attention, the ability to focus on relevant information while ignoring task-irrelevant information, is crucial for learning. Selective attention has largely been studied in motionless individuals. However, body movements are intrinsic to cognition and particularly frequent in children. To test whether movements explain successful attention control throughout childhood, we tracked head rotations while younger children (6-8 years, n = 25), older children (9-10 years, n = 20) and adults (18-30 years; n = 21) identified a spatial target sound under distraction. Distractor reports decreased with age, confirming a developmental increase in attention control. Importantly, a dissociation of two distinct types of movement emerged: Task-dependent head rotation to lateral targets was similar across age groups. Contrary, task-independent movements before and early during a trial decreased with age and predicted attention accuracy. Thus, movements unrelated to the attention goal do not reflect noise but signify attentional control across development.

animal behavior and cognition↗

bioRxiv2026

Auditory Attention Implements Complementary but Independent Cortical Mechanisms of Enhancement and Suppression

In noisy environments, goal-directed behavior requires the brain to prioritize task-relevant sound and to suppress distraction. While mechanisms of proactive attention in the presence of foreknowledge about targets and distractors are well-characterized, the neural dynamics governing reactive auditory attention in the absence of foreknowledge remain less understood. To fill this gap, we recorded the electroencephalogram (EEG) from N = 34 participants performing an auditory search task. Participants identified an amplitude-modulated spoken target number amid distractor numbers of varying salience. Presenting stimuli from three spatial locations enabled isolation of lateralized electrophysiological responses to targets and distractors. We quantified selection of targets versus distractors by continuously tracking participants cursor movements on a virtual response pad. Behaviorally, the target-directedness of cursor movements (i.e., towardness) increased for target repetitions (positive priming) and decreased when the target was a distractor from the previous trial (negative priming), indicating respective enhancement and suppression. Neurally, lateral targets evoked an N2ac component reflecting reactive enhancement. Importantly, we here demonstrate for the first time in an auditory attention task that distracting sounds evoke an auditory distractor positivity (PD) component. Target enhancement and distractor suppression were largely independent: their neural and behavioral markers were not significantly correlated and they originated from distinct cortical sources. Furthermore, shorter N2ac-but not PD-latencies related to higher towardness. By dissociating neural signatures and behavioral relevance of enhancement and suppression, our findings refine biased-competition models of attention, demonstrating that reactive selection relies on separable mechanisms rather than a single competitive gain process. Significance statementEveryday listening requires the rapid selection of relevant sounds and ignoring distraction, even when there is no prior knowledge of what will be heard. Here, we reveal the neural mechanisms that enable such reactive auditory attention. Combining electroencephalography with continuous measures of behavior, we show that target enhancement and distractor suppression are supported by distinct neural processes, indexed by the N2ac and the auditory PD component. These processes are largely independent, with only enhancement predicting behavior. This dissociation challenges unitary accounts of attentional selection and instead supports models in which separable mechanisms of enhancement and suppression operate in parallel. Our findings provide a mechanistic framework for understanding how the human brain flexibly prioritizes information in complex listening environments.

neuroscience↗

bioRxiv2025

Head movements integrate with brain signals to guide attention

The brain is part of a moving body. Most insights about the relationship between neural activity and cognition come from studies involving movement-constrained participants. Here, we test the roles of neural alpha oscillations (~10 Hz) and head movements for auditory spatial attention in human participants (N=33). Neural attention filtering showed up as decreased alpha power in the electroencephalogram (EEG) contralateral to targets and vice versa for distractors. Gyroscopic tracking of head movements revealed consistent head turns towards lateral targets. Lateral distractors induced more variable movement patterns. Systematic miniature movements remained even when listeners were instructed not to move. Head rotations improved task accuracy by reducing target uncertainty. Trial-by-trial modulation of neural filtering and head rotation correlated positively, with neural alpha modulation being followed by lateral eye movements and head rotations. Spatial attention emerges from neural coding of relevant and irrelevant stimuli, co-occurring with lateral head rotations supporting sensory sampling.

