Differentiation of escape and avoidance responding in rats.

Abstract

Escape and avoidance performance was examined in rats by factorially arranging immediate or postponed CS and US termination with shuttle or bar-press escape and avoidance responses. High levels of avoidance responding occurred only when the shuttle response (running) was both the escape and avoidance response, perhaps reflecting that rats are prepared to run but contraprepared to bar press when threatened by aversive stimulation. In addition, postponed US termination reduced avoidance performance drastically while CS termination conditions were without effect. Measures of US duration and US clock terminations also indicated that immediate US termination was superior to postponed US termination but additionally showed that this was so because postponed US termination seriously impaired escape behavior. The results have particular relevance for how escape responses become anticipatory.

Avoidance learning under delayed shock termination in prenatally x‐irradiated rats

“…When rats are unable to cope due t o these punishment effects, the response most likely t o appear is one of freezing, which interferes with shuttlebox performance. This was corroborated by our previous observation, which paralleled the findings of Reynierse (1972), namely, that Wistar rats are seriously retarded in the crossing response if shock termination is postponed more than I sec.…”

“…The shock-escape contingency is also one of the essential components in learning the shuttlebox avoidance response. The absence of this shock-escape contingency due to an inescapable shock of .3-sec duration (Bolles, Stokes, & Younger, 1966; Experiment 1) or 5-sec delayed shock termination (Reynierse, 1972) on escape trials has an adverse influence on the rate of avoidance, because shock termination is the only source of reinforcement for escape responding (Reynierse, 1972).…”

Consistent leverpress avoidance responding by rats

“…Many investigators (e.g., D 'Amato & Schiff, 1964;Meyer, Cho, & Weseman, 1960;Reynierse, 1972;Scheuer & Sutton, 1973) have reported minimal success in attempting to condition leverpress avoidance responding in rats. In most experiments, trial onset is signaled by an increase in illumination or presentation of a tone.…”