According to A.H.C. Van der Heijden (1992), attentional
selection of visual stimuli can be considered as location
selection. Depending on the type of task, location selection
can be considered to be automatic (e.g., in case of abrupt
onsets), directly controlled (e.g., in case of symbolic
precues), or indirectly controlled (e.g., in case of visual
search). In tasks with symbolic precues a contralateral
enhancement of the P1 event-related potential (ERP) component
has been found, whereas in visual search tasks a contralateral
enhancement of the N2 component has been found. We hypothesized
that both lateralized effects reflect the influence of
location selection, which differs only in its moment of
activation. Linear arrays (a target among five distractors,
presented at two eccentricities) requiring left or right
responses, were preceded by cues indicating either the
precise target location or the side of
the target, or by bilateral cues that indicated all
array positions. Array-evoked ERPs, corrected for cue-evoked
and interactive effects, showed not only lateralized but
also target location-specific effects for both components,
which supports the view that, depending on the type of
task, either the P1 or the N2 component reflect the influence
of location selection.