Biology subjects

Getzmann, S.

Publications and source records attributed to Getzmann, S..

14 recordsLinked to original sources

bioRxiv2026

Aperiodic EEG activity is a domain-specific marker of attentional aging in neurotypical adults

Aperiodic neural activity has been reliably shown to be reduced among older adults, and these reductions are associated with age-related cognitive decline. These results suggest that aperiodic activity, as measured by the spectral exponent, might be a viable electrophysiological biomarker for cognitive aging. However, this has not been tested longitudinally, within participants, during normal aging. Here, we used a longitudinal cohort to test whether changes in aperiodic activity between two sessions, approximately 5 years apart, track behavioral change across two domains: sustained attention (Psychomotor Vigilance Test) and executive function (modified Simon task). We found that aperiodic activity declined within individuals after the interval, independent of age at baseline. This within-person change tracked concurrent changes in reaction times during visual attention but was not associated with changes in any Simon task measure. Within a resampling framework, the aperiodic-PVT association was stable across cohort resamples and independently fitted partitions, though it was not confirmed in a small, frozen held-out set. These findings suggest the longitudinal decline in aperiodic activity specifically tracks sustained-attention processing speed rather than general cognitive aging, supporting its potential as a domain-specific biomarker of attentional aging in neurotypical populations.

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bioRxiv2026

Neural reinstatement of features in audiovisual working memory indicatesobject-based retrieval

Selective attention allows us to prioritize or retrieve task-relevant features and items from working memory. However, previous work has largely relied on unisensory paradigms, leaving open the question of how attentional mechanisms act on audiovisual working memory representations. Here, using an EEG-based audiovisual delayed-match-to-sample task, we investigate whether attention to audiovisual working memory contents operates on the level of individual unisensory features or bound cross-modal objects. On each trial, participants memorized an audiovisual item. At test, they were randomly presented with either an auditory, visual, or an audiovisual probe stimulus and indicated whether the latter matched their working memory content. Compared with recalling the entire audiovisual object, recall of unisensory visual or auditory features resulted in poorer behavioral performance and elevated midfrontal theta power. Multivariate pattern analyses (MVPA) showed that task-irrelevant feature representations were retrieved in both auditory and visual probe trials, consistent with object-based retrieval. Moreover, these results shed light on the representational structure underlying cross-modal feature storage in working memory, suggesting that audiovisual features are stored as bound objects and that attentional selection of individual object features in one modality spreads to cross-modal object features in another modality. In task conditions where such incidental recall of task-irrelevant features is detrimental to task performance, this places greater demands on cognitive control mechanisms.

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bioRxiv2025

Tracking neural representations of attended and unattended features in multisensory working memory over time

Working memory supports goal-directed behavior by maintaining task-relevant information. However, a growing number of studies shows that even task-irrelevant features are automatically encoded and can interfere with the recall of task-relevant information. While this phenomenon is well documented in unisensory contexts, it remains unclear whether and how task-irrelevant information persists in multisensory working memory. We examine the role of cross-modal binding by tracking the dynamic neural representation of audio-visual objects under varying selective attention conditions, using an EEG-based audio-visual delayed-match-to-sample task. Participants attended to either auditory or visual features (selective attention), or to both features (conjunction) of two sequential audio-visual items and subsequently compared those task-relevant features to an audio-visual probe. Further, to investigate the influence of bottom-up factors on cross-modal binding, we manipulated spatial congruency by presenting both features from either the same (i.e., in the center) or from disparate positions. Behaviorally, task-irrelevant features interfered with performance even under selective attention, consistent with automatic cross-modal binding and encoding into working memory. This interference was even stronger with spatially disparate presentation, suggesting that bottom-up attentional dynamics strengthen cross-modal bindings and their subsequent storage. Condition-level representational similarity analysis (RSA) showed that EEG activity patterns under selective attention more closely resembled those of conjunction trials than unisensory trials, indicating that task-irrelevant features were incorporated into multisensory object-level representations. This conjunction-similarity persisted in attend-visual trials, but declined over time in attend-auditory trials, reflecting partial filtering of task-irrelevant orientations. Crucially, activity patterns never shifted fully towards an auditory-only profile, indicating that irrelevant visual features were not fully excluded. In addition, feature-level RSA corroborated that both sound frequency-specific and orientation-specific information were present in EEG activity patterns, irrespective of the attended modality. Overall, these results demonstrate the persistence of task-irrelevant information in multisensory working memory and offer critical insights into how attentional processes shape its representational architecture.

