The Infrequency-Posttraumatic Stress Disorder scale (Fptsd) for the MMPI-2: development and initial validation with veterans presenting with combat-related PTSD

Researchers have identified difficulties associated with the use of traditional Minnesota Multiphasic Personality Inventory-2 (MMPI-2; Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) validity scales with survivors of traumatic events. A new scale, the Infrequency-Posttraumatic Stress Disorder scale (Fptsd), was created from MMPI-2 items that were infrequently endorsed by 940 male combat veterans presenting for treatment at the posttraumatic stress disorder (PTSD) clinics of 2 Veterans Affairs Medical Centers. A variety of statistical methods were implemented that preliminarily established Fptsd's validity with a validation sample of 323 additional PTSD-diagnosed combat veterans. Results indicate that, relative to previously established validity and overreporting scales (F, Fb, and Fp), Fptsd was significantly less related to psychopathology and distress and better at discriminating simulated from genuinely reported PTSD. Clinical implications are discussed concerning the use of Fptsd to assess disability-seeking veterans suspected of overreporting PTSD symptoms.     

Generalizing a neuropsychological model of visual categorization to auditory categorization of vowels

Twelve male listeners categorized 54 synthetic vowel stimuli that varied in second and third formant frequency on a Bark scale into the American English vowel categories [see text]. A neuropsychologically plausible model of categorization in the visual domain, the Striatal Pattern Classifier (SPC; Ashby & Waldron, 1999), is generalized to the auditory domain and applied separately to the data from each observer. Performance of the SPC is compared with that of the successful Normal A Posteriori Probability model (NAPP; Nearey, 1990; Nearey & Hogan, 1986) of auditory categorization. A version of the SPC that assumed piece-wise linear response region partitions provided a better account of the data than the SPC that assumed linear partitions, and was indistinguishable from a version that assumed quadratic response region partitions. A version of the NAPP model that assumed nonlinear response regions was superior to the NAPP model with linear partitions. The best fitting SPC provided a good account of each observer's data but was outperformed by the best fitting NAPP model. Implications for bridging the gap between the domains of visual and auditory categorization are discussed.     

Rats use a sense of direction to alternate on T-mazes located in adjacent rooms

Lister hooded rats were trained on a forced-sample T-maze alternation task in an environment lacking spatial landmarks. An early study of spontaneous alternation on the T-maze had shown that rats use a "spatial sense" to select alternate maze arms across mazes. As this phenomenon may provide a useful tool for studying the neural substrates of a directional sense, we wished to confirm this finding on a different version of the T-maze task, with well-trained animals. We found that rats successfully selected the appropriate maze arm when the choice phase of the task was presented on a second maze, oriented in the same direction, and located in an adjacent room. However, choice performance fell to chance level when the second maze was oriented 90° relative to the first. This result suggests that the rats do not simply alternate turns across the two environments, but rather that they rely on a sense of direction that is carried across environments. Electronic Publication     

Linking theory of mind and central coherence bias in autism and in the general population

Three experiments investigated whether 2 characteristic aspects of the psychological profile of autism, theory-of-mind deficits and weak central coherence, might be functionally related. Experiment 1 showed that in the general population, performance on a proposed test of theory of mind was inversely related to speed on the Embedded Figures Test, a measure of central coherence bias. Experiments 2 and 3 confirmed that poor theory-of-mind performance was linked to weak central coherence among typically developing children and among children with autism; however, the correlations between these measures were reliable only after accounting for differences in individuals' verbal mental ages. This pattern of results is interpreted in terms of a relationship between individual differences in theory of mind and central coherence bias, a relationship that is separate from any developmental differences in these domains.     

The effects of age upon the perception of depth and 3-D shape from differential motion and binocular disparity

The ability of younger and older adults to perceive the 3-D shape, depth, and curvature of smooth surfaces defined by differential motion and binocular disparity was evaluated in six experiments. The number of points defining the surfaces and their spatial and temporal correspondences were manipulated. For stereoscopic sinusoidal surfaces, the spatial frequency of the corrugations was also varied. For surfaces defined by motion, the lifetimes of the individual points in the patterns were varied, and comparisons were made between the perception of surfaces defined by points and that of more ecologically valid textured surfaces. In all experiments, the older observers were less sensitive to the depths and curvatures of the surfaces, although the deficits were much larger for motion-defined surfaces. The results demonstrate that older adults can extract depth and shape from optical patterns containing only differential motion or binocular disparity, but these abilities are often manifested at reduced levels of performance.     

Body checking and avoidance and the core features of eating disorders among obese men and women seeking bariatric surgery

This study examined two aspects of body checking and avoidance, and their relations to the core psychopathology of eating disorders (EDs), in severely obese men and women seeking bariatric surgery. A consecutive series of 260 (44 male and 216 female) gastric bypass candidates were administered measures to assess body checking and avoidance, binge eating, restraint, and overevaluation of weight and shape. The majority of patients reported regularly pinching areas of their body to check for fatness and avoided wearing clothing that made them particularly aware of their body. Significant associations were observed between checking and restraint, and between avoidance and binge eating. Both checking and avoidance behaviors were significantly associated with overevaluation of weight and shape. The positive associations between each of the two behaviors (body checking and avoidance) with overevaluation of weight/shape remained significant even after controlling for the effects of avoidance on body checking and vice versa. Stepwise multiple regression analyses revealed that binge eating, body checking, and avoidance behaviors made significant unique contributions and jointly accounted for 22-25% of the variance in overevaluation of weight and shape, respectively. This study documents the presence of eating disorder psychopathology among severely obese patients seeking bariatric surgery. The findings support the view that body checking and avoidance behaviors are manifestations of overevaluation of weight and shape and disordered eating.     

Teamwork in multiteam systems

The authors examined how networks of teams integrate their efforts to succeed collectively. They proposed that integration processes used to align efforts among multiple teams are important predictors of multiteam performance. The authors used a multiteam system (MTS) simulation to assess how both cross-team and within-team processes relate to MTS performance over multiple performance episodes that differed in terms of required interdependence levels. They found that cross-team processes predicted MTS performance beyond that accounted for by within-team processes. Further, cross-team processes were more important for MTS effectiveness when there were high cross-team interdependence demands as compared with situations in which teams could work more independently. Results are discussed in terms of extending theory and applications from teams to multiteam systems.     

Aggression and self-esteem: a diary study of children's reactivity to negative interpersonal events

The study employs a daily diary design to assess self-esteem reactivity and its association with children's aggressive behavior. We test the hypothesis that the self-esteem of aggressive children will be more reactive to negative interpersonal events than the self-esteem of nonaggressive children. Results provide partial support for the aggression/reactivity hypothesis. Aggressive children's self-esteem was more reactive to negative peer events but less reactive to negative adult events than the self-esteem of less aggressive children. These findings are discussed in relation to the experimental literature relating self-esteem instability and ego-threat to aggression and in relation to the extensive body of research on childhood aggression. Intervention implications are also considered.     

The consequences of race for police officers' responses to criminal suspects

The current work examined police officers' decisions to shoot Black and White criminal suspects in a computer simulation. Responses to the simulation revealed that upon initial exposure to the program, the officers were more likely to mistakenly shoot unarmed Black compared with unarmed White suspects. However, after extensive training with the program, in which the race of the suspect was unrelated to the presence of a weapon, the officers were able to eliminate this bias. These findings are discussed in terms of their implications for the elimination of racial biases and the training of police officers.