Some stages of information processing in a choice reaction-time task

Eight pigeons were tested for head nystagmus in a rotating drum with vertical black and white bars on the reside. When the birds viewed monocularly, they gave about four times as many responses to nasalward as to temporalward movement. However, no such asymmetry was observed in a discrimination paradigm. Six pigeons were taught binocularly to discriminate moving lines, which moved equally often to left and fight, from stationary fines. They were then tested monoculaxly, and the discrimination was controlled about equally by nasalward and temporalward movement.