Simplicity as a criterion of theory choice in metaphysics

Metaphysicians frequently appeal to the idea that theoretical simplicity is truth conducive in metaphysics, in the sense that, all other things being equal, simpler metaphysical theories are more likely to be true. In this paper I defend the notion that theoretical simplicity is truth conducive in metaphysics, against several recent objections. I do not give any direct arguments for the thesis that simplicity is truth conducive in metaphysics, since I am aware of no such arguments. I do argue, however, that there is no special problem with the notion that simplicity is truth conducive in metaphysics. More specifically, I argue that if you accept the idea that simplicity is truth conducive in science, then it would be objectionably arbitrary to reject the idea that simplicity is truth conducive in metaphysics.     

Spatial updating of multiple targets: Comparison of younger and older adults

When walking without vision, people mentally keep track of the directions and distances of previously viewed objects, a process called spatial updating. The current experiment indicates that while people across a large age range are able to update multiple targets in memory without perceptual support, aging negatively affects accuracy, precision, and decision time. Participants (20 to 80 years of age) viewed one, three, or six targets (colored lights) on the floor of a dimly lit room. Then, without vision, they walked to a target designated by color, either directly or indirectly (via a forward turning point). The younger adults’ final stopping points were both accurate (near target) and precise (narrowly dispersed), but updating performance did degrade slightly with the number of targets. Older adults’ performance was consistently worse than the younger group, but the lack of interaction between age and memory load indicates that the effect of age on performance was not further exacerbated by a greater number of targets. The number of targets also significantly increased the latency required to turn toward the designated target for both age groups. Taken together, results extend previous work showing impressive updating performance by younger adults, with novel findings showing that older adults manifest small but consistent degradation of updating performance of multitarget arrays.     

THE PERCEIVED IMPORTANCE OF DEVELOPMENTAL RELATIONSHIPS ON WOMEN UNDERGRADUATES' PURSUIT OF SCIENCE

Using a survey of women science majors, we tested the assumption that women mentors and other women guides help women students pursue the sciences. The survey explicitly distinguished among three types of guides: mentors (who provide psychosocial support), sponsors (who provide instrumental support), and role models (who act as examples) encountered before and during college. We found that over 90% of the women had a guide of one type or another, that mentors were most influential to women's pursuit of science, and that guides during college were more influential than guides prior to college. Participants reported having more female than male guides overall, but that some of the most influential guides were men.     

Implementation of a Suicide Nomenclature within Two VA Healthcare Settings

Suicide and suicide attempts are significant issues for military, Veterans Affairs (VA), and civilian healthcare systems. The lack of uniform terms related to self-directed violence (SDV) has inhibited epidemiological surveillance efforts, limited the generalizability of empirical studies of suicide and non-lethal forms of SDV, and complicated the implementation of evidence-based assessment and treatment strategies for individuals with suicidal thoughts and/or behaviors. The Department of Veterans Affairs recently adopted the Centers for Disease Control and Prevention’s (CDC) SDV Classification System (SDVCS). This paper describes an implementation study of the SDVCS in two VA Medical Centers. The Veterans Integrated Service Network (VISN) 19 Mental Illness Research, Education and Clinical Center (MIRECC) training program for the SDVCS, including the SDVCS Clinical Tool (CT), will be discussed. Although preliminary data suggest that the CT and SDVCS are generally perceived as being acceptable and useful, further work will likely be required to facilitate widespread adoption. Potential next steps in this process are presented.     

Career engagement: bridging career counseling and employee engagement

A model of career engagement is presented to help bridge the gap between career counselors' focus on supporting individuals to find meaningful work and employers' desire for an engaged, productive, and committed workforce.     

a review of a quality of life approach to career development

Goeff S. Peruniak. (2010). A Quality of Life Approach to Career Development. Toronto, Ontario, Canada: University of Toronto Press. 221 pages, $29.95 List, ISBN 978–1–4426–1064–4 (paperback).     

Posttraumatic stress disorder, traumatic brain injury, and suicide attempt history among veterans receiving mental health services

History of posttraumatic stress disorder (PTSD) or traumatic brain injury (TBI) has been found to increase risk of suicidal behavior. The association between suicide attempt history among veterans with PTSD and/or TBI was explored. Cases (N = 81) and 2:1 matched controls (N = 160) were randomly selected from a Veterans Affairs Medical Center clinical database. PTSD history was associated with an increased risk for a suicide attempt (OR = 2.8; 95% CI: 1.5, 5.1). This increased risk was present for those with and without a history of TBI. Results support incorporating PTSD history when assessing suicide risk among veterans with and without TBI.     

Age-related susceptibility to the Müller-Lyer and the horizontal-vertical illusions

Participants between the ages of 3 and 20 years adjusted the Müller-Lyer illusion and the inverted-T form of the Horizontal-Vertical illusion. Perceptual error was quantified using signal detection and nonparametric measures of sensitivity and responsivity. Significant changes in sensitivity and responsivity were found for each illusion across participants' ages. No effect of sex of participant was found. Sensitivity and responsivity were largely asymptotic between the ages of 13 to 15 years for the Müller-Lyer illusion and between the ages of 11 to 15 years for the Horizontal-Vertical illusion.     

Combining cues while avoiding perceptual conflicts

A common assumption in cue combination models is that small discrepancies between cues are due to the limited resolution of the individual cues. Whenever this assumption holds, information from the separate cues can best be combined to give a single, more accurate estimate of the property of interest. We examined whether information about the discrepancy itself is lost when this is done. In our experiments, subjects were required to combine cues to match certain properties while avoiding perceptual conflicts. In part 1, they combined expansion and change in disparity to estimate motion in depth; and in part 2, they combined perspective and binocular disparities to estimate slant. We compared the pattern in the way that subjects set the two cues with the patterns predicted by models of cue combination with and without a loss of information about the discrepancy. From this comparison we conclude that little information about the discrepancies between cues is lost when the cues are combined.     

Spatial but not temporal cueing influences the mislocalisation of a target flashed during smooth pursuit

Human subjects misjudge the position of a target that is flashed during a pursuit eye movement. Their judgments are biased in the direction in which the eyes are moving. We investigated whether this bias can be reduced by making the appearance of the flash more predictable. In the normal condition, subjects pursued a moving target that flashed somewhere along its trajectory. After the presentation, they indicated where they had seen the flash. The mislocalisations in this condition were compared to mislocalisations in conditions in which the subjects were given information about when or where the flash would come. This information consisted of giving two warning flashes spaced at equal intervals before the target flash, of giving two warning beeps spaced at equal intervals before the target flash, or of showing the same stimulus twice. Showing the same stimulus twice significantly reduced the mislocalisation. The other conditions did not. We interpret this as indicating that it is not predictability as such that influences the performance, but the fact that the target appears at a spatially cued position. This was supported by a second experiment, in which we examined whether subjects make smaller misjudgments when they have to determine the distance between a target flashed during pursuit and a reference seen previously, than when they have to determine the distance between the flashed target and a reference seen afterwards. This was indeed the case, presumably because the reference provided a spatial cue for the flash when it was presented first. We conclude that a spatial cue reduces the mislocalisation of targets that are flashed during pursuit eye movements. The cue does not have to be exactly at the same position as the flash.