Resistance to extinction in classical GSR conditioning as a function of acquisition trials beyond peak CR size

Abstract

Seventy-two

Persistence of the SCR following few Pavlovian acquisition trials: An instrumental reinforcement process

“…The first few trials of SCR conditioning produce large CRs, which in previous studies (e.g., Schramm & Kimmel, 1970;Silver & Kimmel, 1969;Silver, McCaffrey, & Godfrey , 1978) were followed by the omission of the UCS. The result has been strong persistence of the CR both in magnitude and in trials to the extinction criterion.…”

“…While attenuation of the CR occurs during both PP acquisition and extinction, one might expect extinction trials, and not acquisition trials, beyond the peak CR to enhance attenuation and result in weaker CRs. The results of the Schramm and Kimmel (1970) and Silver and Kimmel (1969) studies indicate the opposite.…”

“…extinction, examining the total number of PP trials (acquisition and extinction) permits a more comprehensive picture of CR strength and also reveals the amount of time a subject continues to respond beyond the peak CR. An examination of the groups that received 2 and 16 PP paired trials in the Silver and Kimmel (1969) study reveals that , on the average , the 2-PP group required 43 trials to reach the extinction criterion , whereas the l6-PP group required only 23 trials beyond the peak CR to reach extinction. Schramm and Kimmel's (1970) replication produced similar results.…”

“…During conditioning, the magnitude of the SCR reaches maximal CR strength within two or three acquisition trials and then declines in strength (Campbell, 1936;Kimmel, 1966). The rapid increase in CR magnitude and subsequent decline was investigated further by Silver and Kimmel (1969). In that study , the number of acquisition trials beyond the maximum, or peak CR, was examined to determine the effect of postpeak (PP) acquisition trials on the resistance to extinction of the CR.…”

Resistance to extinction in classical GSR conditioning

“…When human Ss are given paired CS-UCS presentations beyond that point in the acquisition process at which anticipatory GSRs to the CS have ceased to increase in magnitude and begun to decrease (postpeak paired trials), resistance to extinction also declines (Silver & Kimmel, 1969: Schramm & KimmeL 1970. When only two postpeak paired trials are given, Ss require approximately 40-45 presentations of the CS alone to reach an extinction criterion of two successive zero responses.…”