A unified fielder theory for interception of moving objects either above or below the horizon

A unified fielder theory is presented that explains how humans navigate to intercept targets that approach from either above or below the horizon. Despite vastly different physical forces affecting airborne and ground-based moving targets, a common set of invariant perception-action principles appears to guide pursuers. When intercepting airborne projectiles, fielders keep the target image rising at a constant optical speed in a vertical image plane and moving in a constant optical direction in an image plane that remains perpendicular to gaze direction. We confirm that fielders use the same strategies to intercept grounders. Fielders maintained a cotangent of gaze angle that decreases linearly with time (accounting for 98.7% of variance in ball speed) and a linear optical trajectory along an image plane that remains perpendicular to gaze direction (accounting for 98.2% of variance in ball position). The universality of maintaining optical speed and direction for both airborne and ground-based targets supports the theory that these mechanisms are domain independent.     

Clinicians' judgments of clinical utility: a comparison of the DSM-IV and five-factor models

Clinical utility, or the usefulness of a diagnostic system in clinical practice, has been identified as an important construct in proposed revisions to the diagnostic nomenclature and a significant limitation of dimensional models of personality disorder, such as the 5-factor model (FFM). Only 1 study to date has addressed explicitly the clinical utility of the FFM, and the findings suggested significant limitations. In the current study, 245 practicing psychologists described 3 historic cases using both the FFM and the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV; American Psychiatric Association, 2000) and then rated each model on 6 aspects of clinical utility. In contrast to prior research, the psychologists in this study considered the FFM to have greater clinical utility than the existing diagnostic categories.     

Determinants of justification and self-control

The authors propose that people use 2 routes in justifying self-gratification: 1st through hard work or excellence (entitlement) and the 2nd through the attainment of vices without depleting income. This framework was tested using real tasks and choices adopted from prior research on self-control. The results indicate that (a) higher effort and (bogus) excellence feedback increase preferences for vice rewards, but these effects are reversed or attenuated when the interchangeability of effort and income is implied; (b) willingness to pay in effort is greater for vices than virtues, but willingness to pay in income is higher for virtues; and (c) these effects are magnified among individuals with stronger (chronic or manipulated) guilt. The authors discuss the ability of the justification routes to explain the findings of prior self-control research.     

Producing biased diagnoses with unambiguous stimuli: The importance of feature instantiations

In this article, the authors demonstrate a laboratory analogue of medical diagnostic biasing (V. R. LeBlanc, G. R. Norman, & L. R. Brooks, 2001) in 2 experiments and explore the basis of this effect. Before categorizing novel exemplars, participants first evaluated the likelihood that the item was a member of the category suggested on that trial: either the correct category or a plausible alternative category. This was sufficient to produce a substantial bias toward the suggested category despite the use of unambiguous stimuli, explicit rules, and unhurried conditions--each of which would be likely to limit diagnostic bias. The authors argue that the production of this effect requires distinguishing between particular feature instantiations and more abstract representations of those features as well as allowing people to adopt a particular decision strategy mediating the use of instantiated features: a feature-recognition heuristic.     

Effects of instruction presentation mode in comparative judgments

In each of two experiments, the comparative instructions in a symbolic comparison task were either varied randomly from trial to trial (mixed blocks) or left constant (pure blocks) within blocks of trials. In the first experiment, every stimulus was compared with every other stimulus. The symbolic distance effect (DE) was enhanced, and the semantic congruity effect (SCE) was significantly larger, when the instructions were randomized than when they were blocked. In a second experiment, each stimulus was paired with only one other stimulus. The SCE was again larger when instructions were randomized than when they were blocked. The enhanced SCE and DE with randomized instructions follow naturally from evidence accrual views of comparative judgments.     

Place and summation coding for canonical and non-canonical finger numeral representations

Fingers can be used to express numerical magnitudes, and cultural habits about the fixed order in which fingers are raised determine which configurations become canonical and which non-canonical. Although both types of configuration carry magnitude information, it has been shown that the canonical ones are recognized faster and directly linked to number semantics. Here we tested whether this difference is a consequence of differences in the qualitative way of processing the two types of configurations. When participants named Arabic digits (Experiment 1) or verbal numerals (Experiment 2) primed by canonical and non-canonical finger configurations, qualitatively different priming patterns were observed for the two types of configurations. Canonical configurations activated a place coding representation, with priming spreading to close smaller and larger magnitudes as a function of the prime–target distance. Conversely, non-canonical configurations activated a summation coding representation priming smaller and equal magnitudes independently of the prime–target distance, and larger targets depending on this distance.