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PubMed2001

The effects of event rate and signal probability on children's vigilance.

Using the study of vigilance in adults as their model, the researchers examined task parameters and their interactions in a study of sustained attention in children from a non-clinical population. Two levels of event rate (low and high) were combined with two levels of signal probability (low and high) in 14-minute vigilance tasks in which children viewed small and large squares presented successively on a computer screen. Seven- and eight-year-old children were instructed to press a button whenever a small square appeared. Signal detection analyses were employed, as well as the traditional measures identifying hits, false alarms, and reaction time. The results support the traditional findings in adult tasks: participants performed most accurately and quickly in the high event rate and high probability condition; low probability elicited a more conservative decision-making criterion, a standard characterized by less willingness to risk false alarms; such conservatism increased over the periods of watch; and the vigilance decrement emerged over time. However, the finding that the high event rate condition improved perceptual sensitivity reversed the event rate effect consistently reported in the adult literature. The above findings are discussed in light of both research and clinical implications.

Age Factors↗
PubMed2003

Controlling for causally relevant third variables.

In 3 experiments, the authors tested the conditions under which 3rd variables are controlled for in making causal judgments. The authors hypothesized that 3rd variables are controlled for when the 3rd variables are themselves perceived as causal. In Experiment 1, the participants predicted test performance after seeing information about wearing a lucky garment, taking a test-preparation course, and staying up late. The course (perceived as more causally relevant) was controlled for more than was the garment (perceived as less causally relevant) in assessing the effectiveness of staying up late. In Experiments 2 and 3, to obviate the many alternative accounts that arise from the realistic cover story of Experiment 1, participants predicted flowers' blooming after the presentation or nonpresentation of liquids. When one liquid was trained as causal, it was controlled for more in judging another liquid than when it was trained as neutral. Overall, stimuli perceived as causal were controlled for more when judging other stimuli. The authors concluded that the effect of perceived causal relevance on causal conditionalizing is real and normatively reasonable.

Adolescent↗
PubMed1991

Strategy changes in human contingency judgments as a function of contingency tables.

Judgment strategies of 169 undergraduate students on problems to judge the contingency between two binary events were identified by the method of rule-based analysis to clarify whether or not the strategies the subjects used would be affected by the concrete nature of the contingency table. Problems were constructed along two factors: total cell frequency and width of range of objective contingencies. Although the factor of total cell frequency had no effect on subjects' strategies, the number of subjects who changed strategies corresponding with problem instances increased when the objective contingencies were set closer to zero or when problems became more difficult. These results are discussed in the context of previous studies of this issue in the literature.

Adolescent↗
PubMed1997

Suspiciousness, mental simulation, and norm theory.

Seven studies were conducted to replicate the work of Miller, Turnbull, and McFarland (1989), who tested predictions from norm theory (Kahneman & Miller, 1986). The first three studies with stimulus materials identical to those used by Miller et al. failed to confirm that the ease with which the event might be mentally simulated affected the degree of suspiciousness. In Studies 4, 5, and 6, the improbable events were made objectively more probable, but this did not produce significant results. In the 7th study, the objective probability and attitude toward the target were varied. Although there was a main effect for ease of mental simulation, this effect was produced by only 1 of the 3 vignettes.

Adult↗
PubMed1989

Decision making in sport: the effect of stimulus-response probability on the performance of a coincidence-anticipation task.

The purpose of the present study was to evaluate the quality of a motor response for different levels of expectancy and time constraint, in a two-choice coincidence-anticipation task. The probability of each of the two events likely to be presented were varied across different levels as well as the speed of the stimulus to be intercepted. The results indicated that neither the choice reaction time (CRT) and movement time, nor the performance of coincidence-anticipation were affected by the probability of the stimulus for the low and moderate stimulus speeds. However, when the stimulus traveled at a high speed a trade-off took place. The CRT decreased as the probability of the event increased, whilst the proportion of response initiation errors increased for the low probability events. This trade-off resulted in a better coincidence-anticipation as the probability of the event increased. The results obtained in the present experiment are clearly different from those obtained in a classic CRT-deadline paradigm, in that the trade-off observed between CRT and response initiation errors was far less pronounced in the coincidence-anticipation task. This difference was attributed to the higher negative consequences associated with a response initiation error in a coincidence-anticipation task. It is thus concluded that the tasks used to study the nature of the decision processes taking place in sports and sports-like situations must have some ecological validity to be of some help for the practitioner.

