TY - JOUR
T1 - Covert attention alters visual appearance
AU - Read, Sarah
AU - Ling, Sam
AU - Carrasco, Marisa
N1 - Copyright:
Copyright 2004 Elsevier B.V., All rights reserved.
PY - 2003
Y1 - 2003
N2 - Although it has long been established that covert spatial attention improves performance in a number of visual tasks, there is a long-standing debate as to whether attention actually alters appearance. When attention is allocated to a given location via a brief peripheral cue, contrast thresholds along the psychometric function are decreased for the target (Cameron, Tai & Carrasco, 2002). From such findings, it has been inferred that attention actually changes the appearance of an attended stimulus. In this study, we directly tested whether covert attention alters phenomenological appearance. Observers were presented with either a peripheral cue (a small circle flashed adjacent to the stimulus location to elicit transient covert attention) or a neutral cue (a small circle flashed at fixation) for 40 ms. Following a 60 ms ISI, two Gabor patches of either 2 or 6 cpd appeared for 100 ms at 4° eccentricity along the horizontal meridian. One of the Gabors was always presented at 6% contrast (Standard), and the other ranged from 1-12% in contrast (Test). The stimuli were tilted 45° to the left or right. Observers performed an orientation discrimination task for the Gabor that they perceived to be of higher contrast. We assessed appearance by determining which of the Gabor patches observers reported as appearing higher in contrast. Consistent with previous studies, our results show a threshold shift in orientation discrimination accuracy across the psychometric function with attention. The results indicate that attention decreases threshold in the psychometric function not only in contrast sensitivity, but also in appearance. Although suggested by past studies, these results show that visual attention alters the phenomenological appearance of an attended stimulus.
AB - Although it has long been established that covert spatial attention improves performance in a number of visual tasks, there is a long-standing debate as to whether attention actually alters appearance. When attention is allocated to a given location via a brief peripheral cue, contrast thresholds along the psychometric function are decreased for the target (Cameron, Tai & Carrasco, 2002). From such findings, it has been inferred that attention actually changes the appearance of an attended stimulus. In this study, we directly tested whether covert attention alters phenomenological appearance. Observers were presented with either a peripheral cue (a small circle flashed adjacent to the stimulus location to elicit transient covert attention) or a neutral cue (a small circle flashed at fixation) for 40 ms. Following a 60 ms ISI, two Gabor patches of either 2 or 6 cpd appeared for 100 ms at 4° eccentricity along the horizontal meridian. One of the Gabors was always presented at 6% contrast (Standard), and the other ranged from 1-12% in contrast (Test). The stimuli were tilted 45° to the left or right. Observers performed an orientation discrimination task for the Gabor that they perceived to be of higher contrast. We assessed appearance by determining which of the Gabor patches observers reported as appearing higher in contrast. Consistent with previous studies, our results show a threshold shift in orientation discrimination accuracy across the psychometric function with attention. The results indicate that attention decreases threshold in the psychometric function not only in contrast sensitivity, but also in appearance. Although suggested by past studies, these results show that visual attention alters the phenomenological appearance of an attended stimulus.
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U2 - 10.1167/3.9.329
DO - 10.1167/3.9.329
M3 - Article
AN - SCOPUS:4243176022
SN - 1534-7362
VL - 3
SP - 329a
JO - Journal of vision
JF - Journal of vision
IS - 9
ER -