Biology subjects

Wright-Wieckowski, H.

Publications and source records attributed to Wright-Wieckowski, H..

2 recordsLinked to original sources

bioRxiv2026

Developmental coordination disorder affects the pre-ordering of sequential movements

Research suggests that motor difficulties in Developmental Coordination Disorder (DCD) are related to altered motor sequence planning, but it is unclear which mechanisms are affected, particularly in adults. This study addresses that gap by examining how the order of upcoming movements during the planning of skilled typing sequences affects motor production in adults with DCD. Previous monkey neurophysiology and behavioural findings in humans have shown that elements of a sequence are pre-ordered prior to execution, known as competitive queuing (CQ). CQ quality is predictive of subsequent performance, with skilled performers, those with fewer errors, having a larger position-dependent difference. DCD (N=28) and control participants (N=54) performed two 4-element finger sequences from memory in a delayed sequence production task over 3 sessions. Probe trials, which involved participants performing a single press after the Go Cue, assessed motor planning at each sequence position by measuring reaction time (RT) and error rate. We found that adults with DCD had a higher error rate and were slower to initiate and perform correct sequences. In terms of planning, the DCD group showed reduced preordering of sequence elements. Whilst the DCD group had a higher error rate on a working memory task, this was not correlated with the degree of pre-ordering of presses of the upcoming sequence. These findings suggest that disrupted motor sequence planning in DCD is characterised specifically by a failure to pre-order movements during the retrieval of sequences from memory. Additionally, motor sequence pre-ordering deficits in DCD are independent of general working memory impairments. These results extend prior evidence from motor imagery paradigms, demonstrating that internal modelling deficits are evident during the execution of motor plans. HighlightsO_LIAdults with DCD show diminished pre-ordering of sequential movements during planning. C_LIO_LIThe DCD group were slower to initiate and perform correct sequences from memory. C_LIO_LIMotor sequence planning is distinct from working memory performance. C_LIO_LIThis provides evidence for the IMD hypothesis in a skilled sequential task. C_LI

neuroscience↗

bioRxiv2025

Competitive pre-ordering during planning persists in kinematically fused sequential movements

Results in human and non-human primates have shown that elements of a movement sequence are pre-ordered in parallel competitively before execution, a process known as competitive queueing (CQ). However, it is unclear whether the preplanning of individual movements persists in continuous skilled actions that involve greater biomechanical integration and is associated with the formation of new motor primitives (neural fusion). We investigated how kinematics impact sequence planning in a handwriting-like task asking whether fusing velocity curves between adjacent movements affects movement preparation. Participants were trained and tested for two days to perform two sequences of four sequential centre-out-and-back movements from memory in a delayed sequence production task using a stylus on a Wacom tablet. To manipulate kinematic fusion between subsequent strokes, participants were assigned to one of three groups that were trained to perform the sequences either with acute, right or obtuse angles between sequential targets. Probe trials assessed the availability of constituent movement elements for fast and accurate execution towards each target during planning. Movement elements associated with later sequence positions were less available than earlier movements, regardless of kinematic fusion, in line with CQ findings for discrete typing sequences in humans. Importantly, a more pronounced CQ gradient was associated with higher fusion, faster initiation and greater accuracy of sequence production. These findings indicate that kinematically fused sequential actions do not result in the formation of new movement primitives (neural fusion) with a single movement plan. Instead, they continue to be planned separately and are associated with skilled performance. New & NoteworthyUsing a handwriting-like sequencing task, we manipulated kinematic fusion through target geometry and examined the relative availability of individual movements towards targets as a marker of competitive queuing (CQ) during planning. Contrary to the assumption that behavioural fusion reflects their neural fusion of movements into a new motor primitive, we show that even under high levels of fusion, the underlying sequence elements remain competitively pre-ordered by their sequence position benefitting performance.

neuroscience↗