neuroscience↗

bioRxiv2025

Neural and Behavioral Adaptation to Listening with a Unilateral Cochlear Implant (CI)

The human auditory system must distinguish relevant sounds from noise. Severe hearing loss can be treated with cochlear implants (CIs), but how the brain adapts to electrical hearing remains unclear. This study examined adaptation to unilateral CI use in the first and seventh month after CI-activation using speech comprehension measures and electroencephalography (EEG) recordings, both during passive listening and an active spatial listening task. Neural phase-locking to amplitude-modulated (AM) sounds interacted with time, such that phase-locking longitudinally increased stronger for 40 compared with 4 Hz. In the spatial listening task, the benefit of performing the task with the CI on vs. off was most pronounced when the CI ear was primarily exposed to target speech. Lateralized alpha oscillations ([~]10 Hz) reliably marked CI users focus of spatial attention. Stronger alpha modulation in the hemisphere opposite to the non-implanted ear indicates an attentional bias toward the acoustically hearing ear. Our findings suggest that adaptation to hearing with a CI is accomplished by dynamic changes in auditory phase-locking and a bias in auditory spatial attention. Data availabilityAll data are available from the corresponding author upon request. A table including data for most important behavioural and neural outcome measures is available at https://osf.io/tkurz/.

neuroscience↗

bioRxiv2024

Predicting the irrelevant: Neural effects of distractor predictability depend on load

Distraction is ubiquitous in human environments. Distracting input is often predictable, but we do not understand when or how humans can exploit this predictability. Here we ask whether predictable distractors are able to reduce uncertainty in updating the internal predictive model. We show that utilising a predictable distractor identity is not fully automatic but in part depends on available resources. In an auditory spatial n-back task, listeners (n = 33) attended to spoken numbers presented to one ear and detected repeating items. Distracting numbers presented to the other ear either followed a predictable (i.e., repetitive) sequence or were unpredictable. We used electroencephalography (EEG) to uncover neural responses to predictable versus unpredictable auditory distractors, as well as their dependence on perceptual and cognitive load. Neurally, pairs of targets and unpredictable distractors induced a sign-reversed lateralization of pre-stimulus alpha oscillations ([~]10 Hz) and larger amplitude of the stimulus-evoked P2 event-related potential component. Under low versus high memory load, distractor predictability increased the magnitude of the frontal negativity component. Behaviourally, predictable distractors under low task demands (i.e., good signal-to-noise ratio and low memory load) made participants adopt a less biased response strategy. We conclude that predictable distractors decrease uncertainty and reduce the need for updating the internal predictive model. In turn, unpredictable distractors might mislead proactive spatial attention orientation, elicit larger neural responses, and put higher demand on memory.

neuroscience↗

bioRxiv2022

Auditory neural tracking reflects target enhancementbut not distractor suppression in a psychophysically augmented continuous-speech paradigm

Selective attention modulates the neural tracking of speech in auditory cortical regions. It is unclear whether this attention modulation is dominated by enhanced target tracking, or suppression of distraction. To settle this long-standing debate, we here employed an augmented electroencephalography (EEG) speech-tracking paradigm with target, distractor, and neutral streams. Concurrent target speech and distractor (i.e., sometimes relevant) speech were juxtaposed with a third, never task-relevant speech stream serving as neutral baseline. Listeners had to detect short target repeats and committed more false alarms originating from the distractor than the neutral stream. Speech tracking revealed target enhancement but no distractor suppression below the neutral baseline. Speech tracking of the target (not distractor or neutral speech) explained single-trial accuracy in repeat detection. In sum, the enhanced neural representation of target speech is specific to processes of attentional gain for behaviourally relevant target speech rather than neural suppression of distraction.

neuroscience↗

bioRxiv2020

Unilateral acoustic degradation delays attentional separation of competing speech

