Event detail and confidence in gambling: The role of counterfactual thought reactions

Differences in people’s reactions to the same events described with full vs. sketchy information are examined. It is hypothesized that differences in counterfactual thought reactions to varying levels of event detail shape confidence in, and willingness to gamble on similar, future events. In three experiments, participants were presented with different types and levels of event detail about their performances on a trivia test, on several games of blackjack, or on gambling on a professional horse race. Upward counterfactual thoughts were observed more frequently in response to losing events containing high levels of detail and specificity. Importantly, counterfactual thought frequency also mediated the relationships between event detail and the level of confidence in and willingness to gamble on similar, future events. Evidence also indicates that this relationship is based on the hindsight bias that results from counterfactual thinking. Results are discussed in terms of cognitive processes and decision making research.     

Skill Acquisition and the LISP Tutor

An analysis of student learning with the LISP tutor indicates that while LISP is complex, learning it is simple. The key to factoring out the complexity of LISP is to monitor the learning of the 500 productions in the LISP tutor which describe the programming skill. The learning of these productions follows the power-law learning curve typical of skill acquisition. There is transfer from other programming experience to the extent that this programming experience involves the same productions. Subjects appear to differ only on the general dimensions of how well they acquire the productions and how well they retain the productions. Instructional manipulations such as remediation, content of feedback, and timing of feedback are effective to the extent they give students more practice programming, and explain to students why correct solutions work.     

Defensive burying, nest relocation, and pup transport in lactating female rats

A wire-wrapped wooden dowel was inserted through the wall of the nest compartment of a two-compartment box. There were four conditions. Some lactating female rats were shocked by the dowel when they first touched it, and some were not, after which the dowel was either immediately withdrawn from the chamber or left in place for the duration of the ensuing 30-min test period. Three defensive behaviours were observed during the tests: the mothers buried the shock source with bedding from the floor of the chamber, they transported their pups to the adjoining “safe” chamber, and they built a new nest in the safe chamber from material salvaged from their original nest. The shocked mothers that were confronted with the shock source throughout the test period displayed significantly more of each of these three defensive behaviours than did the mothers in the other three conditions. The methods used in this study provide a simple, reliable, safe paradigm for studying maternal defensive behaviour; the results indicate that the defensive capacities of the rat extend far beyond stereotypical flight, freeze, and fight responses, which have been the focus of most research on rodent defense.     

Spatial memory of four species of parus: Performance in an open-field analogue of a radial maze

The performance of four species of tit (marsh tit, Parus palustris; coal tit, P. ater; blue tit, P. caeruleus; and great tit, P. major) and one finch (greenfinch, Carduelis choris) was compared in an open field analogue of the radial maze. There were no differences between the tit species in either acquisition or asymptotic performance. The greenfinch showed less improvement with experience than the tits. When the retention interval between forced choice of four goal boxes and free choice of all eight was varied between 30 sec and 24 hr, performance declined with increasing interval. After 24 hr some individuals still performed above chance, and the food-storing tits combined (marsh and coal tit) were above chance, whilst the non-storers (blue and great tits) were not (this was primarily due to the poor performance of great tits). The results are discussed in relation to the hypothesis that food-storing tits have a specialized spatial memory.     

Measurement of visual aftereffects and inferences about binocular mechanisms in human vision

There is conflicting evidence concerning the characteristics of binocular channels in the human visual system with respect to the existence of a 'pure' binocular channel that responds only to simultaneous stimulation of both eyes. Four experiments were conducted to resolve these discrepancies and to evaluate the evidence for the existence of such an exclusive binocular channel. In the first three studies, tilt aftereffects were measured after monocular adaptation. The relative sizes of the direct, interocularly transferred, and binocular aftereffects were not influenced by the configuration of the adapting pattern (experiment 1), or by the eye used for adaptation (experiment 2). There were also consistent interobserver differences in the relative sizes of the aftereffect seen after monocular adaptation (experiment 3). Taken together, these data raise questions about the appropriateness of a monocular adaptation paradigm for evaluating the presence of a pure binocular channel in observers with normal binocular vision. In experiment 4, in which the paradigm of alternating monocular adaptation was used, data were obtained that are consistent with the presence of a pure binocular channel.     

Abstract Planning and Perceptual Chunks: Elements of Expertise in Geometry

We present a new model of skilled performance in geometry proof problem solving called the Diagram Configuration model (DC). While previous models plan proofs in a step-by-step fashion, we observed that experts plan at a more abstract level: They focus on the key steps and skip the less important ones. DC models this abstract planning behavior by parsing geometry problem diagrams into perceptual chunks, called diagram configurations, which cue relevant schematic knowledge. We provide verbal protocol evidence that DC's schemas correspond with the step-skipping inferences experts make in their initial planning. We compare DC with other models of geometry expertise and then, in the final section, we discuss more general implications of our research. DC's reasoning has important similarities with Larkin's (1988) display-based reasoning approach and Johnson-Laird's (1983) mental model approach. DC's perceptually based schemas are a step towards a unified explanation of (1) experts' superior problem-solving effectiveness, (2) experts' superior problem-state memory, and (3) experts' ability, in certain domains, to solve relatively simple problems by pure forward inferencing. We also argue that the particular and efficient knowledge organization of DC challenges current theories of skill acquisition as it presents an end-state of learning that is difficult to explain within such theories. Finally, we discuss the implications of DC for geometry instruction.