Biology subjects

Salomoni, S. E.

Publications and source records attributed to Salomoni, S. E..

7 recordsLinked to original sources

bioRxiv2026

The Contextual Specificity of Pausing: Interpreting Electromyographic Partial Responses During Action Cancellation and Attentional Capture

A prominent model of action stopping theorises that the reactive cancellation of movement is underpinned by two dissociable processes: a rapid, involuntary "pause" that transiently suppresses motor output, and a slower, voluntary cancellation of movement. As a fundamental component of motor control, the pause process has been posited to generalise broadly to infrequent and salient stimuli (irrespective of whether they bear an imperative to stop) and to be observable as suppression in electromyographical (EMG) recordings. Over two experiments (N = 24 in each), participants completed standard stop signal and flanker tasks, and novel task variants, where flanking arrows occurred infrequently, with or without a delay (relative to the central go stimulus), or coincident with a stop stimulus. Relative to a standard flanker task, presenting flankers infrequently specifically increased slowing in incongruent trials after at least three preceding trials without flanking stimuli, with no effect in congruent or neutral trials, indicating involuntary delays to infrequent events are sensitive to both stimulus features and the recency of perceptually similar events. Presenting flanker arrows of any congruence alongside a stop stimulus resulted in faster EMG suppression than stop stimuli alone, indicating that additional infrequent stimuli can facilitate inhibitory responses. However, presenting flanker stimuli at an equivalent frequency and delay outside of a stopping task did not reliably elicit EMG suppression or behavioural delays. The current findings challenge current models by demonstrating that physiological signatures previously interpreted as manifestations of a generalisable pause process are instead context specific, requiring the anticipation of action cancellation.

neuroscience↗

bioRxiv2026

Stopping and Changing Expected and Unexpected Movements

The capacity to cancel or adapt planned actions in response to changing environmental demands is essential for navigating our complex world. While past research has shown that an individuals expectations of upcoming movement demands influence the speed of action initiation, the effect this has on subsequent cancellation or adaption of that movement remains unknown. 25 healthy adults completed stop signal tasks and stop change tasks in which biasing cues (e.g., "70% left") accurately indicated the probability that a left, or right button press would be required. As expected, responses that were congruent with the cue were faster than incongruent responses; however, biasing cues had no effect on behavioural or physiological (electromyographical) indices of stopping speed. Stopping latencies were found to be faster in the stop change task than the stop signal task, corroborating other recent work. However, a second experiment (25 healthy adults) which used the same stimuli for both tasks (varying only the instructions), revealed no difference - highlighting the sensitivity of the stop process to stimulus effects, and a common confound in the literature. We also observed that physiological indices of action reprogramming (following a stop) were faster in congruent than incongruent trials. Collectively, these results suggests that preparatory changes that accompany expected movements influence the enaction of movement both prior to, and after stopping, but the stop mechanism itself, remains independent of these preparations. These results inform how action cancellation and adaption are applied in real world environments, where expectations continually interface with our motor plans. HighlightsO_LI* Anticipating a movement increases the speed of its enaction but not subsequent cancellation C_LIO_LI* Expected movements can be reprogrammed more quickly than unexpected movements C_LIO_LI* The latency of action cancellation is highly sensitive to stimulus effects C_LI

neuroscience↗

bioRxiv2025

When Stopping Requires Going; Physiological Similarities Between Action Cancellation and the Cancellation of Action Cancellation

The reactive cancellation of real-world actions typically requires complex combinations of both muscle contraction and/or muscle suppression. However, current experimental paradigms solely examine contexts in which action cancellation requires muscle suppression. To provide fundamental insights into inhibitory control mechanisms, we directly compared the latency of action cancellation in novel paradigms where stopping required either suppression of planned activation or reinstatement of ongoing activity. 20 healthy adults (mean age = 32.2 years) completed novel variants of the stop signal task (SST) in which each trial began with tonic force production to depress two buttons. When a go signal appeared, participants were required to release these buttons. On a subset of trials, a stop signal occurred after a brief delay, and participants were required to cancel the release of one of the buttons. Data in these variants were compared to conventional response-selective SSTs, in which the go signal required bilateral button presses and stop signals necessitated cancellation of one of these responses. Electromyographic (EMG) recordings allowed detailed comparison of the characteristics of muscle contraction and suppression (i.e., stopping speed) across these tasks. When physiological evidence of synchronous action cancellation in both hands was observed (supporting recent models of complex stopping), EMG measures of action cancellation speed did not differ (p = 0.863, BF01 = 8.49) between cancellation of releases and cancellation of presses conditions. This result suggests that response inhibition may broadly characterise reactive control to maintain a current physiological state rather than specific cancellation of a voluntary response.

physiology↗

bioRxiv2024

An exploration of complex action stopping across multiple datasets: Insights into the mechanisms of action cancellation and re-programming

