This study examined how highly trained open- and closed-skill athletes recruit neural resources during cue-supported motor imagery (MI) under two experimentally cued contexts: peak performance imagery (PPI) and routine training imagery (RTI). Thirty-four athletes (17 per group) completed functional magnetic resonance imaging. In planned group-stratified context contrasts, open-skill athletes showed greater activation for RTI than PPI in the occipital pole, precentral gyrus, thalamus, and cerebellum, whereas closed-skill athletes showed greater activation for PPI than RTI in precentral/postcentral regions and the left middle temporal gyrus. These are simple within-group context contrasts, not an omnibus Group & times; Condition interaction; accordingly, the findings are not described as a double dissociation. The neutral condition was passive observation rather than non-motor imagery, and post-scan manipulation checks were not collected. The results therefore indicate context-associated differences in cue-supported imagery-related activity but do not isolate motor imagery from all other forms of mental generation. Within these limits, the findings motivate a provisional Context-Sensitive Imagery Flexibility Model (CS-IFM), in which the relative weighting of visuospatial-executive and sensorimotor-representational processes may vary with sport demands and imagery context.
Human movement relies on coordinating multiple degrees of freedom (DOFs) converging onto fewer DOFs of functional goals. We compared two forms of visual feedback as participants learned a novel motor task: using 18-DOF finger movements to control a 3-joint kinematic chain, ultimately to place a 2-dimensional cursor within targets on a screen. Eighteen participants were randomly assigned to either a Chain group (who could see the chain and cursor) or a No-Chain group (who saw only the cursor). The Chain group had faster performance early in training, despite the identical mechanics faced by the two groups. Both groups improved with training, converging by the end of day one, and retained that performance on the second day. However, neither group learned to aim initial movements more directly to the target. Variance within task and null spaces decreased at similar rates, counter to the minimal intervention principle which posits greater reduction in the task-relevant variability. These results suggest that vision of intermediate control variables provides an early performance advantage, but that learners may adopt consistent control strategies that prioritize stability over directional optimization. These findings offer insights into the role of visual feedback during skill acquisition, with implications for designing feedback-based rehabilitation protocols.
Experimental paradigms of motor sequencing typically examine sequences consisting of near-instantaneous events, such as a key press, where the temporal structure is fixed. However, when sequences consist of behaviors of finite duration, multiple temporal strategies can be used to complete the sequence by segmenting the behaviors (i.e., by switching between different behaviors). Here we used an industrial sewing task to examine: (i) the effect of task difficulty on segmentation and (ii) the impact of segmentation on task performance. Sewing machine operators performed two standardized sewing tasks. Video was used to record and code the temporal sequence of different behaviors. We found that: (i) greater task difficulty resulted in greater segmentation, (ii) there was no clear evidence of an association between segmentation and task performance, indicating that multiple segmentation strategies could achieve the same performance. These results highlight a new experimental paradigm for sequence production with the possibility for different strategies.
Impulsivity, although commonly associated with maladaptive behavior, can influence how individuals manage cognitive and motor demands. This study analyzed the effect of impulsivity on motor control and cognitive effort during manual aiming tasks that varied in cognitive load. From an initial sample of 109 volunteers, a final sample of 63 right-handed adults was classified as high or low impulsive based on Brazilian Portuguese version of the Barratt Impulsiveness Scale-11 scores. Participants performed two aiming task conditions with different execution demands, while electroencephalographic workload and engagement indices were recorded to assess cognitive effort. Motor performance was evaluated through accuracy, temporal, kinematic, and inhibitory control measures. Results showed similar motor performance and kinematic patterns between groups. However, the high impulsive group consistently exhibited higher workload indices across both task conditions and made more response inhibition errors under high execution demand. These findings suggest that highly impulsive individuals mobilize greater cognitive resources to sustain motor performance comparable to that of less impulsive individuals. This compensatory increase in effort highlights the interaction between personality traits, cognitive control, and motor behavior.
