Biology subjects

Bleichner, M. G.

Publications and source records attributed to Bleichner, M. G..

12 recordsLinked to original sources

bioRxiv2025

Neural response attenuation for shorter inter-onset intervals between sounds in a natural soundscape

Sensory attenuation of auditory evoked potentials (AEPs), particularly N1 and P2 components, has been widely demonstrated in response to simple, repetitive stimuli sequences of isolated synthetic sounds. It remains unclear, however, whether these effects generalize to complex soundscapes where temporal and acoustic features vary more broadly and dynamically. In this study, we investigated whether the inter-onset interval (IOI), the time between successive sound events, modulates AEP amplitudes in a complex auditory scene. We derived acoustic onsets from a naturalistic soundscape and applied temporal response function (TRF) analysis to EEG data recorded from normal hearing listeners. Our results showed that shorter IOIs are associated with attenuated N1 and P2 amplitudes, replicating classical adaptation effects in a naturalistic soundscape. These effects remained stable when controlling for other acoustic features such as intensity and envelope sharpness and across different TRF model specifications. Integrating IOI information into predictive modelling revealed that neural dynamics were captured more effectively than simpler onset models when training data were matched. These findings highlight the brains sensitivity to temporal structure even in highly variable auditory environments, and show that classical lab findings generalize to naturalistic soundscapes. Our results underscore the need to include temporal features alongside acoustic ones in models of real-world auditory processing. HighlightsO_LINeural responses (N1, P2) to sound events are attenuated when inter-onset intervals are short, replicating classic attenuation effects in a naturalistic soundscape. C_LIO_LIAutomatic onset detection from complex, ecologically valid soundscapes enables fine-grained analysis of temporal auditory dynamics. C_LIO_LIThese findings highlight that temporal sensitivity in auditory processing persists even in highly variable, real-world acoustic environments. C_LI

neuroscience↗

bioRxiv2025

EEG Signatures of Auditory Distraction: Neural Responses to Spectral Novelty in Real-World Soundscapes

In everyday life, ambient sounds can disrupt our concentration, interfere with task performance, and contribute to mental fatigue. Even when not actively attended to, salient or changing sounds in the environment can involuntarily divert attention. Understanding how the brain responds to these real-world auditory distractions is essential for evaluating the cognitive consequences of environmental noise. In this study, we recorded electroencephalography (EEG) while participants performed different tasks during prolonged exposure to a complex urban soundscape. We identified naturally occurring, acoustically salient events and analyzed the corresponding event-related potentials (ERPs). Auditory spectral novelty reliably elicited a P3a response (250-350 ms), reflecting robust attentional capture by novel environmental sounds. In contrast, the Reorienting Negativity (RON) window (450-600 ms) showed no consistent modulation, possibly due to the continuous and largely behaviorally irrelevant nature of the soundscape. Performance in a behavioral task was briefly disrupted following novel sounds, underscoring the functional impact of attentional capture. Noise sensitivity, measured via the Weinstein Noise Sensitivity Scale (WNSS; 1978), was not associated with ERP amplitudes. Together, these findings demonstrate that the P3a component provides a stable neural marker of attentional shifts in naturalistic contexts and highlight the utility of spectral novelty detection as a tool for investigating auditory attention outside the laboratory.

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bioRxiv2025

The effect of task demand on EEG responses to irrelevant sound and speech in simulated surgical environments.

1Complex soundscapes in high-stakes environments, such as the operating room (OR), are characterized by a variety of overlapping auditory stimuli and present significant challenges for personnel, particularly during periods of high demand. This study investigates how task demand and an OR soundscape including irrelevant speech, influence perceived work-load, surgical performance, and auditory processing in a simulated surgical environment, using mobile electroencephalography (EEG). Participants performed two simulated surgical tasks, namely peg transfer and suturing, representing a low-demand and high-demand task, respectively. The tasks were performed under two sound conditions: An OR soundscape was presented with irrelevant speech or alone. Neural responses to transient and continuous auditory stimuli were analyzed using event-related potentials (ERPs) and temporal response functions (TRFs), respectively. Results showed that irrelevant speech increased self-reported workload and distraction. EEG analyses revealed reduced neural responses to transient sounds and irrelevant speech under high task demand, reflecting early-stage sensory filtering of auditory distractions. Notably, an inverse relationship was observed between neural responses to speech and self-reported workload, indicating that the speech responses may serve as a marker for perceived workload. Overall, this study demonstrates the potential of EEG to assess irrelevant sound processing in realistic work-like settings and highlights the critical role of task demand in modulating neural responses and self-reported workload to soundscapes.

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bioRxiv2024

From Beeps to Streets: Unveiling Sensory Input and Relevance Across Auditory Contexts

This study investigates the neural basis of sound perception in everyday life using EEG data recorded in an office-like environment over 3.5 hours. We investigated how contextual factors such as personal relevance, task complexity and stimulus properties influence auditory processing in ecologically valid settings. By systematically increasing the complexity of acoustic scenes and tasks, we analysed changes in neural responses, particularly in the N100 and P300 components. Our results show that while the P300 is a stable marker of attention in both isolated sounds and complex soundscapes, the N100 is more sensitive to task complexity and environmental factors. This highlights the importance of context in shaping auditory perception. Furthermore, our results suggest that laboratory-based findings can be partially generalised to real-world settings, although task demands significantly influence neural markers. These findings provide new opportunities to study sound perception in naturalistic settings, without sacrificing the control typically afforded by laboratory studies.

