Selective attention to specific location cues: the peak and center of a patch are equally accessible as location cues.

Asymmetric patterns have several spatially distinct cues for spatial localization. These cues include the peak of the luminance distribution, the centroid of the contrast distribution, zero-crossings in the second derivative of the luminance profile, and the midpoint of the visible area. If these cues are represented as primitives in the visual system, the observer should be able to access them at will. To examine whether observers can selectively attend to particular cues, we measured perceived alignment for an asymmetric pattern with two distinct instructions: "align the peak", and "align the center". We found that observers could align the patterns in accord with the instructions with identical precision, suggesting that the peak and the center cues were equally accessible by the observer. We conclude that multiple localization cues are represented in and can be selectively accessed by the visual system.     

Posttraumatic stress symptoms in children following orthopedic or traumatic brain injury.

Examined posttraumatic stress (PTS) symptoms in children following pediatric traumatic brain injury (TBI). Children (ages 6-12) with TBI (n = 81) and orthopedic injury (OI; n = 59) were assessed 6 and 12 months postinjury. Parents of children with severe TBI reported higher levels of child PTS symptoms than did parents of children with moderate TBI or OI at the 6- and 12-month follow-ups. Group differences in child-reported PTS symptoms emerged at the 12-month follow-up with higher symptom levels reported by children with severe TBI than by those with moderate TBI or OI. At both follow-ups, rates of clinically significant symptom levels were higher in the severe TBI group than in the moderate TBI or OI groups. The group differences in parent and child reports were significant even after taking ethnicity, social disadvantage, and age at injury into account. Parent and child reports of child PTS symptoms were related to family socioeconomic status. Implications for clinical intervention with children and families following pediatric TBI are discussed.     

Replies to Comesaña and Yablo

There are few indulgences academics can crave more than to have their work considered and addressed by leading researchers in their field. We have been fortunate to have two outstanding philosophers from whose work we have learned a great deal give ours their thoughtful attention. Grappling with Stephen Yablo’s, and Juan Comesaña’s comments and criticisms has helped us gain a better understanding of our ideas as well as their shortcomings. We are extremely grateful to them for the attentiveness and seriousness with which they have considered our arguments and to philosophical studies for giving us this opportunity. Given the substantive difference between the two response papers, there is not much beyond sincere gratitude that we can covey to them jointly. We will therefore address them in turn.     

Counterexamples to Recovery and the Filtering Condition

David Makinson has argued that the compelling character of counterexamples to the Recovery Condition on contraction is due to an appeal to justificational structure. In “naked theories” where such structure is ignored or is not present, Recovery does apply. This note attempts to show that Makinson is mistaken on both counts. Recovery fails when no appeal is made to justificational structure. This revised version was published online in August 2006 with corrections to the Cover Date.     

Location coding by the human visual system: multiple topological adaptations in a case of strabismic amblyopia

Amblyopia, a major cause of vision loss, is a developmental disorder of visual perception commonly associated with strabismus (squint). Although defined by a reduction in visual acuity, severe distortions of perceived visual location are common in strabismic amblyopia. These distortions can help us understand the cortical coding of visual location and its development in normal vision, as well as in amblyopia. The history of retinotopic mapping in the visual cortex highlights the potential impact of amblyopia. Theories of amblyopia include topological disarray of receptors in primary visual cortex, undersampling from the amblyopic eye compared with normal eyes, and the presence of anomalous retinal correspondence or multiple cortical representations of the strabismic fovea. We examined the distortions in a strabismic amblyope, using a pop-out localization task, in which normal observers made errors dependent on the visual context of the stimulus. The localization errors of the strabismic amblyope were abnormal. We found that none of the available theories could fully explain this one patient's localization performance. Instead, the observed behavior suggests that multiple adaptations of the underlying cortical topology are possible simultaneously in different parts of the visual field.     

Diagnosing organizational cultures: A conceptual and empirical review of culture effectiveness surveys

This review traces the development of survey research methods within the organizational culture tradition and focuses specifically on those instruments that measure the aspects of culture that are related to organizational effectiveness. Our review suggests that the reliability and validity of most instruments in this category is quite limited. This review outlines the recommended logic for the development and validation of culture effectiveness surveys and identifies three key challenges for future culture researchers to address: (1) the confirmatory testing of nested models, (2) the guidelines for aggregating data to the organizational level, and (3) the establishing of criterion-related validity. Using data from the Denison Organizational Culture Survey, we present an empirical illustration of the three challenges identified above and conclude by considering limitations and opportunities for future research.     

Charisma, status, and gender in groups with and without gurus

A number of studies have noted that small religious groups with charismatic leaders seem to have different gender dynamics than do groups without. We argue that the presence of such a leader changes what charisma “means” in such a group. Without such a leader, strong personalities may appear charismatic and lead to positions of high status—and such dynamics historically have tended to be associated with a positional advantage to males. With such a leader, however, charisma is more likely to be compatible with receptivity and decoupled from gender characteristics that tend to disadvantage women, leading charismatic women to have greater status than they would otherwise have.