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DORSAL HIPPOCAMPAL LESIONS AND REWARD MAGNITUDE SHIFTS IN RATS

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Date Issued:
1973
Summary:
Rats with bilateral, electrolytic, dorsal-hippocampal lesions were compared with operated controls in a straight runway to assess the effects of the lesion on the animals' reactions to food-incentive shifts. Within each surgical group, half the animals received 40 preshift trials with low reward while the other half received the same number of trials with high reward, following this all Ss were shifted to the opposite reward magnitude and received 40 additional trials. At this point, the Ss were shifted back to original reward magnitudes for another 40 trials. Finally, all Ss underwent experimental extinction. The data failed to support the hypothesis that dorsal hippocampal rats "overreact" to incentive shifts. Lesion animals, as compared to controls, were less sensitive to the reward shifts and showed more resistance to extinction. The results suggest that the lesion produces a deficit in the Ss ability to vary behavior specially on tasks that require response decrements. However, the lesion-produced hyperactivity introduced confounding aspects to this interpretation.
Title: DORSAL HIPPOCAMPAL LESIONS AND REWARD MAGNITUDE SHIFTS IN RATS.
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Name(s): NUNEZ, ANTONIO ALBERTO.
Florida Atlantic University, Degree grantor
Type of Resource: text
Genre: Electronic Thesis Or Dissertation
Issuance: monographic
Date Issued: 1973
Publisher: Florida Atlantic University
Place of Publication: Boca Raton, Fla.
Physical Form: application/pdf
Extent: 83 p.
Language(s): English
Summary: Rats with bilateral, electrolytic, dorsal-hippocampal lesions were compared with operated controls in a straight runway to assess the effects of the lesion on the animals' reactions to food-incentive shifts. Within each surgical group, half the animals received 40 preshift trials with low reward while the other half received the same number of trials with high reward, following this all Ss were shifted to the opposite reward magnitude and received 40 additional trials. At this point, the Ss were shifted back to original reward magnitudes for another 40 trials. Finally, all Ss underwent experimental extinction. The data failed to support the hypothesis that dorsal hippocampal rats "overreact" to incentive shifts. Lesion animals, as compared to controls, were less sensitive to the reward shifts and showed more resistance to extinction. The results suggest that the lesion produces a deficit in the Ss ability to vary behavior specially on tasks that require response decrements. However, the lesion-produced hyperactivity introduced confounding aspects to this interpretation.
Identifier: 13539 (digitool), FADT13539 (IID), fau:10383 (fedora)
Note(s): Thesis (M.A.)--Florida Atlantic University, 1973.
Charles E. Schmidt College of Science
Subject(s): Hippocampus (Brain)
Extinction (Psychology)
Reward (Psychology)
Held by: Florida Atlantic University Libraries
Persistent Link to This Record: http://purl.flvc.org/fcla/dt/13539
Sublocation: Digital Library
Use and Reproduction: Copyright © is held by the author with permission granted to Florida Atlantic University to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
Use and Reproduction: http://rightsstatements.org/vocab/InC/1.0/
Host Institution: FAU
Is Part of Series: Florida Atlantic University Digital Library Collections.