Human variable ratio performance

The generality of the mathematical principles of reinforcement (MPR) was tested with humans. In Experiment 1A, participants’ mouse clicks were reinforced according to a series of variable-ratio (VR) values. In one condition, a situated task was used (searching for treasure on a map presented via a PC monitor); in the other, abstract version of the task, participants clicked on a white screen. Under the “map” condition, response rates increased with increasing ratio value before decreasing with further ratio increases; under the “no-map” condition, response rates decreased linearly from a peak at the smallest ratio. In Experiment 1B, the pattern of responding was confirmed under the “map” conditions using a different set of ratio values. In Experiment 2, reinforcer magnitude was manipulated using the “map” context. Response rates did not differ significantly when large rather than small cash reinforcers were delivered according to a VR 30 but were significantly higher when large rather than small cash reinforcers were delivered according to a VR 120. Together these experiments offer qualified support for extending MPR to the behavior of human participants.     

Validity of the Suicide Assessment Checklist in an Emergency Crisis Center

Validity of the Suicide Assessment Checklist (SAC; J. R. Rogers, 1990) was investigated in a sample of 1,969 admissions to a psychiatric emergency crisis center. Internal consistency reliability for rated items of the SAC was .87. Supporting construct‐related validity, total score differences were found in the expected directions as a function of referral reason. Convergent validity was based on observed correlations between selected SAC items and conceptually similar items on the Beck Depression Inventory (A. T. Beck, 1970). Supporting criterion‐related validity, total score differences in the expected directions were found as a function of disposition setting. Recommendations are made for the use of the SAC in the practice of counseling.     

Mainstreaming Gender in Theological Education

This article identifies themes and strategies for mainstreaming gender in theological education, based on the author's experience with theological education in Jamaica, the US, and Canada. It begins with the need to “visit the wounds” in such a way that realism about suffering can be accompanied by strategies for healing, transformation, and celebration of the reign of God already with us and in celebration of our agency to work toward it on earth as it is in heaven.     

Reinforcer quality matters: A test of the Mathematical Principles of Reinforcement with domestic hens (Gallus gallus domesticus)

This study evaluated the ability of Killeen's (1994) Mathematical Principles of Reinforcement to account for the effects of changes in reinforcer quality on hens' rates of responding on fixed‐ratio schedules. Hens were trained to peck a key on a fixed‐ratio schedule of reinforcement and then experienced an ascending series of ratio values in two separate conditions. In different conditions, the food reinforcer was either wheat or puffed wheat. Response rates initially increased with increases in ratio requirement before eventually decreasing at larger ratios. Quantitative fits of the model accounted for the data well. The fits revealed that different foods were systematically associated with changes in the specific activation parameter, a, and these were consistent with previous reports of preference for those food items.     

The effects of reinforcer magnitude in the preceding and upcoming ratios on between‐ratio pausing in multiple,mixed, and single fixed‐ratio schedules

Hens responded under multiple fixed‐ratio schedules with equal response requirements and either a 1‐s or a 6‐s reinforcer. Upcoming reinforcer size was indicated by key color. Components were presented in a quasirandom series so that all four component transitions occurred. Postreinforcement pauses were affected by the upcoming and preceding reinforcer size, with longer pauses after large reinforcers followed by small reinforcers than when followed by large ones, and longer pauses after small reinforcers that were followed by small reinforcers rather than large ones. Pauses increased with fixed‐ratio size and the effects of reinforcer size were larger the larger the ratio. When reinforcer size was not signaled—mixed fixed‐ratio schedules—pauses were shorter after small than after large reinforcers. Signalling the upcoming reinforcer attenuated the effect of the previous reinforcer size on pause duration when small was followed by small and when either small or large by large, but enhanced the effect when large was followed by small. There was no effect of reinforcer size on pause duration when single fixed‐ratio schedules were arranged. The effects of reinforcer size on pauses depends on the size and range of the fixed ratios as well as the exact procedures used in the study.     

The Dynamics of a Genetic Counseling Peer Supervision Group

Supervision is a practice that is utilized by a variety of practitioners to hone their counseling skills. Genetic counselors have embraced the supervision process, and some seek out supervision in a group setting with peers. Researchers have described the structure and content of genetic counseling peer supervision groups, and provided evidence for the benefits of seeking peer supervision. This study aimed to describe the interpersonal aspects of one genetic counseling peer supervision group, including personality traits and group dynamics, and how those factors influenced our experiences within the group. We also describe how the process of evaluating these factors impacted us individually and collectively. There was consensus that the group was a safe and trusting one, which was united by similar goals and mutual respect. Members reported gaining insights about how their own personality functioned within the group milieu, and also how the group setting impacted them. Based on our experiences, we recommend that other peer supervision groups consider similar self-evaluations on a periodic basis, both to enhance group functioning and to allow for increased self-awareness and professional growth.     

The role of early visual input in the development of contour interpolation: the case of subjective contours

We tested the effect of early monocular and binocular deprivation of normal visual input on the development of contour interpolation. Patients deprived from birth by dense central cataracts in one or both eyes, and age‐matched controls, discriminated between fat and thin shapes formed by either illusory or luminance‐defined contours. Thresholds indicated the minimum amount of curvature (the fatness or thinness) required for discrimination of the illusory shape, providing a measure of the precision of interpolation. The results show that individuals deprived of visual input in one eye, but not those deprived in both eyes, later show deficits in perceptual interpolation. The deficits were shown mostly for weakly supported contours in which interpolation of contours between the inducers was over a large distance relative to the size of the inducers. Deficits shown for the unilateral but not for the bilateral patients point to the detrimental effect of unequal competition between the eyes for cortical connections on the later development of the mechanisms underlying contour interpolation.