Retroactive amnesia from electroconvulsive shock: Consolidation disruption or interference?

Abstract

The amnesic effect of electroconvulsive shock has been explained in terms of consolidation theory and in terms of interference hypotheses. Crucial evidence is not yet available for choosing between these alternative explanations, and it appears that many variables (including the nature of the response measure used and the number of seizures administered to the S) influence the results of studies in the area. The present study is a modified replication of an earlier experiment, and offers evidence in favor of an interference interpretation of the effects of electroconvulsive shock on learned responses.

Retrograde effects of electroconvulsive shock on learned responses.

“…Thus, McGaugh and Madsen's (1964) results are completely explainable without resort to a prolonged memory-consolidation process. Adams and Peacock (1965) performed a similar experi-ment and obtained exactly opposite results. In their experiment, rats that received ECS 10 seconds after punishing shock discriminated significantly better than rats given ECS at 1 hour.…”

“…Both result in the animal failing to repeat the previously rewarded response. That a single ECS can be aversive was demonstrated by Misanin and Smith (1964) and by Adams and Peacock (1965). How amnestic and aversive properties of ECS might be separated in appetitive learning is not readily apparent.…”

Retrograde amnesia for discriminated taste aversions: A memory deficit.

“…Pentylenetetrazol (Metrazol) has been shown to produce total RA when administered several hours after learning and significant RA even if injected several days later (Pearlman, Sharpless, & Jarvik, 1961). These time intervals are much longer than those generally obtained with ECS (Adams & Peacock, 1965;Lewis, 1969;Thompson & Dean, 1955).…”

Disruptive effects of electroconvulsive shock as a function of current level and mode of delivery.

“…(Chevalier, 1965). Some papers (Adams & Peacock, 1965) report only that a convulsant level was used while others give only the voltage applied (Kincaid, 1967).…”