Biology subjects

Echeverria-Altuna, I.

Publications and source records attributed to Echeverria-Altuna, I..

4 recordsLinked to original sources

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

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↗

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↗

bioRxiv2021

Transient beta activity and connectivity during sustained motor behaviour

Neural oscillations are thought to play a central role in orchestrating activity states between distant neural populations. In humans, long-range neural connectivity has been particularly well characterised for 13-30 Hz beta activity which becomes phase coupled between the motor cortex and the contralateral muscle during isometric contraction. Based on this and related observations, beta activity and connectivity have been linked to sustaining stable cognitive and motor states - or the status quo - in the brain. Recently, however, beta activity has been shown to be short-lived, as opposed to sustained - though so far this has been reported for regional beta activity in tasks without sustained motor demands. Here, we measured magnetoencephalography (MEG) and electromyography (EMG) in 18 human participants performing an isometric-contraction (gripping) task designed to yield sustained behavioural output. If cortico-muscular beta connectivity is directly responsible for sustaining a stable motor state, then beta activity should be (or become) sustained in this context. In contrast, we found that beta activity and connectivity with the downstream muscle were transient, even when participants engaged in sustained gripping. Moreover, we found that sustained motor requirements did not prolong beta-event duration in comparison to rest. These findings suggest that long-range neural synchronisation may entail short bursts of frequency-specific connectivity, even when task demands - and behaviour - are sustained. HighlightsO_LITrial-average 13-30 Hz beta activity and connectivity with the muscle appear sustained during stable motor behaviour C_LIO_LISingle-trial beta activity and connectivity are short-lived, even when motor behaviour is sustained C_LIO_LISustained task demands do not prolong beta-event duration in comparison to resting state C_LI

neuroscience↗