Delayed Matching‐to‐sample Performance: Effects of Relative Reinforcer Frequency and of Signaled Versus Unsignaled Reinforcer Magnitudes

Abstract

Six pigeons were trained on a delayed red-green matching-to-sample task that arranged four delays within sessions. Matching responses intermittently produced either 1.5-s access to food or 4.5-s access to food, and nonmatching responses produced either 1.5-s or 4.5-s blackout. Two phases were conducted: a signaled phase in which the reinforcer magnitudes (small and large) were signaled by houselights (positioned either on the left or right of the chamber), and an unsignaled phase in which there was no correlation between reinforcer magnitude and houselight position. In both phases, the relative frequency with which red and green matching responses produced food was varied across five values. Both matching accuracy and the sensitivity of performance to the distribution of reinforcers for matching responses decreased with increasing delays in both phases. In addition, accuracy and reinforcer sensitivity were significantly lower on signaled small-reinforcer trials compared with accuracy and sensitivity values on signaled large-reinforcer trials and on both types of unsignaled trials. These results are discussed in the context of research on both nonhuman animal and human memory.

Remembering: The role of extraneous reinforcement

“…Their overall short versus long duration, however, is signaled by external stimuli. The result is that initial discriminability is higher when longer reinforcers are signaled, with no change in the rate of forgetting (Brown & White, 2005;Jones et al, 1995;McCarthy & Voss, 1995;Nevin & Grosch, 1990). A similar signaled probability effect was reported by Brown and White.…”

Quantitative Analyses of Matching‐to‐sample Performance

“…Nevertheless, two implications are clear. First, analyses of sample-stimulus discriminability and response bias in prior MTS and DMTS studies warrant careful reexamination (e.g., Godfrey & Davison, 1998;Jones & White, 1992;McCarthy & Davison, 1991;McCarthy & Voss, 1995;White & Wixted, 1999), and second, the advancement of quantitative models of performance in these procedures cannot be without regard to conceptual analyses of the reinforcement contingencies that operate therein.…”

Postevent cues bias recognition performance in pigeons

“…In studies using pigeons as subjects, the stimuli have typically been colored keylights, lines, or forms, and the delays have varied between 0 and 40 sec. Such procedures have been used to explore the effects of many of the variables known to influence the memory function, including those of reinforcement (e.g., McCarthy & Voss, 1995;Nevin & Grosch, 1990), of brain lesions and drugs (e.g., Aggleton, Keith, & Sahgal, 1991;Harper, McLean, & Dalrymple-Alford, 1994;Kirk, White, & McNaughton, 1988), and of various sources of interference (e.g., Edhouse & White, 1988;Harper & White, 1997;Jans & Catania, 1980;Maki, Moe, & Bierley, 1977;Roberts & Grant, 1978;White, 1985).…”

“…In studies using pigeons as subjects, the stimuli have typically been colored keylights, lines, or forms, and the delays have varied between 0 and 40 sec. Such procedures have been used to explore the effects of many of the variables known to influence the memory function, including those of reinforcement (e.g., McCarthy & Voss, 1995;Nevin & Grosch, 1990), of brain lesions and drugs (e.g., Aggleton, Keith, & Sahgal, 1991;Harper, McLean, & Dalrymple-Alford, 1994;Kirk, White, & McNaughton, 1988), and of various sources of interference (e.g., Edhouse & White, 1988;Harper & White, 1997;Jans & Catania, 1980;Maki, Moe, & Bierley, 1977;Roberts & Grant, 1978;White, 1985).With respect to interference effects in DMTS tasks, researchers have examined the influence of events occurring prior to the current trial (proactive interference) and during the delay interval of the current trial (retroactive interference) on recognition performance (Edhouse & White, 1988;White, 1985). Studies that have explored these two types of interference have not only differed with respect to the location of the interfering stimulus, but also with respect to the nature of the extraneous stimuli.…”