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Nobre, A. C.

Publications and source records attributed to Nobre, A. C..

At least 19 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↗
bioRxiv2026

Distinct neural correlates for focusing on similar memory contents originating from current or previous experience

Flexible, goal-directed behavior depends on the ability to select and prioritize information from memory representations freshly encoded from the sensory stream as well as retrieved from previous experience. The spatial gating signatures of internal attention in working memory (WM) are increasingly well characterized, but it remains unclear whether the same neurophysiological mechanisms are recruited for orienting attention to items from long-term memory (LTM). We recorded EEG and eye movements while participants focused on WM versus LTM representations in a unified precision-report task. Retrocues improved performance for both WM and LTM items, but with larger behavioral gains for WM items. Neural and oculomotor markers of spatial orienting, including contralateral posterior alpha suppression and gaze biases toward remembered locations, were robust when focusing on WM items; but were reliably weakened or absent when focusing on LTM items. Multivariate pattern analyses provided complementary evidence for the recruitment of dissociable neural mechanisms when focusing on WM vs. LTM items, which unfolded with similar time courses. Together, the results establish the existence of dissociable neural mechanisms for internal attention, which can be deployed flexibly depending on the relevant memory trace to guide performance. The findings raise interesting and tractable questions about whether differences in representational formats or representational domains drive the distinct internal attention mechanisms.

neuroscience↗
bioRxiv2026

Prediction Is Preserved but Long-Timescale Benefits Are Reduced in ADHD

Attention-deficit/hyperactivity disorder (ADHD) has been associated with atypical temporal processing across multiple cognitive domains. However, most evidence derives from simplified paradigms that isolate timing from spatial behaviour. Here, we examine how temporal prediction operates within a continuous, dynamic visual environment. Using the Dynamic Visual Search (DVS) task, we embedded spatiotemporal regularities into a sustained stream of visual events, allowing observers to implicitly learn and anticipate predictable targets. Continuous mouse tracking provided a fine-grained measure of action planning beyond discrete reaction time and accuracy metrics. Young adults diagnosed with ADHD (N=40) were compared to matched neurotypical controls (N=38). Both groups benefited from target predictability and reduced distractor load, indicating intact early spatiotemporal learning in ADHD. Across the duration of the task, however, the groups diverged. Neurotypical participants showed progressive increases in behavioural benefits from prediction, accompanied by increasingly direct and efficient mouse trajectories. In contrast, individuals with ADHD reached a plateau in prediction benefits midway through the experiment. Their performance remained stable, with minimal evidence of resource depletion, but did not show further optimisation based on learned regularities. These findings suggest that while prediction formation is preserved in ADHD, its progressive utilisation across longer timescales is attenuated. Rather than reflecting a primary deficit in learning or sustained attention, ADHD may involve altered long-timescale integration or weighting of predictive information in dynamic environments.

neuroscience↗
bioRxiv2026

Differences in dynamic motor selection in stuttering

Stuttering involves interruptions to the smooth flow of speech occurring mostly at syllable onset.1 Speech fluency is enhanced in people who stutter (PWS) by external timing cues.2 This has been taken to indicate that difficulties in the temporal organisation of action selection and initiation during speech contribute to stuttering.3 An important unanswered question is whether putative temporal coordination difficulties are specific to speech or generalise to other actions. Here, we examined the temporal organisation of hand action selection in PWS. Twenty PWS and twenty typically fluent speakers (TFS) underwent magnetoencephalography (MEG) recording while performing a visuomotor working-memory task that encouraged temporally specific selection, preparation, and shifts between hand actions. Lateralised sensorimotor mu/beta-frequency (8-30 Hz) activity modulation accompanying hand-action prioritisation was weaker in PWS than TFS. Strikingly, this effect was specific to a period of high uncertainty regarding which action to select and when. Despite these differences, lateralised mu/beta modulation was functionally related to reaction times in both groups and reaction times were well matched between PWS and TFS. The findings suggest a general disruption of temporal structuring of action selection and preparation in stuttering.

neuroscience↗
bioRxiv2025

Robust and replicable effects of ageing on resting state brain electrophysiology measured with MEG.

