Partial visual feedback and spatial end-point accuracy of discrete aiming movements

Five experiments are reported in which the effect of partial visual feedback on the accuracy of discrete target aiming was investigated. Visual feedback was manipulated through a spectacle-mounted liquid-crystal tachistoscope. The length of the visual feedback interval was varied as a percentage of the instructed movement time. In Experiment 1, the length of the vision interval was manipulated symmetrically at the beginning- and end-phase of the movement, whereas in the remaining experiments, the vision time was varied with respect to the end-phase only. The variations at the end were examined for different distances (Experiment 2), different movement speeds at the same distance (Experiment 3), and in small interstep intervals (Experiment 4). A vision time of more than 150 ms at the end-phase of the movement enhanced aiming performance in all experiments. Longer vision times monotonously improved aiming accuracy; the fifth experiment showed that a vision time of about 275 ms was sufficient for near-perfect aiming. Furthermore, the significance of vision during the first phase of a movement was demonstrated again. The results of the five experiments pointed to shorter visuomotor processing times. To explain the beneficial effects of short vision times for aiming accuracy, we propose a model of visuomotor processing that is based on the stochastic optimized submovement model of Meyer, Abrams, Kornblum, Wright, and Smith (1988).     

Motor skill acquisition and retention as a function of average feedback, summary feedback, and performance variability

Summary feedback involves withholding feedback from subjects until the last trial in a block is completed, and then presenting feedback about each trial. A variation of this method, called average feedback (Young & Schmidt, 1992), presents subjects with only the mean of the trial block. We investigated whether these methods have similar effects on acquisition and retention of a simple motor skill. Five groups of subjects (n = 16 per group) performed 60 acquisition trials of an aiming task involving both spatial and temporal accuracy. We presented average and summary feedback based on either 5-trial blocks or 15-trial blocks and compared these schedules with every-trial feedback. During acquisition, all groups improved with practice, with a slight tendency for the every-trial condition to have less absolute error than the longer summary and average conditions. Analysis of delayed no-feedback retention tests, however, revealed a strong advantage for the 5-trial summary and average conditions compared with the every-trial condition. In addition, we found that for long blocks of acquisition trials without augmented feedback, the performance variability of those trials was associated with retention performance. Results are discussed in terms of how these different manipulations may make feedback less useful during acquisition, but foster the use of certain information processing activities that enhance overall learning.     

One Personality, Multiple Selves: Integrating Personality and Social Roles

ABSTRACT How do people maintain multiple, role-specific self-conceptions as well as a consistent sense of self? In a sample of middle-aged women, we examined three issues: (a) the ways in which people view themselves as both different and similar across social roles (e.g., parent, friend, worker), (b) how role-specific self-conceptions and general self-conceptions are related, and (c) the merits of predicting role-specific criteria from role-specific and general self-conceptions. Results showed that subjects' self-conceptions were specific to role contexts, yet highly correlated across those same role contexts. In addition, role-specific self-conceptions were more similar to the general self-concept for roles with which the individual was more satisfied. Finally, as predicted from the bandwidth-fidelity trade-off, ratings of the general self correlated moderately with outcomes across all role domains, whereas ratings of role-specific self-conceptions correlated strongly with outcomes for the same role, but not in other roles.     

Activation of response codes by relevant and irrelevant stimulus information

Single-route models attribute stimulus-response compatibility effects to the difficulty of translation from stimulus to response. Dual-route models propose that compatibility effects reflect in part an additional direct, or automatic, activation route. Selected findings from three lines of research are reported that converge to provide evidence consistent with the view that the automatic activation route plays a role in compatibility effects. The data suggest that the activation produced via this route by relevant stimulus attributes influences response selection only when all mappings of stimuli to responses are known to be compatible.     

CAN MULTI-SOURCE FEEDBACK CHANGE PERCEPTIONS OF GOAL ACCOMPLISHMENT,SELF-EVALUATIONS,AND PERFORMANCE-RELATED OUTCOMES? THEORY-BASED APPLICATIONS AND DIRECTIONS FOR RESEARCH

Multi-source feedback extends traditional performance appraisal by collecting information from subordinates, peers, supervisors, and customers. Ratees often receive the results along with normative data and self-ratings. This paper explores how multi-source feedback goes beyond traditional performance appraisal by providing ratees with comparative information. Focusing on person perception and information processing dynamics, this paper develops a model and associated propositions to explain the effects of multi-source feedback on perceptions of goal accomplishment, re-evaluation of self-image, and changes in outcomes such as goals, development, behavior, and performance. Moderators of relationships between the major components in the model include individual difference variables (self-image, feedback seeking, self-monitoring, task-specific self-efficacy, and impression management) and situational conditions (the content and process of multi-source feedback and organizational performance standards). Issues of research and practice intended to improve understanding and effectiveness of multi-source feedback are discussed.     

AN EMPIRICAL INVESTIGATION OF THE PREDICTORS OF EXECUTIVE CAREER SUCCESS

This study examined the degree to which demographic, human capital, motivational, organizational, and industrylregion variables predicted executive career success. Career success was assumed to comprise objective (pay, ascendancy) and subjective (job satisfaction, career satisfaction) elements. Results obtained from a sample of 1,388 U.S. executives suggested that demographic, human capital, motivational, and organizational variables explained significant variance in objective career success and in career satisfaction. Particularly interesting were findings that educational level, quality, prestige, and degree type all predicted financial success. In contrast, only the motivational and organizational variables explained significant amounts of variance in job satisfaction. These findings suggest that the variables that lead to objective career success often are quite different from those that lead to subjectively defined success.     

ACHIEVING AND MAINTAINING COMPLIANCE WITH THE KETOGENIC DIET

The ketogenic diet, a treatment for intractable epilepsy, is rarely initiated because it requires strict compliance with a diet that is perceived to be unpalatable. In a case study of a 15-year-old girl with uncontrolled epilepsy, we used a stimulus-choice procedure to assess relative preferences of 33 foods from the diet and to develop two treatments based on Premack's principle. The results of a multielement analysis showed that both treatments increased dietary compliance. Compliance was maintained with generalization of treatment across settings, and was associated with a 40% reduction in seizures.     

Predicting and scaling hens' preferences for topographically different responses

Six hens were exposed to several concurrent (second-order) variable-interval schedules in which the response requirements on the alternatives were varied. The response requirements were one key peck versus five key pecks, one key peck versus one door push, and five key pecks versus one door push. Response- and time-allocation ratios undermatched the obtained reinforcement ratios but were well described by the generalized matching law. Time and response bias estimates from two pairs of response requirements were used to predict bias in the third pairing. The predicted values were close to those obtained; this result supports the notion that both numerically and topographically different responses act as constant sources of bias within the generalized matching law. The differences between the response and time biases could be accounted for by the different times needed to complete each response requirement. The results also suggest that the door push is a useful operant for research with domestic hens.     

How (not) to evaluate the comparability of MMPI and MMPI-2 profile configurations: a reply to Humphrey and Dahlstrom

Humphrey and Dahlstrom (1995) presented a study on the comparability of MMPI/MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) profiles in which they concluded that "the bases for clinical interpretation derived from the MMPI and MMPI-2 profiles were sufficiently at variance to require different conclusions" [sic] (p. 2). In this brief critique, we identify procedural and data-analytical deficiencies that invalidate Humphrey and Dahlstrom's argument. Their blanket recommendation based on this argument, namely, that clinicians routinely plot both MMPI and MMPI-2 profiles, is unwarranted.