Understanding the central processing limit in consistent-mapping visual search tasks.
Effects of load (i.e., the number of stimuli in the display) have been observed in multiple-frame studies using a consistent mapping of stimuli to responses (e.g., Fisher, 1982, 1984). In a series of four experiments, it is shown that these effects are not the consequence of differences across the high- and low-load conditions in either decision noise or peripheral masking. Additionally, it is shown that of two modes of limited capacity (a limited-channel and divided-capacity model) considered as possible explanations of load effects in tasks where subjects are required to locate a target, only one--the limited-channel model--is consistent with the results from all three location tasks. Finally, it is argued that the limited-channel model predicts not only the behavior observed in the four consistent-mapping experiments reported in this article but also the behavior observed in several related consistent-mapping tasks (Kleiss & Lane, 1986; Shiffrin & Gardner, 1972).
Fisher
D L
DL
College of Engineering, University of Massachusetts, Amherst 01003.
Duffy
S A
SA
Young
C
C
Pollatsek
A
A
D001288:Attention; D004193:Discrimination Learning; D005556:Form Perception; D006801:Humans; D010364:Pattern Recognition, Visual; D010470:Perceptual Masking; D014794:Visual Fields