Perceived orientation in depth from line-of-sight movement

Twelve college students viewed computer-generated displays of a cross comprised of two orthogonal dotted lines, and judged the apparent in-depth orientation of the horizontal arm by positioning a horizontal bar mounted on a rotary potentiometer. The vertical arm of the simulated cross was always in the observer’s frontal plane, but the randomly textured horizontal arm was in one of nine orientations relative to the line of sight. Each observer viewed displays in which the simulated cross was, alternately, (a) stationary, (b) approaching the viewer, and (c) stationary but expanding in size. The static texture density gradient in the horizontal arm of the simulated stationary cross mediated perceived orientation in depth. Further, when motion perspective was added to the detail perspective, the impression of depth was enhanced, with the greatest enhancement obtaining at the near viewing distance. When dynamic magnification was added to the detail perspective, the impression of depth was attenuated; this effect was interpreted as an illusory case of motion perspective.     

The toll of ethnic discrimination on sleep architecture and fatigue.

Most work on ethnicity tends to focus on daytime health rather than how aspects of ethnicity affect nighttime functioning. The current study examined how discrimination and ethnic identity relate to sleep architecture and fatigue in 37 African Americans and 56 Caucasian Americans. The authors conducted sleep monitoring with standard polysomnography. African Americans had less slow-wave sleep and reported more physical fatigue than did Caucasian Americans (ps < .05). The authors conducted path analyses to examine relationships between ethnic identity, perceived discrimination, sleep, and fatigue. Perceived discrimination mediated ethnic differences in Stage 4 sleep and physical fatigue. Individuals who reported experiencing more discrimination had less Stage 4 sleep and reported experiencing greater physical fatigue (ps < .05). Although ethnic identity did not mediate ethnic differences in sleep latency, there was a significant relationship between ethnic identity and sleep latency, indicating that individuals who felt more connected to their ethnic group had more difficulty falling asleep while in the hospital (p < .05). These observations suggest that the effects of stress related to one's ethnic group membership carry over into sleep.     

Alliance-Outcome Associations in a Community-Based Social Skills Intervention for Youth With Autism Spectrum Disorder

Although the alliance is a consistent predictor of treatment outcomes in psychosocial interventions, few studies have examined this association among youth with autism spectrum disorder (ASD). In particular, youth-therapist alliance has never been examined in social skills interventions (SSIs), a common modality for this population. In this study, thirty-four youth with ASD (M_age = 12.41; 79% male) participated in a community-delivered, group-based SSI in a summer camp format led by eight Head Therapists (M_age = 32.12; 50% male). Early alliance and change in alliance over the course of the treatment were assessed via self- and observer-reported measures. Both self- and observer-rated alliance were associated with positive treatment outcomes as reported by parents (decreased problem behaviors) and other peers in the group (reciprocated friendship and social preference). These results provide the first evidence of the role of the alliance in an SSI for youth with ASD and add to the growing body of literature that demonstrates the importance of assessing and addressing the alliance in treatment for this population.     

A preliminary evaluation of treatment duration on the resurgence of destructive behavior

Quantitative models of resurgence (e.g., Behavioral Momentum Theory, Resurgence as Choice) suggest that resurgence is partly a function of the duration of extinction exposure, with longer histories of extinction producing less resurgence. This prediction is supported by some laboratory research and has been partially supported by clinical translations that did not isolate the effects of extinction exposure prior to testing for resurgence. The degree to which different histories of extinction impact the likelihood of treatment relapse in therapeutic applications of differential reinforcement is of great interest to the clinical community, including insurance carriers and other financial providers. In the present study, we isolated the effects of extinction history for severe destructive behavior across 6 participants referred for treatment services and examined resurgence of destructive behavior when alternative reinforcement terminated. Our within-subject evaluation showed no difference in the level of resurgence or persistence of destructive behavior following short and long exposures to differential reinforcement with extinction. We discuss our failure to replicate in relation to experimental-design considerations for investigating this and other relapse phenomena in future research with clinical populations.     

The optic trajectory is not a lot of use if you want to catch the ball

According to linear optic trajectory (LOT) theory, fielders use the direction of curvature of theoptic trajectory to control the way they run to intercept the ball. Data presented by D. M. Shaffer and M. K. McBeath (2002) as support for LOT theory show that the optic trajectory of balls that will fall behind the fielder provide the cue that LOT theory predicts would send the fielder running forward, not backward. In this article, the authors show that watching these balls would provide the fielder with the cue that the optic acceleration cancellation (OAC) theory of interception predicts would send the fielder running backward. It appears that the fielders studied by Shaffer and McBeath were following the cue predicted by OAC theory, not that predicted by LOT theory.