Monkeys' Performance on Ambiguous-Cue Problems

Abstract

9 experimentally naive rhesus monkeys were tested on ambiguous-cue problems involving three stimuli: P, the positive or rewarded stimulus; N, the negative or nonrewarded stimulus; and A, the ambiguous stimulus which is nonrewarded when paired with P, but rewarded when paired with N. Either the NA pair or the PA pair was presented on every trial. All Ss were tested with two types of stimuli, planometric plaques and stereometric objects. The results corroborate apparently conflicting previous reports of performance by primates on ambiguous-cue problems with these two types of stimuli. That is, performance on PA trials was superior to performance on NA trials with plaque stimuli, but the converse was obtained with objects. A differential S-R spatial discontiguity inherent in only the plaque version of the problem was identified as one cause of the discrepant results.

An investigation of ambiguous-cue learning in pigeons

“…Performance was, however, better on NA trials than on PA trials, a result which may be abbreviated NA>PA. This result has been found in several other experiments using primate subjects (Boyer & Polidora, 1972;Boyer, Polidora, Fletcher, & Woodruff, 1966;Fletcher & Garske, 1972;Fletcher, Grogg, & Garske, 1968).…”

“…Performance was, however, better on NA trials than on PA trials, a result which may be abbreviated NA>PA. This result has been found in several other experiments using primate subjects (Boyer & Polidora, 1972;Boyer, Polidora, Fletcher, & Woodruff, 1966;Fletcher & Garske, 1972;Fletcher, Grogg, & Garske, 1968).These results stand in marked contrast to those produced by a number of other experiments on ambiguous-cue learning in primates. Fletcher and Bordow (1965) and Thompson (1954) found performance to be better on PA trials than on NA trials (PA>NA); Boyer and Polidora (1972) and Boyer et a1.…”

Reinforcement of ambiguous-cue problem performance under various across trial fixed-ratio schedules

“…The continued superiority of NA performance over PA performance throughout the present study is in agreement with apparently every other published ambiguous-cue experiment that has employed distinctive stimuli (Leary, 1958;Zeaman & House, 1962;Boyer et al, 1966;Fletcher et al, 1968;Fletcher & Garske, 1972;Boyer & Polidora, 1972;Richards, 1973). Differential sensitivity of PA and NA performances to the experimental manipulations of the present study was also noted in the present experiment.…”

“…The consistent finding, when the stimuli possess distinctive features, has been that NA trials are learned more quickly and are learned to a higher terminal level than PA trials. This finding has been reported in monkeys (Leary, 1958;Boyer, Polidora, Fletcher, & Woodruff, 1966;Fletcher, Grogg, & Garske, 1968; Retcher & Garske, 1972;Boyer & Polidora, 1972), retarded children (Zeaman & House, 1962; Retcher et al, 1968), normal children (Fletcher et aI, 1968), and most recently in pigeons (Richards, 1973).In all previous ambiguous-cue studies, the across-trial schedule of reinforcement has been continuous reinforcement. That is, reinforcement was received on every trial if the correct response was made.…”

Selective associations in the observational conditioning of fear in rhesus monkeys.

“…By manipulating stimulus salience/complexity, one can obtain the reverse outcome. That is, by making A less salient than P and N, performance on PA problems exceeds that on NA problems, supposedly because A acquires less excitatory strength and hence competes less with P on PA trials than in the case where the three stimuli are equally salient (e.g., Boyer & Polidora, 1972;Boyer, Polidora, Fletcher, & Woodruff, 1966).…”