The spatial distribution of attention within and across objects

Attention operates to select both spatial locations and perceptual objects. However, the specific mechanism by which attention is oriented to objects is not well understood. We examined the means by which object structure constrains the distribution of spatial attention (i.e., a "grouped array"). Using a modified version of the Egly et al. object cuing task, we systematically manipulated within-object distance and object boundaries. Four major findings are reported: 1) spatial attention forms a gradient across the attended object; 2) object boundaries limit the distribution of this gradient, with the spread of attention constrained by a boundary; 3) boundaries within an object operate similarly to across-object boundaries: we observed object-based effects across a discontinuity within a single object, without the demand to divide or switch attention between discrete object representations; and 4) the gradient of spatial attention across an object directly modulates perceptual sensitivity, implicating a relatively early locus for the grouped array representation.     

Reduced looming sensitivity in primary school children with Developmental Co-ordination Disorder

Almost all locomotor animals are sensitive to optical expansion (visual looming) and for most animals this sensitivity is evident very early in their development. In humans there is evidence that responses to looming stimuli begin in the first 6 weeks of life, but here we demonstrate that as children become independent their perceptual acuity needs to be 50 to 100 times better than has been demonstrated in infants in order to be skilful at collision avoidance at a roadside. We have recently established that sensitivity to the detection of visual looming in 6- to 11-year-old children is significantly below that of adults (Wann, Poulter & Purcell, 2011). Here, using comparable methods, we explore looming detection sensitivity in children with Developmental Co-ordination Disorder (DCD), who show broad patterns of impairment in visuo-motor control. We presented visual simulations of approaching vehicles, scaled to represent different approach rates, to children with DCD aged between 6 and 11 years (n = 11) and typically developing age and gender matched controls (n = 11). Looming detection thresholds were measured under foveal and perifoveal viewing conditions, for isotropic expansion and isotropic expansion with simulated viewpoint motion. Our results show that there are situations in which children with DCD may fail to detect vehicles approaching at speeds in excess of 22 km/h, suggesting a developmental immaturity in looming sensitivity. This provides one of the first clear demonstrations of low-level motion processing deficits in children with DCD. The decrement observed may give rise to potential errors in the road crossing behaviour of these children, whereby approaching vehicles could be perceived as stationary. These findings further contribute towards understanding the adverse statistic that children under 9 years of age are four times more likely than adults to be involved in a road accident as a pedestrian.     

A comparison of types of support for lower-skill workers: Evidence for the importance of family supportive supervisors

The work–family literature to date does not offer a clear picture in terms of the relative importance of different types of supports for balancing work and family demands. Grounded in conservation or resources theory, we develop an integrative model relating multiple forms of social support, both formal (i.e., work–life benefit use) and informal (supervisor work–family support and family support) to work-interference-with-family and family-interference-with-work and task and contextual performance. We chose to focus our study on lower-skill workers because, despite being a relatively large segment of the workforce, these workers are relatively understudied in the work–family literature. Results revealed that supervisor support is a key form of support in this sample. Supervisor support had negative same domain (work-interference-with-family) and cross domain (family-interference-with-work) effects with work–family conflict, as well as positive relationships with task and contextual performance. Family support was negatively related to family-interference-with-work; whereas use of work–life benefits was not significantly related to either form of work–family conflict or any of the performance variables. The implications of our results for conservation of resources theory and practical implications to employers of lower-skill workers are discussed.     

Replies to Kane,McCormick, and Vargas

This is a reply to discussions by Robert Kane, Kelly McCormick, and Manuel Vargas of Shaun Nichols, Bound: Essays on Free Will and Responsibility.