| Abstract: | Two experiments examined the effects of chamber illumination during the intertrial interval (ITI) of delayed matching-to-sample by 8 White Carneaux pigeons. Exp I demonstrated that accurate choice of the matching stimulus was disrupted by illumination at long ITIs but not short ITIs. This effect was obtained regardless of the ITI illumination condition during training. The disruption produced by long illuminated ITIs was constant across delay intervals. A strong direct linear relationship between matching accuracy and the log ITI/delay ratio was obtained when the ITI was dark but not when it was illuminated. In Exp II, ITI illumination was more disruptive when it occurred at the end rather than at the beginning of the ITI. Results support the view that trial spacing effects are not due to competing memories from previous trials. A change in ITI illumination may disrupt encoding of the sample stimulus and offset the beneficial effects of trial spacing. (French abstract) (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
