Perceiving possibilities for action: on the necessity of calibration and perceptual learning for the visual guidance of action

Tasks such as steering, braking, and intercepting moving objects constitute a class of behaviors, known as visually guided actions, which are typically carried out under continuous control on the basis of visual information. Several decades of research on visually guided action have resulted in an inventory of control laws that describe for each task how information about the sufficiency of one's current state is used to make ongoing adjustments. Although a considerable amount of important research has been generated within this framework, several aspects of these tasks that are essential for successful performance cannot be captured. The purpose of this paper is to provide an overview of the existing framework, discuss its limitations, and introduce a new framework that emphasizes the necessity of calibration and perceptual learning. Within the proposed framework, successful human performance on these tasks is a matter of learning to detect and calibrate optical information about the boundaries that separate possible from impossible actions. This resolves a long-lasting incompatibility between theories of visually guided action and the concept of an affordance. The implications of adopting this framework for the design of experiments and models of visually guided action are discussed.     

Effects of orthographic consistency, frequency, and letter knowledge on children's vowel spelling development

This study investigated children's sensitivity to spelling consistency, and lexical and sublexical (rime) frequency, and their use of explicitly learned canonical vowel graphemes in the early stages of learning to spell. Vowel spellings produced by 78 British children at the end of reception year (mean age 5 years, 7 months) and 6 months later in mid-Year 1 were assessed. Regression analyses revealed that, at both test times, knowledge of sound-letter correspondences influenced spelling performance; however, unconditional consistency of vowel spellings affected children's spelling most strongly, over and above additional effects of word and rime frequency and the complexity of the target vowel grapheme. The effect of conditional consistency of vowel spellings given coda contexts was not significant. Thus, young children are sensitive to various statistical properties of the orthography from the earliest phases of spelling development and, in particular, to the unconditional consistency of the vowel spelling pattern.     

Relations among categorization, induction, recognition, and similarity: comment on Sloutsky and Fisher (2004)

V. M. Sloutsky and A. V. Fisher reported 5 experiments documenting relations among categorization, induction, recognition, and similarity in children as well as adults and proposed a new model of induction, SINC (similarity, induction, categorization). Those authors concluded that induction depends on perceptual similarity rather than conceptual knowledge. Despite the useful contributions of this work, there are some important limitations. The experimental designs examined a limited range of phenomena that are not the most revealing about the use of nonperceptual information. The main results involved a simple triad task, for which the SINC model's predictions are equivalent to the predictions of previous models of inductive reasoning. It is also unclear whether the SINC model can account for the observed relations between similarity and recognition. Implications for future work on induction and related cognitive activities are discussed.     

Visual guidance of intercepting a moving target on foot

How do people walk to a moving target, and what visual information do they use to do so? Under a pursuit strategy, one would head toward the target's current position, whereas under an interception strategy, one would lead the target, ideally by maintaining a constant target-heading angle (or constant bearing angle). Either strategy may be guided by the egocentric direction of the target, local optic flow from the target, or global optic flow from the background. In four experiments, participants walked through a virtual environment to reach a target moving at a constant velocity. Regardless of the initial conditions, they walked ahead of the target for most of a trial at a fairly constant speed, consistent with an interception strategy (experiment 1). This behavior can be explained by trying to maintain a constant target-heading angle while trying to walk a straight path, with transient steering dynamics. In contrast to previous results for stationary targets, manipulation of the local optic flow from the target (experiment 2) and the global optic flow of the background (experiments 3 and 4) failed to influence interception behavior. Relative motion between the target and the background did affect the path slightly, presumably owing to its effect on perceived target motion. We conclude that humans use an interception strategy based on the egocentric direction of a moving target.     

Psychometric properties of the life events checklist

The Life Events Checklist (LEC), a measure of exposure to potentially traumatic events, was developed at the National Center for Posttraumatic Stress Disorder (PTSD) concurrently with the Clinician Administered PTSD Scale (CAPS) to facilitate the diagnosis of PTSD. Although the CAPS is recognized as the gold standard in PTSD symptom assessment, the psychometric soundness of the LEC has never been formally evaluated. The studies reported here describe the performance of the LEC in two samples: college undergraduates and combat veterans. The LEC exhibited adequate temporal stability, good convergence with an established measure of trauma history -- the Traumatic Life Events Questionnaire (TLEQ) -- and was comparable to the TLEQ in associations with variables known to be correlated with traumatic exposure in a sample of undergraduates. In a clinical sample of combat veterans, the LEC was significantly correlated, in the predicted directions, with measures of psychological distress and was strongly associated with PTSD symptoms.     

Men's and Women's Perceptions of the Gender Typing of Management Subroles

The purpose of this study was to investigate the extent to which subroles inherent in managerial positions are gender-typed and whether men or women engage in relatively more gender typing of managerial roles. We obtained perceptions of 19 management subroles from 263 business students in the United States Results confirmed predictions that some subroles are viewed as more feminine in nature whereas other subroles are perceived as more masculine. Male respondents saw most subroles as more masculine in nature than did female respondents. Results are discussed in terms of implications for researchers studying management, as well as for managers in the workplace.     

Effects of Reasons Analysis on the Accuracy of Predicting Basketball Games1

It is argued that analyzing and listing reasons can lead to poorer predictions because reasoners either access information inappropriate to the task or have difficulty integrating the information they do bring to mind. To test this hypothesis, self-described basketball experts predicted the outcomes of actual basketball games in a national tournament. Half of the participants were asked to analyze and list reasons for their predictions before making them, and half were told explicitly not to analyze their reasons. Compared to nonreasoners, reasoners predicted fewer winners of the games and predicted margins of victory that differed more from both the actual margins of victory and the margins of victory predicted by experts. The relationship between expertise and reasons analysis, and the implications of the results for other domains of prediction are discussed.     

Gender Differences in Depression: The Role Played by Paternal Attitudes of Male Superiority and Maternal Modeling of Gender-Related Limitations

A reanalysis of a large multi-generational,predominantly Caucasian sample of adults found a largegender difference in self-reported depression involvinganxiety, appetite and sleep disturbance, and fatigue (anxious somatic depression) butnot in pure depression unaccompanied bymany of these other symptoms, replicating earlierfindings on high school and college samples. Anxioussomatic depression was prevalent among women whosefathers reported attitudes of male superiority and amongwomen whose mothers reported emphasizing the importanceof professional success but feeling that the jobs they held were not respected by others. Anxioussomatic depression, but not pure depression, was foundto be prevalent among women who did not attend collegeand among those who attended college but felt that the jobs they held were not respected byothers.