Grasping tau.

In the present study a direct manipulation of the optical expansion pattern was carried out. What happens to the timing of the grasp movements involved in catching a ball when optical expansion information is not veridically provided? By using 2 luminescent balls of constant size and a luminescent ball that could change its diameter during flight, it was possible to manipulate the rate of optical expansion directly. The results of 2 experiments (binocular vision in Experiment 1 and monocular vision in Experiment 2) showed that the time of the maximal closing velocity of the hand--which conforms to the prediction if Ss use retinal expansion information--was later for the deflating ball than for the balls of constant size. Adjustments to the aperture of the hand in response to the different ball sizes, especially the adjustment of the hand to the deflating ball (even though Ss were not aware that the ball was deflating during its approach), point to a finely attuned perception-action coupling.     

Hand preference in children with developmental coordination disorders: cause and effect?

Inter- and intra-modal matching by eight-year-old children diagnosed as having hand-eye coordination problems (HECP) and categorized as left-handed, together with a left-handed control group of children without such problems, were tested using a manual sensory matching task. The task required the children to locate target pins, visually (seen target), proprioceptively (felt target) or in combination (felt and seen target), while matching to the located target was always carried out without vision. Performance was superior when the target was located visually or visually/proprioceptively for both groups of children. These results question the conclusion that intra-modal will always be more accurate than inter-modal matching. When the combined scores for both hands were analyzed, the HECP children showed inferior performance to the control children in both inter- and intra-modal matching. Separate right and left hand analyses, demonstrated that the differences between the HECP group and control children could be accounted for by lowered performances when the right hand (nonpreferred) was used to match the located target position. Putative neurological disorders related to the development of the hemisphere controlling the nonpreferred hand (left hemisphere) are invoked to account for the poor performance with the nonpreferred hand of the HECP children.     

Why might language and motor impairments occur together?

A step‐wise methodology is employed in order to identify common neurological factors underlying motor and language impairments where they occur together. A sample of 15 5–10‐year‐old children with predetermined language impairment was tested comprehensively using the Illinois Test of Psycholinguistic Ability (ITPA) and the Movement Assessment Battery for Children (Movement ABC). On the basis of these tests, only four of the sample were found to have generally poor performance both in psycholinguistic (particularly indexed by problems with visual closure and sound blending) and motor abilities (particularly indexed by manual dexterity problems—bimanual co‐ordination and drawing—and static balance. Further detailed examination of the findings fostered a number of plausible hypotheses to account for this communality. The viability of these different alternatives is discussed. Copyright © 2003 John Wiley & Sons, Ltd.     

Posttraumatic Stress Symptoms and Perceived Relationship Safety as Predictors of Dyadic Adjustment: A Test of Mediation and Moderation

The purpose of this study was to examine the predictive value of PTSD symptoms and perceived relationship safety on dyadic adjustment. Participants included 390 individuals who were in a committed romantic relationship. Data were gathered from two populations; clients of a university-based family therapy clinic (n = 132), and community respondents to an announcement on a large university's electronic bulletin board (n = 258). Structural equation modeling was used to test a model of mediation, as well as multiple group analysis to test for moderation by setting (clinical vs. community) and gender. Results indicated that perceived relationship safety fully mediated the relationship between PTSD symptoms and dyadic adjustment. Gender moderated the relationships in the model, but no differences were found between the clinical and community samples. Findings suggest the importance of addressing experiences of safety and security in relationships, as these may be of particular importance for those who have experienced trauma.     

The Development of a Simple Ballistic Skill with and Without Visual Control

80 randomly selected male Ss discriminated the “effort” required to perform a simple 1-handed ballistic aiming task: aligning a Fletcher’s Trolley with a pointer placed at varying distances adjacent to an inclined wooden track. Groups were aged 5-6, 10-11, 15-16, and 18 or more yr., with 10 Ss able to see both hands and target while the other 10 could see neither. A split-plot factorial design was used. On excluding the 5-6 yr.-old “Nonvision” children, the remaining 7 sub-groups were shown to be homogeneous. Mean absolute error scores increased with Distance, and also with a decrease in Age. In the “Non-vision” condition accuracy was reduced still further for all Ss. Age, Vision, and Distance and the interaction of Age with Vision were all significant, p<.01.     

Against Second‐Order Reasons*

A normative reason for a person to φ is a consideration which favours φing. A motivating reason is a reason for which or on the basis of which a person φs. This paper explores a connection between normative and motivating reasons. More specifically, it explores the idea that there are second‐order normative reasons (not) to φ for or on the basis of certain first‐order normative reasons. In this paper, I challenge the view that there are second‐order reasons so understood. I then show that prominent views in contemporary epistemology are committed to the existence of second‐order reasons, specifically, views about the epistemic norms governing practical reasoning and about the role of higher‐order evidence. If there are no second‐order reasons, those views are mistaken.