An analysis of binocular slant contrast

When a small frontoparallel surface (a test strip) is surrounded by a larger slanted surface (an inducer), the test strip is perceived as slanted in the direction opposite to the inducer. This has been called the depth-contrast effect, but we call it the slant-contrast effect. In nearly all demonstrations of this effect, the inducer's slant is specified by stereoscopic signals; and other signals, such as the texture gradient, specify that it is frontoparallel. We present a theory of slant estimation that determines surface slant via linear combination of various slant estimators; the weight of each estimator is proportional to its reliability. The theory explains slant contrast because the absolute slant of the inducer and the relative slant between test strip and inducer are both estimated with greater reliability than the absolute slant of the test strip. The theory predicts that slant contrast will be eliminated if the signals specifying the inducer's slant are consistent with one another. It also predicts reversed slant contrast if the inducer's slant is specified by nonstereoscopic signals rather than by stereo signals. These predictions were tested and confirmed in three experiments. The first showed that slant contrast is greatly reduced when the stereo-specified and nonstereo-specified slants of the inducer are made consistent with one another. The second showed that slant contrast is eliminated altogether when the stimulus consists of real planes rather than images on a display screen. The third showed that slant contrast is reversed when the nonstereo-specified slant of the inducer varies and the stereo-specified slant is zero. We conclude that slant contrast is a byproduct of the visual system's reconciliation of conflicting information while it attempts to determine surface slant.     

Initial hospitalization and community tenure outcomes of intensive case management for children and youth with serious emotional disturbance

Since 1988 New York State's Children and Youth Intensive Camse Management (CYICM) program has enrolled more than 1,700 children. The program goal is to maintain children in the least restrictive environment approriate to their needs. This linkagke and advocacy focussed program uses a small caseload and flexible service money to meet its goal. We review the program model, describe the enrolled children, highlight some of the problems associated with determining program outcomes, and present the outcomes related to hospitalization and community tenure. Using two analytic techniques, CYICM was shown to be associated with fewer hospital admissions and fewer days in the hospital over a two-year period following the intervention of CYICM than prior to enrollment.     

The asymmetry of lateral interference in visual letter identification

Asymmetry of masking refers to the fact that a masking letter placed on the peripheral side of a target in the visual field will interfere more with recognition of the target than will a masking letter placed on the central side of the target. The experiments in this paper show that lateral masking for a pair consisting of a single target and a single mask cannot be entirely explained by processing interference caused by the mask but that masking ]has a component of purely sensory interference. Furthermore, the asymmetry of masking at the sensory level, when all sources of processing interference are eliminated, can be explained in terms of the falloff in acuity from the center to the periphery of the retina. The sensory component of masking is asymmetrical because, with the target at a constant retinal location, the target-plus-mask configuration is, as a whole, more peripherally located with a peripheral mask than a central one, and it is the location of the target-plus-mask configuration that determines performance.     

Discontinuity of seen motion reduces the visual motion aftereffect

Would a motion-picture film of a rotating spiral induce a spiral aftereffect? This question was studied in two experiments in which Ss viewed an animated film of circles collapsing to a point. The rate of apparent motion of the collapsing circles and the discontinuity of motion—the length of jump between successively projected circles—were varied independently. A visual aftereffect like the spiral aftereffect was created. The aftereffect increased in strength and duration with the rate of motion, but at all rates of motion it declined as discontinuity of motion increased. The results are taken as evidence that motion aftereffects are caused by selective fatigue of small, directionally sensitive motion-receptive fields.     

The effect of head tilt on meridional differences in acuity: Implications for orientation constancy

Horn and Hill (1969) and others have reported that a small number of units in the cat visual cortex undergo changes in receptive field orientation associated with body tilt. Such units reportedly compensate for tilt and may represent a mechanism for human orientation constancy. To test this, we measured meridional differences in visual acuity for head-vertical and head-tilted viewing conditions. The results of Experiment 1 did not directly support or refute the involvement of tilt-compensatory units. The results of Experiment 2, in which we controlled for countertorsion of the eyes, showed that meridional acuity differences correspond to the retinal and not the spatial orientation of the stimulus. We conclude that tilt-compensatory cortical units are not involved in human orientation constancy. The physiological evidence indicating the existence of tilt-compensatory units in the visual cortex is also reexamined.     

Vocational Satisfaction Among Ministerial Students

84 graduate students attending the Seventh-day Adventist Seminary for North America Q-sorted 50 self-relevant, socially neutral statements to measure self-concept and occupational role percept of the “ideal” Seventh-day Adventist minister. Correlations were computed for congruence between self-percepts and occupational role percepts, as an operational approximation to the construct “vocational satisfaction.” Mean correlations in extreme quartiles of the resultant distribution differed beyond .001; subjects in extreme quartiles were accordingly regarded as “more” or “less” vocationally satisfied. Significant differences were found between more- and less-satisfied subjects on 3 of 16 personality factors (adventuresomeness, shrewdness, ergic tension); on 1 of 6 values (social); on 1 of 10 vocational interests (social service); and on 2 of 15 elements of educational-social history (extent of previous church-conducted education, vocational preference during high school).     

Perceiving heading with different retinal regions and types of optic flow

We examined the ability to use optic flow to judge heading when different parts of the retina are stimulated and when the specified heading is in different directions relative to the display. To do so, we manipulated retinal eccentricity (the angle between the fovea and the center of the stimulus) and heading eccentricity (the angle between the specified heading and the center of the stimulus) independently. Observers viewed two sequences of moving dots that simulated translation through a random cloud of dots. They reported whether the direction of translation—the heading—in the second sequence was to the left or right of the direction in the first sequence. The results revealed a large and consistent effect of heading eccentricity: Judgments were much more accurate with radial flow fields (small heading eccentricities) than with lamellar fields (large heading eccentricities), regardless of the part of the retina being stimulated. The results also revealeda smaller and less consistent effect of retinal eccentricity: With radial flow (small heading eccentricities), judgments were more accurate when the stimulus was presented near the fovea. The variation of heading thresholds from radial to lamellar flow fields is predicted by a simple model of two-dimensional motion discrimination. The fact that the predictions are accurate implies that the human visual system is equally efficient at processing radial and lamellar flow fields. In addition, efficiency is reasonably constant no matter what part of the retina is being stimulated.     

A psychological laboratory based on a PDP-11/10 with graphics

This article describes a laboratory computer system that uses a PDP-11/10 CPU and a graphics processor to simulate a multifield tachistoscope and to run a great number of psychological experiments. The potential of the hardware is discussed, and two useful programs are presented.     

Study Preregistration: An Evaluation of a Method for Transparent Reporting

Study preregistration promotes transparency in scientific research by making a clear distinction between a priori and post hoc procedures or analyses. Management and applied psychology have not embraced preregistration in the way other closely related social science fields have. There may be concerns that preregistration does not add value and prevents exploratory data analyses. Using a mixed-method approach, in Study 1, we compared published preregistered samples against published non-preregistered samples. We found that preregistration effectively facilitated more transparent reporting based on criteria (i.e., confirmed hypotheses and a priori analysis plans). Moreover, consistent with concerns that the published literature contains elevated type I error rates, preregistered samples had fewer statistically significant results (48%) than non-preregistered samples (66%). To learn about the perceived advantages, disadvantages, and misconceptions of study preregistration, in Study 2, we surveyed authors of preregistered studies and authors who had never preregistered a study. Participants in both samples had positive inclinations towards preregistration yet expressed concerns about the process. We conclude with a review of best practices for management and applied psychology stakeholders.