Matching-to-sample by pigeons: The dissociation of comparison choice frequency from the probability of reinforcement

Abstract

It has been proposed that comparison choice in matching-to-sample should depend on two factors, the relative probability of reinforcement associated with each of the comparison stimuli and the conditional probability of each comparison stimulus being correct given presentation of one of the samples. DiGian and Zentall (in press) have shown that sample frequency together with the probability of choosing each of the comparison stimuli in training can influence comparison choice when delays are introduced, when the number of reinforcements associated with each of the comparison stimuli is equated. Furthermore, Clement and Zentall (2002) have found that sample frequency can affect comparison choice when delays are introduced independently of the number of choices of each of the comparison stimuli in training and the number of reinforcements associated with each of the comparison stimuli is equated. In the present experiment we found that the probability of choosing each of the comparison stimuli in training can affect comparison choice when delays are introduced, independently of sample frequency and when the number of reinforcements associated with each of the comparison stimuli is equated. Together, these experiments suggest that when the sample is not available, there is a partial dissociation between comparison choice and the probability of reinforcement associated with each of the comparison stimuli.

Delayed matching-to-sample: A tool to assess memory and other cognitive processes in pigeons

“…11). Instead of considering the probability of each sample given the pair of comparison stimuli presented, it appears that they considered the overall probability that it was the red sample, in spite of the fact that half of those presentations were not relevant to the two comparisons presented on that trial (see also, DiGian and Zentall, 2007;Zentall et al, 2008). Thus, it appears that animals too are susceptible to base-rate neglect and that basic behavioral processes are involved (see also Goodie and Fantino, 1996).…”

“…If so, Zentall et al (2008) have shown that pigeons tend to judge intervals as shorter when they are pecking than when they are not pecking. However, Santi et al (2010) tested this hypothesis by requiring that pigeons refrain from pecking during both the filled and unfilled intervals and it did not eliminate the judgments that the filled intervals were shorter than the unfilled intervals.…”

“…In the second phase, they gave the pigeon experience with pecking and the absence of pecking using a differential autoshaping procedure (e.g., presentation of a yellow stimulus for 4 s was followed by food and resulted in pecking the yellow stimulus, whereas presentation of a blue stimulus followed by the absence of food resulted in the absence of pecking the blue stimulus). On rarely occurring probe trials, Zentall et al followed the yellow and blue stimuli with a choice between red and green stimuli and found a strong tendency to choose red after yellow and green after blue (see also Singer and Zentall, 2007;Zentall et al, 2008Zentall et al, 2008. Thus, it can be argued that the appearance of yellow resulted in pecking because it signaled the appearance of food and the appearance of blue resulted in no pecking because it signaled the absence of food but on probe trials, instead of those outcomes, the pigeon was asked "Do you remember what you did?…”

“…Psychophysical tests of pigeons' judgments of sample durations between 2 and 10 s (see, e.g., Zentall et al, 2008) suggest that indifference between the two comparison alternatives (temporal bisection test) occurs very close to the geometric mean (about 4.5 s). Thus, memory for the 10 s sample would have to subjectively shorten by 50% within 5 s.…”

The Monty Hall dilemma with pigeons: No, you choose for me

“…By doing so, they neglect the base rate with which choice of the comparison colors is reinforced. Interestingly, when pigeons are given the same task, they show better sensitivity to the base rates and get more correct than humans do (Fantino, Kanevsky, & Charlton, 2005); however, if pigeons are given extensive training on matching to sample with 100% reinforcement for matching and then are transferred to the task in which choice of one of the comparisons is reinforced most of the time, they, too, show evidence of base-rate neglect (see also DiGian & Zentall, 2007;Zentall & Clement, 2002;Zentall, Singer, & Miller, 2008). Thus, extensive experience with a task in which a stimulus (in this case, the sample) provides a highly reliable cue for correct comparison choice biases, pigeons tend to neglect the fact that the stimulus is no longer a reliable cue, resulting in suboptimal choice by the pigeons.…”