Effect of attention division on movement detection and execution in dual-task conditions

Dual tasking refers to the simultaneous execution of two tasks with different demands. In this study, we aimed to investigate the effect of a second task on a main task of motor execution and on the ability to detect the cortical potential related to the main task from non-invasive electroencephalographic (EEG). Participants were asked to perform a series of cue-based ankle dorsiflexions as the primary task (single task level). In some experimental runs, in addition to the primary task they concurrently attended an auditory oddball paradigm consisting of three tones while they were asked to count the number of sequences of special tones (dual task level). EEG signals were recorded from nine channels centered on Cz. Analysis of event-related potential (ERP) signals from Cz confirmed that the oddball task decreased the attention to the ankle dorsiflexion significantly. Furthermore, movement-related cortical potential (MRCP) analysis revealed that the amplitude of the MRCP and pre-movement slopes were changed significantly. These variations were significantly greater for the EEG channels corresponding to the motor cortex and the frontal-central cortex.