Use of the MMPI-2 in American Indians: II. Empirical correlates

R. W. Robin, R. L. Greene, B. Albaugh, A. Caldwell, and D. Goldman (2003) reported that members of 2 American Indian tribal groups had statistically significant higher T scores on several MMPI-2 clinical, content, and supplementary scales than did the MMPI-2 normative group. The present study investigated the empirical correlates of the MMPI-2 scales in these American Indian tribal members. There were a large number of significant correlates reflecting antisocial symptoms with Scales 4 (Psychopathic Deviate), 9 (Hypomania), Anger, and Antisocial Practices. There were even a larger number of significant correlates reflecting generalized distress and negative affect with Scales 7 (Psychosthenia), 8 (Schizophrenia), Anxiety, Obsessions, Depression, and Welsh Anxiety. The rationally derived MMPI-2 content scales generally had larger correlations with these constructs than the clinical scales. Thus, the differences reported by R. W. Robin et al. (2003), appear to reflect behaviors and symptoms that American Indians participants were experiencing rather than test bias.     

The effects of aging on reaction time in a signal detection task

The effects of aging on response time are examined in 2 simple signal detection tasks with young and older subjects (age 60 years and older). Older subjects were generally slower than young subjects, and standard Brinley plot analyses of response times showed typical results: slopes greater than 1 and (mostly) negative intercepts. R. Ratcliff, D. Spieler, and G. McKoon (2000) showed that the slopes of Brinley plots measure the relative standard deviations of the distributions of response times for older versus young subjects. Applying R. Ratcliff's (1978) diffusion model to fit the response times, their distributions, and response accuracy, it was found that the larger spread in older subjects' response times and their slowness relative to young subjects comes from a 50-ms slowing of the nondecision components of response time and more from conservative settings of response criteria.     

On the limits of advance preparation for a task switch: do people prepare all the task some of the time or some of the task all the time?

This study investigated the nature of advance preparation for a task switch, testing 2 key assumptions of R. De Jong's (2000) failure-to-engage theory: (a) Task-switch preparation is all-or-none, and (b) preparation failures stem from nonutilization of available control capabilities. In 3 experiments, switch costs varied dramatically across individual stimulus-response (S-R) pairs of the tasks-virtually absent for 1 pair but large for others. These findings indicate that, across trials, task preparation was not all-or-none but, rather, consistently partial (full preparation for some S-R pairs but not others). In other words, people do not prepare all of the task some of the time, they prepare some of the task all of the time. Experiments 2 and 3 produced substantial switch costs even though time deadlines provided strong incentives for optimal advance preparation. Thus, there was no evidence that people have a latent capability to fully prepare for a task switch.     

Cultural differences in affective forecasting: the role of focalism

The impact bias in affective forecasting-a tendency to overestimate the emotional consequences of future events-may not be a universal phenomenon. This prediction bias stems from a cognitive process known as focalism, whereby predictors focus attention narrowly on the upcoming target event. Three studies supported the hypothesis that East Asians, who tend to think more holistically than Westerners, would be less susceptible to focalism and, consequently, to the impact bias. In Studies 1 and 2, Euro-Canadians exhibited the impact bias for positive future events, whereas East Asians did not. A thought focus measure indicated that the cultural difference in prediction was mediated by the extent to which participants focused on the target event (i.e., focalism). In Study 3, a thought focus manipulation revealed that defocused Euro-Canadians and East Asians made equally moderate affective forecasts.     

Conceptually driven pharmacologic approaches to acute trauma

Secondary prevention of posttraumatic stress disorder (PTSD) entails intervening in the aftermath of a traumatic event to forestall the development of PTSD. There has been little psychopharmacologic research in this area. This is surprising, given that PTSD is the mental disorder with the most clearly identified cause and onset. In a translational model of PTSD's pathogenesis presented herein: A traumatic event (unconditioned stimulus) overstimulates endogenous stress hormones (unconditioned response); these mediate an overconsolidation of the event's memory trace; recall of the event in response to reminders (conditioned stimulus); releases further stress hormones (conditioned response); these cause further overconsolidation; and the overconsolidated memory generates PTSD symptoms. Noradrenergic hyperactivity in the basolateral amygdala is hypothesized to mediate this cycle. Preventing pre-synaptic norepinephrine release with alpha2-adrenergic agonists or opioids, or blocking post-synaptic norepinephrine receptors with beta-adrenergic antagonists such as propranolol, reduces hormonally enhanced memories and fear conditioning. Two controlled studies of trauma victims presenting to emergency rooms suggest that posttrauma propranolol reduces subsequent PTSD, as does one naturalistic clinical study of morphine treatment of burned children. Cortisol both enhances memory consolidation and reduces memory retrieval, leading to mixed predictions. Two controlled studies of intensive care unit patients found that cortisol reduced PTSD. One study did not find benzodiazepines effective in preventing PTSD. Selective serotonin reuptake inhibitors, antiepileptics, and alpha2-adrenergic agonists have yet to be tried.     

Episodic memory change in late adulthood: Generalizability across samples and performance indices

Younger adults recall more information from episodic memory tasks than do older adults. Because longitudinal studies are rare and often incompatible, the extent of actual late-life memory change is not well established. We assemble two different longitudinal samples of normal older adults, each of which is tested twice at a 3-year interval, using a large battery of episodic memory indicators. Together, two-wave data from both the Victoria Longitudinal Study in Canada (n = 400) and the Kungsholmen Project in Sweden (n = 168) cover a 40-year span of adulthood, ranging from 54 to 94 years of age. Principal memory tasks include categorizable word lists, story recall, and random word lists, as well as indicators of cognitive support. Overall, an examination of performance on sets of common and complementary episodic tasks reveals that, for both samples, actual 3-year changes are modest and that, when decline occurs, it is gradual. The exception-greater decline for more supported tasks-suggests that these may be especially sensitive to late-life changes.     

Perceptions of causes of performance-related injuries by music health experts and injured violinists

Skilled violin and viola players, all of whom had a current performance-related musculoskeletal injury, were asked to report their perceptions of contributing risk factors, consistent with a participatory ergonomics approach. The 26 players, age 18 to 60 years, had been playing for a minimum of 10 years and averaged three hours of practice per day. In addition, 7 music health experts, all with more than 10 years of clinical experience in treating musicians, were asked to report on the risk factors for musicians' performance-related injuries. A high correlation between the perceptions of these two groups was found, with the same top five factors in terms of severity indicated by both groups. Factors rated as high risk were primarily intrinsic and related to the manner in which respondents practiced, to playing posture, and to flaws in skill technique.     

Comparing categorization models

Four experiments are presented that competitively test rule- and exemplar-based models of human categorization behavior. Participants classified stimuli that varied on a unidimensional axis into 2 categories. The stimuli did not consistently belong to a category; instead, they were probabilistically assigned. By manipulating these assignment probabilities, it was possible to produce stimuli for which exemplar- and rule-based explanations made qualitatively different predictions. F. G. Ashby and J. T. Townsend's (1986) rule-based general recognition theory provided a better account of the data than R. M. Nosofsky's (1986) exemplar-based generalized context model in conditions in which the to-be-classified stimuli were relatively confusable. However, generalized context model provided a better account when the stimuli were relatively few and distinct. These findings are consistent with multiple process accounts of categorization and demonstrate that stimulus confusion is a determining factor as 10 which process mediates categorization.