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bioRxiv2025

Electrophysiological resting-state signatures link polygenic scores to general intelligence

Intelligence is associated with important life outcomes. Behavioral, genetic, structural, and functional brain correlates of intelligence have been studied for decades, but questions remain as to how genetics are related to trait expression and what intermediary role brain properties play. This study investigated these mediations in a representative sample of 434 individuals, comprising young and older adults. Polygenic scores (PGS) for intelligence were calculated. Resting-state EEG recordings were analyzed using graph theory quantifying functional connectivity across different frequencies. We tested whether global and local graph metrics like efficiency and clustering mediated the association between PGS and intelligence. PGS significantly predicted variance in intelligence and were related to frequency-specific graph metrics in areas predominantly located in parieto-frontal regions, which in turn were associated with intelligence. These findings, which are based on the first study linking PGS to intelligence using EEG-derived graph metrics, advance our understanding of the neurogenetics of intelligence.

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bioRxiv2024

EEG Correlates of Cognitive Dynamics in Task Resumption after Interruptions: The Impact of Available Time and Flexibility

Interruptions are a common aspect of everyday working life, negatively affecting both task performance and long-term psychological well-being. However, research suggests that the effects of interruptions can be mitigated in several ways, such as the opportunity to anticipate the interruptions and preparation time. Here, we used a retrospective visual working memory task to investigate the effects of duration and flexible resumption after interruptions, with 28 participants (18-30 years old) attending the experiment. For this main task participants were required to remember the orientations of a set of colored bars and retrieve one at the end of the trial in response to a retro-cue. This task was sometimes interrupted with an arithmetic task that was presented before the retro-cue. The period after the interruptions and the retro-cue was either short (no additional time), long (additional 1000 ms), or self-determined. Interruptions affected the main task performance irrespective of duration condition, while response times were shorter with the flexible condition. EEG analysis showed that having more time before resuming the interrupted task enabled stronger beta suppression which in turn modulated task performance, helping participants to safely disengage from the interrupting task, and refocus their attention back more efficiently. Further, flexibility in the timing of resumption provided additional benefits as seen in stronger oscillatory alpha and beta suppression to the retro-cue, also being related to better task performance. These results demonstrate the important role of resumption time and individual flexibility in dealing with interruptions.

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bioRxiv2024

The Interplay Between Multisensory Processing and Attention in Working Memory: Behavioral and Neural Indices of Audio-Visual Object Storage

Although real-life events are multisensory, how audio-visual objects are stored in working memory is an open question. At a perceptual level, evidence shows that both top-down and bottom-up attentional processes can play a role in multisensory interactions. To understand how attention and multisensory processes interact in working memory, we designed an audio-visual delayed match-to-sample task in which participants were presented with one or two audio-visual memory items, followed by an audio-visual probe. In three different blocks, participants were instructed to either (a) attend to the auditory features, (b) attend to the visual features, or (c) attend to both auditory and visual features. Participants were instructed to indicate whether the task-relevant features of the probe matched one of the task-relevant feature(s) or objects in working memory. Behavioral results showed interference from task-irrelevant features, suggesting bottom-up integration of audio-visual features and their automatic encoding into working memory, irrespective of their task relevance. Yet, ERP analyses revealed no evidence for active maintenance of these task-irrelevant features, while they clearly taxed greater attentional resources during recall. Notably, alpha oscillatory activity revealed that linking information between auditory and visual modalities required more attentional demands at retrieval. Overall, these results offer critical insights into how and at which processing stage multisensory interactions occur in working memory. Public Significance StatementCurrent working memory research is dominated by investigations of the visual domain. Yet, understanding how more complex representations, e.g., based on multisensory inputs, are formed, stored, and recalled is crucial to obtaining a more realistic understanding of working memory function. The present study shows that when confronted with audio-visual inputs at the same time and location, features from both modalities are combined into a working memory representation, irrespective of their task relevance. During maintenance, alpha oscillations serve to flexibly gate information flow in the cortex, allowing for the re-distribution of attentional resources between modalities depending on their task-relevance. Notably, when the task instructions explicitly involve the storage of audio-visual objects as a whole, recall requires more attentional resources.

