SIGNALLED AND UNSIGNALLED FREE‐OPERANT AVOIDANCE IN THE PIGEON¹

Abstract

Pigeons were trained to depress a lever to avoid electric shock under free-operant avoidance schedules without a warning signal, or with a warning signal that could be terminated only by a response. Most birds in the signalled avoidance procedure terminated more than 50% of the warning signals before shock. In the unsignalled avoidance procedure, several birds formed a temporal discrimination and received relatively few shocks; other birds responded only in post-shock bursts, and received many more shocks.

Multiple DRO CRF escape avoidance: Contributions of shock duration and response requirements on avoidance

“…The present results indicate that intermittent escape schedules influence avoidance levels initially established with CRF escape (see Pisacreta, 1980Pisacreta, , 1981. Also similar to Pisacreta's resuits, the present study showed that intermittent escape schedules virtually eliminate the "warm-up effects" that several researchers have reported (Foree & Lolordo, 1970;Hoffman, FleshIer, & Chorny, 1961).…”

WARMUP IN AVOIDANCE AS A FUNCTION OF TIME SINCE PRIOR TRAINING1

“…The phenomenon is not limited to rodents, however. Warmup effects have been reported in avoidance experiments with pigeons, using either a key-peck (Foree and LoLordo, 1974;Ferrari, Todorov, and Graeff, 1973) or a treadle-press response (Foree and LoLordo, 1970;Rilling, 1972, 1974).…”

“…For rats and pigeons, warmup effects may occur irrespective of whether warning stimuli are included in the avoidance procedure (Foree and LoLordo, 1970;Hoffman, 1966), although these stimuli have occasionally been seen to affect the degree of warmup, either decreasing it (Ulrich, Holz, and Azrin, 1964) or increasing it (Powell, 1972).…”

IN COMPATABILITY BETWEEN THE PIGEONS' UNCONDITIONED RESPONSE TO SHOCK AND THE CONDITIONED KEY‐PECK RESPONSE1

“…However, successful avoidance and escape behaviors in pigeons have been conditioned when responses other than key pecking have been selected. Hoffman and Fleshler (1959) obtained conditioning when a head-lifting response was used; Macphail (1968) and Bedford and Anger (1968) reported successful conditioning using a shuttle response; Smith and Keller (1970) and Foree and LoLordo (1970) obtained conditioning using a treadle response, and Graf and Bitterman (1963) The present study employed high-speed photography of food-reinforced key pecking and unconditioned responses (UCRs) to shock in order to determine whether the topography of the key-peck response would oppose the topography of the UCR to shock.…”