Publications by authors named "Lorraine G Allan"

We demonstrate large differences in judging positive and null contingencies between younger and older adults with a task commonly used to explore cue competition in both contingency and causality judgements. The one-phase blocking task uses two cues, with separate contingencies with the same outcome. The age differences persisted even when participants knew in advance which of the two contingencies to judge.

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Siegel, Allan, Hannah, and Crump (2009) demonstrated that cue interaction effects in human contingency judgments reflect processing that occurs after the acquisition of information. This finding is in conflict with a broad class of theories. We present a new postacquisition model, the criterion-calibration model, that describes cue interaction effects as involving shifts in a report criterion.

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The present study captures the dynamics of neural processing across positively contingent, negatively contingent, and noncontingent relations. In the setting of a hypothetical chat room conversation, participants rated the contingency of emotional response between two individuals. Event-related potentials (ERPs) were time-locked to the onset of each emotional event.

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The authors previously described a procedure that permits rapid, multiple within-participant assessments of the contingency between a cue and an outcome (the "streamed-trial" procedure, Crump, Hannah, Allan, & Hord, 2007). In the present experiments, the authors modified this procedure to investigate cue-interaction effects, replicating conventional findings in both the one- and two-phase blocking paradigms. The authors show that the streamed-trial procedure is not restricted to the geometric forms used as cues and outcomes by Crump et al.

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The authors previously described a procedure that permits rapid, multiple within-participant evaluations of contingency assessment (the "streamed-trial" procedure, M. J. C.

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The present research was conducted to establish the validity of a novel procedure for measuring human contingency judgements aimed at shortening the length of conventional procedures. Cues and outcomes were simple geometric shapes that were presented in a rapid streaming fashion, reducing the length of a block of trials from several minutes to a few seconds. We establish the reliability of the procedure by replicating two central findings in the contingency judgement literature, and we elaborate on the importance of this method for future research.

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In one form of a contingency judgement task individuals must judge the relationship between an action and an outcome. There are reports that depressed individuals are more accurate than are non-depressed individuals in this task. In particular, nondepressed individuals are influenced by manipulations that affect the salience of the outcome, especially outcome probability.

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Many studies of contingency judgments have used a task in which, on each trial, the participant is free either to respond or not to respond, and an outcome may, or may not, be presented. Typically, the experimenter specifies a nominal value for the contingency between responding and outcome, but the actual values of a variety of variables experienced by a particular participant depend on that participant's frequency of responding. The results of computer simulations of various strategies for implementing the contingency manipulation, and the results of an experiment, indicate that the same nominal contingency value will lead to considerable variability in the actual contingency experienced by participants.

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There are many psychological tasks that involve the pairing of binary variables. The various tasks used often address different questions and are motivated by different theoretical issues and traditions. Upon closer examination, however, the tasks are remarkably similar in structure.

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A decade ago, Allan (1993) concluded that associative models provided the best account of data generated in tasks that require human observers to judge the relationship between binary events. In the intervening years, new data have been reported that provide evidence for higher-order processes. Some have argued that these new data pose a serious threat to the viability of the associative account.

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In four experiments, the predictions made by causal model theory and the Rescorla-Wagner model were tested by using a cue interaction paradigm that measures the relative response to a given event based on the influence or salience of an alternative event. Experiments 1 and 2 uncorrelated two variables that have typically been confounded in the literature (causal order and the number of cues and outcomes) and demonstrated that overall contingency judgments are influenced by the causal structure of the events. Experiment 3 showed that trial-by-trial prediction responses, a second measure of causal assessment, were not influenced by the causal structure of the described events.

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The two experiments reported examine the role of temporal contiguity on judgments of contingency in a human analogue of the Pavlovian task. The data show that the effect of the actual delay on contingency judgment depends on the observer's expectation regarding the delay. For a fixed contingency between the cue and the outcome, ratings of the contingency are higher when the actual delay is congruent with the observer's expectation than when it is incongruent.

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In a recent theoretical paper, Cheng (1997) presented a new causal model, power PC. She argued that power PC was able to account for data in the literature that raised problems for associative models--notably, the Rescorla-Wagner model (Rescorla & Wagner, 1972). The purpose of the present paper is threefold: (1) to show that, overall, the data in the literature, which Cheng relied on to make her case, do not in fact provide support for power PC, (2) to show that, overall, the experiments reported in the literature since the publication of Cheng, designed specifically to evaluate the predictions of power PC, also do not provide support for power PC, and (3) to suggest that Cheng's assessment of associative models was too narrowly defined.

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It is well established that two predictor cues (A and B) of a common outcome interact in that the judgement of the relationship between each cue and the outcome is influenced by the pairing history of the other cue with that outcome. For example, when the contingency of A with an outcome is weaker than the contingency of B with that outcome, the rating of the predictiveness of A is reduced relative to a situation where only A is paired with the outcome. One explanation of such cue interaction effects is provided by the conditional deltaP account.

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Some instances of the placebo effect may be understood as a particular type of error made by the patient--a false positive error. False positive errors are common (indeed, frequently encouraged) in medical decision making, both by diagnosticians and by patients, and are the inevitable consequence of concluding that an ambiguous signal (e.g.

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In a temporal bisection task with humans, the observer is required to decide whether a probe duration (t) is more similar to the short referent (S), an R(S) response, or to the long referent (L), an RL response. Temporal bisection yields a psychometric function relating the proportion of long responses, P(R(L)), to probe duration t. The value of t at which R(S) and R(L) occur with equal frequency, P(R(L)) = .

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