Figure 1.

The attention paradigm used in this study. The visual and auditory trials started with cue stimuli of a given modality: a short diffuse flash behind the frontal wall or a white noise delivered from the frontal loudspeaker. In a given modality trial, the animal anticipated the target stimulus for 8–14 s, with no stimulation present until a small spot of light or white noise from the side loudspeaker was delivered. Two seconds later, the transparent screen was removed, and the cat was allowed to open the indicated door for a food reward. Visual trials (16–20) were randomly intermingled with auditory (16–20) trials. During the experiment, the cage was covered by a removable ceiling. See Materials and Methods for details.