Habituation to shock and learned persistence in preweanling, juvenile, and adult rats.

Abstract

Five experiments addressed the relation between habituation to shock and subsequent persistence (resistance to extinction and to punished extinction) in preweanling, juvenile, and adult rats. In Experiment 1, a prolonged shock-habituation treatment given between runway acquisition and simple extinction promoted persistence in both preweanling and juvenile rats. Experiment 2 showed even stronger persistence effects in a punished-extinction test given after shock treatment, the effects being stronger in preweanlings than in juveniles. Experiment 3 demonstrated that shock treatment at infant-to-preweanling age resulted in increased persistence that survived a 42-day retention interval in a nonreward extinction test, but not a punished-extinction test. Experiment 4 demonstrated habituation to shock in preweanlings and juveniles in terms of recovery of suppression of milk intake in the shock situation and, compared with controls, in terms of reduced latency to eat in a punished-reward test at several retention intervals. Experiment 5 tested the relation between strength of habituation and persistence in 70-day-old rats by manipulating shock parameters that are known to affect habituation-number of shocks, intershock interval, and gradually increasing versus constant shock durations. In every case, strength of persistence to approach in a runway reflected the presumed degree of habituation induced by varying these factors.

Uncontrollable shock proactively increases sensitivity to response-reinforcer independence in rats.

“…This suggestion is consistent with the Welker and McAuley (1978) observation that animals in this condition spend a large amount of time facing away from the magazine wall, because animals exposed to primary frustration are known to actively engage in behavior to escape frustrating stimuli (e.g., Daly, 1969;Rosellini & Seligman, 1975). The increased resistance to extinction in inescapably shocked animals may result from increased tolerance to primary frustration, as suggested both by Chen and Amsel (1982) and by Rosellini and Seligman (1975). Thus nonshocked animals may appear less resistant to extinction than do inescapably shocked animals because they are relatively less tolerant to frustration, which would lead to escape re-sponses competing with the learned response and therefore to more rapid extinction.…”

A single dose of nicotine proactively enhances the partial reinforcement extinction effect in the rat

“…An effect of this kind might arise if the additional six injections (whether of saline or nicotine) that differentiate the multiple-injection regime from the single-injection regime led to adaptational changes, which then influenced the degree offrustration experienced during acquisition of the running response. Transfer of adaptational effects between different stressors in this way has been reported in other paradigms (e.g., Brown & Wagner, 1964;Chen & Amsel, 1982). Interestingly, the combined analysis of the data from the two sets of experiments reflected these separate effects of each drug regime on its own, the influence of nicotine pretreatment being apparent in both the start section and (though not clearly) the goal section and in both the linear and the quadratic components of the shape of the extinction curve.…”

Learned industriousness.

“…Consistent with this view, a schedule of intermittent reinforcement increased (a) a response's later persistence when punished with aversive stimulation (Brown & Wagner, 1964; Dyck, Mellgren, & Nation, 1974; Halevy, Feldon, & Weiner, 1987) and (b) a different behavior's subsequent resistance to punishment (Eisenberger et al 1989). Moreover, habituation to aversive stimulation increased the later extinction performance of an appetitively reinforced response (Chen & Amsel, 1982). With the exception of the latter finding, these results would also follow from the secondary reward theory.…”