Effects of serial CS presentation on a finger-withdrawal avoidance response to shock.

Abstract

Experiment I compared the performance of two serial (Si followed by S a ) and two nonserial CS conditions on a finger-withdrawal avoidance response. The CS-US interval was 800 msec. Light served as the CS and shock served as the US. Nonserial CS conditions produced faster response latencies and more responding than serial CS conditions. Experiment II provided data suggesting that the differences noted in Exp. I were a function of the length of the CS-US interval employed. Shorter intervals (300 and 600 msec.) eliminated the latency difference between conditions, while a longer interval (1,200 msec.) increased it. Possible interpretations of the data were discussed.

Some parameters affecting shuttle-box avoidance responding with rats receiving serially presented conditioned stimuli.

“…The above findings in distribution of avoidance latencies are also consistent with data presented at the human level on finger-withdrawal avoidance conditioning (Levis, 1971). Longer CS-US intervals were found to produce the serial response-delay effect (800 and 1,200 msec.…”

“…The delayed-responding effect reported by Levis and Stampfl (1972) for subjects presented with a serial CS procedure has also been noted with the use of other paradigms including classical appetitive conditioning with dogs (Williams, 1965), appeti-tive conditioned reinforcement with rats (Baker, 1972), human avoidance conditioning (Levis, 1971), and conditioned suppression of lever pressing with rats (Brahlek, 1968;Kamin, 1965). The present study is concerned with isolating some of the variables responsible for either producing or altering the delayed avoidance responding noted for subjects in serial CS groups.…”

Synaptic transmission correlates of general mental ability

“…= 0.038) is within the range reported in relation to conditioned responses (Levis, 1971). The expected positive skewed distribution was demonstrated for response time to shock (z = 3.48).…”

“…Its internal oscillator provides optically isolated 60-Hz constant current AC stimulation. The actual shock level for individuals is normally predetermined by each participant via a scaling procedure, which establishes the level acceptable (see Elias, 1965;Levis, 1971). Such a workup procedure however would establish different levels of stimulation and serve to increase variance between participants.…”

A demonstration of persistent human avoidance in extinction

“…Meyer (1970) and Drake and Meyer (1972) found that, after 40 training trials, subjects extinguished within 47 and 25 trials, respectively (also see Maxwell, Miller, & Meyer, 1971;Moffat & Koch, 1974). However, the Levis (1971) and Levis and Levin (1972) data suggest that extreme resistance to extinction is possible. Although their group means for extinction trials ranged between 60 and 82 trials, many of their subjects reached the imposed 100 extinction trial limit without extinguishing.…”