Patricia Xi

Pigeons can learn structured sequences of cued responses and perform them quickly, even when random variability is later introduced into the originally learned sequence, making some cue locations unpredictable. In order to determine if initial learning shows the same tolerance of spatial variability as steady-state performance, naïve pigeons were trained on random distortions around a structured sequence without having seen the original sequence itself. Learning was possible, but accommodated less variability than did performance of the same sequence previously learned in an undistorted context. Analysis of results indicated that performance of a randomly distorted sequence is best when birds are initially trained with little or no variability, and randomness is later introduced in a gradual fashion.

Change blindness is a phenomenon in which even obvious details in a visual scene change without being noticed. Although change blindness has been studied extensively in humans, we do not yet know if it is a phenomenon that also occurs in other animals. Thus, investigation of change blindness in a nonhuman species may prove to be valuable by beginning to provide some insight into its ultimate causes. Pigeons learned a change detection task in which pecks to the location of a change in a sequence of stimulus displays were reinforced. They were worse at detecting changes if the stimulus displays were separated by a brief interstimulus interval, during which the display was blank, and this primary result matches the general pattern seen in previous studies of change blindness in humans. A second experiment attempted to identify specific stimulus characteristics that most reliably produced a failure to detect changes. Change detection was more difficult when interstimulus intervals were ...