Hearing loss is often asymmetric, such that hearing thresholds differ substantially between the two ears. The extreme case of such asymmetric hearing is single-sided deafness. A unilateral cochlear implant (CI) on the more severely impaired ear is an effective treatment to restore hearing. The interactive effects of unilateral acoustic degradation and spatial attention to one sound source in multi-talker situations are at present unclear. Here, we simulated some features of listening with a unilateral CI in young, normal-hearing listeners (N = 22) who were presented with 8-band noise-vocoded speech to one ear and intact speech to the other ear. Neural responses were recorded in the electroencephalogram (EEG) to obtain the spectro-temporal response function (sTRF) to speech. Listeners made more mistakes when answering questions about vocoded (versus intact) attended speech. At the neural level, we asked how unilateral acoustic degradation would impact the attention-induced amplification of tracking target versus distracting speech. Interestingly, unilateral degradation did not per se reduce the attention-induced amplification but instead delayed it in time: Speech encoding accuracy, modelled on the basis of the sTRF, was significantly enhanced for attended versus ignored intact speech at earlier neural response latencies (<~250 ms). This attentional enhancement was not absent but delayed for vocoded speech. These findings suggest that attentional selection of unilateral, degraded speech is feasible, but induces delayed neural separation of competing speech, which might explain listening challenges experienced by unilateral CI users.

neuroscience↗

bioRxiv2020

Orienting spatial attention in time: Lateralized alpha power reflects spatio-temporal filtering

The deployment of neural alpha (8-12 Hz) lateralization in service of spatial attention is well-established: Alpha power increases in the cortical hemisphere ipsilateral to the attended hemifield, and decreases in the contralateral hemisphere, respectively. Much less is known about humans ability to deploy such alpha lateralization in time, and to thus exploit alpha power as a spatio-temporal filter. Here we show that spatially lateralized alpha power does signify - beyond the direction of spatial attention - the distribution of attention in time and thereby qualifies as a spatio-temporal attentional filter. Participants (N = 20) selectively listened to spoken numbers presented on one side (left vs right), while competing numbers were presented on the other side. Key to our hypothesis, temporal foreknowledge was manipulated via a visual cue, which was either instructive and indicated the to-be-probed number position (70% valid) or neutral. Temporal foreknowledge did guide participants attention, as they recognized numbers from the to-be-attended side more accurately following valid cues. In the magnetoencephalogram (MEG), spatial attention to the left versus right side induced lateralization of alpha power in all temporal cueing conditions. Modulation of alpha lateralization at the 0.8-Hz presentation rate of spoken numbers was stronger following instructive compared to neutral temporal cues. Critically, we found stronger modulation of lateralized alpha power specifically at the onsets of temporally cued numbers. These results suggest that the precisely timed hemispheric lateralization of alpha power qualifies as a spatio-temporal attentional filter mechanism susceptible to top-down behavioural goals.

neuroscience↗

bioRxiv2020

The vulnerability of working memory to distraction is rhythmic

Recent research posits that the cognitive system samples target stimuli in a rhythmic fashion, characterized by target detection fluctuating at frequencies of ~3-8 Hz. Besides prioritized encoding of targets, a key cognitive function is the protection of working memory from distractor intrusion. Here, we test to which degree the vulnerability of working memory to distraction is rhythmic. In an Irrelevant-Speech Task, N = 23 human participants had to retain the serial order of nine numbers in working memory while being distracted by task-irrelevant speech with variable temporal onsets. The magnitude of the distractor-evoked N1 component in the event-related potential as well as behavioural recall accuracy, both measures of memory distraction, were periodically modulated by distractor onset time in approximately 2-4 cycles per second (Hz). Critically, an underlying 2.5-Hz rhythm explained variation in both measures of distraction such that stronger phasic distractor encoding mediated lower phasic memory recall accuracy. In a behavioural follow-up experiment, we tested whether these results would replicate in a task design without rhythmic presentation of target items. Participants (N = 6 with on average >2,500 trials, each) retained two line-figures in memory while being distracted by acoustic noise of varying onset across trials. In agreement with the main experiment, the temporal onset of the distractor periodically modulated memory performance. These results suggest that during working memory retention, the human cognitive system implements distractor suppression in a temporally dynamic fashion, reflected in ~400-ms long cycles of high versus low distractibility.

