Processing demand modulates the effects of spatial attention on the judged duration of a brief stimulus

How does attention influence the judged duration of a brief stimulus? In the four experiments reported here, we show that the effect of spatial attention on duration judgment depends on the processing demand of the concurrent nontemporal task. When participants had to perform a speeded letter discrimination task in addition to duration rating, the judged duration was longer at a cued location than at an uncued location, regardless of whether the cue was exogenous or endogenous. However, when the same stimuli were presented but no concurrent nontemporal task was required, duration was judged to be shorter at the cued location, as compared with the uncued locations. Furthermore, although spatial attention influenced duration judgment, no object-based attentional effects were found. These findings suggest that, although spatial attention plays an important role in the judged duration of a briefly presented stimulus, its effect is mediated by the processing demand of the task.     

Intolerance of Uncertainty and Anxiety Symptoms: Examining the Indirect Effect Through Anxiety Sensitivity Among Adults with Anxiety-Related Disorders

Journal of Psychopathology and Behavioral Assessment - The conceptual overlap between intolerance of uncertainty (IU) and anxiety sensitivity (AS) has gained recent attention, with researchers...     

Proofs,Grounds and Empty Functions: Epistemic Compulsion in Prawitz’s Semantics

Journal of Philosophical Logic - Prawitz has recently developed a theory of epistemic grounding that differs in many respects from his earlier semantics of arguments and proofs. An innovative...     

Response competition effects insame-different judgments

An account ofsame-different discriminations that is based upon a continuous-flow model of visual information processing (C. W. Eriksen & Schultz, 1979) and response competition and inhibition between the responses by which the subject signifies his judgment is presented. We show that a response signifyingsame will on the average be executed faster due to less priming or incipient activation of the competing response,different. In the experiment, the subjects matched letters on the basis of physical identity. The degree of priming ofdifferent responses on same trials and ofsame responses ondifferent trials was manipulated by an extraneous noise letter placed in the display. Latency for judgments onsame trials increased as the feature overlap of noise and target letters decreased. Latencies were shorter ondifferent trials when the noise letter was dissimilar to either target letter than when the noise letter was the same as one of the targets. These results were consistent with the response-competition interpretation.     

Bidirectional Links Between Teachers’ Disciplinary Practices,Students’ Peer Status,and Students’ Aggression in Kindergarten

Research on Child and Adolescent Psychopathology - This study examined bidirectional links between teachers’ disciplinary practices (punitive and educational), students’ peer status in...     

Proving quadratic reciprocity: explanation,disagreement, transparency and depth

Gauss’s quadratic reciprocity theorem is among the most important results in the history of number theory. It’s also among the most mysterious: since its discovery in the late eighteenth century, mathematicians have regarded reciprocity as a deeply surprising fact in need of explanation. Intriguingly, though, there’s little agreement on how the theorem is best explained. Two quite different kinds of proof are most often praised as explanatory: an elementary argument that gives the theorem an intuitive geometric interpretation, due to Gauss and Eisenstein, and a sophisticated proof using algebraic number theory, due to Hilbert. Philosophers have yet to look carefully at such explanatory disagreements in mathematics. I do so here. According to the view I defend, there are two important explanatory virtues—depth and transparency—which different proofs (and other potential explanations) possess to different degrees. Although not mutually exclusive in principle, the packages of features associated with the two stand in some tension with one another, so that very deep explanations are rarely transparent, and vice versa. After developing the theory of depth and transparency and applying it to the case of quadratic reciprocity, I draw some morals about the nature of mathematical explanation.

     

Nonsuicidal Self-injury,Suicide Planning,and Suicide Attempts Among High-risk Adolescents Prior to Psychiatric Hospitalization

Research on Child and Adolescent Psychopathology - The purpose of this study was to understand the trajectories of nonsuicidal self-injury (NSSI) and suicide plans (SP) in the 90 days...     

An X Windows tool for synthesizing face images from eigenvectors

An X Windows software tool for the construction of faces with a weighted combination of eigenvectors is described. The eigenvectors were extracted from an autoassociative matrix that comprised 100 face images. The program input consists of eigenvectors and sets of weights that describe individual faces and combines these to create face images. The tool creates a panel of buttons that permits the display of individual eigenvectors and the display of an average face as well. Facilities for on-line changes to the intensity of individual eigenvectors can be used to change the appearance of a face. Previously, O’Toole, Abdi, Deffenbacher, and Bartlett (1991) have shown that the intensity of certain individual eigenvectors contains reliable information for determining the sex and race of the face.     

Perceived motion in structure from motion: Pointing responses to the axis of rotation

We investigated the ability to match finger orientation to the direction of the axis of rotation in structure-from-motion displays. Preliminary experiments verified that subjects could accurately use the index finger to report direction. The remainder of the experiments studied the perception of the axis of rotation from full rotations of a group of discrete points, the profiles of a rotating ellipsoid, and two views of a group of discrete points. Subjects’ responses were analyzed by decomposing the pointing responses into their slant and tilt components. Overall, the results indicated that subjects were sensitive to both slant and tilt. However, when the axis of rotation was near the viewing direction, subjects had difficulty reporting tilt with profiles and two views and showed a large bias in their slant judgments with two views and full rotations. These results are not entirely consistent with theoretical predictions. The results, particularly for two views, suggest that additional constraints are used by humans in the recovery of structure from motion.