Search PubMed⌕ Search

Biomedical subjects

E M Macphail

Publications and source records attributed to E M Macphail.

25 records · Page 2Linked to original sources

Hyperstriatal function in the pigeon: response inhibition or response shift?

Experiment 1 showed that pigeons with lesions of the anterior or posterior hyperstriatum were impaired relative to unoperated controls and to control operates having neostriatal lesions on both acquisition and reversal of a simultaneous position discrimination. The observation that hyperstriatal birds showed more tendency than controls to halt responding altogether in this situation cast doubt on the notion that the reversal deficit was due to a loss of response inhibition. A second experiment supported an alternative hypothesis, that hyperstriatal birds have a deficit in the ability to shift responding to an alternative stimulus as a consequence of nonreinforcement.

Animals↗

Avoidance responding in pigeons.

Four pigeons were trained in a one-way shuttle box avoidance situation. Three of the birds met the criterion of 90% avoidances; the fourth, although frequently avoiding successfully, was too erratic to meet the criterion. Avoidance responding in two of the birds was subsequently extinguished, showing that the response was true avoidance, and not escape from the buzzer warning stimulus. In Experiment 2, the three birds that had met criterion in Experiment 1 were trained in a two-way avoidance task, and all three met the criterion of 90% avoidances. The shuttle box therefore provides a rapid and reliable method of obtaining avoidance performance in pigeons.

Animals↗