Brain mechanisms associated with single and dual-tasks during locomotion

Numerous studies have examined behavioural outcomes, such as task completion time and/or errors made, when we execute a single task (e.g. locomotion) or a dual task (e.g., locomotion whilst conducting a cognitive task). Yet few studies have examined the underlying neural mechanisms which can potentially explain behavioural differences in the execution of single and dual tasks. With neural drive by the central nervous system controlling movement, any impairment in these processes may result in a variety of performance decrements including suboptimal dual-task performance. This study examined brain activity while individuals performed a locomotor (single) task or locomotor task and cognitive (dual) task Method: We developed a novel approach to examine the relationship between behavioural and mechanistic measures of single and dual-task performance by recording both EEG and eye tracking in healthy young (18 - 35 years) participants. In the single task condition participants walked around a grid-based track performing left and right hand turns at each T-junction in response to either a low (1000 Hz) or high (2000 Hz) auditory command tone. In the dual-task condition participants performed the same primary task while at the same time performing a memory task (remembering a shopping list). Results: Preliminary results indicate a trend in the event-related potential P3 recorded at both Cz and CPz, towards both an increase in P3 amplitude (d = 1.32 and 0.67 respectively) and decrease in latency (d = 0.42 and 0.53 respectively) in the dual compared to the single-task condition. Conclusion: We suggest that the increase in amplitude and decrease in latency may indicate an increase in motor network coherence (functional connectivity) resulting in improved performance as observed in previous research during dual-task performance and/or that a more efficient allocation of attentional resources occurs to perform a more complex and attention demanding task