
Psychology ETDs
Publication Date
5-9-1968
Abstract
Implications that the hippocampus plays a major role in mediating behavior have been described by animal lesion and human clinical studies. The exact function of this structure is, however, in dispute. This is particularly true with regard to orienting, learning and decision making as reflected by electrical activity (theta) recorded from this structure. Contrary evidence concerning these functions has been obtained by Grastyán, Adey and their associates. In the present research, three task variables which may have accounted for their different findings were examined. These methodological variations included the modality of the stimuli presented to the animal, the presence of an alerting signal and whether the rewarded and unrewarded stimuli were presented successively or simultaneously. Varying the modality of the positive stimulus and whether the rewarded and unrewarded stimuli were presented successively or simultaneously did not have a differential effect on the electrical activity of the hippocampus and adjacent entorhinal cortex. In a simple task, which required an approach to the reward after presentation of a signal, theta appeared only when the animal made orienting types of responses. In a stimulus discrimination task, where the animals were rewarded for pressing a paddle during periods when the positive stimulus was on, theta was elicited by the onset of a buzzer which preceded the positive stimulus. Extensive theta was also recorded between incorrect responses. The development of this EEG response correlated with acquisition of the stimulus discrimination task as measured by the animal's ability to withhold responses when the positive stimulus was off. The results implied that hippocampal theta activity may reflect the role of this structure in inhibiting a previously reinforced response. The present research also indicated that although Adey's findings suggest the hippocampus plays a general role in information processing and memory consolidation as reflected by theta activity, some of his findings probably reflect the role of the hippocampus in mediating complex orienting types of responses.
Degree Name
Psychology
Level of Degree
Doctoral
Department Name
Psychology
First Committee Member (Chair)
John Marshall Rhodes
Second Committee Member
Marvin LeRoy Riedesel
Third Committee Member
Henry Carleton Ellis
Fourth Committee Member
David Wilmot Bessemer
Fifth Committee Member
Frank Anderson Logan, Sixth Committee Member: Sidney Rosenblum
Language
English
Document Type
Dissertation
Recommended Citation
Bennett, Thomas LeRoy Jr.. "Hippocampal EEG Correlates of Behavior." (1968). https://digitalrepository.unm.edu/psy_etds/482