Non-invasive recordings using brain electrophysiology provide credible insights into decline in neuronal functioning with age. New approaches are required to translate these results into compelling clinical metrics and meet the global challenge of preserving brain health in ageing. Changes in neuronal dynamics with ageing are observable in the power spectra of EEG and MEG recordings. Highly promising candidates for electrophysiological markers have been identified, but progress is hindered by substantial methodological variability across studies. This makes it challenging to establish a clear consensus on the frequency, location, and direction of any single reported effect within the larger body of research. We estimate a full-frequency whole-head profile of the ageing effect on eyes-closed resting-state MEG using the GLM-Spectrum. This data representation is easily sharable, facilitates meta-analyses and provides a framework for estimating statistical power of age effects for future study planning. We use this to show that the effect of age replicates across open-access MEG datasets and is robust to modelling of common covariates. Distinct components within the full frequency profile have different effect sizes, indicating that sample-size planning for ageing effects must consider the specific features of interest. The frequency profile of ageing is strongly robust to a range of common covariates and partially robust to modelling of grey matter volume. We establish that what seems a well-powered study may become underpowered when analyses target an age effect that is linearly separable from an age-relevant covariate such as grey matter volume. These results provide a pathway towards formal comparison and assessment of candidate markers for brain health in ageing. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=151 SRC="FIGDIR/small/668093v3_ufig1.gif" ALT="Figure 1"> View larger version (37K): org.highwire.dtl.DTLVardef@1a9c351org.highwire.dtl.DTLVardef@563837org.highwire.dtl.DTLVardef@84b898org.highwire.dtl.DTLVardef@1730472_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIThere is a strong effect of ageing across the adult lifespan on neuronal oscillations across a range of frequencies and spatial locations. C_LIO_LIThe effect is replicable across multiple open-access datasets. C_LIO_LIThe effect is robust to a range of sources of inter-subject variability. C_LIO_LIThe age effect has heterogeneous effect size across space and frequency with implications for future study planning. C_LI

neuroscience↗
bioRxiv2025

Feature-temporal predictions dynamically modulate performance, feature-based attentional capture, and motor response activity during visual search

Recent research has investigated visual search in dynamic environments and considered how temporal predictions modulate behaviour over time. Spatiotemporal predictions have been shown to adaptively guide behaviour during search to improve target detection at temporally-likely locations. The utility of non-spatial, feature-temporal predictions is less intuitive. The present study investigated whether and how behaviour may be guided toward feature-temporally predictable targets during visual search in crowded and dynamic displays. We tested 1) whether visual attention is guided toward target-relevant features in a temporally specific manner and 2) whether our motor system is temporally tuned accordingly. Participants searched for two distinct targets (non-overlapping colour-shape combinations) in a free-viewing dynamic visual-search task. During an initial learning session, each target identity appeared at a predictable time. In a following testing session, some targets appeared at unpredicted times. Targets locations were always unpredictable. We compared the efficiency of identifying targets appearing at predicted versus unpredicted times to test for performance benefits of feature-temporal predictability. In addition, we measured whether gaze fixation was captured by distractors that shared overlapping features with temporally predicted targets. Electromyography recordings were used to test for anticipatory muscle activity tuned to the timing of predictable targets. Results indicated that learning the task regularities led to dynamic modulation of participants efficiency at identifying targets, their feature-based attentional capture, and temporally tuned muscle activity. The work highlights the flexibility of temporal expectations in guiding behaviour even under spatial uncertainty.

animal behavior and cognition↗
bioRxiv2025

Neural signatures of flexible temporal orienting under spatial and motor uncertainty