A long history of psychological experiments has utilised stop signal paradigms to assess action inhibition. Recent studies have investigated complex stopping behaviours, such as response-selective stopping where only one component of a bimanual action requires cancellation. A current emphasis has been to utilise electromyographical (EMG) recordings to assess the temporal dynamics of action inhibition at the level of the muscle, beyond those based solely on observable behavioural events. Here, we combine EMG and behavioural data from 17 cohorts of healthy younger and older adults yielding over 42,000 response-selective stopping trials, providing unique insights into this emerging field. Expanding from past research in this area, our robust single-trial EMG analyses permit detection of cancelled (partial) and response-generating EMG bursts in both hands, revealing substantial overlaps in the distributions of timing of action cancellation and re-programming. These findings are consistent with recent experimental and modelling evidence, suggesting that response- selective stopping involves two independent processes: a discrete bimanual stop and initiation of a new unimanual response. This overlap appears incompatible with the recent pause-then-cancel model, and more consistent with a broader "pause-then-retune" account, where a slower process mediates any action updating, not just cancellation. Moreover, this independence means that cancellation can happen at any time during motor planning and execution, against the notion of an observable "point of no return" in motor actions. We also discuss best practices for the analysis of EMG data and indicate how methodological aspects, such as choosing appropriate reference time points, can influence the outcomes and their interpretation.

neuroscience↗

bioRxiv2024

Stopping Speed to Auditory and Visual Stop Signals Depends on Go Signal Modality

Past research has found that the speed of the action cancellation process is influenced by the sensory modality/modalities of the environmental change that triggers it. However, the effect on selective stopping processes (where participants must cancel only one component of a multi-component movement) remains unknown, despite these complex movements often being required as we navigate our busy modern world. Thirty healthy adults (mean age = 31.1 years, SD = 10.5) completed five response-selective stop signal tasks featuring different combinations of "go signal" modality (the environmental change baring an imperative to initiate movement; auditory or visual) and "stop signal" modality (the environmental change indicating that action cancellation is required; auditory, visual, or audiovisual). Electromyographical (EMG) recordings of effector muscles allowed detailed comparison of the characteristics of voluntary action and cancellation between tasks. Behavioural and physiological measures of stopping speed demonstrated that the modality of the go signal influenced how quickly participants cancelled movement in response to the stop signal: stopping was faster in two cross-modal experimental conditions (auditory go - visual stop; visual go - auditory stop), than in two conditions using the same modality for both signals. A separate condition testing for multisensory facilitation revealed that stopping was fastest when the stop signal consisted of a combined audiovisual stimulus, compared to all other go-stop stimulus combinations. These findings provide novel evidence regarding the role of attentional networks in action cancellation and suggest modality specific cognitive resources influence the latency of the stopping process.

neuroscience↗

bioRxiv2023

Selective Cancellation of Reactive and Anticipated Movement: Differences in Speed of Action Reprogramming, but not Stopping.

The ability to inhibit movements is an essential component of a healthy executive control system. Two distinct but commonly used tasks to assess motor inhibition are the stop signal task (SST) and the anticipated response inhibition (ARI) task. The SST and ARI tasks are similar in that they both require cancelation of a prepotent movement; however, the SST involves cancelation of a speeded reaction to a temporally unpredictable signal, while the ARI task involves cancelation of an anticipated response that the participant has prepared to enact at a wholly predictable time. 33 participants (mean age = 33.3 years, range = 18-55 years) completed variants of the SST and ARI task. In each task, the majority of trials required bimanual button presses, while on a subset of trials a stop signal indicated that one of the presses should be cancelled (i.e., motor selective inhibition). Additional variants of the tasks also included trials featuring signals which were to be ignored, allowing for insights into the attentional component of the inhibitory response. Electromyographic (EMG) recordings allowed detailed comparison of the characteristics of voluntary action and cancellation. The speed of the inhibitory process was not influenced by whether the enacted movement was reactive (SST) or anticipated (ARI task). However, the ongoing (non-cancelled) component of anticipated movements was more efficient than reactive movements, as a result of faster action reprogramming (i.e., faster ongoing actions following successful selective inhibition). Older age was associated with both slower inhibition and slower action reprogramming across all reactive and anticipated tasks.

neuroscience↗

bioRxiv2023

Faster action reprogramming, but not stopping, with proactive cues: Combining EMG and computational modelling in response-selective stop signal tasks

The ability to stop simple ongoing actions has been extensively studied using the stop signal task, but less is known about inhibition in more complex scenarios. Here we used a task requiring bimanual responses to go stimuli, but selective inhibition of only one of those responses following a stop signal. We assessed how proactive cues affect the nature of both the responding and stopping processes, and the well-documented "stopping delay" in the continuing action following successful stopping. In this task, estimates of the speed of inhibition based on a simple-stopping model are inappropriate, and have produced inconsistent findings about the effects of proactive control on motor inhibition. We instead used a multi-modal approach, based on improved methods of detecting and interpreting partial electromyographical (EMG) responses and the recently proposed SIS (simultaneously inhibit and start) model of selective stopping behaviour. Our results provide clear and converging evidence that proactive cues reduce the stopping delay effect by slowing bimanual responses and speeding unimanual responses, with a negligible effect on the speed of the stopping process.

neuroscience↗