Relation between conditioned stimulus-elicit responses and unconditioned response diminution in long-interval human heart-rate classical conditioning

Transfer of conditioned fear and avoidance: Concurrent measurement of arousal and operant responding

A reversal design was employed for the analysis of transfer of fear and avoidance through equivalence classes. Two 5-member equivalence classes (A1-B1-C1-D1-E1 and A2-B2-C2-D2-E2) were established. Then B1 and C1 were paired with shock (CS+) and served as S^D s in avoidance training (B2 and C2 were trained as CS-/S^∆ s for avoidance). Further avoidance training followed with D1 and E1 (as S^D s) and D2 and E2 (as S^∆ s), with the first presentation of each of these stimuli serving as the first transfer test. Afterwards, aversive conditioning contingencies were reversed: B2 and D2 were paired with shock and trained as S^D s for avoidance, B1 and D1 were presented without shock (CS-/S^∆ s). Transfer was tested again with C1, E1, C2 and E2. This reversal was implemented to allow for the within-subject replication of transfer effects upon changes in the function of only a subset of each class's elements. Avoidance (key presses) and conditioned fear (skin conductance and heart rate) were simultaneously measured. Results show a clear transfer effect for avoidance, with between- and within-subject replications. For physiological measures, transfer effects in the first test could only be imputed on the basis of group-based inferential statistical analysis. Evidence for between-subject replication was weaker, with only a limited proportion of participants meeting the individual criterion for transfer.

Pavlovian conditioned diminution of the neurobehavioral response to threat

An important function of emotion is that it motivates us to respond more effectively to threats in our environment. Accordingly, healthy emotional function depends on the ability to appropriately avoid, escape, or defend against threats we encounter. Thus, from a functional perspective, it is important to understand the emotional response to threat. However, prior work has largely focused on the emotional response in anticipation of threat, rather than the emotional response to the threat itself. The current review is focused on recent behavioral, psychophysiological, and neural findings from Pavlovian conditioning research that is centered on the expression and regulation of the emotional response to threat. The current evidence suggests that a neural network that includes the prefrontal cortex, hippocampus, and amygdala underlies learning, expression, and regulation processes that modulate emotional responses to threat. This line of research has important implications for our understanding of emotion regulation and stress resilience.

Learned changes in outcome associability

When a cue reliably predicts an outcome, the associability of that cue will change. Associative theories of learning propose this change will persist even when the same cue is paired with a different outcome. These theories, however, do not extend the same privilege to an outcome; an outcome's learning history is deemed to have no bearing on subsequent new learning involving that outcome. Two experiments were conducted which sought to investigate this assumption inherent in these theories using a serial letter-prediction task. In both experiments, participants were exposed, in Stage 1, to a predictable outcome ('X') and an unpredictable outcome ('Z'). In Stage 2, participants were exposed to the same outcomes preceded by novel cues which were equally predictive of both outcomes. Both experiments revealed that participants' learning towards the previously predictable outcome was more rapid in Stage 2 than the previously unpredicted outcome. The implications of these results for theories of associative learning are discussed.