Journal of Experimental Psychology-Animal Learning and Cognition最新文献

Retrieval of a flavor-illness association has been found to show contextual dependence when the association is learned after a nontarget flavor-illness association has been extinguished in what has been named as the extinction makes acquisition context-specific (EMACS) effect. Four experiments were designed to further explore the EMACS effect in conditioned taste aversion. Experiments 1 and 2 replicated the EMACS effect using rats that did not experience extinction, and rats that underwent extinction of a different flavor as controls. Experiments 3 and 4 found that the experience of extinction with the nontarget Flavor X in a given context (A) led to context-specificity of performance to the target Flavor Y both, when Y was trained in a highly familiar context (B) and tested in the context where X had been trained (Context A, Experiment 3), and when the test was conducted in a less familiar context (C) where no cues or outcomes were presented before (Experiment 4). These results are consistent with the idea that the experience of extinction encourages organism's attention to the contexts, making retrieval of new learning context-specific. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Pavlovian conditioning procedures result in dramatic individual differences in the topography of learnt behaviors in rats: When the temporary insertion of a lever into an operant chamber is paired with food pellets, some rats (known as sign-trackers) predominantly interact with the lever, while others (known as goal-trackers) predominantly approach the food well. Two experiments examined the sensitivity of these two behaviors to changing reinforcement contingencies in groups of male and female rats exhibiting the different phenotypes (i.e., sign-trackers and goal-trackers). In both phenotypes, behavior oriented to the food well was more sensitive to contingency changes (e.g., a reversal in which of two levers was reinforced) than was lever-oriented behavior. That is, the nature of the two behaviors differed independently of the rats in which they were manifest. These results indicate that the behavioral phenotypes reflect the parallel operation of a stimulus-stimulus associative process that gives rise to food-well activity and a stimulus-response process that gives rise to lever-oriented activity, rather than the operation of a single process (e.g., stimulus-stimulus) that generates both behaviors. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Cognitive models of habituation and dishabituation postulate that the latter is attributable to the perturbation of the model of the repeated stimulation stored in short-term memory (STM) by the occurrence of a new stimulus, called dishabituator. However, although both behavioral phenomena depend on STM, previous studies in Aplysia have found that dishabituation seems to require further steps of development of the STM system to emerge. Here, we addressed whether this is a universal condition for the appearance of the 2 forms of learning, namely whether dishabituation must necessarily follow habituation. To this aim, we studied habituation and dishabituation of the freezing response to a sudden acoustic stimulation in newly hatched chicks (1 day old vs. 3 days old). The results showed that in chicks, dishabituation was fully present a few hours after hatching, a pattern of results indicating that, in this precocial avian species, habituation and dishabituation share the same developmental trajectory and the underlying STM mechanisms are simultaneously operative soon after birth. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

A key insight of associative learning theory is that learning depends on the actions of prediction error: a discrepancy between the actual and expected outcomes of a conditioning trial. This view of learning has inspired, and in turn been supported by, work in the neurosciences ranging from single unit recording and neuroimaging studies to pharmacological, chemogenetic, and optogenetic interventions. Here we review evidence describing how error-correcting learning rules are instantiated in the activity of distributed neural circuits controlling the effectiveness of unconditioned stimuli during Pavlovian fear conditioning. We show that these prediction error signals, controlling variations in event processing, are fundamental to Pavlovian fear association formation. We also argue that variations in event processing are embedded within multiplexed learning signals and that a coherent understanding of the nature and relationships between these multiple signals at specific times during the conditioning trial is needed. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Using signal detection theory, we investigated whether human participants represent time linearly or logarithmically in a bisection task. Participants saw a stimulus 1.0 to 1.5 s in duration, and then judged whether the stimulus duration was closer to 1.0 s or to 1.5 s, and how sure they were of their response. Whereas the mean of the subjective stimulus duration was a linear function of the objective stimulus duration, participants produced remarkably different psychophysical functions-linear for some participants, concave for others, and convex for still others. Hence, the appropriate question might not be whether humans encode time linearly or logarithmically, but for which participants and under which conditions is time encoded linearly, logarithmically, or even exponentially. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Goal-directed actions are instrumental behaviors whose performance depends on the organism's knowledge of the reinforcing outcome's value. In contrast, habits are instrumental behaviors that are insensitive to the outcome's current value. Although habits in everyday life are typically controlled by stimuli that occasion them, most research has studied habits using free-operant procedures in which no discrete stimuli are present to occasion the response. We therefore studied habit learning when rats were reinforced for lever pressing on a random-interval 30-s schedule in the presence of a discriminative stimulus (S) but not in its absence. In Experiment 1, devaluing the reinforcer with taste aversion conditioning weakened instrumental responding in a 30-s S after 4, 22, and 66 sessions of instrumental training. Even extensive practice thus produced goal-directed action, not habit. Experiments 2 and 3 contrastingly found habit when the duration of S was increased from 30 s to 8 min. Experiment 4 then found habit with the 30-s S when it always contained a reinforcer; goal-directed action was maintained when reinforcers were earned at the same rate but occurred in only 50% of Ss (as in the previous experiments). The results challenge the view that habits are an inevitable consequence of repeated reinforcement (as in the law of effect) and instead suggest that discriminated habits develop when the reinforcer becomes predictable. Under those conditions, organisms may pay less attention to their behavior, much as they pay less attention to signals associated with predicted reinforcers in Pavlovian conditioning. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Allan and collaborators (Allan, Hannah, Crump, & Siegel, 2008; Allan, Siegel, & Tangen, 2005; Siegel, Allan, Hannah, & Crump, 2009) recently proposed to apply signal detection theory to the analysis of contingency judgment tasks. When exposed to a flow of stimuli, participants are asked to judge whether there is a contingent relation between a cue and an outcome, that is, whether the subjective cue-outcome contingency exceeds a decision threshold. In this context, we tested the following hypotheses regarding the relation between objective and subjective cue-outcome contingency: (a) The underlying distributions of subjective cue-outcome contingency are Gaussian; (b) The mean distribution of subjective contingency is a linear function of objective cue-outcome contingency; and (c) The variance in the distribution of subjective contingency is constant. The hypotheses were tested by combining a streamed-trial contingency assessment task with a confidence rating procedure. Participants were exposed to rapid flows of stimuli at the end of which they had to judge whether an outcome was more (Experiment 1) or less (Experiment 2) likely to appear following a cue and how sure they were of their judgment. We found that although Hypothesis A seems reasonable, Hypotheses B and C were not. Regarding Hypothesis B, participants were more sensitive to positive than to negative contingencies. Regarding Hypothesis C, the perceived cue-outcome contingency became more variable when the contingency became more positive or negative, but only to a slight extent. (PsycINFO Database Record

