Event-Related Potential Elicited in Response to A Colour-Word Stroop Task in Young, Middle-Aged and Old Participants

Abstract

Electroencephalography (EEG) was used to record the brain electrical activity in healthy participants (Young, middle-aged, and old) who were carrying out a Stroop task, with the aim of studying the neurofunctional changes associated with processing stimuli and responses in healthy aging. The EEG data were subsequently processed to obtain the Event-Related Potentials (ERPs). Reaction Times (RT) and number of hits were also obtained. The RTs were longer in the old and middle-aged participants than in the young participants, and the middle-aged participants made more hits in response to incongruent stimuli than the old participants. The N2, P3b and LRP-S latencies and the time between the onset latency of LRP-R and the TR increased with age. Thus, the older and middle-aged participants processed the information more slowly that the young participants, and the slowing affected the evaluation and classification of the stimuli and the initiation and duration of the motor activity associated with the response. The frontal P3b amplitude was larger in middle-aged and old than in young participants, increasing towards posterior regions only in the young group. The central LRP-S and LRP-R amplitudes were larger in the old and middle-aged than in the young participants, which may indicate greater frontal recruitment for processing the stimuli and the responses from middle-age onwards.