Attending to a misoriented word causes the eyeball to rotate in the head

Torsional eye movements are triggered by head tilt and a rotating visual field. We examined whether attention to a misoriented form could also induce torsion. Thirty-six observers viewed an adapting field containing a bright vertical Une, and then they viewed a display that was composed of two misoriented words (one rotated clockwise, the other counterclockwise, by 15°, 30°, or 45°). The subjects were instructed to attend to one of the words. The subjects’ adjustments of a reference line to match the tilt of the afterimage showed that attention to a misoriented word produces torsional eye movement (verified with direct measurements on 4 additional subjects). This eye movement reduces the retinal misorientation of the word by about 1°. The results of this study reinforce the linkage between selective attention and eye movements and may provide a useful tool for dissecting different forms of “mental rotation” and other adjustments in internal reference frames. Apparent-motion displays confirming that the eye rotated in the head may be downloaded from www.psychonomic.org/archive.     

Strategies in probabilistic categorization: results from a new way of analyzing performance

The "Weather Prediction" task is a widely used task for investigating probabilistic category learning, in which various cues are probabilistically (but not perfectly) predictive of class membership. This means that a given combination of cues sometimes belongs to one class and sometimes to another. Prior studies showed that subjects can improve their performance with training, and that there is considerable individual variation in the strategies subjects use to approach this task. Here, we discuss a recently introduced analysis of probabilistic categorization, which attempts to identify the strategy followed by a participant. Monte Carlo simulations show that the analysis can, indeed, reliably identify such a strategy if it is used, and can identify switches from one strategy to another. Analysis of data from normal young adults shows that the fitted strategy can predict subsequent responses. Moreover, learning is shown to be highly nonlinear in probabilistic categorization. Analysis of performance of patients with dense memory impairments due to hippocampal damage shows that although these patients can change strategies, they are as likely to fall back to an inferior strategy as to move to more optimal ones.     

Actuarial models for assessing prison violence risk: revisions and extensions of the Risk Assessment Scale for Prison (RASP)

An investigation and extension of the Risk Assessment Scale for Prison (RASP-Potosi), an actuarially derived scale for the assessment of prison violence, was undertaken through a retrospective review of the disciplinary records of the first 12 months of confinement of a cohort of inmates entering the Florida Department of Corrections in 2002 and remaining throughout 2003 (N=14,088). A near replication of the RASP-Potosi and additional analyses based on other weighted logistic regression models were performed on an inmate subsample for whom all information categories were available (n=13,341). Younger age and shorter sentences were associated with increased violent misconduct. Older age, drug conviction, and higher educational attainment were associated with reduced violent misconduct. Regardless of whether the original RASP-Potosi or its progeny were utilized, or the custody level of the inmate sample, the models were modestly successful in predicting prison violence, with the area under the curve (AUC) ranging from .645 to .707.     

Do chimpanzees (Pan troglodytes) understand single invisible displacement?

Previous research suggests that chimpanzees understand single invisible displacement. However, this Piagetian task may be solvable through the use of simple search strategies rather than through mentally representing the past trajectory of an object. Four control conditions were thus administered to two chimpanzees in order to separate associative search strategies from performance based on mental representation. Strategies involving experimenter cue-use, search at the last or first box visited by the displacement device, and search at boxes adjacent to the displacement device were systematically controlled for. Chimpanzees showed no indications of utilizing these simple strategies, suggesting that their capacity to mentally represent single invisible displacements is comparable to that of 18-24-month-old children.