A chimeric point-light walker

Ambiguity has long been used as a probe into visual processing. Here, we describe a new dynamic ambiguous figure-the chimeric point-light walker--which we hope will prove to be a useful tool for exploring biological motion. We begin by describing the construction of the stimulus and discussing the compelling finding that, when presented in a mask, observers consistently fail to notice anything odd about the walker, reporting instead that they are watching an unambiguous figure moving either to the left or right. Some observers report that the initial percept fluctuates, moving first to the left, then to the right, or vice versa; others always perceive a constant direction. All observers, when briefly shown the unmasked ambiguous figure, have no difficulty in perceiving the novel motion pattern once the mask is returned. These two findings--the initial report of unambiguous motion and the subsequent 'primed' perception of the ambiguity--are both consistent with an important role for top-down processing in biological motion. We conclude by suggesting several domains within the realm of biological-motion processing where this simple stimulus may prove to be useful.     

Neuropsychological mediators of the links among age, chronic illness, and everyday problem solving

Reductions in everyday problem solving (EPS) are often reported in older age, although the underlying mechanisms remain unclear. The authors examined the role of 2 variables predicted to mediate (neuropsychological abilities and health status) or moderate (health status) the relationship between age and EPS performance. Toward these ends, they compared EPS and neuropsychological performance in 50 functionally independent adults with chronic kidney disease (CKD) and 64 control participants matched on age and education. Both older age and CKD were associated with worse performance on measures of EPS and memory/executive abilities. Neuropsychological abilities were positively associated with EPS performance. In both the full sample and control participants only, memory/executive functioning mediated the association between presence of chronic illness and EPS. Furthermore, memory/executive functioning partially mediated the link between age and EPS. Findings indicate that relations among age, health status, and EPS are not straightforward. Although performance on neuropsychological measures appeared to underlie EPS declines in chronic illness, increasing age remained independently associated with reduced EPS. The authors discuss implications for models of adult developmental changes in everyday cognition.     

The new philosophy of psychiatry: its (recent) past, present and future: a review of the Oxford University Press series International Perspectives in Philosophy and Psychiatry

There has been a recent growth in philosophy of psychiatry that draws heavily (although not exclusively) on analytic philosophy with the aim of a better understanding of psychiatry through an analysis of some of its fundamental concepts. This 'new philosophy of psychiatry' is an addition to both analytic philosophy and to the broader interpretation of mental health care. Nevertheless, it is already a flourishing philosophical field. One indication of this is the new Oxford University Press series International Perspectives in Philosophy and Psychiatry seven volumes of which (by Bolton and Hill; Bracken and Thomas; Fulford, Morris, Sadler, and Stanghellini; Hughes, Louw, and Sabat; Pickering; Sadler; and Stanghellini) are examined in this critical review.     

Representation recovers information

Early agreement within cognitive science on the topic of representation has now given way to a combination of positions. Some question the significance of representation in cognition. Others continue to argue in favor, but the case has not been demonstrated in any formal way. The present paper sets out a framework in which the value of representation use can be mathematically measured, albeit in a broadly sensory context rather than a specifically cognitive one. Key to the approach is the use of Bayesian networks for modeling the distal dimension of sensory processes. More relevant to cognitive science is the theoretical result obtained, which is that a certain type of representational architecture is necessary for achievement of sensory efficiency. While exhibiting few of the characteristics of traditional, symbolic encoding, this architecture corresponds quite closely to the forms of embedded representation now being explored in some embedded/embodied approaches. It becomes meaningful to view that type of representation use as a form of information recovery. A formal basis then exists for viewing representation not so much as the substrate of reasoning and thought, but rather as a general medium for efficient, interpretive processing.     

Wounds of Dislocation and the Yearning for Home: Re-Imagining Pastoral Theology

This article contributes to current conversations concerning the role pastoral care and theology can play in the renewal of public life.     

Higher Cost,Lower Validity and Higher Utility: Comparing the Utilities of Two Tests that Differ in Validity,Costs and Selectivity

Traditional approaches to comparing the utility of two tests have not systematically considered the effects of different levels of selectivity that are feasible and appropriate in various selection situations. For example, employers who hope to avoid adverse impact often find they can be more selective with some tests than with others. We conducted two studies to compare the utilities of two tests that differ in costs, validity, and feasible levels of selectivity which can be employed. First, an analytical solution was conducted starting with a standard formula for utility. This analysis showed that for both fixed and variable hiring costs, a higher-cost, lower-validity procedure can have higher utility than a lower-cost, higher-validity procedure when the selection ratios permissible using the two procedures are sufficiently (yet realistically) different. Second, using a computer simulation method, several combinations of the critical variables were varied systematically to detect the limits of this effect in a finite set of specific selection situations. The results showed that the existence of more severe levels of adverse impact greatly reduced the utility of a written test with relatively high validity and low cost in comparison with an assessment center with lower validity and higher cost. Both studies showed that the consideration of selectivity can yield surprising conclusions about the comparative utility of two tests. Even if one test has lower validity and higher cost than a second test, the first may yield higher utility if it allows the organization to exercise stricter levels of selectivity.     

On the electrophysiology of effective visual memory as measured by QEEG

An investigation into the QEEG parameters of effective cognitive functioning of visual memory for six Korean figures was conducted employing 69 normal subjects. Subjects studied the figures for 1 minute, engaged in an immediate 30-second quiet recall period, which was then followed by the subjects drawing the figures. A delayed recall of 45 minutes later followed the same methodology. The recall performances were correlated with the QEEG variables. For the input stage, total memory was determined predominantly by specific patterns of left frontal (F7, F3, Fpl) projections (phase and coherence activity) and left central/posterior (T3, C3, P3) phase (Alpha and Betal( 13–32 Hz)) projections. Success during immediate silent recall was determined by left frontal (F7, Fpl, F3) projections and left central/posterior (T3, T5, Ol, P3) projections in the Beta frequencies. Long term-delayed recall was determined by Ol coherence Alpha projection activity and Symmetry of Beta2 (32–64 Hz) at F8. Degree of activation variables (from visual attention and eyes closed) showed different patterns of successful activations.