neuroscience↗

bioRxiv2019

Alpha oscillations in the human brain implement distractor suppression independent of target selection

In principle, selective attention is the net result of target selection and distractor suppression. The way in which both mechanisms are implemented neurally has remained contested. Neural oscillatory power in the alpha frequency band (~10 Hz) has been implicated in the selection of to-be-attended targets, but there is lack of empirical evidence for its involvement in the suppression of to-be-ignored distractors. Here, we use electroencephalography (EEG) recordings of N = 33 human participants (males and females) to test the pre-registered hypothesis that alpha power directly relates to distractor suppression and thus operates independently from target selection. In an auditory spatial pitch discrimination task, we modulated the location (left vs right) of either a target or a distractor tone sequence, while fixing the other in the front. When the distractor was fixed in the front, alpha power relatively decreased contralaterally to the target and increased ipsilaterally. Most importantly, when the target was fixed in the front, alpha lateralization reversed in direction for the suppression of distractors on the left versus right. These data show that target-selection-independent alpha power modulation is involved in distractor suppression. While both lateralized alpha responses for selection and for suppression proved reliable, they were uncorrelated and distractor-related alpha power emerged from more anterior, frontal cortical regions. Lending functional significance to suppression-related alpha oscillations, alpha lateralization at the individual, single-trial level was predictive of behavioral accuracy. These results fuel a renewed look at neurobiological accounts of selection-independent suppressive filtering in attention.\n\nSignificance statementAlthough well-established models of attention rest on the assumption that irrelevant sensory information is filtered out, the neural implementation of such a filter mechanism is unclear. Using an auditory attention task that decouples target selection from distractor suppression, we demonstrate that two sign-reversed lateralized alpha responses reflect target selection versus distractor suppression. Critically, these alpha responses are reliable, independent of each other, and generated in more anterior, frontal regions for suppression versus selection. Prediction of single-trial task performance from alpha modulation after stimulus onset agrees with the view that alpha modulation bears direct functional relevance as a neural implementation of attention. Results demonstrate that the neurobiological foundation of attention implies a selection-independent alpha oscillatory mechanism to suppress distraction.

neuroscience↗

bioRxiv2018

Does closing the eyes enhance auditory attention? Eye closure increases attentional alpha-power modulation but not listening performance

In challenging listening conditions, closing the eyes is a strategy with intuitive appeal to improve auditory attention and perception. On the neural level, closing the eyes increases the power of alpha oscillations ([~]10 Hz), which are a prime signature of auditory attention. Here, we test whether eye closure benefits neural and behavioural signatures of auditory attention and perception. Participants (N = 22) attended to one of two alternating streams of spoken numbers with open or closed eyes in a darkened chamber. After each trial, participants indicated whether probes had been among the to-be-attended or to-be-ignored numbers. In the electroencephalogram, states of relative high versus low alpha power accompanied the presentation of attended versus ignored numbers. Importantly, eye closure did not only increase the overall level of absolute alpha power but also the attentional modulation thereof. Behaviourally, however, neither perceptual sensitivity nor response criterion was affected by eye closure. To further examine whether this behavioural null-result would conceptually replicate in a simple auditory detection task, a follow-up experiment was conducted that required participants (N = 19) to detect a near-threshold target tone in noise. As in the main experiment, our results provide evidence for the absence of any difference in perceptual sensitivity and criterion for open versus closed eyes. In sum, we demonstrate here that the modulation of the human alpha rhythm by auditory attention is increased when participants close their eyes. However, our results speak against the widely held belief that eye closure per se improves listening behaviour.

neuroscience↗

bioRxiv2018

Prestimulus neural alpha power predicts confidence in discriminating identical tones

