Effects of spatial cuing on luminance detectability: psychophysical and electrophysiological evidence for early selection.
Three experiments were conducted to determine whether attention-related changes in luminance detectability reflect a modulation of early sensory processing. Experiments 1 and 2 used peripheral cues to direct attention and found substantial effects of cue validity on target detectability; these effects were consistent with a sensory-level locus of selection but not with certain memory- or decision-level mechanisms. In Experiment 3, event-related brain potentials were recorded in a similar paradigm using central cues, and attention was found to produce changes in sensory-evoked brain activity beginning within the 1st 100 ms of stimulus processing. These changes included both an enhancement of sensory responses to attended stimuli and a suppression of sensory responses to unattended stimuli; the enhancement and suppression effects were isolated to different neural responses, indicating that they may arise from independent attentional mechanisms.
Luck
S J
SJ
Department of Neurosciences, University of California, La Jolla 92093-0608.
Hillyard
S A
SA
Mouloua
M
M
Woldorff
M G
MG
Clark
V P
VP
Hawkins
H L
HL
D000293:Adolescent; D000328:Adult; D001288:Attention; D001921:Brain / Q000502:physiology; D002755:Choice Behavior; D004193:Discrimination Learning; D004569:Electroencephalography; D006801:Humans; D010470:Perceptual Masking; D013028:Space Perception; D013037:Spatial Behavior; D014796:Visual Perception