98 Event-related brain potentials in the study of visual selective attention

Event-related brain potentials in the study of visual selective attention
STEVEN A. HILLYARD* AND LOURDES ANLLO-VENTO

ABSTRACT Event-related brain potentials (ERPs) pro-vide
high-resolution measures of the time course of neuronal
activity patterns associated with perceptual and cognitive
processes. New techniques for ERP source analysis and com-parisons
with data from blood-flow neuroimaging studies
enable improved localization of cortical activity during visual
selective attention. ERP modulations during spatial attention
point toward a mechanism of gain control over information
f low in extrastriate visual cortical pathways, starting about 80
ms after stimulus onset. Paying attention to nonspatial fea-tures
such as color, motion, or shape is manifested by qual-itatively
different ERP patterns in multiple cortical areas that
begin with latencies of 100–150 ms. The processing of non-spatial
features seems to be contingent upon the prior selec-tion
of location, consistent with early selection theories of
attention and with the hypothesis that spatial attention is
‘‘special.’’