| Abstract: | Conducted 7 experiments with a total of 256 1-3 day old Vantress * Arbor Acre chicks to investigate the effects of interactions between the S and its sensory environment on both emergence of brightness preferences and modification by conditioning. In a simultaneous brightness discrimination, Ss were rewarded with heat for approaching either a bright or dim stimulus. Results indicate (a) brightness preference was so stable that it could not be eliminated by incubating, hatching, and rearing in the dark; (b) light experience significantly increased this preference; and (c) modification of this preference by heat reinforcement depended on age of S, prior rearing condition, sensory stimulation between testing sessions, and the length of interval between testing sessions. (28 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
