Lateralization reversal after intertectal commissurotomy in the pigeon.

After transection of the intertectal commissures, the lateralization of a visually controlled behaviour of pigeons was reversed to a degree proportional to the extent of the commissurotomy. Preoperatively, the pigeons produced higher pecking rates in a successive pattern discrimination task when seeing with the right eye. Postoperatively, this lateralization reversed to show a superiority with the left eye. Visual lateralization may depend on an asymmetrical intertectal interaction.