Biology subjects

Gresch, D.

Publications and source records attributed to Gresch, D..

4 recordsLinked to original sources

bioRxiv2026

Searching across working memory and perception

Searching for objects of interest is an essential and pervasive activity in adaptive cognition. In everyday situations, we often search for relevant content in our surroundings and in mind at the same time, yet most experimental tasks consider search behavior in perception or in working memory separately. To address the gap, we designed tasks to investigate perceptual and working-memory search proceeding in tandem. Participants viewed successive arrays of two real-world objects, separated by a delay, and then were prompted to search for a specific object, while the second array remained visible. The probed target was equally likely to be in the previously encoded array, available only in working memory, or in the visible array. Behavioral performance across four experiments with different response demands and delays yielded a consistent pattern of findings. Accuracy was better for detecting perceptual targets than working-memory targets. However, search speed was equivalent for targets in both domains in all cases, suggesting parallel search functions co-existing across the two domains. The final experiment combined continuous color reproduction with eye tracking and neural recordings. Neural measures of posterior alpha lateralization, tracking the neural selection of working-memory and perceptual targets, suggested parallel search functions developing with similar time courses. Intriguingly, oculomotor gaze shifts showed a divergent pattern, with earlier gaze shifts associated with perceptual targets and later shifts with working-memory targets. Overall, the present studies establish a means for investigating search across working-memory and perceptual domains, suggest the co-existence of parallel search mechanisms, and invite new lines of enquiry.

neuroscience↗

bioRxiv2026

Dynamic prioritisation of attention when external and internal demands compete

Attention enables the prioritisation of task-relevant information, whether encountered in the external world or maintained as internal representations. While the mechanisms of attention have been extensively studied within perception and working memory, everyday cognition often confronts us with competing demands from both domains simultaneously. How attention is divided under such cross-domain demands remains poorly understood. Here, participants performed a combined perception and working-memory task in which an informative cue appeared between a working-memory display and a subsequent perceptual display. On most trials, this cue simultaneously indicated two items for prioritisation: either two encoded working-memory items or two upcoming perceptual items (within-domain attention), or one item from each domain (cross-domain attention). Combining behavioural measures with electroencephalography allowed us to characterise how dividing attention across domains shapes performance and neural activity relative to dividing attention within one domain. Behaviourally, we observed a striking asymmetry: perceptual performance benefited from cross-domain versus within-domain attention, whereas working-memory performance showed the opposite pattern. Mirroring this behavioural imbalance, time-resolved decoding revealed distinct cross-versus within-domain competition in both perception and working memory, suggesting that external and internal attention are neurally separable even when engaged simultaneously. This competition between domains was also evident in neural markers of spatial attentional orienting: while initially impaired during cross-domain attention, orienting progressively favoured external over internal information. Together, these findings show that when perception and working memory compete, attention is not divided evenly. Instead, cross-domain attention constitutes a distinct attentional state, with its own prioritisation dynamics and neural representation. Significance statementPerception and working memory are typically studied as separate targets of attention, yet real-world behaviour requires continuous negotiation between what is currently available in the external environment and what is held in mind. This study addresses how that negotiation unfolds when both sources of information become relevant at once. By directly comparing divided attention across versus within domains, we show that competition between perception and working memory is not neutral: it produces asymmetric behavioural consequences, distinct neural states, and a progressive bias in attentional prioritisation towards upcoming perceptual input. These findings suggest that cross-domain attention is not a balanced extension of within-domain attention, but a domain-biased prioritisation regime in which perception and working memory systematically trade off against each other.

neuroscience↗

bioRxiv2024

Neural dynamics of reselecting visual and motor contents in working memory after external interference

In everyday tasks, we must often shift our focus away from internal representations held in working memory to engage with perceptual events in the external world. Here, we investigated how our internal focus is reestablished following an interrupting task by tracking the reselection of visual representations and their associated action plans in working memory. Specifically, we ask whether reselection occurs for both visual and motor memory attributes and when this reselection occurs. We developed a visual-motor working-memory task in which participants were retrospectively cued to select one of two memory items before being interrupted by a perceptual discrimination task. To determine what information was reselected, the memory items had distinct visual and motor attributes. To determine when internal representations were reselected, the interrupting task was presented at one of three distinct time points following the retro-cue. We employed electroencephalography time-frequency analyses to track the initial selection and later reselection of visual and motor representations, as operationalized through modulations of posterior alpha (8-12 Hz) activity relative to the memorized item location (visual) and of central beta (13-30 Hz) activity relative to the required response hand (motor). Our results showed that internal visual and motor contents were concurrently reselected immediately after completing the interrupting task, rather than only when internal information was required for memory-guided behavior. Thus, following interruption, we swiftly resume our internal focus in working memory through the simultaneous reselection of memorized visual representations and their associated action plans, thereby restoring internal contents to a ready-to-use state. Significance statementA key challenge for working memory is to maintain past visual representations and their associated actions while engaging with the external environment. Our cognitive system must, therefore, often juggle multiple tasks within a common time frame. Despite the ubiquity of multi-task situations in everyday life, working memory has predominantly been studied devoid of additional perceptual, attentional, and response demands during the retention interval. Here, we investigate the neural dynamics of returning to internal contents following task-relevant interruptions. Particularly, we identify which attributes of internal representations are reselected and when this reselection occurs. Our findings demonstrate that both visual and motor contents are reselected immediately and in tandem after completion of an external, interrupting task.

neuroscience↗

bioRxiv2024

Neural dynamics of shifting attention between perception and working-memory contents

In everyday tasks, our focus of attention shifts seamlessly between contents in the sensory environment and internal memory representations. Yet, research has mainly considered external and internal attention in isolation. We used magnetoencephalography to compare the neural dynamics of shifting attention to visual contents within vs. between the external and internal domains. Participants performed a combined perception and working-memory task in which two sequential cues guided attention to upcoming (external) or memorised (internal) sensory information. Critically, the second cue could redirect attention to visual content within the same or alternative domain as the first cue. Multivariate decoding unveiled distinct patterns of human brain activity when shifting attention within vs. between domains. Brain activity distinguishing within- from between-domain shifts was broadly distributed and highly dynamic. Intriguingly, crossing domains did not invoke an additional stage prior to shifting. Alpha lateralisation, a canonical marker of shifting spatial attention, showed no delay when cues redirected attention to the same vs. alternative domain. Instead, evidence suggested that neural states associated with a given domain linger and influence subsequent shifts of attention within vs. between domains. Our findings provide the first insights into the neural dynamics that govern attentional shifts between perception and working memory. Significance StatementDuring almost every natural behaviour, our attention regularly shifts between sensory and memory contents. Although the systems and mechanisms of attentional control and modulation within the external and internal domains have been heavily studied in isolation, how attention crosses between these domains remains uncharted territory. Here, we provide the first study to investigate brain dynamics associated with shifting attention between contents in the sensory environment and memory representations. Using a novel experimental design, we isolated the patterns and dynamics of brain activity associated with shifting attention within vs. between the external and internal domains. Our findings reveal early, dynamic, and distributed patterns of activity that distinguish within- from between-domain shifts, offering fascinating initial insights, and opening new questions for investigation.

neuroscience↗