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bioRxiv2023

Modeling the impact of genotype, age, sex, and continuous navigation on pathway integration performance

The Path Integration (PI) task stands as a fundamental activity within spatial navigation, encompassing a multifaceted underlying process that requires extensive computation of both translational and directional information during navigation. This task is postulated to engage the entorhinal cortex (EC), a critical brain region. Although rodent studies have firmly linked the EC with the PI task, such a correlation has yet to be definitively established in humans. Individuals harboring high-risk genes associated with Alzheimers disease (AD) present a unique opportunity to explore PI task performance in humans because EC is the first targeted region during the pathological development of AD. Furthermore, the execution of the PI task is also susceptible to the influences of age and gender. In order to methodically probe the influences of various factors on PI performance, we conducted a PI task in a cohort characterized by high-risk AD-associated genes in a virtual island environment with surrounding landmarks. Our findings unveiled intricate interactions between these risk genes, age, and gender in shaping PI performance, an influence primarily mediated through distance and angle estimation. This study provides an illuminating perspective on the investigation into the functional role of the entorhinal cortex within the context of the PI task.

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bioRxiv2022

Cross-modal interactions at the audiovisual cocktail-party revealed by behavior, ERPs, and neural oscillations

Theories of attention argue that objects are the units of attentional selection. In real-word environments such objects can contain visual and auditory features. To understand how mechanisms of selective attention operate in multisensory environments, we created an audiovisual cocktail-party situation, in which two speakers (left and right of fixation) simultaneously articulated brief numerals. In three separate blocks, informative auditory speech was presented (a) alone or paired with (b) congruent or (c) uninformative visual speech. In all blocks, subjects localized a pre-defined numeral. While audiovisual-congruent and uninformative speech improved response times and speed of information uptake according to diffusion modeling, an ERP analysis revealed that this did not coincide with enhanced attentional engagement. Yet, consistent with object-based attentional selection, the deployment of auditory spatial attention (N2ac) was accompanied by visuo-spatial attentional orienting (N2pc) irrespective of the informational content of visual speech. Notably, an N2pc component was absent in the auditory-only condition, demonstrating that a sound-induced shift of visuo-spatial attention relies on the availability of audio-visual features evolving coherently in time. Additional analyses revealed cross-modal interactions in working memory and modulations of cognitive control. The preregistered methods and hypotheses of this study can be found at https://osf.io/vh38g.

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bioRxiv2022

Age influences audiovisual speech processing in multi-talker scenarios - Evidence from cortical oscillations

Age-related differences in the processing of audiovisual speech in a multi-talker environment were investigated analyzing event-related spectral perturbations (ERSPs), focusing on theta, alpha, and beta oscillations that are assumed to reflect conflict processing, multisensory integration, and attentional mechanisms, respectively. Eighteen older and 21 younger healthy adults completed a two-alternative forced-choice word discrimination task, responding to audiovisual speech stimuli. In a cocktail-party scenario with two competing talkers (located at-15{degrees} and 15{degrees} azimuth), target words (/yes/ or /no/) appeared at a pre-defined (attended) position, distractor words at the other position. In two audiovisual conditions, acoustic speech was combined either with congruent or uninformative visual speech. While a behavioral benefit for congruent audiovisual speech occurred for both age groups, differences between audiovisual conditions in the theta and beta band were only present for older adults. A stronger increase in theta perturbations for stimuli containing uninformative visual speech could be associated with early conflict processing, while a stronger suppression in beta perturbations for congruent audiovisual speech could be associated to audiovisual integration. Compared to the younger group, the older group showed generally stronger beta perturbations. No condition differences in the alpha band were found. Overall, the findings suggest age-related differences in audiovisual speech integration in a multi-talker environment. While the behavioral benefit of congruent audiovisual speech was unaffected by age, older adults had a stronger need for cognitive control when processing conflicting audiovisual speech input. Furthermore, mechanisms of audiovisual integration are differently activated depending on the informational content of the visual information.

