How motor-skill experiences modulate executive control : differentiation of proactive and reactive controls

Abstract

People with motor-skill expertise have higher level of executive control than the novices. There are two types of motor skills: open skills mostly require players to react in changeable and externally-paced environments (e.g., badminton) and closed skills mostly require players to perform in stable and self-paced environments (e.g., track and field). Proactive and reactive controls of executive function are dissociated in the practices between open with closed skills. This study was aimed to: 1) examine the differences in the behavioral performance of proactive and reactive controls for task switching between open and closed-skilled participants; 2) investigate the effects of open and closed-skilled experiences on modulating the neural processes associated with proactive and reactive controls for task switching; and 3) examine the correlations between proactive and reactive control processes and the performance on task switching between the open- and closed-skilled participants, and their control counterparts. Fifty-four participants who were open-skilled (n = 18) and closed-skilled sport athletes (n = 18), and university students (n = 18) completed the cued task-switching paradigm and the simple reaction task. The cued task-switching paradigm drew on proactive and reactive controls of executive function, whereas the simple reaction task tapped on processing speed. The electrical activities associated with the task performance were captured with a 64-channel electroencephalogram (EEG) machine. Behavioral results showed marginally significant validity × group effects (P = 0.053) on the switch cost of response time when the cue was 100% valid. When the cue was 100% valid, the open-skilled participants showed significantly lower switch cost of response time than the closed-skilled participants (P = 0.023) and the control participants (P < 0.001). When the cue was 50% valid, the open and closed-skilled participants had comparable switch cost of response time (P = 0.473), of whom the switch costs of response times (open-skilled: P < 0.001; closed-skilled: P = 0.033) were significantly less than the control participants. These behavioral findings suggested that the open-skilled participants had better performance on the proactive control for task switching than the closed-skilled participants, while both the open- and closed-skilled participants had better performance on the reactive control for task switching than the control participants. However, there were no significant differences in the response times (P = 0.372) and accuracy rates (P = 0.940) among the three groups in the simple reaction task, suggesting that the processing speed performances were comparable among the open- and closed-skilled participants, and the control participants. The open-skilled participants were found to elicit less positive-going cue-locked P3 at the parietal region in switch trials than that in repeat trials in the 100% validity condition (P = 0.011). In contrast, the cue-locked P3 of the control participants were more positive-going (P = 0.004), while the closed-skilled participants had no significant differences in the cue-locked P3 (P = 0.523). Findings on the cue-locked P3 suggested that, when engaging in proactive control for task switching, the open-skilled participants appeared to deploy less attentional resources than the closed-skilled and control participants to update the new action rule when the cue was predictive of the subsequent stimulus. However, both open- and closed-skilled participants yielded comparable results when engaging in reactive control for task switching, i.e. 50% validity condition. Less positive-going stimulus-locked P3 at the parietal region in switch trials than that in repeat trials was elicited by the participants with open (P < 0.001) and closed (P = 0.038) skills. No difference in the stimulus-locked P3 at the parietal region between switch and repeat trials was found in the control participants (P = 0.838). The ERP findings in the 50% validity condition suggested that in the reactive control for task switching, both the open and closed-skilled participants deployed less switch-related attentional resources than the control participants to update the new action rule when the cue was not predictive of the subsequent stimulus. Better proactive control for task switching in terms of lower switch cost of response time in the 100% validity condition was found associated with the differences in the amplitudes of the cue-locked P3 between switch and repeat trials for the open-skilled participants (β = 0.475, P = 0.007), but not for the closed-skilled and control participants. However, better reactive control for task switching in terms of lower switch cost of response time in the 50% validity condition was associated with the differences in the amplitudes of the stimulus-locked P3 between switch and repeat trials for the control participants (β = -0.550, P = 0.020). The behavioral and electrophysiological findings suggested that firstly, intensive experience of open-skilled training modulated the proactive control for task switching process, because the open-skilled participants showed higher efficiency in updating the environment changes in advance anticipation than the closed-skilled and control participants. Secondly, both intensive experience of open- and closed-skilled training modulated the reactive control for task switching process, because the closed-skilled participants showed higher efficiency in updating the unpredictable environment changes in the imperative response than the control participants.