Conditional probability of reinforcement and sequential behavior in human conditioning with intermittent reinforcement schedules

Abstract

Fourteen Ss were exposed to three 50%-reinforcement sclledllills in human eyelid conditioning. The In the typical 50% reinforcement schedule the conditional probability of a reinforced trial following a reinforced trial, P(R IR), as weil as the conditional probability of a nonreinforced trial following a nonreinforced trial, P(R I ~), is . 5. When both P(R I R) and P(R I R) are increased (maintaining the 50% reinforcement ratio) increments and decrements in response prob ability following, respectively, reinforced and nonreinforced trials are larger, but they are sm aller when P(R I R) and p(R I R) are less than .5 (Prokasy, earlton, & Higgins, 1967; Higgins & Prokasy, 1968). The purpose of this study was to extend these observations by determining (a) if differential sequential effects could be obtained when the same Ss are exposed to different values of P(R I R) and p(R I R) in different sessions and (b) whether the sequential effeets would be maintained with extensive training. In all eases, P(R I R) = P(R IR). METHOD The method of transducing and reeording eyelid responses is reported elsewhere (Prokasy et al, 1967). The es was a 600-msee, lOOO-Hz tone, the interstimulus interval was 600 msec, and the ues was a 50-msee puff of nitrogen of suffieient intensity to support a 150-mm column of mereury. A total of 14 Ss, paid for their services, served in 15 conditioning sessions of 360 trials each. The first 10 trials of eaeh session were composed of five eS-alone and UeS-alone trials. The average intertrial interval was 10 sec, varying from 6 to 14 sec. Three 50%-reinforcement schedules were employed, these differing only in that P(R IR) =.3, .5, or .7. The three sehedules were randomized over sessions so that each S reeeived five sessions at each p(R I R) value in an unsystematic order. Through a scheduling error, two Ss received six sessions of the .7 schedule and only four of the .3 schedule. Also, for two Ss the original data for one of the .7 schedules were misplaced and, consequently, not employed in the analyses. All Ss reeeived standard instructions (i.e., to relax and let their responses take eare of themselves) for each session.RESUL TS AND DISCUSSION The basic analyses were conducted on sequential behavior. Response probability following either zero, one, two, or three sueeessive reinforcements was caJculated for the first and last halves of training. These calculations were performed separately for the three different P(R I R) values, thus permitting a eomparison of the first two-and-a-half sessions with the last two-and-a-half sessions for each of the three kinds of schedule. The summary da ta are provided in Table I.

Trace and Delay Eyeblink Conditioning: Contrasting Phenomena of Declarative and Nondeclarative Memory

“…The finding that conditioned responding was influenced not by expectancy but by the recent frequency of CS-alone and CS-US trials provides particularly strong evidence that delay eyeblink conditioning in humans is an example of nondeclarative memory and is unrelated to awareness (Clark & Squire, 1998;Grant, 1973;Papka, Ivry, & Woodruff-Pak, 1997). This view of delay conditioning is similar to earlier accounts of classical conditioning that emphasized the importance of associative strength (Bush & Mosteller, 1951;Prokasy & Kumpfer, 1969).…”

Dissociating conscious expectancies from automatic link formation in associative learning: A review on the so-called Perruchet effect.

“…I have not been able to gain access to this document, and as a consequence, these data were not included. Note that Prokasy and Kumpfer (1969) also reported data that, when reorganized as in Perruchet (1985), exhibited the same upward trend. However, the data were reported in a way that makes it impossible to infer whether the linear trend was significant.…”

“…1This terminology, however, does not do justice to earlier seminal studies by William Prokasy (Prokasy & Kumpfer, 1969; Williams & Prokasy, 1977). …”

Classical Skin Conductance Response Conditioning: Effects of Random Intermittent Reinforcement

“…In other words, the nient ratio facilitated awareness of the CS-UCS fine-grain sequential trends were exactiy opposite contingency. That is, since it has been reported that to those obtained with skeletal response systems differential performance does not occur until that (Holmes & Gormezano, 1970;Prokasy & Kumpfer, 1969;Thomas & Wagner, 1964).…”