The capacity to predict future events permits a creature to detect, model, and manipulate the causal structure of its interactions with its environment. Behavioral experiments suggest that learning is driven by changes in the expectations about future salient events such as rewards and punishments. Physiological work has recently complemented these studies by identifying dopaminergic neurons in the primate whose fluctuating output apparently signals changes or errors in the predictions of future salient and rewarding events. Taken together, these findings can be understood through quantitative theories of adaptive optimizing control.

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A Neural Substrate of Prediction and Reward

Well-being : the foundations of hedonic psychology

This article considers the role of the hippocampus in memory function. A central thesis is that work with rats, monkeys, and humans--which has sometimes seemed to proceed independently in 3 separate literatures--is now largely in agreement about the function of the hippocampus and related structures. A biological perspective is presented, which proposes multiple memory systems with different functions and distinct anatomical organizations. The hippocampus (together with anatomically related structures) is essential for a specific kind of memory, here termed declarative memory (similar terms include explicit and relational). Declarative memory is contrasted with a heterogeneous collection of nondeclarative (implicit) memory abilities that do not require the hippocampus (skills and habits, simple conditioning, and the phenomenon of priming). The hippocampus is needed temporarily to bind together distributed sites in neocortex that together represent a whole memory.

Memory and the hippocampus: A synthesis from findings with rats, monkeys, and humans.

the total number of papers may exceed 10,000. Nevertheless, cost consideration forced us to consider mostly published papers and technical reports in English. 4 Formula 4 in Seifert (1991) is in error—a multiplier of n, of cell size, is missing in the numerator. 5 Unfortunately, the technique of meta-analysis cannot be applied, at present time, to such effects because the distribution of dis based on a sampling of people, whereas the statistics of techniques such as ARIMA are based on the distribution of a sampling of observations in the time domain regardless of the size of the people sample involved (i.e., there is no way to compare a sample of 100 points in time with a sample of 100 people). That is, a sample of 100 points in time has the same degrees of freedom if it were based on an observation of 1 person or of 1,000 people. 258 KLUGER AND DENISI From the papers we reviewed, only 131 (5%) met the criteria for inclusion. We were concerned that, given the small percentage of usable papers, our conclusions might not fairly represent the larger body of relevant literature. Therefore, we analyzed all the major reasons to reject a paper from the meta-analysis, even though the decision to exclude a paper came at the first identification of a missing inclusion criterion. This analysis showed the presence of review articles, interventions of natural feedback removal, and papers that merely discuss feedback, which in turn suggests that the included studies represent 1015% of the empirical FI literature. However, this analysis also showed that approximately 37% of the papers we considered manipulated feedback without a control group and that 16% reported confounded treatments, that is, roughly two thirds of the empirical FI literature cannot shed light on the question of FI effects on performance—a fact that requires attention from future FI researchers. Of the usable 131 papers (see references with asterisks), 607 effect sizes were extracted. These effects were based on 12,652 participants and 23,663 observations (reflecting multiple observations per participant). The average sample size per effect was 39 participants. The distribution of the effect sizes is presented in Figure 1. The weighted mean (weighted by sample size) of this distribution is 0.41, suggesting that, on average, FI has a moderate positive effect on performance. However, over 38% of the effects were negative (see Figure 1). The weighted variance of this distribution is 0.97, whereas the estimate of the sampling error variance is only 0.09. A potential problem in meta-analyses is a violation of the assumption of independence. Such a violation occurs either when multiple observations are taken from the same study (Rosenthal, 1984) or when several papers are authored by the same person (Wolf, 1986). In the present investigation, there were 91 effects derived from the laboratory experiments reported by Mikulincer (e.g., 1988a, 1988b). This raises the possibility that the average effect size is biased, because his studies manipulated extreme negative FIs and used similar tasks. In fact, the weighted average d in Mikulincer's studies was —0.39; whereas in the remainder of the

The effects of feedback interventions on performance: A historical review, a meta-analysis, and a preliminary feedback intervention theory.

In this article we propose mechanisms that govern the processing of emotional information, particularly those involved in fear reduction. Emotions are viewed as represented by information structures in memory, and anxiety is thought to occur when an information structure that serves as program to escape or avoid danger is activated. Emotional processing is denned as the modification of memory structures that underlie emotions. It is argued that some form of exposure to feared situations is common to many psychotherapies for anxiety, and that confrontation with feared objects or situations is an effective treatment. Physiological activation and habituation within and across exposure sessions are cited as indicators of emotional processing, and variables that influence activation and habituation of fear responses are examined. These variables and the indicators are analyzed to yield an account of what information must be integrated for emotional processing of a fear structure. The elements of such a structure are viewed as cognitive representations of the stimulus characteristic of the fear situation, the individual's responses in it, and aspects of its meaning for the individual. Treatment failures are interpreted with respect to the interference of cognitive defenses, autonomic arousal, mood state, and erroneous ideation with reformation of targeted fear structures. Applications of the concepts advanced here to therapeutic practice and to the broader study of psychopathology are discussed.

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Emotional processing of fear : exposure to corrective information

A comparison of responses and stimuli as time markers

The schedule of punishment, like the schedule of positive reinforcement, is an important determinant of response rate. The amount of response suppression of rats in a free-responding situation was considerably greater for those given a variable-interval schedule of punishment than for those given a fixed-ratio schedule of punishment, even under conditions that roughly equated the frequency of punishments.

/pdf/response-suppression-as-a-function-of-the-schedule-of-ctrngdc52i.pdf

Response suppression as a function of the schedule of punishment

Behavioristic, Cognitive, Biological, and Quantitative Explanations of Timing

Pinworm infection in rodent laboratories is common and often treated with fenbendazole, which is effective and has a low toxicity level. However, very little is known about the behavioral effects of the drug. The purpose of this study was to determine the behavioral effects of fenbendazole on rats tested by using various conditioning and timing procedures. These behavioral effects were examined both between animals (i.e., control versus medicated treatments) and within animals (baseline-treatment-baseline design). Fenbendazole reduced the detection of pinworm eggs, and it had no significant behavioral effects across multiple levels of analysis (e.g., from overall response rates to response patterns to interresponse intervals). All behavioral differences (e.g., discrimination ratios) were a result of task variables. These results suggest that behavioral studies are unlikely to be influenced by fenbendazole treatment given before or during a study.

The lack of behavioral effects of fenbendazole: a medication for pinworm infection.

Classical conditioning is normally thought to strengthen associations between stimuli, and instrumental conditioning is thought to select responses. This difference has been used to account for the usual result that instrumental conditioning produces higher response rates than classical conditioning. The present experiment suggests that the comparison of instrumental and classical tasks has overlooked temporal cues that are often confounded with response contingency, and that the time cues exert a critical influence on response rate. When the two tasks are equated for temporal cues, the response rate of rats is similar in classical and instrumental tasks.

Russell M. Church

Papers

A comparison of responses and stimuli as time markers

Response suppression as a function of the schedule of punishment

Behavioristic, Cognitive, Biological, and Quantitative Explanations of Timing

The lack of behavioral effects of fenbendazole: a medication for pinworm infection.

Response Rates Are Governed More by Time Cues Than Contingency