Prism adaptation in left-handers

Two experiments with left-handers examined the features of prism adaptation established by previous research with right-handers. Regardless of handedness, (1) rapid adaptation occurs in exposure pointing with developing error in the opposite direction after target achievement, especially with early visual feedback in target pointing; (2) proprioceptive or visual aftereffects are larger, depending on whether visual feedback is available early or late, respectively, in target pointing; (3) the sum of these aftereffects is equal to the total aftereffect for the eye-hand coordination loop; (4) intermanual transfer of visual aftereffects occurs only for the dominant hand; and (5) visual aftereffects are larger in left space when the dominant hand is exposed to leftward displacement. A notable handedness difference is that, while transfer of proprioceptive aftereffects only occurs to the nondominant hand in right-handers, transfer occurs in both directions for left-handers, but regardless of handedness, such transfer only occurs when the exposed hand is tested first after exposure. A discussion then focuses on the implications of these data for a theory of handedness.     

Left-hemisphere activation and deficient response modulation in psychopaths

Psychopathic offenders have difficulty processing contextual or secondary cues once they have initiated goal-directed behavior or allocated attention to a primary task. To test the hypothesis that this deficit in response modulation is specific to conditions in which psychopaths' left-hemisphere resources are engaged, we administered a serial recall task to 21 incarcerated psychopaths and 21 control subjects. Subjects were instructed to memorize eight words that were presented one at a time, each in one of the four corners of the visual display. Subjects' primary task was to recall the words in serial order. Then, without forewarning, they were asked to recall the words' locations. As predicted, psychopaths performed as well as control subjects in recalling words from the left and right spatial fields, but recalled significantly fewer locations from the right spatial field. Thus, psychopaths' deficient response modulation was specific to conditions in which their left-hemisphere resources were actively engaged.     

The dimensions of change in therapeutic community treatment instrument

In this article, the authors describe the refinement and preliminary evaluation of the Dimensions of Change in Therapeutic Community Treatment Instrument (DCI), a measure of treatment process. In Study 1, a 99-item DCI, administered to a cross-sectional sample of substance abuse clients (N = 990), was shortened to 54 items on the basis of results from confirmatory factor analyses and item response theory invariance tests. In Study 2, confirmatory factor analyses of the 54-item DCI, completed by a longitudinal cohort of 993 clients, established and validated an 8-factor solution across 2 subpopulations (adults and adolescents) and 2 time points (treatment entry and 30-days postentry). The results of the 2 studies are encouraging and support use of the 54-item DCI as a tool to measure treatment process.     

Comparative analysis of movement characteristics during dead-reckoning-based navigation in humans and rats

Human and rat movement organization was investigated as they searched for randomly located rewards without access to visual information. Under dark conditions, rats foraged for randomly located food pellets (Experiment 1). Blindfolded humans were instructed to search for an ostensible hidden coin using a metal detector (Experiment 2). After locating the food pellet, rats carried it back to the refuge, and after a designated searching time, humans were instructed to return to the start location. Although both species exhibited a high degree of similarity in searching path movement organization and ability to return to the start location, disruption of human searching path organization was associated with impairments in returning to the start location. These results support the vestibular "gain" account of movement organization during dead-reckoning-based navigation.     

Diplomates Certified in 2005

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Diplomates Certified in 2005     

A comparison of the correlational structures and elevation patterns of the MMPI-2 restructured clinical (RC) and clinical scales

The relationship between the MMPI-2 restructured clinical scales and the original clinical scales was evaluated using an outpatient clinical sample (N = 150). Similar patterns of correlations to those reported by Tellegen et al. in 2003, such as high correlations between the restructured scales and their original scale counterparts and lower intercorrelations among the restructured scales than among the original scales, were found in the outpatient sample. The former provided evidence of convergence between the two sets of scales, whereas the latter increases the potential for discriminant validity in the restructured scale profiles. Mean T-scores of the restructured scales were significantly lower than their original scale counterparts for every clinical scale except Scale 1 (hypochondriasis). Individual profiles exhibited fewer scale elevations using the restructured clinical scales (M = 2.15, Mdn = 2.0) than the original clinical scales (M = 3.29, Mdn = 3.0). The majority of client profiles (56%) had fewer scale elevations when plotted using the restructured scales versus the original clinical scales.     

First-trial adaptation to prism exposure

Terminal target-pointing error on the 1st trial of exposure to optical displacement is usually less than that expected from the optical displacement magnitude. Such 1st trial adaptation was confirmed in 2 experiments (N = 48 students in each) comparing pointing toward optically displaced targets and toward equivalent physically displaced targets (no optical displacement), with visual feedback delayed until movement completion. First-trial performance could not be explained by ordinary target undershoot, online correction, or reverse optic flow information about true target position and was unrelated to realignment aftereffects. Such adaptation might be an artifact of the asymmetry of the structured visual field produced by optical displacement, which induces a felt head rotation opposite to the direction of the displacement, thereby reducing the effective optical displacement.     

Parental assessment and treatment of food selectivity in natural settings

This study evaluated the effects of a parent-conducted functional analysis and treatment consisting of differential reinforcement of an alternative behavior, escape extinction, and demand fading on food selectivity in a young child with autism. Increases in food acceptance at home and in a restaurant were obtained.     

Changes in behavior and behavioral intentions among middle-age women: results from an osteoporosis prevention program

The purpose of this study was to evaluate changes in behaviors and behavioral intentions that occurred among 342 middle-age women (M age 49.5 yr.) after participating in an Osteoporosis Prevention Program. The valid and reliable Osteoporosis Preventing Behaviors Survey (developed by Doheny and Sedlak) and a survey developed for this work were measures. Significant changes in behaviors were reported, especially increases in weight-bearing physical activity, dairy product intake, and decreases in consumption of caffeine-containing beverages. Many subjects reported intentions to increase physical activity and calcium intake. An Osteoporosis Prevention Program may help promote osteoporosis prevention behaviors, but intents must be followed up to check actual change.     

Rapid assessment of the effects of restraint on self-injury and adaptive behavior

We evaluated the effects of restraint on occurrences of self-injurious behavior (SIB) and adaptive responses exhibited by 2 individuals across eight response-effort conditions: baseline (no restraints); restraint sleeves without stays; restraints with 5, 10, 15, 20, or 25 thin metal stays; and restraints with five thick metal stays. From this analysis, we identified a restraint level for each participant that reduced SIB but did not inhibit adaptive responding.