Abstract
Identifying and locating a target can be difficult when uncertainty exists about what to look for or even where to look. Cognitive research in matching and classification tasks (Neely, 1977; Posner & Snyder, 1975) have shown that uncertainty is reduced both by semantic priming, which is fast-acting but decays rapidly, and by expectancy, which has a slower onset but persists much longer.
The current study extended their cognitive approach to a visual search paradigm in the perceptual-cognitive domain. We manipulated visual-relatedness between prime and target so that they were either identical (same) or different. We manipulated expectancy by varying the proportion of validly primed trials. The inter-stimulus interval (ISI) between offset of prime and onset of search display also was varied.
Our goals were two-fold: (a) Does visual priming affect a brief sensory store that decays rapidly (e.g., Sperling, 1960) or a longer-lasting store, such as a visuo-sketchpad (Baddeley, 1993) or visual-implicit memory (Schacter & Cooper, 1993)? (b) Do the onsets of expectancy and priming occur simultaneously or does one precede the other?
Twelve college-age subjects were tested and, at the beginning of the session, were informed of the prime's validity (20%, 50%, or 80%). They had to identify and locate the target within a brief visual search display of four objects.
Response accuracy data indicated that the effects of visual priming decayed very rapidly, implying a sensory store mechanism rather than a visuo-spatial sketchpad or visual implicit memory. Moreover, visual priming effects occurred before the onset of expectancy.
Supported by the National Science Foundation