Competing response and amnesic effects of electroconvlusive shock under extinction and incentive shifts.

Abstract

112 rats were assigned to 7 orders of treatments designed to detect such ECS effects as freezing responses, activity from emotional arousal, and amnesia. In the first 8 trials experimental Ss received footshock or ECS as punishment for stepping off a small platform while control Ss received no shock. On subsequent trials ECS and No-Shock groups were transferred to footshock; Footshock and No-Shock groups to ECS conditions; and Footshock and No-Shock groups to No Shock. The results did not indicate the presence of either conditioned freezing or competing activity responses although an amnesia interpretation was supported.

Dissociation of conditioned emotional and avoidance responses due to ECS

“…In substantiation of results obtained in a previous study (Gerbrandt & Thomson, 1964), footshock was far superior to ECS in producing avoidance responding during trials 1-4 (X 2 =44.5i df=l; p< .001) and trials 5-8 (X 2 =58.9; df=l; p< .001). In support of the notion that ECS produces a dissociation between the CER and avoidance responding, however, ECS was even more effective than was footshock in producing emotionality during trials 1-4 (X 2 =12:9; df=2i p< .01), trials 5-8 (X2=13.6i df=2; p< .01), and in the treatment and trials interaction (X 2 = 13.6; df = 2; P < .01).…”

“…after daily trials. It would then seem that conclusions for the existence of amnesic effects of ECS are 386 justified (Madsen & McGaugh, 1961;Hudspeth, McGaugh, & Thomson, 1964;Gerbrandt & Thomson, 1964). No justification for the competing response theory (Lewis & Maher, 1965) has been found either in these investigations or in the present study.…”

“…Maher & McIntyre (1960) have reported no differences in CER between frontal cortex lesioned and control rats, even though strong deficits in avoidance responding have been found as a result of frontal lesions (Thompson, 1964), There is also some reason to believe electroconvulsive shock (ECS) can produce a dissociation between avoidance responding and the CER. Although Coons & Miller (1960) report a greatly increased CER as a result of ECS treatments, Gerbrandt & Thomson (1964) and Hudspeth et al (1964) have found very little evidence for an avoidance of ECS as compared to footshock. The present study will directly compare the formation of a CER with the acquisition of an avoidance response when either footshock or ECS are used as punishment.…”

“…Thirty-two naive descendents of the Tryon Maze Dull (S3) strain of rats were given one of two types of punishment in the passive avoidance situation and apparatus described previously (Gerbrandt & Thomson, 1964). One half of the animals received a footshock of 80 v ac when they stepped from the small "safe" platform onto the floor.…”

ECS-induced retrograde amnesia for one trial active avoidance

“…This omission in the data occasionally has been misinterpreted to infer that ECS acts selectively upon passive avoidance responses or, more particularly, upon CERs which are indistinguishable from discriminated avoidance in the passive situation. SUch a selectivity may hold in multiple ECS paradigms (Gerbrandt & Thomson, 1964) but the relevant data from single ECS studies have been lacking.…”