Effect of contrast level and temporal order on the Ebbinghaus circles illusion

Forty-eight undergraduates between 17 and 24 years of age judged the size of the central circle in Ebbinghaus figures presented under either simultaneous or successive viewing conditions. Successive presentation diminished the magnitude of illusion produced by the underestimated Ebbinghaus figure and totally eliminated the illusion normally produced by the overestimated figure. Variations in lightness contrast of the central and surrounding circles significantly altered the magnitude of illusion produced by both simultaneous Ebbinghaus figures as well as that produced by the successive underestimated figure. These data suggest the presence of a contour interaction process in both simultaneous Ebbinghaus illusions.     

Concept attainment,generalization, and retention through observation and verbal coding

Observationally induced acquisition, generalization, and retention of a novel clustering concept were studied in second-graders. All children earned zero scores in baseline (which were maintained by the no-modeling controls), demonstrating initial ignorance of the concept. No extrinsic reinforcers were promised or dispensed. In separate groups, a model accompanied performance of correct responses with no verbalization, with provision of a weak verbal code, a strong verbal code, or the strong code plus a rule to guide correct response. Concept acquisition and generalization to new stimuli were found, and were partially retained at retesting after several weeks delay. Strength of immediate concept attainment and generalization were related to amount and saliency of information verbally coded by the model, but more complex results were obtained with the retention data.     

Health-Related Quality of Life Among Substance Abusers in Residential Drug Abuse Treatment

Health-related quality of life (HRQOL) in substance abusers remains an area of inquiry in need of investigation. The few studies on the topic have found substance abuser HRQOL less than that of the general population. The present research compared 303 substance abusers in long-term residential therapeutic community treatment in New York with a general non-institutionalized adult sample from New York (N = 27,465) whose data were collected between 2002 and 2006 during the yearly administrations of the Behavioral Risk Factor Surveillance System (BRFSS), a state-based system of health surveys gathering data from upwards of 350,000 adults per year across all 50 states. One sample t-tests found that the in-treatment substance abusers reported significantly more physically and mentally unhealthy days over the past 30 days, as well as significantly more inactive days over the past 30 days due to illness.     

Perceptual learning on inspection time and motion perception

Perceptual learning on simple perceptual tasks is interpreted as plasticity of neuronal populations in the sensory cortex (M. Fahle & T. Poggio, 2002). The authors examined individual differences on perceptual learning for 2 tasks-inspection time (IT) and a motion direction discrimination task that was instantiated as random dot kinematograms. The authors' main questions were whether individual differences in perceptual learning were consistent across the 2 tasks and whether perceptual learning correlated with cognitive abilities test scores. In all, 56 young adults completed 16 threshold estimations on 1 of 2 orthogonal versions of each task. Then, the authors made 2 further threshold estimations for the untrained, orthogonal version. Participants also completed a battery of 6 cognitive abilities tests that measured fluid ability (Gf) and perceptual speed (Gs). Perceptual learning was demonstrated for both tasks, but the degree of learning across tasks was not characteristic of the individual. Learning on IT correlated with Gs (r = .35), but learning on the motion direction discrimination task was unrelated to cognitive ability. Correlations of IT with cognitive measures were stable over the training period. IT was correlated with both the motion direction discrimination task (r = -.39) and an unmasked line length judgment task (r = -.31). The authors concluded that perceptual learning on IT correlates with cognitive abilities test scores, that correlations of IT with cognitive abilities test scores are stable as task performance improves with practice, and that the IT task is psychologically complex.