Does induced recovery from amnesia represent a disinhibition effect?
Induced recovery from amnesia appears similar to disinhibition effects obtained when response strength is weakened in various ways. Therefore, the possibility that reexposure to the amnestic treatment acts as a "disinhibitor" is problematic for a retrieval interpretation of recovery following amnesia. Two experiments examined the question of whether or not hypothermia treatment (i.e., deep body cooling) acts as a disinhibitor for an extinguished fear response in Sprague-Dawley rats. The results of Experiment 1 indicate that deep body cooling did not significantly disinhibit a passive-avoidance response that had previously been extinguished with a 4-min nonreinforced exposure to the shock chamber of the apparatus. Experiment 2 further examined this negative effect by using a modified passive-avoidance procedure and lengthening the extinction session from 4 to 12 min. Similar to Experiment 1, the results of the second experiment also suggested that if the subject's body temperatures were reduced prior to the retention test, no disinhibitory effect of fear conditioning was manifested. These findings support the notion that memory retrieval (i.e., the contextual cue explanation) is the basis for the alleviation of amnesia by reexposure to the amnestic agent.
Harrod
S B
SB
Kent State University, OH 44242, USA. sharrod@kentvm.kent.edu
Metzger
M M
MM
Riccio
D C
DC
D000647:Amnesia / Q000523:psychology*; D000818:Animals; D001362:Avoidance Learning / Q000502:physiology; D003216:Conditioning, Operant / Q000502:physiology; D005108:Extinction, Psychological; D007036:Hypothermia, Induced; D007266:Inhibition, Psychological; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley