The order of continuous, partial and nonreward trials and resistance to extinction

Persistence: The role of partial reinforcement in psychotherapy.

“…In recent separate-phase investigations of the effects on persistence of continuous reward -partial reward acquisition (C-P shifts), interest has centered on the differential effects of reward magnitude (Dyck, Dresel, & Suthons, 1978) and numbers of trials (Mellgren, Seybert, & Dyck, 1978) prior to the shift. It appears that either greater reward magnitude or a greater number of trials during the preshift (C) phase results in increased resistance to extinction.…”

“…It appears that either greater reward magnitude or a greater number of trials during the preshift (C) phase results in increased resistance to extinction. Most dramatic are results from the Mellgren et al (1978) experiments, which provide clear evidence that the effect of increasing the number of C trials (0, 48, or 96) before a constant number of P trials (32) is to increase persistence during extinction. These results, which are somewhat consistent with earlier findings (Mellgren et al, 1973;Theios & McGinnis, 1967;Traupmann et al, 1973), are more difficult to interpret theoretically.…”

Hypotheses of neuroleptic action: Levels of progress

“…The hypothesis that neuroleptics block or blunt the effects of primary reinforcers is testable and falsifiable. For example, a well-known finding in the runway-extinction literature is that rats, given a series of nonrewarded trials prior to a series of continuously reinforced trials, will show greater resistance to extinction than rats given only the continuously reinforced trials (Capaldi & Waters 1970;Capaldi, Ziff & Godbout 1970;Mellgren, Seybert & Dyck 1978;Spear, Hill & O'Sullivan 1965). This effect is sometimes called the initial nonreinforcement effect, or INE.…”

“…For example, Jenkins (1977) has demonstrated that both stimulus-reinforcer and responsereinforcer associations are learned in operant situations, and the nature of the response system may affect the sensitivity of the different types of associations (expectancies, if you prefer). Mellgren and Olson (1980) have shown that the persistence of bar-pressing by rats in extinction is a joint function of response-reinforcer and stimulus-reinforcer expectancies. The first point, then, is that there is not one single expectancy that determines the course of extinction.…”

The Effect of Different Combinations of Continuous and Partial Reinforcement Schedules on Response Persistence in Mentally Handicapped Children

“…However, there is evidence that the type of reinforcement schedule used during the initial stages of training also can have important effects on subsequent resistance to extinction. For example, using rats as subjects, Mellegren et al (1978) demonstrated that a series of non-rewarded trials prior to the introduction of rewarded trials greatly increased resistance to extinction. In addition, following partial reinforcement training, Sutherland et al (1965) found that resistance to extinction in rats was greatly diminished if the partial reinforcement phase was preceded by a series of continuously reinforced trials.…”