Between-measure consistency in social-skills assessment

The purpose of the present study was to assess the between-measure consistency of general and specific social-skills assessment strategies. Nineteen mentally retarded adults were assessed using both common and newly devised measures of social skills: (1) specific (molecular) behavior ratings from role-play assessments, (2) general (molar) ratings based on the role plays, staff (3) molar and (4) molecular predictions of client social skills use in the described role-play situations, (5) peer sociometric ratings, and molecular in vivoobservations conducted in (6) cafeteria and (7) party settings. For all molecular measures, the subjects were assessed on eye contact, response relevance, response latency, voice volume, and appropriate affect, which allowed for direct comparisons to be made between each of these assessment modalities. In addition, the role-play assessment was conducted under two distinct conditions to determine whether role-play performance varied between standard and reinforced administrations; however, multivariate analyses (MANOVA) revealed no differences between the two assessments. Correlations between the molar and the molecular measures suggested a substantial overlap between the measures, with staff ratings having the highest consistency with the other measures. Furthermore, MANOVAs calculated between role-play ratings and those of staff revealed little difference between the two. The limitations on and practical significance of these findings are discussed.     

Proactive Socialization and Behavioral Self-Management

The purpose of this study was to examine behavioral self-management as a form of newcomer proactive socialization behavior. A longitudinal field study was conducted with a sample of 153 entry-level professionals who completed questionnaires during their first month of entry and 6 months after entry. The results indicated that self-management behavior was related to newcomers’ general anxiety and stress at entry, and to internal motivation, ability to cope, and task-specific anxiety 6 months later. In addition, anxiety and stress at entry were found to mediate the relationships between self-management and ability to cope and task-specific anxiety. The research and practical implications of these findings are discussed. It is recommended that future research integrate the self-management and information seeking perspectives to provide a more complete theory of proactive socialization.     

Detection and discrimination of coherent motion

When viewing a pair of bars defined by the difference of spatial Gaussian functions (DOGs), human observers can discriminate accurately the relative movements of the bars, even when they differ in spatial frequency. On each trial, observers viewed two brief presentation intervals in which a pair of vertically oriented DOGs moved randomly back and forth within a restricted range. During one interval, both bars moved in the same horizontal direction and by the same magnitude (correlated movements); in the other interval, their movements were uncorrelated. When discrimination accuracy is related to the simultaneous detection of two independent movements, it was found that, if observers can detect the movements of spatially separated bars, they can tell whether their relative movements are correlated. Performance remained remarkably accurate even when the two bars differed in spatial frequency by more than two octaves or were presented separately to the two eyes. Apparently, the accurate discrimination of coherent motion involves an efficient spatial integration of optical motion information over multiple spatial locations and multiple spatial scales.     

The psychophysical inquiry into binocular summation

Experiments that compare monocular and binocular visual performance of human psychophysical Os on a variety of visual tasks are reviewed. The review attempts to include all experiments published in English in this century, excluding work on stereopsis, rivalry, and evoked potentials. The concept of probability summation as a baseline for assessing the presence of neural summation is discussed, and the assumptions of several models for estimating probability summation are considered. Experiments are classified in terms of visual task, major categories being increment detection, flicker fusion, brightness magnitude, and contour resolution. A major conclusion is that binocular performance is superior for essentially all task categories and in most cases by a magnitude greater than that predicted by appropriate probability summation models.     

Parallel processing of position and form information in young children

Young children and adults were compared in their processing of position and form information when only one type of information was processed and when both types of information were processed. For adults, position information in both the single and combined tasks showed a linear increase in report accuracy with increasing duration. For children, this linear increase was found only in the single task, at longer durations, resulting in a loss of parity across tasks for position information among children. No loss of parity was found for form information for either age group. The children’s loss of parity in processing position information when combined with form information replicates their previously demonstrated inability to process multiple-form arrays using a parallel independent strategy.     

How contrast affects stereoacuity

Stereoacuity and its dependence on contrast were measured at four spatial frequencies separated by 1 octave steps. Using a method of adjustment, observers adjusted the retinal disparity of an aperiodic narrow-band stimulus until it appeared in the depth plane defined by two flanking reference lines. Variations in contrast affected stereoacuity (the standard deviation of ten depth settings), with better performance observed at higher contrasts. Data were fit with straight lines (on a log-log plot), indicating a power-law dependence on contrast; the slope was steeper at lower spatial frequencies. These findings are consistent with the idea that disparity is computed from the responses of size-tuned mechanisms characterized by nonlinear contrast transfer functions. In a second experiment, the effects of interocular differences in contrast on stereoacuity were studied for two conditions. In the first condition, one eye always viewed a high-contrast target while the other eye viewed targets of successively lower contrast; in the second condition, one eye always saw a target of near-threshold contrast while the other eye saw targets of successively higher contrast. When the fixed contrast was high, stereoacuity deteriorated steadily as the interocular difference in contrast increased; the loss of stereoacuity was greatest at the lowest spatial frequency. When the fixed contrast was low, however, small increases in the contrast to one eye had no deleterious effect on stereoacuity. Once interocular contrast settings exceeded a certain difference, stereoscopic acuity began to deteriorate at lower spatial frequencies. These results address the issue of the stage of visual processing at which contrast exerts its influence on stereopsis.     

The Macintosh as a user-friendly laboratory for perception and cognition

We present a radically user-friendly Macintosh laboratory, MindLab, for instruction in perception and cognition. MindLab’s forte is its ability to display pictorial stimuli, including digitized photographs, transferred via the clipboard from Macintosh graphics applications. An experiment is programmed by specifying sequences of event primitives, represented by icons, to which stimuli, temporal parameters, and feedback options are assigned.     

Uncertainty impairs grating detection performance in the cat

Using behavioral techniques, contrast thresholds for detection of grating patterns by the cat were measured under conditions of certainty and uncertainty. For certainty trials, the same combination of spatial and temporal frequencies was presented throughout a test session, whereas with uncertainty, the cat was unable to anticipate which of two spatial (or temporal) frequencies would be presented on a given trial. For most spatiotemporal combinations, uncertainty served to elevate contrast thresholds by almost .3 log units, a finding that parallels the outcome found in human vision. The uncertainty paradigm may provide a useful inferential tool for determining channel bandwidth in cat vision.