A cultural-contextual perspective on the validity of the MMPI-2 with American Indians

This study investigated the normative validity of the MMPI-2 with two distinct American Indian tribes. Differences occurred on 8 of the 13 basic validity and clinical scales (F, 1, 4, 5, 6, 7, 8, 9) between the MMPI-2 norms and both tribal samples. Elevated MMPI-2 scores of American Indians may not only reflect the possibility of psychological distress spurred by historical oppression and present adversity, but also an expression of a divergent worldview. Considering the context of the historical and social production of knowledge about American Indians, it is argued that researchers and practitioners, when interpreting MMPI-2 results for American Indians, should seriously consider their interpretive points of reference, which may be impacted by dominant cultural belief systems.     

All symptoms are not created equal: the prominent role of hyperarousal in the natural course of posttraumatic psychological distress

This 3-wave longitudinal study examined the natural course of posttraumatic stress disorder symptoms using data collected from young adult survivors of community violence. Three key findings emerged. 1. Mean levels of distress for each symptom cluster decreased over time, with reexperiencing decreasing most rapidly. 2. Cross-lagged panel analysis revealed that hyperarousal strongly influences, but is not generally influenced by, other symptoms clusters. 3. Trajectory analysis demonstrated that respondents for whom hyperarousal was the most pronounced baseline symptom showed lower overall symptom improvement relative to trauma exposed counterparts for whom hyperarousal was a less prominent early symptom. Implications for theory, research, and clinical practice are discussed.     

Preference for progressive delays and concurrent physical therapy exercise in an adult with acquired brain injury

The purpose of this study was to increase self-control and engagement in a physical therapy task (head holding) for a man with acquired traumatic brain injury. Once impulsivity was observed (i.e., repeated impulsive choices), an experimental condition was introduced that consisted of choices between a small immediate reinforcer, a large fixed-delay reinforcer, and a large progressive-delay reinforcer. The participant showed a preference for the progressive-delay option, even when the duration of the delay exceeded that of the fixed delay. The results have implications for establishing optimal choice making and teaching life-enhancing skills.     

Adaptation-level theory, opponent process theory, and dispositions: an integrated approach to the stability of job satisfaction

Research suggests that the stability of job satisfaction is partially the result of dispositions (J. J. Connolly & C. Viswesvaran, 2000; C. Dormann & D. Zapf, 2001; T. A. Judge & J. E. Bono, 2001a; T. A. Judge, D. Heller, & M. K. Mount, 2002). Opponent process theory (R. L. Solomon & J. D. Corbit, 1973, 1974) and adaptation-level theory (H. Helson, 1948) are alternative explanations of this stability that explain how environmental effects on job satisfaction dissipate across time. On the basis of an integration of these explanations, the authors propose that dispositions (a) influence employees' equilibrium or adaptation level of job satisfaction, (b) influence employees' sensitivity to workplace events, and (c) influence the speed at which job satisfaction returns to equilibrium after one is exposed to a workplace event. Research and applied implications are discussed.     

The interaction of the explicit and the implicit in skill learning: a dual-process approach

This article explicates the interaction between implicit and explicit processes in skill learning, in contrast to the tendency of researchers to study each type in isolation. It highlights various effects of the interaction on learning (including synergy effects). The authors argue for an integrated model of skill learning that takes into account both implicit and explicit processes. Moreover, they argue for a bottom-up approach (first learning implicit knowledge and then explicit knowledge) in the integrated model. A variety of qualitative data can be accounted for by the approach. A computational model, CLARION, is then used to simulate a range of quantitative data. The results demonstrate the plausibility of the model, which provides a new perspective on skill learning.     

The emergence of words: attentional learning in form and meaning

Children improve at word learning during the 2nd year of life—sometimes dramatically. This fact has suggested a change in mechanism, from associative learning to a more referential form of learning. This article presents an associative exemplar-based model that accounts for the improvement without a change in mechanism. It provides a unified account of children's growing abilities to (a) learn a new word given only 1 or a few training trials ("fast mapping"); (b) acquire words that differ only slightly in phonological form; (c) generalize word meanings preferentially along particular dimensions, such as object shape (the "shape bias"); and (d) learn 2nd labels for already-named objects, despite a persisting resistance to doing so ("mutual exclusivity"). The model explains these improvements in terms of increased attention to relevant aspects of form and meaning, which reduces memory interference. The interaction of associations and reference in word learning is discussed.     

