Perceptual grouping boosts visual working memory capacity and reduces effort during retention

Consistent, robust boosts to visual working memory capacity are observed when colour–location arrays contain duplicate colours. The prevailing explanation suggests that duplicated colours are encoded as one perceptual group. If so, then we should observe not only higher working memory capacity overall for displays containing duplicates, but specifically an improved ability to remember unique colours from displays including duplicates compared with displays comprising all uniquely coloured items. Furthermore, less effort should be required to retain displays as colour redundancy increases. I recorded gaze position and pupil sizes during a visual change detection task including displays of 4–6 items with either all unique colours, two items with a common colour, or three items with a common colour in samples of young and healthy elderly adults. Increased redundancy was indeed associated with higher estimated working memory capacity, both for tests of duplicates and uniquely coloured items. Redundancy was also associated with decreased pupil size during retention, especially in young adults. While elderly adults also benefited from colour redundancy, spillover to unique items was less obvious with low redundancy than in young adults. This experiment confirms previous findings and presents complementary novel evidence linking perceptual grouping via colour redundancy with decreased mental effort.     

Change in posttraumatic stress disorder symptoms: do clinicians and patients agree?

This study assessed the longitudinal association between clinician and patient ratings of posttraumatic stress disorder (PTSD) symptoms over the course of 2 different randomized clinical trials of veterans with chronic PTSD. One trial, the Department of Veterans Affairs Cooperative Study 420 (CSP 420; N = 360) compared trauma-focused and present-centered group therapies, and the 2nd trial compared cognitive processing theory and a waitlist control condition (N = 60). Linear mixed effects modeling revealed significant associations between clinician ratings (Clinician-Administered PTSD Scale; CAPS; D. D. Blake et al., 1990) and patient ratings (Posttraumatic Stress Disorder Checklist; PCL; F. W. Weathers, B. T. Litz, J. A. Herman, J. A. Huska, & T. M. Keane, 1993) in total and symptom clusters of PTSD. Contrary to hypothesis, the amount of change on the CAPS ranged from .75 to .82 standard deviations for every 1 standard deviation change on the PCL. The CAPS and PCL were more closely associated in the trauma-focused vs. present-centered treatment condition in CSP 420, and especially regarding hyperarousal symptoms. When comparing categorization of clinically significant change on the CAPS and PCL, the authors found no differences in the percentages of agreement between clinicians and patients in improvement and exacerbation. The value of multimodal assessment of PTSD treatment outcomes is discussed.     

The basolateral amygdala modulates specific sensory memory representations in the cerebral cortex

Stress hormones released by an experience can modulate memory strength via the basolateral amygdala, which in turn acts on sites of memory storage such as the cerebral cortex [McGaugh, J. L. (2004). The amygdala modulates the consolidation of memories of emotionally arousing experiences. Annual Review of Neuroscience, 27, 1–28]. Stimuli that acquire behavioral importance gain increased representation in the cortex. For example, learning shifts the tuning of neurons in the primary auditory cortex (A1) to the frequency of a conditioned stimulus (CS), and the greater the level of CS importance, the larger the area of representational gain [Weinberger, N. M. (2007). Associative representational plasticity in the auditory cortex: A synthesis of two disciplines. Learning & Memory, 14(1–2), 1–16]. The two lines of research suggest that BLA strengthening of memory might be accomplished in part by increasing the representation of an environmental stimulus. The present study investigated whether stimulation of the BLA can affect cortical memory representations. In male Sprague–Dawley rats studied under urethane general anesthesia, frequency receptive fields were obtained from A1 before and up to 75 min after the pairing of a tone with BLA stimulation (BLAstm: 100 trials, 400 ms, 100 Hz, 400 μA [±16.54]). Tone started before and continued after BLAstm. Group BLA/1.0 (n = 16) had a 1 s CS–BLAstm interval while Group BLA/1.6 (n = 5) has a 1.6 s interval. The BLA/1.0 group did develop specific tuning shifts toward and to the CS, which could change frequency tuning by as much as two octaves. Moreover, its shifts increased over time and were enduring, lasting 75 min. However, group BLA/1.6 did not develop tuning shifts, indicating that precise CS–BLAstm timing is important in the anesthetized animal. Further, training in the BLA/1.0 paradigm but stimulating outside of the BLA did not produce tuning shifts. These findings demonstrate that the BLA is capable of exerting highly specific, enduring, learning-related modifications of stimulus representation in the cerebral cortex. These findings suggest that the ability of the BLA to alter specific cortical representations may underlie, at least in part, the modulatory influence of BLA activity on strengthening long-term memory.     