Much of everyday behavior involves serial decision-making, in which the outcome of 1 choice affects another. An example is setting rules for oneself: choosing a behavioral rule guides appropriate choices in the future. How the brain links decisions across time is poorly understood. Neural mechanisms could be studied in monkeys, as it is known that they can select and use behavioral rules, but existing psychophysical paradigms are poorly suited for the constraints of neurophysiology. Therefore, we designed a streamlined task that requires sequential, linked decisions, and trained 2 rhesus monkeys (Macaca mulatta) to perform it. The task features trial-by-trial consistency, visual stimuli, and eye movement responses to optimize it for simultaneous electrophysiological inquiry. In the first stage of each trial, the monkeys selected a rule or a rule was provided to them. In the second stage, they used the rule to discriminate between 2 test stimuli. Our hypotheses were that they could use self-selected rules and could deliberately select rules based on reinforcement history. We found that the monkeys were as proficient at using self-selected rules as instructed rules. Their preferences for selecting rules correlated with their performance in using them, consistent with systematic, rather than random, strategies for accomplishing the task. The results confirm and extend prior findings on rule selection in monkeys and establish a viable, experimentally flexible paradigm for studying the neural basis of serial decision-making. (PsycINFO Database Record

Although there has been extensive research in both humans and rodents regarding the influence of excitatory predictions on action selection, the influence of inhibitory reward predictions is less well understood. We used a feature-negative conditioned inhibition procedure to generate Pavlovian excitors and inhibitors, predicting the presence or absence of specific outcomes, and assessed their influence on action selection using a Pavlovian-instrumental transfer test. Inhibitors predicting the absence of a specific outcome reversed the bias in action selection elicited by outcome-specific excitors; whereas excitors promoted responding on the action associated with the same outcome as the cue, inhibitors shifted responding away from such actions and toward other actions. Furthermore, the influence of the inhibitors on choice reflected the nature of the inhibitory associations learned by participants; those encoding outcome-specific inhibitory associations showed a strong reversal in the bias elicited by the excitors, selectively biasing performance away from the action associated with the to-be-omitted outcome and toward other actions. In contrast, those encoding only general inhibitory associations did not show any bias during the transfer test and instead reduced their performance of both actions. (PsycINFO Database Record

Early in the 20th century, individual differences were a central focus of psychologists. By the end of that century, studies of individual differences had become far less common, and attention to these differences played little role in the development of contemporary theory. To illustrate the important role of individual differences, here we consider variations in intelligence as a compelling example. General intelligence (g) has now been demonstrated in at least 2 distinct genera: primates (including humans, chimpanzees, bonobos, and tamarins) and rodents (mice and rats). The expression of general intelligence varies widely across individuals within a species; these variations have tremendous functional consequence, and are attributable to interactions of genes and environment. Here we provide evidence for these assertions, describe the processes that contribute to variations in general intelligence, as well as the methods that underlie the analysis of individual differences. We conclude by describing why consideration of individual differences is critical to our understanding of learning, cognition, and behavior, and illustrate how attention to individual differences can contribute to more effective administration of therapeutic strategies for psychological disorders. (PsycINFO Database Record