Changes in corticospinal drive to spinal motoneurones following tablet-based practice of manual dexterity

Abstract

The use of touch screens, which require a high level of manual dexterity, has exploded since the development of smartphone and tablet technology. Manual dexterity relies on effective corticospinal control of finger muscles, and we therefore hypothesized that corticospinal drive to finger muscles can be optimized by tablet‐based motor practice. To investigate this, sixteen able‐bodied females practiced a tablet‐based game (3 × 10 min) with their nondominant hand requiring incrementally fast and precise pinching movements involving the thumb and index fingers. The study was designed as a semirandomized crossover study where the participants attended one practice‐ and one control session. Before and after each session electrophysiological recordings were obtained during three blocks of 50 precision pinch movements in a standardized setup resembling the practiced task. Data recorded during movements included electroencephalographic (EEG) activity from primary motor cortex and electromyographic (EMG) activity from first dorsal interosseous (FDI) and abductor pollicis brevis (APB) muscles. Changes in the corticospinal drive were evaluated from coupling in the frequency domain (coherence) between EEG–EMG and EMG–EMG activity. Following motor practice performance improved significantly and a significant increase in EEG‐EMGAPB and EMGAPB‐EMGFDI coherence in the beta band (15–30 Hz) was observed. No changes were observed after the control session. Our results show that tablet‐based motor practice is associated with changes in the common corticospinal drive to spinal motoneurons involved in manual dexterity. Tablet‐based motor practice may be a motivating training tool for stroke patients who struggle with loss of dexterity.

Corticomuscular coherence in the acute and subacute phase after stroke

“…It may therefore be that the changes in performance that we observed are primarily related to recovery of muscle strength rather than improved muscle coordination. This would be consistent with the increase in MVC and it might also provide a possible explanation why we observed no change in CMC from T1 to T2, since changes in CMC have mainly been observed in other studies in relation to improvements in coordination (Larsen et al , 2016).…”

“…motor training (Kristeva-Feige et al , 2002, Perez et al , 2006. Studies investigating CMC following a single bout of training in healthy participants have demonstrated that CMC is enhanced shortly after training and return to baseline within minutes despite maintained motor performance abilities (Perez et al , 2006, Geertsen et al , 2013, Larsen et al , 2016. Hence, we speculate that CMC may contribute to recovery by helping preserve and strengthen newly formed projections in a time-dependent manner.…”

Impaired corticomuscular and interhemispheric cortical beta oscillation coupling in amyotrophic lateral sclerosis

“…Periods of elevated beta synchrony have been associated with prolonged reaction time latencies (Gilbertson et al, 2005;Matsuya et al, 2013) and beta CMC reliably dissipates with movement. Reduced CMC might therefore result from ALS patients' disproportional need to mentally prepare for the upcoming movement, ostensibly in keeping with subjectively greater task difficulty since task practice has been shown to result in higher levels of beta CMC (Larsen et al, 2016). Relative CMC lateralisation in the ALS group might simultaneously have been compromised by dysfunction of interhemispheric communication (Karandreas et al, 2007).…”

Influence of dual-task on postexercise facilitation: a transcranial magnetic stimulation study

“…Another possible hypothesis indicates that PEF of the corticospinal system might be linked either to the higher level of arousal and changes in neurotransmitters induced by the exercise ( Tomporowski, 2003 ) or to feedback and feed-forward activation of sensory afferents and spinal neurons ( Jain et al, 2013 ; Ludyga et al, 2016 ). Therefore, it is likely that PEF of MEPs, postexercise cortical changes in β-band oscillations ( Witham and Baker, 2007 ) and corticomuscular coherence ( Larsen et al, 2016 ) represent temporary corticospinal plastic changes that have positive effects on subsequent task performance. Based on previous work it is conceivable that the higher attentional demands of a DT would have negative effect of exercise-induced sensorymotor plasticity ( Rosenkranz and Rothwell, 2006 ).…”