Self-report and physiologic responding during in vivo flooding

Self-report and physiologic measures of arousal were obtained during in vivo flooding sessions. Minimal correspondence was found between these two assessment modalities. The significance of these findings for treatment is discussed.     

Effects of stress and retesting on role play tests of social skill

The purpose of this study was to examine the role of stress in performance on role play tests of social skill. Chronic psychiatric patients were tested in a formal videotape studio or in an informal consulting room setting. Motoric and physiological measures were secured. In addition, one-half of the subjects were retested one week later. In contrast to previous studies, results indicated that the assessment was not stressful. The two groups were not different on any measure, and the mean heart rates ranged from only 80 to 84 b.p.m. The effects of retesting were difficult to interpret. There were reductions in motoric indices of anxiety (speech disruptions) but not on physiological indices. Overall, testretest reliability was quite high. The results raise several questions which affect interpretation of many social skills studies in the literature.     

An animal model of the hyperactive-child syndrome suitable for the study of the effects of food additives

This report describes the use of an animal model for testing the relationship between the effects of ingesting food additives and hyperactivity. Telomian × beagle hybrid dogs were chosen as subjects because this breed has been observed to exhibit behavior seen as analogous to the hyperactivity of children. Two studies were conducted by adding or deleting butylated hydroxyanisole and Food, Drug, and Cosmetic red dye number 40 to the diet of each dog. A test of sitting was performed to measure the level of activity. While a relationship was not observed between the ingestion of the additive and the level of activity, several issues pertaining to the use of the animal model became apparent. These issues and the use of animals for future research in this area are discussed.     

Hemispheric symmetry in duration of visible persistence

Nine right-handed subjects performed a visual task requiring perceptual integration of a pattern whose parts were displayed sequentially in time. Correct performance on the task depended critically on the simultaneous visibility of all parts of the pattern; duration of visible persistence could therefore be gauged by varying the duration of the temporal interval between successive portions of the display. The pattern was displayed either foveally or parafoveally in either visual field. Analysis of overall performance and of distribution of errors at each temporal interval revealed more accurate performance for foveal displays but no hemispheric asymmetries in duration of visible persistence. These and other results reported in the literature are interpreted in terms of Moscovitch’s (1979) information-processing model of hemispheric functioning.     

Duration of visible persistence in relation to range of spatial frequencies

Five experiments examined the relationship between range of spatial frequencies contained in a visual display and duration of visible persistence. The high spatial frequency contents of the display were reduced by defocusing the image at the retina. Duration of visible persistence was measured by a task that required perceptual integration of a pattern whose parts were displayed sequentially in time. Experiments 1 and 2 showed that progressive reductions in the high-frequency contents of the display produced corresponding decrements in the duration of visible persistence. Experiments 3, 4, 5 showed that decrements in the duration of visible persistence could not be attributed to changes in the apparent size or in the brightness of the display brought about by defocusing. The results were interpreted in terms of the temporal response properties of perceptual mechanisms attuned to separate ranges of spatial frequencies. Strong parallels were drawn with the multichannel theory of visual information processing proposed by Breitmeyer and Ganz.     

A spectral-analysis tutorial with examples in FORTRAN

A procedure for performing spectral analysis using a digital computer is described. The relevant analysis parameters and their interaction are reviewed, and the underlying mathematical theory of the analysis is annotated with page references to a standard reference text. A computer program that implements the procedure is presented in a general form of FORTRAN. Examples of the spectra produced by a variety of input time histories are shown.     

Perceptual degradation due to signal alteration: implications for auditory pattern processing.

When a passage is alternately presented to the right and left ears over headphones, perceptual processing is disrupted under certain conditions: When the signal alternation rate is approximately 3-4 cps, intelligibility is greatly reduced. Experiment 1 demonstrated that contrary to previous theorizing, the effect is not mediated by the disruption of syllabic units. Experiment 2 explored the generality of the perceptual degradation by testing perception of simple piano melodies. The basic effect holds for these complex auditory patterns. The final experiment tested a source-effect explanation of the phenomenon by using 3 signal locations (right, middle, and left) rather than 2. The degree of disruption depends on the likelihood that sounds are assigned to different sources. Together, the experiments help to account for the strikingly selective breakdown in perceptual processing and speak to the issues of perceptual units, domain specificity, and auditory source assignment.     

A study of hyperlexia

Twelve children with early intense reading and superior word recognition skills coupled with disordered language and cognitive behavior are described. Cognitive, linguistic, and reading measures evidenced a generalized cognitive deficit in forming superordinate schemata which was not specific to visual or auditory modalities. Positive family histories for reading problems were present for 11 of the 12 children, suggesting a relationship between hyperlexia and dyslexia.