Subtelencephalic visual discrimination in selected lines of Japanese quail.

We studied visual discrimination capabilities of the avian brain stem in genetic lines of Japanese quail artificially selected for unconditional approach preference for blue, red or an achromatic pattern stimulus. Complete telencephalectomy did not abolish approach behavior and visual discrimination. Our data indicate that visual feature extraction and motor coordination related to early approach preferences in birds may be mediated by brain stem and thalamic circuitries which do not require input from higher level visual and motor regions.