Efficacy of dialectical behaviour therapy for adolescents

The current review provides a qualitative assessment of the efficacy of dialectical behaviour therapy (DBT) as adapted for adolescents. The aim was to assess the efficacy of DBT compared to usual methods in the treatment of adolescent mental health symptoms, inclusive of suicidal ideation and self‐harm. Computerised databases including Medline and PsycINFO were accessed and knowledgeable informants in the area of DBT were contacted. Inclusion criteria required the studies to be clinical trials on DBT provided to adolescents. Due to the requirements on research design only three studies were appropriate for review. The review focused on quality assessment of the current data, including investigation into the effects of selection bias, confounding variables, outcome measures and measurement errors. The data suggest that there is some evidence for DBT being effective in reducing symptoms of mental health, especially those consistent with borderline personality disorder. The resultant data, however, are of very poor quality, and as such the review addresses ways to improve the quality of research and offers suggestions for future research.     

The development of social networks from early to middle childhood: Gender differences and the relation to school competence

The purpose of this study was to examine gender differences in social network development from early to middle childhood and the relation of network characteristics to school competence. Maternal report of 75 children's kin, nonkin adult, and friendship networks were collected at 3, 6, and 9 years of age. Teacher ratings of school competence were obtained at 9 years. While children showed changes in their social networks over time, expected gender differences were not found in the extensive nature of the nonkin network. However, as expected, preference for same-sex friends was noted in early childhood and intensified with age into middle childhood. For girls, but not for boys, social network characteristics were related to teacher ratings of social competence in school.The preparation of this paper was made possible by the support of the William T. Grant Foundation.     

The child's social network: Sex differences from three to six years

The social networks of 85 young children as they make the transition from a home-centered to a more school-centered existence is examined using longitudinal data. When the children were three and six years of age, their mothers completed a questionnaire of network structure; at six years both the child and mother independently reported the friends that the child would invite to a birthday party. The effects of age and sex of child on the number and daily contact with peers, adults, kin, nonkin, males, and females were found. As expected, as children reached formal school age they had increased contact with peers and decreased contact with kin, while adult contact remained fairly consistent over the three- to six-year age period. Sex differences were also apparent. As predicted, children as early as 3 years, and to an even greater extent at six years, showed more same-sex compared to opposite-sex peer contact. At six years both children and mothers reported more same- as compared to opposite-sex friends who would be invited by the child to a birthday party. The findings suggest how children's social networks, as shaped by their parents and themselves, provide a framework within which experience and interaction is structured to fit cultural norms.     

Visual working memory depends on attentional filtering

Working memory holds information actively being used in cognitive performance. Two important aspects of working memory are how many items it can hold, and how efficiently it can be used. Recently, Vogel and colleagues used event-related brain potentials to show that these two things are related. People who could remember more objects from a spatial array also more efficiently excluded irrelevant objects. The results raise important questions about what aspect of working memory is most fundamental.     

When do visual and verbal memories conflict? The importance of working-memory load and retrieval

Examinations of interference between verbal and visual materials in working memory have produced mixed results. If there is a central form of storage (e.g., the focus of attention; N. Cowan, 2001), then cross-domain interference should be obtained. The authors examined this question with a visual-array comparison task (S. J. Luck & E. K. Vogel, 1997) combined with various verbal memory load conditions. Interference between tasks occurred if there was explicit retrieval of the verbal load during maintenance of a visual array. The effect was localized in the maintenance period of the visual task and was not the result of articulation per se. Interference also occurred when especially large silent verbal and visual loads were held concurrently. These results suggest central storage along with code-specific passive storage.     

Nipping psychopathy in the bud: an examination of the convergent, predictive, and theoretical utility of the PCL-YV among adolescent girls

Over the last decade rates of violence among adolescent girls have increased. Within high-risk contexts, urgent calls for assessment options have resulted in the extension of adult and male-based instruments to adolescent females in spite of the absence of strong empirical support. The current study evaluates the downward extension of psychopathy within a population of female juvenile offenders (N=125). The convergent and predictive validity of the Psychopathy Checklist-Youth Version (PCL-YV) were evaluated within a structural equation modeling (SEM) framework. Results indicated that while a specific component of psychopathy, deficient affective experience, was related to aggression, the effect was negated once victimization experiences were entered into the models. In addition, PCL-YV scores were not predictive of future offending, while victimization experiences significantly increased the odds of re-offending. Implications for research, policy, and clinical practice are discussed.