Adult↗
PubMed2004

The difference between generating counter examples and using them during reasoning.

The aim of this article is to provide insight into the types of long-term knowledge that are used for solving causal conditional inferences. Two taxonomies were constructed to map the types of counter example. The available counter examples are traditionally probed via a counter example generation task. We observed that there are some significant differences in the types of counter example retrieved in the reasoning task versus the generation task. The generation task can be used for predicting answers that sprout from a reasoning process that takes counter example into account, but some participants use a different reasoning process in which the available semantic information is not used as contrasting evidence. Nonetheless, we found that the results of the generation task validly predicted the proportion of inferences accepted as well as the number of counter examples used during reasoning.

Classification↗
PubMed2005

Generation of hypotheses in Wason's 2-4-6 task: an information theory approach.

We explored the "context of discovery" in Wason's 2-4-6 task, focusing on how the first hypothesis is generated. According to Oaksford and Chater (1994a) people generate hypotheses extracting "common features", or regularities, from the available triples, but their model does not explain why some regularities contribute to the hypothesis more than do other regularities. Our conjecture is that some regularities contribute to the hypothesis more than do other regularities because people estimate the amount of information in the perceived regularities and try to preserve as much information as possible in their initial hypotheses. Experiment 1, which used two initial triples, showed that the presence of high-information relational regularities in the initial triples affected the information in the initial hypotheses more than did the presence of low-information object regularities. Experiment 2 extended the results to the classic situation in which only one initial triple is given. It also suggested that amount of information is the only aspect of the structure of the triple that affects hypotheses generation. Experiment 3 confirmed the latter finding: Although relations are commonly distinguished between first-order and higher order relations, the latter being most important for generating hypotheses (Gentner, 1983), higher order relations do have an effect on Wason's 2-4-6 task only if their presence incre ases information. In the conclusion we discuss the statistical soundness of human hypotheses generation processes, and we ask an unanswered question: Amount of information explains why some regularities are preferred to others, but only within a set of "nonarbitrary" regularities; there are object regularities that are rich in information content, but are considered "arbitrary", and are not used in generating hypotheses. Which formal property can distinguish between these two sets of regularities?

Adult↗
PubMed2005

Categorical reasoning from multiple diagrams.

Syllogistic reasoning from categorical premise pairs is generally taken to be a multistep process. Quantifiers (all, no, some, some ... not) must be interpreted, representations constructed, and conclusions identified from these. Explanations of performance have been proposed in which errors may occur at any of these stages. The current paper contrasts (a) representation explanations of performance, in which errors occur because not all possible representations are constructed, and/or mistakes are made when doing so (e.g., mental models theory), and (b) conclusion identification explanations, in which errors occur even when information has been correctly and exhaustively represented, due to systematic difficulties that people may have when identifying particular conclusions, or in identifying conclusions in particular circumstances. Three experiments are reported, in which people identified valid conclusions from diagrams analogous to Euler circles, so that the first two stages of reasoning from premise pairs were effectively removed. Despite this, several phenomena associated with reasoning from premise pairs persisted, and it is suggested that whereas representation explanations may account for some of these phenomena, conclusion identification explanations, which have never previously been considered, are required for others.

Adolescent↗
PubMed1992

Heuristics in medical and non-medical decision-making.

