Long-Term Effects of Concussions on Psychomotor Speed and Cognitive Control Processes During Motor Sequence Learning

Abstract

Abstract. In asymptomatic multiple-concussion athletes, studies evidenced long-term impairments in psychomotor speed, motor sequence learning, and cognitive control processes, as indexed by the Error Negativity (Ne), also commonly referred to as the Error-related Negativity (ERN). In healthy controls, motor sequence learning during a Serial Reaction Time (SRT) task is associated with an increase in Ne/ERN amplitude. The objective of this paper is to investigate whether concussion effects on cognitive control are associated with sequence learning changes in asymptomatic multi-concussion athletes. Thirty-seven athletes (18 nonconcussed; 19 concussed) completed a SRT task during which continuous electroencephalographic (EEG) activity was recorded. Ne/ERN amplitude modulation from early to late learning blocks of the task was measured. Median reaction times (RTs) were computed to assess psychomotor speed and motor sequence learning. Psychomotor speed was significantly reduced in concussed athletes. Accentuated Ne/ERN amplitude from early to late learning blocks significantly correlated with motor sequence learning in nonconcussed athletes. In contrast, Ne/ERN amplitude was found to decrease significantly with task progression in concussed athletes who nonetheless achieved normal motor sequence learning. Multiple concussions detrimentally affect psychomotor speed. Unlike nonconcussed athletes, motor sequence learning in multi-concussion athletes was not associated with Ne/ERN amplitude modulation, indicating that cognitive control processes do not centrally contribute to learning of a motor sequence after repeated concussions.