Effects of Medial and Lateral Septal Lesions on the Partial Reinforcement Extinction Effect at One Trial a Day

1979 ◽  
Vol 31 (4) ◽  
pp. 653-674 ◽  
Author(s):  
J. Feldon ◽  
J. A. Gray
Keyword(s):  
Theta Rhythm ◽  
Food Reward ◽  
Straight Alley ◽  
Partial Reinforcement ◽  
Partial Reinforcement Extinction Effect ◽  
Resistance To Extinction ◽  
Double Dissociation ◽  
Electrolytic Lesions ◽  
Septal Lesions ◽  
Hippocampal Theta

Rats sustained electrolytic lesions of either the medial septal (MS) area (of a kind known to eliminate the hippocampal theta rhythm) or the dorso-lateral septal (LS) area (of a kind known to spare theta) or both (a “total septal”, TS, lesion). They were compared to sham-operated controls in three experiments in the straight alley with food reward on continuous (CRF) or partial (PRF) reinforcement at one trial a day. MS lesions either left the partial reinforcement extinction effect (PREE) unchanged or enhanced it; LS lesions substantially reduced the PREE. The latter effect was due to a fall in resistance to extinction in PRF animals with no change in CRF animals. MS lesions greatly increased resistance to extinction in both CRF and PRF animals in one experiment but increased resistance to extinction only marginally and only in PRF animals in a second experiment. The TS lesion acted like the LS lesion. These results demonstrate a clear double dissociation between the effects of MS and LS lesions, especially in the PRF condition (LS lesions reduce resistance to extinction, MS lesions increase it).

Effects of Medial and Lateral Septal Lesions on the Partial Reinforcement Extinction Effect at Short Inter-Trial Intervals

1979 ◽  
Vol 31 (4) ◽  
pp. 675-690 ◽  
Author(s):  
J. Feldon ◽  
J. A. Gray
Keyword(s):  
Theta Rhythm ◽  
Food Reward ◽  
Straight Alley ◽  
Partial Reinforcement ◽  
Partial Reinforcement Extinction Effect ◽  
Resistance To Extinction ◽  
Electrolytic Lesions ◽  
Medial Septal Area ◽  
Septal Lesions ◽  
Hippocampal Theta

Rats sustained electrolytic lesions either in the medial septal (MS) area (of a kind known to eliminate the hippocampal theta rhythm) or in the dorso-lateral septal (LS) area (of a kind known to spare theta) and were compared to sham-operated controls in three experiments in the straight alley with food reward on continuous (CRF) or partial (PRF) reinforcement and inter-trial intervals of 3-8 min. With 6 acquisition trials MS lesions increased resistance to extinction and enhanced the partial reinforcement extinction effect (PREE). With 48 acquisition trials MS lesions did not alter resistance to extinction after either CRF or PRF training, but LS lesions abolished the PREE by increasing resistance to extinction in rats trained with CRF and decreasing it in rats trained with PRF. With 96 acquisition trials LS lesions were without effect on resistance to extinction after either CRF or PRF training, as previously reported by Henke (1974) using total septal lesions. Thus the impairment in the PREE previously shown after large septal lesions is due to damage to the lateral, not the medial, septal area.

Resistance to Extinction as a Function of Reinforcement Schedule and Training Level: A Test of Theios and Brelsford's Theory

1978 ◽  
Vol 42 (3_suppl) ◽  
pp. 1091-1096 ◽  
Author(s):  
William N. Boyer ◽  
Henry A. Cross ◽  
David D. Avery
Keyword(s):  
Reinforcement Schedule ◽  
Incentive Motivation ◽  
Partial Reinforcement ◽  
Habit Strength ◽  
Training Level ◽  
Partial Reinforcement Extinction Effect ◽  
Resistance To Extinction ◽  
And Training

