An assessment of adjunctive behavior in a safety-signal paradigm

Three groups of rats were exposed to 0.4 mA shock presentations on a VT 30-sec schedule. Behavior was monitored during 35-sec shock-free periods inserted randomly after 15 of the 60 shocks per session. In the no-signal and random-signal control groups the behavior patterns which developed were similar to defense or fear reactions. In the safety-signal group, in which a tone signalled the 35-sec no-shock periods, a pattern of adjunctive and facultative behaviors developed including marked increases in grooming and rearing behaviors. No evidence of adjunctive drinking was found in any of the three groups.