Luminance-increment detection: Capacity-limited or not?

Abstract

Three experiments investigated whether spatial cuing influences luminance-increment detection accuracy. Ss saw multiple-target displays and responded yes or no to 4 locations, including cued position. To test whether cuing effects are due to the load on visual short-term memory from the number of locations, Experiments 1 and 2 presented displays with 4 or 8 relevant locations. Experiment 1 used peripheral cues; Experiment 2 used central cues. Significant cuing effects were less marked with 4- than 8-location displays. Cuing effects were largest with multiple targets, but a small reliable effect remained even with single targets. Experiment 3 replicated the single-target effect with predominantly multiple- and single-target displays. A capacity-limited selection account is developed for these findings and their implications are discussed for separate central and peripheral cuing mechanisms and the locus of spatial cuing effects.

Spatial distribution of visual attention: Perceptual sensitivity and response latency

“…A posttarget mask also served as a probe to indicate the location at which a targetpresent/absent decision had to be made. This paradigm was similar to that used by both Downing (1988) and Muller & Humphreys (1991), with modifications to avoid possible confounds related to target localization, memory decay, and preferential maintenance/rehearsal of cued location information (Hawkins et al, 1990;Luck et aI., 1994). RT and A' were measured for target detections at each spatial location in all possible combinations of attended and unattended conditions.…”

“…Using methodology similar to Downing's (1988), Muller and Humphreys (1991) measured both d' and peA) in a luminance-increment detection task with fourand eight-location circular displays. Although the primary focus of their study was to investigate whether spatial cuing influenced perceptual sensitivity, they also addressed the gradient issue.…”

“…Although RT and SD measures may, in fact, index different aspects of attention-related processing, thereby offering an explanation for the differences between RT and SD gradients, some recently formulated methodological concerns raise doubts about the accuracy of the attentional distributions in Downing's (1988) and Muller & Humphreys's (1991) studies. Specifically, Hawkins et al (1990) pointed out two problems relevant to the methodology of both studies.…”

“…We also thank Steve Luck, Jon Hansen, and ClifKussmaul for their assistance, and to Art Kramer, Hermann Miiller, and two anonymous reviewers for helpful comments on an early version of this manuscript. The data from Experiment I were originally presented at the inaugural meeting of the Cognitive Neuroscience Society, San Francisco, March, 1994. opposed to unattended locations (e.g., Bashinski & Bacharach, 1980;Downing, 1988;Hawkins et al, 1990;Heinze & Mangun, 1995;Luck et al, 1994;Mangun & Hillyard, 1988;Muller & Humphreys, 1991).…”

“…opposed to unattended locations (e.g., Bashinski & Bacharach, 1980;Downing, 1988;Hawkins et al, 1990;Heinze & Mangun, 1995;Luck et al, 1994;Mangun & Hillyard, 1988;Muller & Humphreys, 1991).…”