There is growing evidence that the power of prestimulus neural alpha oscillations ([~]10 Hz) holds information on a perceivers bias or confidence in an ensuing perceptual decision, rather than perceptual sensitivity per se. Obviously, however, confidence also depends on the physical evidence available in the stimulus as well as on task performance. If prestimulus alpha power has a direct impact on decision confidence, this link should hold independent of variations in stimulus evidence and performance. We tested this assertion in a paradigm where human listeners (n = 17) rated their confidence in the discrimination of the pitch of two identical tones. Lower prestimulus alpha power in the electroencephalogram (EEG) was predictive of higher confidence ratings, but not of the decision outcome (i.e., judging the first or the second tone as being higher in pitch). Importantly, the link between prestimulus alpha power and decision confidence was not mediated by auditory evoked activity. Our findings demonstrate that the link between prestimulus alpha power and decision confidence does not hinge on physical evidence in the stimulus or task performance. Instead, these results speak to a model wherein low prestimulus alpha power increases neural baseline excitability, which is reflected in enhanced stimulus-evoked neural responses and higher confidence.\n\nSignificance statementIn order to understand the mechanistic relevance of neural oscillations for perception, we here relate these directly to changes in human auditory decision confidence. Human subjects rated their confidence in the discrimination of the pitch of two tones, which were, unbeknownst to the listener, physically identical. In the absence of changing evidence in the physical stimulus or changes in task performance, we demonstrate that prestimulus alpha power negatively relates to decision confidence. Our results support a model of cortical alpha oscillations as a proxy for neural baseline excitability in which lower prestimulus alpha power does not lead to more precise but rather to overall amplified neural representations.

neuroscience↗

bioRxiv2018

Probing the limits of alpha power lateralization as a neural marker of selective attention in middle-aged and older listeners

In recent years, hemispheric lateralization of alpha power has emerged as a neural mechanism thought to underpin spatial attention across sensory modalities. Yet, how healthy aging, beginning in middle adulthood, impacts the modulation of lateralized alpha power supporting auditory attention remains poorly understood. In the current electroencephalography (EEG) study, middle-aged and older adults (N = 29; ~40-70 years) performed a dichotic listening task that simulates a challenging, multi-talker scenario. We examined the extent to which the modulation of 8-12 Hz alpha power would serve as neural marker of listening success across age. With respect to the increase in inter-individual variability with age, we examined an extensive battery of behavioral, perceptual, and neural measures. Similar to findings on younger adults, middle-aged and older listeners' auditory spatial attention induced robust lateralization of alpha power, which synchronized with the speech rate. Notably, the observed relationship between this alpha lateralization and task performance did not co-vary with age. Instead, task performance was strongly related to an individuals attentional and working memory capacity. Multivariate analyses revealed a separation of neural and behavioral variables independent of age. Our results suggest that in age-varying samples as the present one, the lateralization of alpha power is neither a sufficient nor necessary neural strategy for an individuals auditory spatial attention, as higher age might come with increased use of alternative, compensatory mechanisms. Our findings emphasize that explaining inter-individual variability will be key to understanding the role of alpha oscillations in auditory attention in the aging listener.

neuroscience↗

bioRxiv2017

Unfolding of a noise-invariant neural representation of attended speech

Listening requires selective neural processing of the incoming sound mixture, which in humans is borne out by a surprisingly clean representation of attended-only speech in auditory cortex. How this neural selectivity is achieved even at negative signal-to-noise ratios (SNR) remains unclear. We show that, under such conditions, a late cortical representation (i.e., neural tracking) of the ignored acoustic signal is key to successful separation of attended and distracting talkers (i.e., neural selectivity). We recorded and modelled the electroencephalographic response of 18 participants who attended to one of two simultaneously presented stories, while the SNR between the two talkers varied dynamically. The neural tracking showed an increasing early-to-late attention-biased selectivity. Importantly, acoustically dominant ignored talkers were tracked neurally by late involvement of fronto-parietal regions, which contributed to enhanced neural selectivity. This neural selectivity by way of representing the ignored talker poses a mechanistic neural account of attention under real-life acoustic conditions.