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bioRxiv2021

Attentional Modulations of Alpha Power Are Sensitive to the Task-relevance of Auditory Spatial Information

The topographical distribution of oscillatory power in the alpha band is known to vary depending on the current focus of spatial attention. Here, we investigated to what extend univariate and multivariate measures of post-stimulus alpha power are sensitive to the required spatial specificity of a task. To this end, we varied the perceptual load and the spatial demand in an auditory search paradigm. A centrally presented sound at the beginning of each trial indicated the to-be-localized target sound. This spatially unspecific pre-cue was followed by a sound array, containing either two (low perceptual load) or four (high perceptual load) simultaneously presented lateralized sound stimuli. In separate task blocks, participants were instructed either to report whether the target was located on the left or the right side of the sound array (low spatial demand) or to indicate the exact target location (high spatial demand). Univariate alpha lateralization magnitude was neither affected by perceptual load nor by spatial demand. However, an analysis of onset latencies revealed that alpha lateralization emerged earlier in low (vs. high) perceptual load trials as well as in low (vs. high) spatial demand trials. Finally, we trained a classifier to decode the specific target location based on the multivariate alpha power scalp topography. A comparison of decoding accuracy in the low and high spatial demand conditions suggests that the amount of spatial information present in the scalp distribution of alpha-band power increases as the task demands a higher degree of spatial specificity. Altogether, the results offer new insights into how the dynamic adaption of alpha-band oscillations in response to changing task demands is associated with post-stimulus attentional processing.

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bioRxiv2020

Short-term audiovisual spatial training enhances electrophysiological correlates of auditory selective spatial attention

Audiovisual cross-modal training has been proposed as a tool to improve human spatial hearing. Here, we investigated training-induced modulations of auditory-evoked event-related potential (ERP) components that have been associated with processes of auditory selective spatial attention when a speaker of interest has to be localized in a multiple speaker ("cocktail-party") scenario. Forty-five healthy subjects were tested, including younger (19-29 yrs; n = 21) and older (66-76 yrs; n = 24) age groups. Three conditions of short-term training (duration 15 minutes) were compared, requiring localization of non-speech targets under "cocktail-party" conditions with either (1) synchronous presentation of co-localized auditory-target and visual stimuli (audiovisual-congruency training) or (2) immediate visual feedback on correct or incorrect localization responses (visual-feedback training), or (3) presentation of spatially incongruent auditory-target and visual stimuli presented at random positions with synchronous onset (control condition). Prior to and after training, subjects were tested in an auditory spatial attention task (15 minutes), requiring localization of a predefined spoken word out of three distractor words, which were presented with synchronous stimulus onset from different positions. Peaks of ERP components were analyzed with a specific focus on the N2, which is known to be a correlate of auditory selective spatial attention. N2 amplitudes were significantly larger after audiovisual-congruency training compared with the remaining training conditions for younger, but not older, subjects. Also, at the time of the N2, electrical imaging revealed an enhancement of electrical activity induced by audiovisual-congruency training in dorsolateral prefrontal cortex (Brodmann area 9) for the younger group. These findings suggest that cross-modal processes induced by audiovisual-congruency training under "cocktail-party" conditions at a short time scale resulted in an enhancement of correlates of auditory selective spatial attention.

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bioRxiv2020

Congruent lip movements facilitate speech processing in a dynamic audiovisual multi-talker scenario: An ERP study with older and younger adults

