title: Nondiscriminated avoidance of shock by pigeons pecking a key.
abstract: Four pigeons were trained to avoid shock by pecking a key on a free-operant avoidance schedule in which no exteroceptive stimulus signalled impending shock. Response rate was an inverse function of response-shock interval when shock-shock interval was held constant at 2 sec and response-shock intervals varied from 5 to 40 sec. Amphetamine increased response rates in two subjects and reserpine markedly reduced responding in one.
authors.forename: E A
authors.initials: EA
authors.lastname: Ferrari
authors.forename: J C
authors.initials: JC
authors.lastname: Todorov
authors.forename: F G
authors.initials: FG
authors.lastname: Graeff