The effects of hippocampal-area parahippocampalis lesions on discrimination learning in the pigeon.
Three experiments examined the behavioural effects of bilateral ablation of the avian hippocampus-area parahippocampalis (Hp-APH), a region which is considered to be the homologue of the mammalian hippocampal formation. Pigeons with lesions of the Hp-APH were impaired in learning the reversal (but not the acquisition) of a position (left/right) discrimination (Expt. 1). In contrast, lesion birds were unimpaired relative to controls in both the acquisition and reversal of a visual (pattern) discrimination (Expt. 2) in terms of errors to criterion; there was evidence, however, that the pattern of responding differed between groups during reversal. Finally, Hp-APH pigeons were impaired in the acquisition of a conditional discrimination (Expt. 3). The results are compared with the effects of hippocampal ablation in mammals, and their implications for a behavioural homology between the avian Hp-APH and the mammalian hippocampal formation are considered.
Department of Psychology, University of York, Heslington, U.K.
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M
Good
D000818:Animals; D010856:Columbidae / Q000502:physiology*; D003213:Conditioning, Psychological / Q000502:physiology; D004193:Discrimination Learning / Q000502:physiology*; D006624:Hippocampus / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology; D012193:Reversal Learning / Q000502:physiology