The goal-dependent use of temporal expectations enhances visual performance, even without concurrent spatial or motor predictions, yet the underlying neural mechanisms remain unclear. To identify the stages of stimulus processing influenced by temporal orienting of attention, we recorded EEG while participants performed a visual identification task manipulating relevance and temporal predictability of targets. Colored targets appeared in one of two simultaneous visual streams. One color appeared unpredictably while two others appeared predictably early or late. Targets appeared in either stream and required a localization response using the corresponding hand. On each trial, one target was cued as task-relevant. Behaviorally, participants used temporal expectations flexibly to optimize processing of goal-relevant targets. The target-defining cue elicited a contingent negative variation (CNV), modulated by the temporal predictability of anticipated early vs. late targets. Target-related event related potentials (ERP) showed strong modulation by target relevance at multiple stages. Modulations impacted target-selection (N2pc), motor preparation (LRP), and late decision-related factors (P300). Interestingly, only the P300 was additionally modulated by the temporal predictability of targets. The findings reveal how temporal attention can impact multiple stages of stimulus processing through the relevance and temporal predictability of targets even without spatial or motor certainty.

neuroscience↗
bioRxiv2025

Identifying mood instability and circadian rest-activity patterns using digital remote monitoring and actigraphy in participants at risk for bipolar disorder

Mood instability and circadian rhythm disruptions are both of increasing interest with regard to a number of psychiatric disorders, notably bipolar disorder (BD), but understanding of their nature and their interrelationship are incomplete. By definition, both have an integral temporal component and, as such, measuring them longitudinally and remotely is desirable. We conducted the Cognition and Mood Evolution across Time (COMET) study to assess the feasibility and value of digital devices to capture mood, its instability, and daily rest-activity patterns, over a 10-week period, in two groups of participants. The first group (n=37) were selected as scoring >7 on the Mood Disorder Questionnaire (MDQ) ( high MDQ), thereby having a history of mood elevation and being at risk for BD. They were compared with a group (n=37) scoring <5 on the MDQ ( low MDQ). Over a 10-week period, using a tablet, mood was rated daily, clinical ratings of depression, mania, and anxiety were captured weekly via the True Colours app, and a GENEactiv actigraph was worn to capture rest-activity pattern data. The main findings are that (1) MDQ score predicts mood instability; (2) high MDQ score is associated with more negative affect and mood symptoms than people with low MDQ, and with a different circadian activity profile; and (3) mood instability and circadian indices appear uncorrelated. The implications are that (1) remote monitoring of these domains is feasible and valuable; (2) selection of participants based on MDQ score is useful for studying mood (in)stability; and (3) the approach has potential for studies of clinical populations and for experimental medicine studies assessing interventions to reduce mood instability.

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

Dynamic prioritisation of sensory and motor contents in working memory

Internal selective attention prioritises both sensory and motor contents in working memory to guide prospective behaviour. Prior research has shown how attention modulation of sensory contents is flexible and temporally tuned depending on access requirements, but whether the prioritisation of motor contents follows similar flexible dynamics remains elusive. Also uncharted is the degree of co-dependence of sensory and motor modulation, which gets at the nature of both working-memory representations and internal attention functions. To address these questions, we independently tracked the prioritisation of sensory and motor working-memory contents as a function of dynamically evolving temporal expectations. The design orthogonally manipulated when an item location (left vs right side) and associated prospective action (left vs right hand) would be relevant. Contralateral modulation of posterior alpha (8-12 Hz) activity in electroencephalography (EEG) tracked prioritisation of the item location, while contralateral modulation of central mu/beta (8-30 Hz) activity tracked response prioritisation. Proactive and dynamic alpha and mu/beta modulation confirmed the flexible and temporally structured prioritisation of sensory and motor contents alike. Intriguingly, the prioritisation of sensory and motor contents was temporally uncoupled, showing dissociable patterns of modulation. The findings reveal multiple modulatory functions of internal attention operating in tandem to prepare relevant aspects of internal representations for adaptive behaviour.

