Pavlovian Conditioning Requires Ruling Out Nonassociative Factors to Claim Conditioning Occurred

According to Grau and Joynes (2005), (1) the current classification of types of learning is based on methodology and assumes a correspondence between types of learning and distinct neural-functional mechanisms; (2) this assumption is wrong because experiments show that different mechanisms may underlie the same type of learning; consequently, (3) we should change the teaching of the psychology of learning. I argue that because Grau and Joynes misunderstood the nature of the classification of learning phenomena and cloaked their research findings with a garb of conceptual errors and infelicities, their recommendations concerning the teaching of learning should be rejected

Partial reinforcement in serial autoshaping: The role of attentional and associative factors

In Experiment 1, pigeons were autoshaped to two stimuli (A and B) each followed by delayed reinforcement on 50% of trials. A different stimulus (X) was presented in the interval between stimulus A and reinforcement (A-X-US) and not when stimulus A was nonreinforced (A---). The X stimulus was also presented following the stimulus B trials that were nonreinforced (B-X) and was absent when stimulus B was reinforced (B---US). Not only was the response rate to A higher, but so was the rate in the intervals immediately following A, whether or not these intervals contained X. This latter finding is inconsistent with the interpretation that pigeons discriminated between X when it followed A and when it followed B and leaves open the possibility that X acts as a “catalyst”. The same general design was employed in Experiment 2 as was used in Experiment 1 with the exception that the catalytic function of X was equated for A and B by presenting reinforcement on B-X trials. The A stimulus, however, still generated the higher response rate. A new interpretation is offered that suggests that variable reward magnitude will maintain attention to a stimulus and that attention will generate keypecking

Metabotropic glutamate receptor subtype 5 antagonism in learning and memory

The role of the metabotropic glutamate receptor 5 (mGlu(5) receptor) in learning and memory and other behaviors are reviewed by examining the influence of selective antagonists and genetic knockout on performance. This receptor is involved in spatial learning, contextual fear conditioning, inhibitory avoidance, fear potentiated startle, and conditioned taste aversion. However, mGlu(5) receptor antagonists have proven to be ineffective in other learning tasks, such as the delayed-match-to-position test and a three-hole spatial learning task. Locomotion is often decreased by mGlu(5) receptor antagonists; and other behaviors such as social interaction and consummatory responses can also be affected. In mGlu(5) receptor knockout mice, performance in contextual fear conditioning and spatial water maze tasks is impaired. Although the available evidence is suggestive of an important contribution of mGlu(5) receptors to cognitive functions, further studies are needed, particularly those with in vivo evaluation of the role of mGlu(5) receptors in selective brain regions in different stages of memory formation

Unexpected Post-CS Events During Extinction and the Slow Reacquisition Effect

Rats were used to examine the effects of a surprising post-CS event on reacquisition of an extinguished conditioned taste aversion. One flavor CS was paired with LiCl and then followed by many CS-alone extinction trials. Following these extinction trials, subjects received the CS paired again with LiCl to assess the extent of reacquisition. For some subjects, the final extinction exposure was immediately followed by a surprising second flavor CS. The surprising event did not influence the degree of reacquisition. Additional results found that the second flavor did influence habituation of neophobia to a flavor showing that the event does influence consumption in some circumstances. These results are discussed with respect to the role of attention on extinction and reacquisition of a conditioned taste aversion

Unexpected Post-CS Events During Extinction and the Slow Reacquisition Effect

Rats were used to examine the effects of a surprising post-CS event on reacquisition of an extinguished conditioned taste aversion. One flavor CS was paired with LiCl and then followed by many CS-alone extinction trials. Following these extinction trials, subjects received the CS paired again with LiCl to assess the extent of reacquisition. For some subjects, the final extinction exposure was immediately followed by a surprising second flavor CS. The surprising event did not influence the degree of reacquisition. Additional results found that the second flavor did influence habituation of neophobia to a flavor showing that the event does influence consumption in some circumstances. These results are discussed with respect to the role of attention on extinction and reacquisition of a conditioned taste aversion