Adaptation to Reversal of Retinal Feedback of Eyemovements

Both optical and hybrid-computer methods were devised to reverse the visual feedback which the eye gets of its own movements. Optical reversal by a contact lens device caused persisting, unstable, skittered, blurred vision, to which the subject made no effective adaptation. Using a hybrid analog-digital-analog computer, eyemovement-retinal feedback was reversed by yoking oscilloscope targets to the transduced electrical signals of ocular movements and reversing the sign of input-output control of the computer system. Vision with such computer-reversed feedback from ocular movements duplicated the experiences with the contact-lens method. Practice over five sessions of 50 trials indicated that three Ss showed no significant improvement in eye-tracking accuracy with the reversed vision. Perception of direction in vision and the basic signal processes of vision were thus found to be dependent on built-in direction specificity of eyemovement-retinal feedback interactions which also govern dynamic specialization and control of pursuit, saccadic, and fixation movements.     

A Modeling Study of Potential Sources of Curvature in Human Reaching Movements

The authors of this article suggest that the slight but consistent posture-dependent curvature of the spatial paths in the kinematic transformation between intrinsic and extrinsic coordinates may result in a systematic curvature of movements initially planned as straight-line trajectories toward the target. A kinematic planning model is presented that takes into account the anisotropy of the intrinsic and extrinsic transformation and tends to avoid movements that require excessive joint rotations by introducing slight deviations from a straight-line trajectory. Preliminary simulations showed reasonably good agreement with experimental data, especially considering that the current model is strictly based on kinematics. A quantitative analysis showed that the strategy used in the model achieves a favorable compromise between straight-line movements and angular joint changes: By slightly increasing the spatial length of the movement (i.e., by introducing curvature), an individual can greatly reduce the total amount of joint rotation required to produce the movement.     

Adaptation to Combined Reversal and Delay of Eyemovement-Retinal Feedback

A real-time computer system was used to calibrate eye position with respect to the position of an oscilloscope target, to yoke transduced eyemovement signals to the target, and to program variable feedback reversal and delays into the closed eyemovement-retinal interaction. S was required to compensate a sine-wave movement of the target by opposed movements of the eyes. Experimental transmission lags of 0.0, 0.1, and 0.2 sec. were introduced into the closed eyemovement-retinal yoke. Results indicated that both reversal and delay of eyemovement-retinal feedback degraded primary visual processes and their ocular control by pursuit, saccadic, and fixation motions, causing blurred, skittered, and unstable vision, and that there was limited adaptation to distortion of eyemovement-retinal feedback timing as well as to the spatial reversal of such feedback.     

A Comparison between Certain Properties of the Level of Aspiration and Random Guessing

Differential predictions have been made concerning the effect of external beliefs on the skilled performance of Negroes. In the present study i was found that among black college athletes, externality covaried with elevated attainment on unobtrusive tasks.     

The Role of Self-Compassion in Physical and Psychological Well-Being

The relation of self-compassion to physical and psychological well-being was investigated among 182 college students. The self-compassion scale was delineated into three composites, following the proposition by Neff that self-compassion consists of three main components: self-judgment versus self-kindness (SJ–SK), a sense of isolation versus common humanity (I–CH), and over-identification versus mindfulness (OI–M). Findings support the association between self-compassion and psychological and physical well-being, but the composites demonstrate different influences. SJ–SK and I–CH were predictive of both depressive symptomatology and physical well-being, and SJ–SK and OI–M were predictive of managing life stressors. The results of this study support and expand prior research on self-compassion.     

Verbally Expressed Wishes of Children and College Women Students

This research examined the relationship between locus of control and two academic-related variables: study habits and attitudes, and college academic performance. Subjects were administered (a) the Brown-Holtzman Survey of Study Habits and Attitudes and (b) the Levenson Internal, Powerful Others, and Chance scales, the latter providing separate measures of two external control dimensions. Results indicated that internal control was related positively to effective study habits and attitudes and to college academic success, while the opposite was true for powerful others and chance control. Additional findings demonstrated significant differences between powerful others and chance control as related to study habits and attitudes and to college grade-point averages.     

A Rigorous Test of the Fit of the Circumplex Model to Big Five Personality Data: Theoretical and Methodological Issues and Two Large Sample Empirical Tests

Our objective was to apply the rigorous test developed by Browne (1992) to determine whether the circumplex model fits Big Five personality data. This test has yet to be applied to personality data. Another objective was to determine whether blended items explained correlations among the Big Five traits. We used two working adult samples, the Eugene-Springfield Community Sample and the Professional Worker Career Experience Survey. Fit to the circumplex was tested via Browne's (1992) procedure. Circumplexes were graphed to identify items with loadings on multiple traits (blended items), and to determine whether removing these items changed five-factor model (FFM) trait intercorrelations. In both samples, the circumplex structure fit the FFM traits well. Each sample had items with dual-factor loadings (8 items in the first sample, 21 in the second). Removing blended items had little effect on construct-level intercorrelations among FFM traits. We conclude that rigorous tests show that the fit of personality data to the circumplex model is good. This finding means the circumplex model is competitive with the factor model in understanding the organization of personality traits. The circumplex structure also provides a theoretically and empirically sound rationale for evaluating intercorrelations among FFM traits. Even after eliminating blended items, FFM personality traits remained correlated.     

The Contributions of Memory and Attention Processes to Cognitive Abilities

In two experiments, the contributions of memory and attention processes to the cognitive abilities of reasoning and perceptual speed were investigated. Two measures of speed of information retrieval from long-term and short-term memory (Posner paradigm, Sternberg paradigm) and two attention measures (continuous attention test, attention switching test) were included in the first experiment (N = 220). The memory tests led to correlations with the measures of cognitive abilities, whereas the attention test did not. The same tests as well as one additional memory test and one attention test (working memory test, test of covert orientation) were administered in the second experiment (N = 116). Again, the memory tests led to the larger correlations with the measures of cognitive abilities. Two components were obtained in components analysis, of which the first was characterized by high loadings of the memory tests and the second by high loadings of the attention tests. Only the memory component contributed to the prediction of cognitive abilities.