neuroscience↗
bioRxiv2024

Effects of age on resting-state cortical networks

Understanding how ageing affects brain function remains a central challenge in neuroscience. Electrophysiological brain imaging techniques provide a near-direct measure of neuronal activity, which is useful for characterising neurophysiological health. They offer us the ability to track large-scale networks of functional activity with high temporal precision. The effects of healthy ageing on these networks remain poorly understood, in part due to small sample sizes and limited control for confounding factors in previous studies. Here, we analysed resting-state source-reconstructed magnetoencephalography (MEG) data from a large cross-sectional cohort of healthy adults (N =612, 18-88 years old) to characterise the effect of age using not only time-averaged (static), but also transient (dynamic) network activity. We examined time-averaged power and coherence across canonical frequency bands ({delta}, {theta}, , {beta}, {gamma}), as well as transient network dynamics identified using Hidden Markov Modelling. We included many confounding variables known to be affected by age, such as brain volume, as well as head size and position, which have previously been overlooked. Ageing was associated with frequency-specific changes in oscillatory power, with decreases in low-frequency ({delta}, {theta}) power and increases in high-frequency ({beta}) power. Coherence increased across all frequency bands and was positively associated with cognitive performance. Transient network analyses additionally revealed that frontal network occurrences declined with age, with evidence suggesting a compensatory role in supporting cognition. These findings provide a more comprehensive electrophysiological signature for healthy ageing and establish a baseline for detecting pathological change. HighlightsO_LIUsing source reconstructed magnetoencephalography data, we studied cortical functional networks of oscillatory activity from a large healthy population (612 subjects, 18-88 years old). C_LIO_LITime-averaged (static) network analysis in canonical frequency bands ({delta}, {theta}, , {beta}, {gamma}) showed: {beta} power and coherence increased with age; {delta}/{theta} power decreased with age, but coherence increased. Coherence in all frequencies increased with cognitive performance. C_LIO_LITransient (dynamic) network analysis showed frontal networks decreased in occurrence with age and their relation to cognitive performance showed that these changes were compensatory. The other networks showed a decreased occurrence with age. C_LIO_LIIn testing age and cognitive performance effects for statistical significance, we included a comprehensive set of confounds, such as brain volumes, head size and position, which has previously been overlooked. C_LIO_LIWe provide a comprehensive electrophysiological signature for healthy ageing and establish a baseline for detecting pathological change. C_LI

neuroscience↗
bioRxiv2024

Confidence and insight into working memories are shaped by attention and recent performance

Working memory (WM) is capacity-limited, and our ability to access information from WM is variable, but selective attention to working memory contents can improve performance. People are able to make introspective judgements regarding the quality of their memories, and these judgements are linked to objective memory performance. However, it remains unknown whether benefits of internally directed attention on memory performance occur alongside commensurate changes in introspective judgments. Across two experiments, we used retrospective cues (retro-cues) during working-memory maintenance to direct attention to items in memory. We then examined their consequence on introspective judgements. In the second experiment, we provided trial-wise feedback on performance. We found that selective attention improved confidence judgements and not just performance of the probed item. We were also able to judge participants genuine insight into working-memory contents through the correlation between confidence judgements and memory quality. Neurophysiologically, alpha desynchronization correlated first with memory error and then confidence during retro-cueing, suggesting a sequential process of attentional enhancement of memory contents and introspective insight. Further, we showed that participants can use feedback on the accuracy of confidence judgements to update their beliefs across time, according to performance. Our results emphasize flexibility in working memory by showing we can selectively modulate our confidence about its contents based on internally directed attention or objective feedback.

neuroscience↗
bioRxiv2024

Comparing the impact of contextual associations and statistical regularities in visual search and attention orienting

During visual search, we quickly learn to attend to an objects likely location. Research has shown that this process can be guided by learning target locations based on consistent spatial contextual associations or statistical regularities. Here, we tested how these different types of learning aid the utilisation of established memories for different purposes. Participants learned contextual associations or statistical regularities that predicted target locations within different scenes. The consequences of this learning for subsequent performance were then evaluated on attention-orienting and memory-recall tasks. Participants demonstrated facilitated attention-orienting and recall performance based on both contextual associations and statistical regularities. Contextual associations facilitated attention orienting with a different time course compared to statistical regularities. Benefits to memory-recall performance depended on the alignment between the learned association or regularity and the recall demands. The distinct patterns of behavioural facilitation by contextual associations and statistical regularities show how different forms of long-term memory may influence neural information processing through different modulatory mechanisms.

