Effects of hippocampal lesions on spatial operant discrimination in pigeons

In experiment 1, pigeons were trained on spatial or color autodiscrimination. Presentation of one of two keys or one of two colors was followed by food presentation. However, the other side of the keys or the other color was not. The hippocampal lesions disturbed the acquisition of spatial discrimination but not of color discrimination. In experiment 2, pigeons were preoperatively trained the spatial autodiscrimination, then received the hippocampal lesions. The subjects maintained the discrimination. These results suggest that the avian hippocampus plays a crucial role in acquisition of spatial discrimination.