Resistance to extinction after schedules of partial delay or partial reinforcement in rats with hippocampal lesions.

Two experimental procedures were employed to establish the reason why hippocampal lesions apparently block the development of tolerance for aversive events in partial reinforcement experiments, but do not do so in partial punishment experiments. Rats were trained to run in a straight alley following...

Full description

Bibliographic Details
Main Authors: Rawlins, J, Feldon, J, Ursin, H, Gray, J
Format: Journal article
Language:English
Published: 1985
_version_ 1797081824136003584
author Rawlins, J
Feldon, J
Ursin, H
Gray, J
author_facet Rawlins, J
Feldon, J
Ursin, H
Gray, J
author_sort Rawlins, J
collection OXFORD
description Two experimental procedures were employed to establish the reason why hippocampal lesions apparently block the development of tolerance for aversive events in partial reinforcement experiments, but do not do so in partial punishment experiments. Rats were trained to run in a straight alley following hippocampal lesions (HC), cortical control lesions (CC) or sham operations (SO), and resistance to extinction was assessed following differing acquisition conditions. In Experiment 1 a 4-8 min inter-trial interval (ITI) was used. Either every acquisition trial was rewarded immediately (Continuous Reinforcement, CR), or only a randomly selected half of the trials were immediately rewarded, the reward being delayed for thirty seconds on the other trials (Partial Delay, PD). This delay procedure produced increased resistance to extinction in rats in all lesion groups. In Experiment 2 the ITI was reduced to a few seconds, and rats were trained either on a CR schedule, or on a schedule in which only half the trials were rewarded (Partial Reinforcement, PR). This form of partial reinforcement procedure also produced increased resistance to extinction in rats in all lesion groups. It thus appears that hippocampal lesions only prevent the development of resistance to aversive events when the interval between aversive and subsequent appetitive events exceeds some minimum value.
first_indexed 2024-03-07T01:19:29Z
format Journal article
id oxford-uuid:8fdb9113-614a-458e-b2d8-bc97c19dc373
institution University of Oxford
language English
last_indexed 2024-03-07T01:19:29Z
publishDate 1985
record_format dspace
spelling oxford-uuid:8fdb9113-614a-458e-b2d8-bc97c19dc3732022-03-26T23:07:18ZResistance to extinction after schedules of partial delay or partial reinforcement in rats with hippocampal lesions.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:8fdb9113-614a-458e-b2d8-bc97c19dc373EnglishSymplectic Elements at Oxford1985Rawlins, JFeldon, JUrsin, HGray, JTwo experimental procedures were employed to establish the reason why hippocampal lesions apparently block the development of tolerance for aversive events in partial reinforcement experiments, but do not do so in partial punishment experiments. Rats were trained to run in a straight alley following hippocampal lesions (HC), cortical control lesions (CC) or sham operations (SO), and resistance to extinction was assessed following differing acquisition conditions. In Experiment 1 a 4-8 min inter-trial interval (ITI) was used. Either every acquisition trial was rewarded immediately (Continuous Reinforcement, CR), or only a randomly selected half of the trials were immediately rewarded, the reward being delayed for thirty seconds on the other trials (Partial Delay, PD). This delay procedure produced increased resistance to extinction in rats in all lesion groups. In Experiment 2 the ITI was reduced to a few seconds, and rats were trained either on a CR schedule, or on a schedule in which only half the trials were rewarded (Partial Reinforcement, PR). This form of partial reinforcement procedure also produced increased resistance to extinction in rats in all lesion groups. It thus appears that hippocampal lesions only prevent the development of resistance to aversive events when the interval between aversive and subsequent appetitive events exceeds some minimum value.
spellingShingle Rawlins, J
Feldon, J
Ursin, H
Gray, J
Resistance to extinction after schedules of partial delay or partial reinforcement in rats with hippocampal lesions.
title Resistance to extinction after schedules of partial delay or partial reinforcement in rats with hippocampal lesions.
title_full Resistance to extinction after schedules of partial delay or partial reinforcement in rats with hippocampal lesions.
title_fullStr Resistance to extinction after schedules of partial delay or partial reinforcement in rats with hippocampal lesions.
title_full_unstemmed Resistance to extinction after schedules of partial delay or partial reinforcement in rats with hippocampal lesions.
title_short Resistance to extinction after schedules of partial delay or partial reinforcement in rats with hippocampal lesions.
title_sort resistance to extinction after schedules of partial delay or partial reinforcement in rats with hippocampal lesions
work_keys_str_mv AT rawlinsj resistancetoextinctionafterschedulesofpartialdelayorpartialreinforcementinratswithhippocampallesions
AT feldonj resistancetoextinctionafterschedulesofpartialdelayorpartialreinforcementinratswithhippocampallesions
AT ursinh resistancetoextinctionafterschedulesofpartialdelayorpartialreinforcementinratswithhippocampallesions
AT grayj resistancetoextinctionafterschedulesofpartialdelayorpartialreinforcementinratswithhippocampallesions