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Gaissmaier and Schooler (2008) [Gaissmaier, W., & Schooler, L. J. (2008). The smart potential behind probability matching. Cognition, 109, 416-422] argue that probability matching, which has traditionally been viewed as a decision making error, may instead reflect an adaptive response to environments in which outcomes potentially follow predictable patterns. In choices involving monetary stakes, we find that probability matching persists even when it is not possible to identify or exploit outcome patterns and that many "probability matchers" rate an alternative strategy (maximizing) as superior when it is described to them. Probability matching appears to reflect a mistaken intuition that can be, but often is not, overridden by deliberate consideration of alternative choice strategies.

The effects of alcohol (1.0 ml/kg body weight) and practice (2 sessions) were investigated in 2-, 4-, and 8-choice reaction time (RT) tasks with 24 male subjects. The number of errors increased with alcohol, practice, and increasing task complexity (choice). Mean RT decreased with practice, but increased with alcohol and complexity. Both the alcohol and practice effects on mean RT increased as complexity increased. The effects of alcohol, practice, and complexity were all larger for the higher percentiles of the RT distributions than for the lower percentiles. RT distributions were further analysed at each level of choice by plotting percentiles (5th, 10th, ... , 95th) for alcohol conditions against corresponding percentiles for no-alcohol conditions, and percentiles obtained early in practice (Session 1) against those obtained later in practice (Session 2). These plots revealed that whereas at all levels of choice the effect of alcohol could be expressed as a simple linear transformation of all RTs, the effect of practice required a more complex curvilinear transformation. Thus, alcohol produces a general slowing of all RTs, whereas practice produces a disproportionate improvement at the slower end of the RT distribution.

Probability matching in sequential decision making is a striking violation of rational choice that has been observed in hundreds of experiments. Recent studies have demonstrated that matching persists even in described tasks in which all the information required for identifying a superior alternative strategy-maximizing-is present before the first choice is made. These studies have also indicated that maximizing increases when (1)the asymmetry in the availability of matching and maximizing strategies is reduced and (2)normatively irrelevant outcome feedback is provided. In the two experiments reported here, we examined the joint influences of these factors, revealing that strategy availability and outcome feedback operate on different time courses. Both behavioral and modeling results showed that while availability of the maximizing strategy increases the choice of maximizing early during the task, feedback appears to act more slowly to erode misconceptions about the task and to reinforce optimal responding. The results illuminate the interplay between "topdown" identification of choice strategies and "bottom-up" discovery of those strategies via feedback. Keywords Probability matching . Maximizing . Decision making . Heuristics . Rational choice theory When faced with a choice between two options, one of which offers a higher probability of receiving a fixed payoff than does the other, a rational agent should always choose the option with the higher payoff probability. For example, if one option delivers one dollar 70 % of the time (and nothing the rest of the time), while the other pays one dollar only 30 % of the time (and otherwise nothing), a rational agent should choose the 70 % option. This is true whether the choice is faced once or repeatedly: The option offering the higher probability of receiving the payoff should always be chosen.Despite the clear superiority of this strategy (referred to as maximizing), participants faced with a series of such choices often show responding closer to probability matching-allocating responses to the two options in proportion to their relative probabilities of occurrence. In other words, people bet on the 30 % option 30 % of the time, and the 70 % option 70 %

The effects of alcohol and extended practice on divided attention were investigated using a visual tracking task and an auditory detection task. Subjects performed the tasks with and without alcohol, under single-task (S) and dual-task (D)conditions, both before and after they had received extended practice under single-task conditions without alcohol. Tracking accuracy improved with practice and was impaired under divided-attention conditions but was not affected by alcohol. Speed of detection was impaired by alcohol, improved by practice, and impaired by divided attention. Extended practice did not reduce the influence of alcohol. The effects of both alcohol and practice on speed of detection were significantly greater under dual-task conditions than under single-task conditions. Analysis of detection-task reaction times in terms of relative dividedattention costs, (D-S)/S, showed no effect of alcohol, but a highly significant reduction in costs with extended practice. It is concluded that (1) alcohol and practice can have quantitatively, but not qualitatively, similar effects on speeded performance, and (2) the effect of alcohol is not influenced by the attentional requirements of the task.A common strategy for research on the effects of alcohol has been to construct exhaustive catalogs of "components" of the human information-processing system that are, and are not, sensitive to its effects. The result has been that deficits have been proposed at almost every stage of information processing (Wallgren & Barry, 1970). Many of the conclusions are based on marked interactions between alcohol and task complexity, which have been interpreted as the effect of alcohol on specific informationprocessing subsystems (e.g., Huntley, 1974).However, recent work on the complexity effect, particularly in gerontology, has suggested that some caution is necessary in using this methodology to demonstrate localized effects (Cerella, 1985; Myerson, Hale, Wagstaff, Poon, & Smith, in press;Salthouse, 1985). Thus, it is argued that many of the results interpreted as evidence for an effect on a specific mechanism could also be produced by a general mechanism, such as a generalized slowing of information-processing speed. If we assume that the absolute effect of alcohol upon performance increases with increased task complexity (which could perhaps be defined in terms of the number of mental operations presumed necessary to perform the task), it is clear that virtually any manipulation that produces a substantial increase in the level of task complexity will also result in an interaction between alcohol and that manipulation.