Two experiments were run in which one group of rats received 100% reward with 16 pellets per trial (100%-16), a second group received 50% reward with 16 pellets on rewarded trials (50%-16), and a third group got 50% reward with 32 pellets on rewarded trials (50%-32). From Theios and Brelsford's theory it was predicted that Group 50%-32 should show less resistance to extinction than Group 50%-16, since both were equated for habit strength but differed on incentive motivation. In Exp. 1 all groups had 32 acquisition trials whereas in Exp. 2 all groups had 64 acquisition trials. Aside from this difference the two experiments were identical. The partial reinforcement extinction effect occurred in both studies. In Exp. 1, Group 50%-32 did not show less resistance to extinction than Group 50%-16, however, in Exp. 2 this result was obtained and confirmed the prediction under test.

Effects of Partial Reinforcement on Speed of Approach Responses in Goldfish (Carassius Auratus)

1968 ◽  
Vol 22 (3) ◽  
pp. 741-744 ◽  
Author(s):  
John J. Boitano ◽  
Mary Day Foskett
Keyword(s):  
Partial Reinforcement Effect ◽  
Carassius Auratus ◽  
Straight Alley ◽  
Partial Reinforcement ◽  
Relative Influence ◽  
Distributed Practice ◽  
Reinforcement Effect ◽  
Resistance To Extinction ◽  
Goldfish Carassius Auratus

Under widely distributed practice in a straight alley, partially reinforced goldfish did not exhibit greater resistance to extinction than consistently reinforced animals. The relative influence of equating trials or reinforcements in generating the partial reinforcement effect could not be evaluated since the partially reinforced Ss were significantly less resistant than either the equated-reinforcement Ss or the equated-trials Ss.

Inhibition Effects with Abbreviated Training

1968 ◽  
Vol 23 (3_suppl) ◽  
pp. 1099-1103 ◽  
Author(s):  
James E. Spivey ◽  
David T. Hess ◽  
Diane Black
Keyword(s):  
Straight Alley ◽  
Partial Reinforcement ◽  
Albino Rats ◽  
Partial Reinforcement Extinction Effect

In an experiment in which 3 groups of albino rats were given abbreviated training in a straight alley runway, both the partial reinforcement extinction effect (PRE) and its opposite, a “reversed PRE,” were obtained.

Septal Driving of the Hippocampal Theta Rhythm Produces a Long-Term, Proactive and Non-Associative Increase in Resistance to Extinction

1983 ◽  
Vol 35 (2b) ◽  
pp. 97-118 ◽  
Author(s):  
Lee Holt ◽  
Jeffrey A. Gray
Keyword(s):  
Theta Rhythm ◽  
Fixed Ratio ◽  
Treatment Phase ◽  
Food Delivery ◽  
Subsequent Performance ◽  
Hippocampal Theta Rhythm ◽  
Resistance To Extinction ◽  
Treatment Conditions ◽  
Cast Doubt ◽  
Hippocampal Theta

Previous experiments employing electrical or pharmacological induction, or instrumental reinforcement, of hippocampal theta rhythm in rats have reported subsequent performance changes in a number of learning situations. In all these studies theta induction took place either concurrent with or following the behaviour under investigation. In the present two experiments, a treatment phase of electrically-induced hippocampal theta (by septal stimulation at 7·7 Hz) preceded acquisition of a discrete trial, barpress response on a fixed ratio 5 reinforcement schedule. In one of three treatment conditions animals received electrical stimulation (1) on its own, or (2) in a classical conditioning relationship with food delivery as unconditioned stimulus, or (3) temporally uncorrelated with food delivery; controls were implanted with electrodes but not stimulated. After 15 days’ acquisition of barpressing, all animals were extinguished over the subsequent 12 days. Results indicated that theta-driving stimulation, independent of any association with food, resulted in increased resistance to extinction of barpressing. In addition, conditions (1) and (3) enhanced the speed of response during early acquisition. These findings cast doubt on a “memory consolidation” hypothesis of hippocampal theta function and demonstrate a non-associative, long-lasting, proactive effect of theta induction on behaviour.

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