| Abstract: | Electrocortical recordings were made from monkeys performing in a multidimensional visual task. Wave forms dependent on the stimulus presented (irrespective of task required) were recorded immediately following the stimulus primarily from electrodes implanted in the striate and prestriate cortex. Wave forms dependent on the panel pressed (irrespective of the stimulus or of the task) were recorded especially from motor and post-central cortex, and to a lesser extent in anterior frontal cortex, always just prior to or following the time of the response. Wave forms dependent on the task as determined by the reinforcing contingencies (but independent of the particular stimulus presented or the particular panel pressed) were recorded primarily from the inferior temporal cortex, and rarely from prestriate and anterior frontal cortex. While task-related wave forms began to appear shortly after stimulus presentation, they became especially apparent around the time of the response. This response-linking increased in prominence as the subject achieved 90% proficiency in each task, only to drop off with overtraining. Further, the task-related wave form does not change as rapidly as does overt behavior when the reinforcement contingency is shifted from one stimulus dimension to another. The relevance of these results to an understanding of the process of selective attention is discussed. |
