Role of the amygdala in the reinforcement omission effect.

José Lino De Oliveira Bueno,Danielle Marcilio Judice-Daher,Tatiane Ferreira Tavares

doi:10.3922/j.psns.2012.2.18

José Lino De Oliveira Bueno, Danielle Marcilio Judice-Daher + Show 1 more

Open Access

https://doi.org/10.3922/j.psns.2012.2.18

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Abstract

The reinforcement omission effect (ROE) has been attributed to both motivational and attentional consequences of surprising reinforcement omission. Recent evidence suggests that the basolateral complex of the amygdala is involved in motivational components related to reinforcement value, whereas the central nucleus of the amygdala is involved in the processing of the attentional consequences of surprise. This study was designed to verify whether the mechanisms involved in the ROE depend on the integrity of either the basolateral amygdala complex or central nucleus of the amygdala. The ROE was evaluated in rats with lesions of either the central nucleus or basolateral complex of the amygdala and trained on a fixed-interval schedule procedure (Experiment 1) and fixed-interval with limited hold signaled schedule procedure (Experiment 2). The results of Experiment 1 showed that sham-operated rats and rats with lesions of either the central nucleus or basolateral area displayed the ROE. In contrast, in Experiment 2, subjects with lesions of the central nucleus or basolateral complex of the amygdala exhibited a smaller ROE compared with sham-operated subjects. Thus, the effects of selective lesions of amygdala subregions on the ROE in rats depended on the training procedure. Furthermore, the absence of differences between the lesioned groups in either experiment did not allow the dissociation of attentional or motivational components of the ROE with functions of specific areas of the amygdala. Thus, results did not show a functional double-dissociation between the central nucleus and basolateral area in the ROE.

Highlights

In animals that respond on intermittent schedules of reinforcement, response rates are often higher after reinforcement omission than after reinforcement
Several studies showed that the amygdala may be involved in the modulation of attentional and motivational processes and, the modulation of processes that are likely involved in the reinforcement omission effect (ROE), the present results did not show that the basolateral amygdala (BLA) and central nucleus of the amygdala (CeA) lesions interfered with the ROE
When the partial reinforcement schedule was introduced in the FI 60-s schedule procedure, rats in the three groups exhibited a higher response percentage average after nonreinforcement than after reinforcement (0-15-s period)

Summary

Introduction

In animals that respond on intermittent schedules of reinforcement, response rates are often higher after reinforcement omission than after reinforcement. Amsel & Roussel (1952) reported that the introduction of partial reinforcement in the first goal of a double runway paradigm led to the greatest response on the second runway immediately after omission than after reinforcement delivery. This effect was explained by increments in the drive induced by primary frustration (Amsel & Roussel, 1952; Amsel, 1992; Papini, 2003; Papini & Dudley, 1997). McDonough & Manning (1979) found an opposite effect in which rats with lesions of the amygdaloid complex and that were trained to respond on a FI 60-s schedule were more responsive to occasional reinforcement omission than rats in the sham-operated group

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