EFFECTS OF THE NUMBER AND FORM OF STIMULI ON VISUAL-SEARCH IN THE PIGEON

Three White Carneaux pigeons' pecks at small luminous forms on a large display field were photoelectrically recorded. Pecks to target (positive stimulus) forms were reinforced with food; pecks to distractor (negative stimulus) forms produced a short time-out. The speed and accuracy of search for a target declined as the number of distractors increased to a maximum of 15. Search was further impaired when the distractors were quite similar to the target. However, search was unaffected by a change in the number of potential targets (memory set size) from 1 to 2, nor was it clearly affected by the use of several different distractor forms instead of a single repeated form. Search was swift over a large (50|) visual field, in the apparent absence of substantial head and eye movements. (20 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1979 American Psychological Association.