Presence as determined by fractal perceptual-motor dynamics.

This paper presents a tentative model of the role of perceptual-motor dynamics in the emergence of the feeling of presence. A new method allowing the measure of how gaze probes three-dimensional space in immersion is used to support this model. Fractal computations of gaze behavior are shown to be more effective than standard computations of eye movements in predicting presence.     

An Internal Version of Epistemic Logic

Representing an epistemic situation involving several agents obviously depends on the modeling point of view one takes. We start by identifying the types of modeling points of view which are logically possible. We call the one traditionally followed by epistemic logic the perfect external approach, because there the modeler is assumed to be an omniscient and external observer of the epistemic situation. In the rest of the paper we focus on what we call the internal approach, where the modeler is one of the agents involved in the situation. For this approach we propose and axiomatize a logical formalism based on epistemic logic. This leads us to formalize some intuitions about the internal approach and about its connections with the external ones. Finally, we show that our internal logic is decidable and PSPACE-complete.     

Visual Perception Modifies Goal-directed Movement Control: Supporting Evidence from a Visual Perturbation Paradigm

It is well known that dynamic visual information influences movement control, whereas the role played by background visual information is still largely unknown. Evidence coming mainly from eye movement and manual tracking studies indicates that background visual information modifies motion perception and might influence movement control. The goal of the present study was to test this hypothesis. Subjects had to apply pressure on a strain gauge to displace in a single action a cursor shown on a video display and to immobilize it on a target shown on the same display. In some instances, the visual background against which the cursor moved was unexpectedly perturbed in a direction opposite to (Experiment 1), or in the same direction as (Experiment 2) the cursor controlled by the subject. The results of both experiments indicated that the introduction of a visual perturbation significantly affected aiming accuracy. These results suggest that background visual information is used to evaluate the velocity of the aiming cursor, and that this perceived velocity is fed back to the control system, which uses it for on-line corrections.     

Parental Knowledge/Monitoring and Depressive Symptoms During Adolescence: Protective Factor or Spurious Association?

Research on Child and Adolescent Psychopathology - Parental knowledge/monitoring is negatively associated with adolescents’ depressive symptoms, suggesting monitoring could be a target for...     

The use of event‐related potentials in the study of early cognitive development

The article by Guillaume Thierry is a welcome one, alerting the field to the exciting ways in which event‐related potentials (ERPs) can be used to study cognitive development. It is also timely: there is great interest in the brain sciences, and in how neuroscience can be applied to cognitive development and indeed to education. In my view, however, the article is perhaps too cautious. It does not seem necessary to delay the use of ERPs in cognitive work until all in the field have agreed on the sound characterization of ERP components. It should be possible for further characterization to proceed hand‐in‐hand with data gathering on applied questions. In fact, as partly noted by Thierry, in the auditory domain well‐characterized ERP components are already available, even for infants (e.g. Cheour et al., 1997; Leppänen and Lyytinen, 1997). Furthermore, it is of developmental interest to study older children as well as infants. If ERPs are seen as a tool to complement existing behavioural investigations, rather than as a stand‐alone method to be used independently, then auditory ERPs can certainly be used in current cognitive‐developmental work. Copyright © 2005 John Wiley & Sons, Ltd.     

Intact Procedural Knowledge in Patients with Alzheimer's Disease: Evidence from Golf Putting

Can Alzheimer's disease (AD) patients efficiently learn to perform a complex motor skill when relying on procedural knowledge? To address this question, the authors compared the golf-putting performance of AD patients, older adults, and younger adults in 2 different learning situations: one that promotes high error rates (thus increasing the reliance on declarative knowledge) or one that promotes low error rates (thus increasing the reliance on procedural knowledge). Motor performance was poorer overall for AD patients and older adults relative to younger adults in the high-error condition but equivalent between similar groups in the low-error condition. Also, AD patients in the low-error condition had better performance at the final putting distance relative to those in the high-error condition. This performance facilitation for AD patients likely stems from intact procedural knowledge.     

Online Module for Carrier Screening in Ashkenazi Jewish Individuals Compared with In-Person Genetics Education: A Randomized Controlled Trial

To increase accessibility to genetics services for low-urgency patients seeking Ashkenazi Jewish (AJ) carrier screening, we designed an interactive computer (IC) module that provides pre-test genetics education and allows genetics professionals to order the test without meeting the patients beforehand. We compared this module with in-person genetic counseling (GC) using a randomized trial. AJ individuals were randomized to undergo genetics education via the IC module (n = 26) or GC (n = 28). We compared post-interventional genetics knowledge, perceived genetic risk, and anxiety between the two groups, after accounting for pre-interventional scores, using ANCOVA. Wilcoxon Rank-Sum test was used to compare post-interventional satisfaction. Post-interventional genetics knowledge, risk perception, or anxiety were not significantly different between the two groups after accounting for baseline scores (p = 0.50–0.54), although the data are inconclusive regarding the module’s non-inferiority at a 5% margin. Post-intervention satisfaction scores were generally higher in the GC group than the IC module group. Our IC module has the potential to improve access to clinical genetics services for patients and staff, but it is not suitable for all AJ patients and cannot completely replace the benefits of in-person consultations.     

Implicit attitudes and the improvement of exercise capacity during pulmonary rehabilitation

The aim of this study was to examine the role of explicit and implicit attitudes in the improvement of exercise capacity during a 5-week pulmonary rehabilitation (PR). A total of 105 patients performed walking tests at baseline and at the end of PR. Change between performances was computed at the end of PR, and Minimal-Clinically-Important-Difference (MCID) were used to categorize patients as responders (i.e. change above MCID, N = 54) or non-responders (i.e. change below MCID, N = 51). At baseline, implicit attitudes were measured through a physical activity versus sedentary behavior Implicit Association Test; explicit attitudes toward physical activity and sedentary behavior were measured by questionnaires. Only implicit attitudes significantly differed between the two groups (p = .015), responders displaying implicit attitudes significantly more in favor of physical activity (M = .91, SD = .54) than non-responders (M = .60, SD = .71) at baseline. Measuring implicit attitudes in PR could help to accurately estimate patients’ motivation, and design more individualized rehabilitation programs.