Pairs of hypothetical medical and non-medical problems were given to 44 pediatric residents at three levels of hospital training. Each problem was designed to detect a specific heuristic-based bias in making diagnoses. Discounting, disregarding base rate, and over-confidence in contextually embedded redundant information were more evident on medical than on non-medical problems. In particular, a greater number of third-year residents disregarded base-rate information than did first- and second-year residents on medical but not on non-medical problems. On medical problems, a greater number of first-year residents expressed greater confidence in redundant information that was contextually embedded than in information that was presented in a listed format. Over one-third of the residents confused prospective and retrospective probabilities; three-fourths showed evidence of augmentation; virtually all residents expressed greater confidence in a diagnosis based on redundant rather than on non-redundant listed information. These latter effects were consistent across training level and occurred on both medical and non-medical problems. The results are discussed in terms of prototype theory and the nature of medical training.

Adult↗
PubMed2003

The relative effect of cue interaction.

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. Spellman (1996b) derived a counterintuitive prediction of the conditional deltaP account where cue interaction should not occur under certain conditions even though a relatively poor predictor of an outcome is paired with a relatively good predictor of that outcome. However, Spellman (1996b) did not provide data to evaluate this prediction. In the present paper, we report the relevant data and show that they are consistent with the conditional deltaP account. A competing account of cue interaction is provided by the Rescorla-Wagner (RW) model. We derive the predictions of the RW model for the conditions specified by Spellman (1996b), and show that at asymptote the predictions of the RW model are identical to those of the conditional deltaP account.

Adult↗
PubMed2006

Dynamic perception in chess.

The present study examines the dynamic aspects of perceptual processes in expert chess players. This topic is approached in terms of the anticipation processes carried out by experienced players during the encoding of chess positions. The aim of the first experiment, which used a short-term comparison task, was to stress the role of anticipation, which allows expert players to focus their attention on the area of the studied position where they expect the likely standard move to occur. The second experiment used a long-term recognition task. The results showed that expert players made many false recognitions on the new positions that could be expected from the positions presented in the preliminary study phase. Taken together, the results of the two experiments highlight the anticipatory component of expert perception.

Adolescent↗
PubMed2006

Working memory capacity and the construction of spatial mental models in comprehension and deductive reasoning.

We asked 149 high-school students who were pretested for their working memory capacity (WMC) to read spatial descriptions relating to five objects and to evaluate conclusions asserting an unmentioned relationship between two of the objects. Unambiguous descriptions were compatible with a single spatial arrangement, whereas ambiguous descriptions permitted two arrangements; a subset of the ambiguous descriptions still determined the relation asserted in the conclusion, whereas another subset did not. Two groups of participants received different instructions: The deduction group should accept conclusions only if they followed with logical necessity from the description, whereas the comprehension group should accept a conclusion if it agreed with their representation of the arrangement. Self-paced reading times increased on sentences that introduced an ambiguity, replicating previous findings in deductive reasoning experiments. This effect was also found in the comprehension group, casting doubt on the interpretation that people consider multiple possible arrangements online. Responses to conclusions could be modelled by a multinomial processing model with four parameters: the probability of constructing a correct mental model, the probability of detecting an ambiguity, and two guessing parameters. Participants with high and with low WMC differed mainly in the probability of successfully constructing a mental model.

Adolescent↗
PubMed1996

To forget or not to forget: the effect of probability of test on directed forgetting.

Two experiments investigated how individuals use explicit memory cues that designate different probabilities of test. As in typical directed forgetting studies, subjects received words explicitly cued as having either a 0% or a 100% chance of being on a subsequent memory test (i.e. forget and remember cues, respectively). In addition, some words were explicitly cued as having the potential to be either forgotten or remembered (i.e. a 50% cue). Recall of 50% words was between that of 0% and 100% words. In addition, the presence of 50% words lowered recall of the 100% words compared to that of a control group that did not receive 50% words, but received the same number of 100% words. A think-aloud task indicated that these results were due to 50% words being treated like either 100% of 0% words at encoding. The results are discussed in terms of the effect of different probabilities of test on the strategic processing and representation of information.

Adult↗