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bioRxiv2024

Sound perception in realistic surgery scenarios: Towards EEG-based auditory work strain measures for medical personnel.

Surgical personnel face various stressors in the workplace, including environmental sounds. Mobile electroencephalography (EEG) offers a promising approach for objectively measuring how individuals perceive sounds. In this study, we utilized mobile EEG to explore how a realistic soundscape is perceived during simulated laparoscopic surgery. To examine the varying demands placed on personnel in different situations, we manipulated the cognitive demand during the surgical task, using a memory task. To assess responses to the soundscape, we calculated event-related potentials for distinct sound events and temporal response functions for the ongoing soundscape. Although participants reported varying degrees of demand under different conditions, no significant effects were observed on surgical task performance or EEG parameters. However, changes in surgical task performance and EEG parameters over time were noted, while subjective results remained consistent over time. These findings highlight the importance of using multiple measures to fully understand the complex relationship between sound processing and cognitive demand. Furthermore, in the context of combined EEG and audio recordings in real-life scenarios, sparse representations of the soundscape have advantages over more detailed representations. Our results indicate that both types of representations are equally effective in eliciting neural responses. Overall, this study marks a significant step towards objectively investigating sound processing in applied settings.

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bioRxiv2023

Smartphone-based ear-EEG to study sound processing in everyday life

In everyday life, people differ in their sound perception and thus sound processing. Some people may be distracted by construction noise while others do not even notice. With smartphone-based mobile earelectroencephalography we can measure and quantify sound processing in everyday life by analyzing presented sounds and also naturally occurring ones. Twenty-four participants completed four controlled conditions in the lab (1h) and one condition in the office (3h). All conditions used the same paired-click stimuli. In the lab, participants listened to click tones under four different instructions: no task towards the sounds, reading a newspaper article, listening to an audio article, or counting a rare deviant sound. In the office recording, participants followed daily activities while they were sporadically presented with clicks, without any further instruction. In addition to the presented sounds, environmental sounds were recorded as acoustic features (i.e., loudness, power spectral density, sounds onsets). We found task-dependent differences in the auditory event-related potentials (ERPs) to the presented click sounds in all lab conditions, which underline that neural processes related to auditory attention can be differentiated with ear-EEG. In the office condition, we found ERPs comparable to some of the lab conditions. The N1 amplitude to the click sounds beyond the lab was dependent on the background noise, probably due to energetic masking. Contrary to our expectation, we did not find a clear ERP in response to the environmental sounds. Overall, we showed that smartphone-based ear-EEG can be used to study sound processing of well defined-stimuli in everyday life.

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bioRxiv2022

Recording brain activity with ear-EEG (cEEGrids)

The cEEGrid (ear-electroencephalography; ear-EEG) is an unobtrusive and comfortable electrode array affixed around the ear. It is suited to investigate brain activity outside of the laboratory for long durations. Previous research established that cEEGrids can be used to study various cognitive processes in and also beyond the lab, even for a whole day. To record high-quality ear-EEG data, careful preparation is necessary. In this protocol, we explain the steps needed for successful experimenting with cEEGrids: First, we show how to test the functionality of the cEEGrid prior to a recording. Second, we describe how to prepare the participant and to fit the cEEGrid, which is the most important step to record high-quality data. Third, we outline how to connect the cEEGrids to the amplifier and how to check the signal quality. In this protocol, we give best practice recommendations and tips that make cEEGrid recordings easier. If researchers follow this protocol, they are comprehensively equipped for experimenting with the cEEGrid in and beyond the lab. SUMMARYThe cEEGrid (ear-electroencephalography) allows to record brain activity in and beyond the lab for extended duration. In this protocol, we describe how to set up and record with cEEGrids.

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bioRxiv2022

Investigating the attentional focus to workplace-related soundscapes in a complex audio-visual-motor task using EEG

In demanding work situations (e.g., during a surgery) the processing of complex soundscapes varies over time and can be a burden for medical personnel. Here we study, using mobile electroencephalography (EEG), how humans process workplace-related soundscapes while performing a complex audio-visual-motor task (3D Tetris). Specifically, we wanted to know how the attentional focus changes the processing of the soundscape as a whole. Participants played a game of 3D Tetris in which they had to use both hands to control falling blocks. At the same time, participants listened to a complex soundscape, similar to what is found in an operating room (i.e., sound of machinery, people talking in the background, alarm sounds, and instructions). In this within-subject design, participants had to react to instructions (e.g., "place the next Block in the upper left corner") and to sounds depending on the experimental condition, either to a specific alarm sound originating from a fixed location or to a beep sound that originated from varying locations. Attention to the alarm reflected a narrow attentional focus, as it was easy to detect and most of the soundscape could be ignored. Attention to the beep reflected a wide attentional focus, as it required the participants to monitor multiple different sound streams. Results show the robustness of the N1 and P3 event related potential response during this dynamic task with a complex auditory soundscape. Furthermore, we used temporal response functions to study auditory processing to the whole soundscape. This work is a step towards studying workplace-related sound processing in the operating room using mobile EEG.

