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When information about an event is perceptually occluded, individuals might recognize that the event may be present but that they cannot detect it because of the occluder. In such situations, an individual should continue to believe that the prevailing contingencies have not changed. This is in stark contrast to conditions where an expected event is explicitly absent, which should lead the individual to update their contingency knowledge. In an autoshaping procedure, we tested whether pigeons can discriminate conditions of perceptual ambiguity from perceptual certainty. Pigeons first learned to peck at two Pavlovian visual cues, followed by extinction of one of the cues. During extinction, the feeder was occluded by a metal shield for pigeons in Group Occluded, while the metal shield was placed next to but not covering the feeder for pigeons in Group Un-Occluded. On a final test with the metal shield removed, pigeons in Group Un-occluded pecked less at the extinguished cue than at the un-extinguished cue; while pigeons in Group Occluded pecked at an equally high rate to both cues. These results replicate in pigeons with similar results reported in rats by Waldmann et al. (2012) and show that pigeons are able to discriminate conditions of certainty from conditions of ambiguity. 

Abstract Humans and other animals are capable of reasoning. However, there are overwhelming examples of errors or anomalies in reasoning. In two experiments, we studied if rats, like humans, estimate the conjunction of two events as more likely than each event independently, a phenomenon that has been called conjunction fallacy. In both experiments, rats learned through food reinforcement to press a lever under some cue conditions but not others. Sound B was rewarded whereas Sound A was not. However, when B was presented with the visual cue Y was not rewarded, whereas AX was rewarded (i.e., A-, AX+, B+, BY-). Both visual cues were presented in the same bulb. After training, rats received test sessions in which A and B were presented with the bulb explicitly off or occluded by a metal piece. Thus, on the occluded condition, it was ambiguous whether the trials were of the elements alone (A or B) or of the compounds (AX or BY). Rats responded on the occluded condition as if the compound cues were most likely present. The second experiment investigated if this error in probability estimation in Experiment 1, could be due to a conjunction fallacy, and if this could be attenuated by increasing the ratio of element/compound trials from the original 50-50 to 70-30 and 90-10. Only the 90-10 condition (where 90% of the training trials were of just A or just B) did not show a conjunction fallacy, though it emerged in all groups with additional training. These findings open new avenues for exploring the mechanisms behind the conjunction fallacy effect. 

Abstract The present study evaluated the role of inhibition in paradoxical choice in pigeons. In a paradoxical choice procedure, pigeons receive a choice between two alternatives. Choosing the “suboptimal” alternative is followed 20% of the time by one cue (the S+) that is always reinforced, and 80% of the time by another cue (S-) that is never reinforced. Thus, this alternative leads to an overall reinforcement rate of 20%. Choosing the “optimal” alternative, however, is followed by one of two cues (S3 or S4), each reinforced 50% of the time. Thus, this alternative leads to an overall reinforcement rate of 50%. González and Blaisdell (2021) reported that development of paradoxical choice was positively correlated to the development of inhibition to the S- (signal that no food will be delivered on that trial) post-choice stimulus. The current experiment tested the hypothesis that inhibition to a post-choice stimulus is causally related to suboptimal preference. Following acquisition of suboptimal preference, pigeons received two manipulations: in one condition one of the cues in the optimal alternative (S4) was extinguished and, in another condition, the S- cue was partially reinforced. When tested on the choice task afterward, both manipulations resulted in a decrement in suboptimal preference. This result is paradoxical given that both manipulations made the suboptimal alternative the richer option. We discuss the implications of our results, arguing that inhibition of a post-choice cue increases attraction to or value of that choice. 

Humans and other animals make decisions under uncertainty. Choosing an option that provides information can improve decision making. However, subjects often choose information that does not increase the chances of obtaining reward. In a procedure that promotes such paradoxical choice, animals choose between two alternatives: The richer option is followed by a cue that is rewarded 50% of the time (No-info) and the leaner option is followed by one of two cues, one always rewarded (100%), and the other never rewarded, 0% (Info). Since decisions involve comparing the subjective value of options after integrating all their features perhaps including information value, preference for information may rely on cortico-amygdalar circuitry. To test this, male and female Long-Evans rats were prepared with bilateral inhibitory DREADDs in the anterior cingulate cortex (ACC), orbitofrontal cortex (OFC), basolateral amygdala (BLA), or null virus infusions as a control. Using a counterbalanced design, we inhibited these regions after stable preference was acquired and during learning of new Info and No-info cues. We found that inhibition of ACC, but not OFC or BLA, selectively destabilized choice preference in female rats without affecting latency to choose or the response rate to cues. A logistic regression fit revealed that the previous choice strongly predicted preference in control animals, but not in female rats following ACC inhibition. BLA inhibition tended to decrease the learning of new cues that signaled the Info option, but had no effect on preference. The results reveal a causal, sex-dependent role for ACC in decisions involving information. 

The acquisition of instrumental responding can be supported by primary reinforcers or by conditional (also known as secondary) reinforcers that themselves have an association to a primary reinforcer. While primary reinforcement has been heavily studied for the past century, the associative basis of conditioned reinforcement has received comparatively little experimental examination. Yet conditioned reinforcement has been employed as an important behavioral assay in neuroscience studies, and thus an analysis of its associative basis is called for. We evaluated the extent to which an element from a previously trained compound would facilitate conditioned reinforcement. Three groups of rats received Pavlovian conditioning with a visual-auditory compound cue followed by food. After training, a lever was made available that, when pressed, produced the same trained compound (group compound), only the auditory cue (group element), or a novel auditory cue (group control). The rats in group compound pressed the lever at a higher rate than did rats in either group element or group control, demonstrating a strong conditioned reinforcement effect only in group compound. Interestingly, there was almost no difference in responding between group element and group control. The implications of this generalization decrement in conditioned reinforcement are discussed—particularly as they relate to research in behavioral neuroscience. 

The acquisition of instrumental responding can be supported by primary reinforcers or by conditional (also known as secondary) reinforcers that themselves have an association to a primary reinforcer. While primary reinforcement has been heavily studied for the past century, the associative basis of conditioned reinforcement has received comparatively little experimental examination. Yet conditioned reinforcement has been employed as an important behavioral assay in neuroscience studies, and thus an analysis of its associative basis is called for. We evaluated the extent to which an element from a previously trained compound would facilitate conditioned reinforcement. Three groups of rats received Pavlovian conditioning with a visual-auditory compound cue followed by food. After training, a lever was made available that, when pressed, produced the same trained compound (group compound), only the auditory cue (group element), or a novel auditory cue (group control). The rats in group compound pressed the lever at a higher rate than did rats in either group element or group control, demonstrating a strong conditioned reinforcement effect only in group compound. Interestingly, there was almost no difference in responding between group element and group control. The implications of this generalization decrement in conditioned reinforcement are discussed—particularly as they relate to research in behavioral neuroscience.