neuroscience↗

bioRxiv2017

Neural noise in the age-varying human brain predicts perceptual decisions

Sensory representations of the physical world and thus human percepts are susceptible to fluctuations in brain state or \"neural irregularity\". Furthermore, aging brains display altered levels of irregularity. We here show that a single, within-trial information-theoretic measure (weighted permutation entropy) captures neural irregularity in the human electroencephalogram as a proxy for both, trait-like differences between individuals of varying age, and state-like fluctuations that bias perceptual decisions. First, the overall level of neural irregularity increased with participants age, paralleled by a decrease in variability over time, likely indexing age-related disintegration on structural and functional levels of brain activity. Second, states of higher neural irregularity were associated with optimized sensory encoding and a subsequently increased probability of choosing the first of two physically identical stimuli. In sum, neural irregularity not only characterizes behaviorally relevant brain states, but also can identify trait-like changes that come with age.

neuroscience↗

bioRxiv2016

Large-scale network dynamics of beta-band oscillations underlie auditory perceptual decision making

Perceptual decisions vary in the speed at which we make them. Evidence suggests that translating sensory information into behavioral decisions relies on distributed interacting neural populations, with decision speed hinging on power modulations of neural oscillations. Yet, the dependence of perceptual decisions on the large-scale network organization of coupled neural oscillations has remained elusive. We measured magnetoencephalography signals in human listeners who judged acoustic stimuli made of carefully titrated clouds of tone sweeps. These stimuli were used under two task contexts where the participants judged the overall pitch or direction of the tone sweeps. We traced the large-scale network dynamics of source-projected neural oscillations on a trial-by-trial basis using power envelope correlations and graph-theoretical network discovery. Under both tasks, faster decisions were predicted by higher segregation and lower integration of coupled beta-band (~16-28 Hz) oscillations. We also uncovered brain network states that promoted faster decisions and emerged from lower-order auditory and higher-order control brain areas. Specifically, decision speed in judging tone-sweep direction critically relied on nodal network configurations of anterior temporal, cingulate and middle frontal cortices. Our findings suggest that global network communication during perceptual decision-making is implemented in the human brain by large-scale couplings between beta-band neural oscillations.\n\nAuthor SummaryThe speed at which we make perceptual decisions varies. This translation of sensory information into behavioral decisions hinges on dynamic changes in neural oscillatory activity. However, the large-scale neural network embodiment supporting perceptual decision-making is unclear. Alavash et al. address this question by experimenting two auditory perceptual decision-making situations. Using graph-theoretical network discovery, they trace the large-scale network dynamics of coupled neural oscillations to uncover brain network states supporting the speed of auditory perceptual decisions. They find that higher network segregation of coupled beta-band oscillations supports faster auditory perceptual decisions over trials. Moreover, when auditory perceptual decisions are relatively difficult, the decision speed benefits from higher segregation of frontal cortical areas, but lower segregation and integration of auditory cortical areas.

neuroscience↗

bioRxiv2016

Single-channel in-Ear-EEG predicts the focus of auditory attention to concurrent tone streams and mixed speech

Conventional, multi-channel scalp electroencephalography (EEG) allows the identification of the attended speaker in concurrent-listening (\"cocktail party\") scenarios. This implies that EEG might provide valuable information to complement hearing aids with some form of EEG and to install a level of neuro-feedback. To investigate whether a listeners attentional focus can be predicted from single-channel hearing-aid-compatible EEG configurations, we recorded EEG from three electrodes inside the ear canal (\"in-Ear-EEG\") and additionally from 64 electrodes on the scalp. In two different, concurrent listening tasks, participants (n = 7) were fitted with individualized in-Ear-EEG pieces and were either asked to attend to one of two dichotically-presented, concurrent tone streams or to one of two diotically-presented, concurrent audiobooks. A forward encoding model was trained to predict the EEG response at single EEG channels. We found that all individual participants attentional focus could be predicted from single-channel EEG response recorded from short-distance configurations consisting only of a single in-Ear-EEG electrode and an adjacent scalp-EEG electrode. The responses to attended and ignored stimuli reveal differences consistent across subjects. In sum, our findings show that the EEG response from a single-channel, hearing-aid-compatible configuration provides valuable information to identify a listeners focus of attention.

bioengineering↗