ERPs associated with visual duration discriminations in prefrontal and parietal cortex

An event-related potentials (ERP) study was undertaken to examine the role of prefrontal and parietal association cortices on selective attention and short-term memory functions in a duration discrimination task. Subjects performed better when discriminating the first stimulus relative to the second and not the reverse. Two contingent negative variations (CNV) were obtained for each stimulus duration at prefrontal regions, as well as two P300s at parietal regions. The CNVS1 component recorded during the first stimulus (S1) appeared to be involved in selective attention at bilateral sites, while the P300S1 component in the left hemisphere may be implicated in retaining it. The CNVS2 wave, displayed during the second stimulus (S2), at bilateral sites and the right-sided P300S2 wave seem to be implicated in working memory. The results indicate that recorded activity at prefrontal and parietal association cortices is tightly linked to task parameters and behavioral performances.