Arousal, valence, and memory for detail

A common finding in the emotion-memory literature is that memory is enhanced for positively arousing stimuli and negatively arousing stimuli relative to neutral stimuli. We tested the notion that post-stimulus elaboration is responsible for these effects. Post-stimulus elaboration refers to the process of thinking about an event (after its offset) more frequently or more in-depth. We tested the hypothesis by presenting participants with 36 slides depicting events that varied in arousal (low and high) and valence (positive and negative). The opportunity for elaboration was manipulated by requiring participants, during the interslide interval, to complete addition problems, simply view the addition problems, or view a blank slide. Cued recall memory was tested for central and background details. Based on the post-stimulus elaboration hypothesis it was expected that the greatest memory decline would occur for the central details of negatively and positively arousing slides when participants were required to complete addition problems (i.e., a distractor task x arousal x detail interaction). Contrary to the hypothesis, we found that filling the inter-slide interval with a distractor task decreased memory for negative stimuli compared to positive stimuli. This effect was independent of arousal. We also found that arousal increased central detail memory for positive and negative stimuli and background detail memory for positive stimuli but not for negative stimuli. This interaction was explained on the basis of pre-attentive encoding and cue utilisation. It was concluded that in order to understand the complex relationship between emotion and memory, future studies should include, as a minimum, the variables of valence, arousal, and detail.     

Plasticity and functions of the orbital frontal cortex

We compare the effects of psychoactive drugs such as morphine and amphetamine on the synaptic organization of neurons in the orbital frontal (OFC) and medial frontal (mPFC) regions in the rat. Both regions are altered chronically by exposure to intermittent doses of either drug but the effects are area-dependent. For example, whereas morphine produces increased spine density in OFC but decreased spine density in mPFC. The differential response of the OFC and mPFC to drugs is paralleled by an areal-dependent effect of gonadal hormones on these regions as well: males have greater dendritic arborization in the mPFC whereas females have a greater arborization in the OFC. We also compared the effects of neonatal injury to the OFC and mPFC on cognitive, motor, and social behaviors as well as on the anatomical organization of the remaining brain. Again, there were differential effects of the treatments to the OFC and mPFC. Neonatal OFC lesions allowed virtually complete functional recovery of cognitive and motor behaviors, which was correlated with mild abnormalities in cerebral development compared to the more severe deficits and morphological sequelae following mPFC lesions at the same ages. One exception was the effect of OFC on social behavior, which was severe regardless of whether the injury was in infancy or adulthood. It is proposed that both drug-induced and developmental abnormalities in the integrity of OFC neurons may lead to deficits in social behavior or other behavioral pathologies, possibly including depression.     

Incremental exercise, plasma concentrations of catecholamines, reaction time, and motor time during performance of a noncompatible choice response time task

The primary purpose was to examine the effect of incremental exercise on a noncompatible response time task. Participants (N=9) undertook a 4-choice noncompatible response time task under 3 conditions, following rest and during exercise at 70% and 100% of their maximum power output. Reaction and movement times were the dependent variables. Maximum power output had been previously established on an incremental test to exhaustion. A repeated-measures multivariate analysis of variance yielded a significant effect of exercise intensity on the task, observation of the separate univariate repeated-measures analyses of variance showed that only movement time was significantly affected. Post hoc Tukey tests indicated movement time during maximal intensity exercise was significantly faster than in the other two conditions. The secondary purpose of the study was to assess whether increases in plasma concentrations of adrenaline and nor-adrenaline during exercise and power output would act as predictor variables of reaction and movement times during exercise. Catecholamine concentrations were based on venous blood samples taken during the maximum power output test. None of the variables were significant predictors of reaction time. Only power output was a significant predictor of movement time (R2 = .24). There was little support for the notion that peripheral concentrations of catecholamines directly induce a central nervous system response.