Induced recovery from amnesia appears similar to disinhibition effects
obtained when response strength is weakened in various ways. Therefor
e, the possibility that reexposure to the amnestic treatment acts as a
''disinhibitor'' is problematic for a retrieval interpretation of rec
overy following amnesia. Two experiments examined the question of whet
her or not hypothermia treatment (i.e., deep body cooling) acts as a d
isinhibitor for an extinguished fear response in Sprague-Dawley rats.
The results of Experiment 1 indicate that deep body cooling did not si
gnificantly disinhibit a passive-avoidance response that had previousl
y been extinguished with a 4-min nonreinforced exposure to the shock c
hamber of the apparatus. Experiment 2 further examined this negative e
ffect by using a modified passive avoidance procedure and lengthening
the extinction session from 3 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 disinhi
bitory effect of fear conditioning was manifested. These findings supp
ort the notion that memory retrieval (i.e., the contextual cue explana
tion) is the basis for the alleviation of amnesia by reexposure to the
amnestic agent. Copyright (C) 1996 Elsevier Science Inc.