Inter- and intraocular transfer of colour discriminations with mandibulation as an operant in the head-fixed pigeon

Abstract

Lower mandible abduction of pigeons was instrumentally conditioned with water<br />as reinforcer. The subjects were restrained and their head was held fixed. The<br />response was sensed with a piezoelectric transducer. High rates of responding could be obtained using variable ratio reinforcement schedules. Differential stimulus control with coloured lights presented in the frontal and lateral field of view was demonstrated. Interocular transfer of these visual discriminations was good when the stimuli were presented frontally and poor when they were presented laterally. Intraocular discrimination transfer, where the stimuli were shifted from a frontal to a lateral position and vice-versa within the field of view of the same eye, was poor. No evidence of a functional hemispheric lateralization was found. The method is considered useful for studies demanding precise stimulus positioning and requiring acute access to central nervous structures while learning is in progress.