In natural conversations, visible mouth and lip movements play an important role in speech comprehension. There is evidence that visual speech information improves speech comprehension, especially for older adults and under difficult listening conditions. However, the neurocognitive basis is still poorly understood. The present EEG experiment investigated the benefits of audiovisual speech in a dynamic cocktail-party scenario with 22 (aged 20 to 34 years) younger and 20 (aged 55 to 74 years) older participants. We presented three simultaneously talking faces with a varying amount of visual speech input (still faces, visually unspecific and audiovisually congruent). In a two-alternative forced-choice task, participants had to discriminate target words ("yes" or "no") among two distractors (one-digit number words). In half of the experimental blocks, the target was always presented from a central position, in the other half, occasional switches to a lateral position could occur. We investigated behavioral and electrophysiological modulations due to age, location switches and the content of visual information, analyzing response times and accuracy as well as the P1, N1, P2, N2 event-related potentials (ERPs) and the contingent negative variation (CNV) in the EEG. We found that audiovisually congruent speech information improved performance and modulated ERP amplitudes in both age groups, suggesting enhanced preparation and integration of the subsequent auditory input. In the older group, larger amplitude measures were found in early phases of processing (P1-N1). Here, amplitude measures were reduced in response to audiovisually congruent stimuli. In later processing phases (P2-N2) we found decreased amplitude measures in the older group, while an amplitude reduction for audiovisually congruent compared to visually unspecific stimuli was still observable. However, these benefits were only observed as long as no location switches occurred, leading to enhanced amplitude measures in later processing phases (P2-N2). To conclude, meaningful visual information in a multi-talker setting, when presented from the expected location, is shown to be beneficial for both younger and older adults.

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bioRxiv2019

A dual mechanism underlying retroactive shifts of auditory spatial attention: dissociating target- and distractor-related modulations of alpha lateralization

Attention can be allocated to mental representations to select information from working memory. To date, it remains ambiguous whether such retroactive shifts of attention involve the inhibition of irrelevant information or the prioritization of relevant information. Investigating asymmetries in posterior alpha-band oscillations during an auditory retroactive cueing task, we aimed at differentiating those mechanisms. Participants were cued to attend two out of three sounds in an upcoming sound array. Importantly, the resulting working memory representation contained one laterally and one centrally presented item. A centrally presented retro-cue then indicated the lateral, the central, or both items as further relevant for the task (comparing the cued item(s) to a memory probe). Time-frequency analysis revealed opposing patterns of alpha lateralization depending on target eccentricity: A contralateral decrease in alpha power in target lateral trials indicated the involvement of target prioritization. A contralateral increase in alpha power when the central item remained relevant (distractor lateral trials) suggested the de-prioritization of irrelevant information. No lateralization was observed when both items remained relevant, supporting the notion that auditory alpha lateralization is restricted to situations in which spatial information is task-relevant. Altogether, the data demonstrate that retroactive attentional deployment involves excitatory and inhibitory control mechanisms.

neuroscience↗

bioRxiv2019

Unraveling the relation between EEG-correlates of attentional orienting and sound localization performance: a diffusion model approach

Understanding the contribution of cognitive processes and their underlying neurophysiological signals to behavioral phenomena has been a key objective in recent neuroscience research. Using a diffusion-model framework, we investigated to what extent well-established correlates of spatial attention in the electro-encephalogram contribute to behavioral performance in an auditory free-field sound-localization task. Younger and older participants were instructed to indicate the horizontal position of a pre-defined target among three simultaneously presented distractors. The central question of interest was whether posterior alpha lateralization and amplitudes of the anterior contralateral N2 subcomponent (N2ac) predict sound localization performance (accuracy, mean reaction time) and/or diffusion model parameters (drift rate, boundary separation, non-decision time). Two age groups were compared to explore whether in older adults, who struggle with multi-speaker environments, the brain-behavior relationship would differ from younger adults. Regression analyses revealed that N2ac amplitudes predicted drift rate and accuracy, whereas alpha lateralization was not related to behavioral or diffusion modeling parameters. This was true irrespective of age. The results indicate that a more efficient attentional filtering and selection of information within an auditory scene, reflected by increased N2ac amplitudes, was associated with a higher speed of information uptake (drift rate) and better localization performance (accuracy), while the underlying response criteria (threshold separation), mean reaction times, and non-decisional processes remained unaffected. The lack of a behavioral correlate of post-stimulus alpha power lateralization constrast the well-established notion that pre-stimulus alpha power reflects a functionally relevant attentional mechanism. This highlights the importance of distinguishing anticipatory from post-stimulus alpha power modulations.

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