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↗
bioRxiv2023

Reliability of dynamic causal modelling of resting state magnetoencephalography

This study assesses the reliability of resting-state dynamic causal modelling (DCM) of magneto-electroencephalography under conductance-based canonical microcircuit models, in terms of both posterior parameter estimates and model evidence. We use resting state magneto-electroencephalography (MEG) data from two sessions, acquired two weeks apart, from a cohort with high between-subject variance arising from Alzheimers disease. Our focus is not on the effect of disease, but on the predictive validity of the methods implicit in their reliability, which is crucial for future studies of disease progression and drug intervention. To assess the predictive validity of first-level DCMs, we compare model evidence associated with the covariance among subject-specific free energies (i.e., the quality of the models) with vs. without interclass correlations. We then used parametric empirical Bayes (PEB) to investigate the predictive validity of DCM parameters at the between subject level. Specifically, we examined the evidence for or against parameter differences (i) within-subject, within-session, between-epochs; (ii) within-subject between-session and (iii) within-site between-subjects, accommodating the conditional dependency among parameter estimates. We show that for data acquired close in time, and under similar circumstances, more than 95% of inferred DCM parameters are unlikely to differ, speaking to mutual predictability over sessions. Using PEB, we show a reciprocal relationship between a conventional definition of reliability and the conditional dependency among inferred model parameters. Our analyses confirm the predictive validity and reliability of the conductance-based DCMs for resting-state neurophysiological data. In this respect, the implicit generative modelling is suitable for interventional and longitudinal studies of neurological and psychiatric disorders. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=147 SRC="FIGDIR/small/562379v1_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@135c964org.highwire.dtl.DTLVardef@38e4a7org.highwire.dtl.DTLVardef@12bc358org.highwire.dtl.DTLVardef@25f110_HPS_FORMAT_FIGEXP M_FIG C_FIG

biophysics↗
bioRxiv2023

Time for What? Dissociating Explicit Timing Tasks Through Electrophysiological Signatures

Estimating durations between hundreds of milliseconds and seconds is essential for several daily tasks. Explicit timing tasks, which require participants to estimate durations to make a comparison (time for perception) or to reproduce them (time for action), are often used to investigate psychological and neural timing mechanisms. Recent studies have proposed that mechanisms may depend on specific task requirements. In this study, we conducted electroencephalogram (EEG) recordings on human participants as they estimated intervals in different task contexts to investigate the extent to which timing mechanisms depend on the nature of the task. We compared the neural processing of identical visual reference stimuli in two different tasks, in which stimulus durations were either perceptually compared or motorically reproduced in separate experimental blocks. Using multivariate pattern analyses, we could successfully decode the duration and the task of reference stimuli. We found evidence for both overlapping timing mechanisms across tasks as well as recruitment of task-dependent processes for comparing intervals for different purposes. Our findings suggest both core and specialised timing functions are recruited to support explicit timing tasks.

neuroscience↗
bioRxiv2023

Focusing attention in human working memory and long-term memory: benefits through dissociable processes

We developed a new experimental approach to compare how attentional orienting facilitates retrieval from working memory (WM) and long-term memory (LTM), and how selective attention within these two memory types impacts incoming sensory information processing. In three experiments with healthy young adults, retrospective attention cues prioritized an item represented in WM or LTM. Participants then retrieved a memory item or performed a perceptual task. The retrocue was informative for the retrieval task but not for the perceptual task. Attentional orienting benefited performance for both WM and LTM, with stronger effects for WM. Eye-tracking revealed significant gaze shifts and microsaccades correlated with attention in WM but not LTM. Visual discrimination of unrelated visual stimuli was consistently improved for items matching attended WM locations. Similar effects occurred at LTM locations but less consistently. The findings suggest potent and at least partly dissociable attention-orienting processes for different memory types.

neuroscience↗