Descartes' Quantity of Motion: 'New Age' Holism Meets the Cartesian Conservation Principle

This essay explores various problematical aspects of Descartes' conservation principle for the quantity of motion (size 3 speed), particularly its largely neglected dual role as a measure of both durational motion and instantaneous tendencies towards motion. Overall, an underlying non-local, or holistic, element of quantity of motion (largely derived from his statics) will be revealed as central to a full understanding of the conservation principle's conceptual development and intended operation; and this insight can be of use in responding to some of the recent and traditional criticisms of Descartes' physics.     

Interventions With Juvenile Offenders: Strategies to Prevent Acting Out Behavior

In this article Moral Dilemma Discussion Groups, Just Communities, Positive Peer Culture and the EQUIP program are reviewed for their appropriateness for intervening with juvenile offenders in residential settings. The suitability of these interventions for diverse populations is also examined.     

But is it evolution…?

We applaud Müller & Schumann (M&S) for bringing needed attention to the problem of motivation for common non-addictive drug use, as opposed to the usual focus on exotic drugs and addiction. Unfortunately, their target article has many underdeveloped and sometimes contradictory ideas. Here, we will focus on three key issues.     

Examination of the PC-PTSD in previously deployed Air Force Medical Service personnel

This study assessed the performance of the PC-PTSD in diagnosing postdeployment posttraumatic stress disorder (PTSD) in a cohort of Air Force Medical Services personnel (N = 18,530). The prevalence of PTSD in the cohort was 5.18% based on medical record data. The area under the receiver operating characteristic curve was 0.69, indicating poor classification accuracy. Sensitivity was 47.55%, specificity was 90.68%, positive predictive value was 21.79%, and negative predictive value was 96.94%. The positive and negative likelihood ratios were 5.10 and 0.58, respectively. Several risk factors were found to be associated with a diagnosis of postdeployment PTSD: being a nurse, being enlisted in the medical service career field, being enlisted in the mental health service career field, those over age 30, being a member of the Active Duty service component, and having one’s first deployment be to Iraq. Being an officer was found to be a protective characteristic. These factors could potentially improve screening for PTSD among Air Force healthcare personnel.     

The influence of semantic relationships on older adult map memory

Research has shown that nonspatial features, including semantic categories, can bias younger adults' spatial location memory. For example, semantically related information is remembered as being closer in space than semantically unrelated information (Hirtle & Mascolo, 1986). These findings suggest that verbal information is concurrently encoded with spatial information and influences younger adults' spatial information retrieval. The present study explored whether older adults have a similar dependency between verbal and spatial information. In Experiment 1, older and younger adults learned maps depicting semantically categorizable landmarks. After learning, participants completed landmark free recall and distance estimation tasks. Younger adults recalled more landmarks from semantically organized maps compared with older adults. In addition, younger adults were more likely to underestimate the distance between semantically related landmarks than were older adults. Experiment 2 examined whether supportive instructions would influence older adults' use of verbal information when learning maps. When given instructions that encouraged semantic feature use, older adults remembered more landmarks, were more likely to cluster landmarks semantically, and demonstrated biases in distance estimation based on semantic relationships. These findings suggest that verbal influences on spatial/map learning in older adults depends on explicit instructions or environmental support at encoding. (PsycINFO Database Record (c) 2012 APA, all rights reserved).