Orientation-contingent color aftereffects mediated by subjective transparent structures

We examined whether the orientation-contingent color aftereffect (the McCollough effect) could be mediated by subjective horizontal and vertical structure induced by the perception of transparency. In our experiments, red vertical bars and green horizontal bars were alternated as an adapting stimulus. After adaptation, subjects (n=6) were asked to adjust the green and red saturation of a test pattern until they obtained a neutral gray. Horizontal and vertical stripes were combined in the test pattern in three different ways: (1) overlapping with a luminance combination that gave rise to a perception of transparent overlays of horizontal and vertical stripes (valid transparency condition), (2) overlapping with luminance combinations that did not induce a perception of transparency (invalid transparency condition) and that appeased more as a patchwork of checks, and (3) presented in adjacent, nonoverlapping areas. Our results showed that the McCollough effect was significantly greater in the valid transparency condition than in the invalid transparency conditions. The effect in the valid transparency condition was nevertheless less strong than was the effect seen with the standard test stimulus made up of nonoverlapping vertical and horizontal stripes, Our results suggest that the McCollough effect can be mediated by the subjective spatial organization (inner representation of vertical and horizontal stripes) that accompanies the perception of transparency in our stimulus.     

Disputation through audiotaping

This therapy note discusses the use and desirability of audiotaping homework assignments of disputation of irrational beliefs. General advantages as well as specific advantages to both therapist and client are pointed out.He also lectures in clinical psychology and maintains a private practice.     

Punishment of SΔ responding of humans in conditional matching to sample by time-out

Human subjects were intermittently reinforced with money for performing correctly on a conditional matching-to-sample task. The matching performance was examined as a function of a) the duration of Time-Outs (TOs) which followed every incorrect response and b) the frequency (FR value) with which TOs followed incorrect responses. The matching accuracy increased with longer TOs and decreased with less frequent presentation of TOs.     

Some notes on time out from reinforcement

Pigeons produced food on a fixed-ratio schedule by pecking at one key, and an S^Δ period by pecking at a second (switching) key. Switching behavior was examined as a function of (a) size of the fixed ratio, (b) whether the S^Δ was of fixed duration or could be determined by the bird, (c) the introduction of a novel food S^D, (d) extinction of food responding, and (e) the stimuli associated with the S^D and S^Δ conditions. No monotonic relationship was obtained between ratio size and switching behavior. Switching behavior was, however, influenced by many variables. The results suggest that an interpretation of switching behavior in terms of its being reinforced by the removal of aversive conditions, is open to considerable question.     

The role of a language scale for infant and preschool assessment

The PLS-4 (Preschool Language Scale, 4th edition) is a psychometrically sound instrument constructed to assess language skills in children from birth to 6 years 11 months. It is a useful diagnostic and research tool that can be used to identify current comprehension and expressive language skills and can measure changes in language skills over time. The test is individually administered and includes tasks that assess skills in the areas of preverbal behaviors, as well as linguistic skills in the areas of semantics, morphology, syntax, integrative language skills, and preliteracy skills. Extensive reliability and validity evidence are presented. The test has been used extensively in research examining language development of young children from different home environments, children with identified medical conditions, and children participating in a variety of habilitation and intervention programs. Both the previous edition (PLS-3) and the new PLS-4 English and Spanish editions are used extensively in clinical, medical, and research settings to examine developmental language patterns of infants, toddlers, and preschoolers.