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bioRxiv2022

"Um... it's really difficult to... um.. speak fluently": Neural tracking of spontaneous speech

Spontaneous real-life speech is imperfect in many ways. It contains disfluencies and ill-formed utterances and has a highly variable rate. When listening to spontaneous speech, the brain needs to contend with these features in order to extract the speakers meaning. Here, we studied how the neural response is affected by four specific factors that are prevalent in spontaneous colloquial speech: (1) the presence of non-lexical fillers, (2) the need to detect syntactic boundaries in disfluent speech, and (3) variability in speech rate. Neural activity (EEG) was recorded from individuals as they listened to an unscripted, spontaneous narrative, which was analyzed in a time-resolved fashion to identify fillers and detect syntactic boundaries. When considering these factors in a speech-tracking analysis, which estimates a temporal response function (TRF) to describe the relationship between the stimulus and the neural response it generates, we found that the TRF was affected by both of them. This response was observed for lexical words but not for fillers, and it had an earlier onset for opening words vs. closing words of a clause and for clauses with slower speech rates. These findings broaden ongoing efforts to understand neural processing of speech under increasingly realistic conditions. They highlight the importance of considering the imperfect nature of real-life spoken language, linking past research on linguistically well-formed and meticulously controlled speech to the type of speech that the brain actually deals with on a daily basis.

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bioRxiv2021

Real-time audio processing of real-life soundscapes for EEG analysis: ERPs based on natural sound onsets

With smartphone-based mobile electroencephalography (EEG), we can investigate sound perception beyond the lab. To understand sound perception in the real world, we need to relate naturally occurring sounds to EEG data. For this, EEG and audio information need to be synchronized precisely, only then it is possible to capture fast and transient evoked neural responses and relate them to individual sounds. We have developed Android applications (AFEx and Record-a) that allow for the concurrent acquisition of EEG data and audio features, i.e., sound onsets, average signal power (RMS) and power spectral density (PSD) on smartphone. In this paper, we evaluate these apps by computing event-related potentials (ERPs) evoked by everyday sounds. One participant listened to piano notes (played live by a pianist) and to a home-office soundscape. Timing tests showed that the temporal precision of the system is very good. We calculated ERPs to sound onsets and observed the typical P1-N1-P2 complex of auditory processing. Furthermore, we show how to relate information on loudness (RMS) and spectra (PSD) to brain activity. In future studies, we can use this system to study sound processing in everyday life.

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bioRxiv2020

Mobile ear-EEG to study auditory attention in everyday life

Most research investigating auditory perception is conducted in controlled laboratory settings, potentially restricting its generalizability to the complex acoustic environment outside the lab. The present study, in contrast, investigated auditory attention with long-term recordings (>6 h) beyond the lab using a fully mobile, smartphone-based ear-centered electroencephalography (EEG) setup with minimal restrictions for participants. Twelve participants completed iterations of two variants of an oddball task where they had to react to target tones and to ignore standard tones. A rapid variant of the task (tones every 2 seconds, 5 minutes total time) was performed seated and with full focus in the morning, around noon and in the afternoon under controlled conditions. A sporadic variant (tones every minute, 160 minutes total time) was performed once in the morning and once in the afternoon while participants followed their normal office day routine. EEG data, behavioural data, and movement data (with a gyroscope) were recorded and analyzed. The expected increased amplitude of the P3 component in response to the target tone was observed for both the rapid and the sporadic oddball. Miss rates were lower and reaction times were faster in the rapid oddball compared to the sporadic one. The movement data indicated that participants spent most of their office day at relative rest. Overall, this study demonstrated that it is feasible to study auditory perception in everyday life with long-term ear-EEG.

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bioRxiv2019

Say what I mean - Expectancy effects in the EEG during joint and spontaneous word-by-word sentence production

Our aim in the present study is to measure neural correlates during spontaneous interactive sentence production. We present a novel approach using the word-by-word technique from improvisational theatre, in which two speakers jointly produce one sentence. This paradigm allows the assessment of behavioural aspects, such as turn-times, and electrophysiological responses, such as event-related-potentials (ERPs). Twenty-five participants constructed a cued but spontaneous four-word German sentence together with a confederate, taking turns for each word of the sentence. In 30% of the trials, an unexpected gender-marked article was uttered by the confederate. To complete the sentence in a meaningful way, the participant had to detect the violation, (possibly) inhibit a prepared response, and retrieve and utter a new fitting response. We found significant increases in response times after unexpected words and - despite allowing unscripted language production and naturally varying speech material - successfully detected significant N400 and P600 ERP effects for the unexpected word. The N400 EEG activity further significantly predicted the response time of the subsequent turn. Our results show that combining behavioural and neuroscientific measures of verbal interactions while retaining sufficient experimental control is possible, and that this combination provides promising insights into the mechanisms of spontaneous spoken dialogue.

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