Finger-digit compatibility in Arabic numeral processing

Finger-digit response compatibility was tested by asking participants to identify Arabic digits by pressing 1 of 10 keys with all 10 fingers. The direction of the finger-digit mapping was varied by manipulating the global direction of the hand-digit mapping as well as the direction of the finger-digit mapping within each hand (in each case, from small to large digits, or the reverse). The hypothesis of a left-to-right mental number line predicted that a complete left-to-right mapping should be easier whereas the hypothesis of a representation based on finger counting predicted that a counting-congruent mapping should be easier. The results show that when all 10 fingers are used to answer, a mapping congruent with the prototypical finger-counting strategy reported by the participants leads to better performance than does a mapping congruent with a left-to-right oriented mental number line, both in palm-down and palm-up postures of the hands, and they demonstrate that finger-counting strategies influence the way that numerical information is mentally represented and processed.     

Development of short and very short forms of the Children's Behavior Questionnaire

Using data from 468 parents and taking into account internal consistency, breadth of item content, within-scale factor analysis, and patterns of missing data, we developed short (94 items, 15 scales) and very short (36 items, 3 broad scales) forms of the Children's Behavior Questionnaire (CBQ; Rothbart, Ahadi, & Hershey, 1994; Rothbart, Ahadi, Hershey, & Fisher, 2001), a well-established parent-report measure of temperament for children aged 3 to 8 years. We subsequently evaluated the forms with data from 1,189 participants. In mid/high-income and White samples, the CBQ short and very short forms demonstrated both satisfactory internal consistency and criterion validity, and exhibited longitudinal stability and cross-informant agreement comparable to that of the standard CBQ. Internal consistency was somewhat lower among African American and low-income samples for some scales. Very short form scales demonstrated acceptable internal consistency for all samples, and confirmatory factor analyses indicated marginal fit of the very short form items to a three-factor model.     

The ground dominance effect in the perception of 3-D layout

The relative effectiveness of the ground surface and other environmental surfaces (the ceiling and sidewalls) in determining perceived layout was investigated in five experiments and a real-world demonstration. In the first three experiments, two vertical or horizontal posts were positioned between two surfaces (ground and ceiling in all three experiments, left wall and right wall in Experiment 1), and optical contact was manipulated so that the two surfaces provided contradictory information about the relative distances of the posts. Observers judged which of the two posts appeared to be closer. In Experiment 4, to control the height on the posts at which the distance judgments were made, a blue dot was attached to both vertical posts at varying heights and observers judged which dot appeared closer. In Experiment 5, the posts were replaced by two gray ellipses to eliminate the effects of the regular shape and texture. Our findings were that (1) among all four surfaces tested, observers showed a preference to respond according to the optical contact information provided by the ground surface--a ground dominance effect, (2) this effect did not depend on the height of the posts in the image, (3) as the scene was tilted away from a ground/ceiling orientation, the ground dominance effect decreased, and (4) this effect was not due to the location of the judgment.     

Family Correlates of Oppositional and Conduct Disorders in Children With Attention Deficit/Hyperactivity Disorder

Comorbidities among children with ADHD are key determinants of treatment response, course, and outcome. This study sought to separate family factors (parental psychopathology and parenting practices) associated with comorbid Oppositional Defiant Disorder (ODD) from those associated with Conduct Disorder (CD) among children with Attention Deficit/Hyperactivity Disorder. Clinic-referred families (n = 149) were diagnosed using DSM-IV criteria. Parents completed measures of parenting practices. Comorbid ODD and CD were significantly associated with maternal negative/ineffective discipline. Comorbid CD, but not ODD, was significantly associated with lack of maternal warmth and involvement, paternal negative/ineffective discipline, and with paternal Antisocial Personality Disorder (APD). However, the risk of CD posed by parenting appeared concentrated among children without a father having APD. While consistent discipline appears important for addressing comorbid ODD and CD, paternal psychopathology and the quality of the relationship between mother and child may pose risk specifically for comorbid CD. Efforts to prevent and/or treat CD should consider not only provision of structure and prudent discipline, but also the affective qualities of the relationship between the primary caretaker and child.     

Parametric adjustment in saccadic eye movements

During a change-of-fixation eye movement, the target toward which S was shifting his gaze was displaced 1° toward the original point of fixation so that the eye made an overshoot with respect to the new target position. When this was repeated several times in succession, the eye movement control system made an adjustment such that the overshoot gradually diminished. Ihe end-result of this “parametric adjustment” was that a visual target 10° from the fovea elicited an eye movement of only 9.1°.