UNCONDITIONAL DISCRIMINATION AS A PARADIGM FOR INVESTIGATING VISUAL PROCESSING IN THE AVIAN BRAIN-STEM

Visual discrimination between colors and patterns was studied in telen cephalectomized chicks of Japanese quail lines that were artificially selected for early approach preferences for particular colors and patt erns. Since these preferences are not conditional on prior learning, t hey provide an effective experimental paradigm to study visual discrim ination without reliance an acquired stimulus discrimination. The data indicate that the quail's brainstem-thalamus complex is sufficient fo r relatively fine discriminations between various colors and achromati c patterns.