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.     

Associative and strategic components of episodic memory: a life-span dissociation

The authors investigated the strategic component (i.e., elaboration and organization of episodic features) and the associative component (i.e., binding processes) of episodic memory and their interactions in 4 age groups (10-12, 13-15, 20-25, and 70-75 years of age). On the basis of behavioral and neural evidence, the authors hypothesized that the two components are functionally related but follow different life-span gradients. In a fully crossed design, age differences in recognition memory for single words versus word pairs (associative demand manipulation) were examined under instructions that emphasized item, pair, or elaborative-pair encoding (strategy manipulation). As predicted, the results showed that the strategic and associative components follow different life-span trajectories. Relative to younger adults, children's difficulties in episodic memory primarily reflected lower levels of strategic functioning. In contrast, older adults showed impairments in both strategic and associative components. The authors conclude that the comparison of strategic and associative components of episodic memory across the life span helps to delineate the two components' unique and interactive contributions to episodic memory performance.     

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.     

Hippocampal alpha 5 subunit-containing GABA A receptors are involved in the development of the latent inhibition effect

Hippocampal GABA(A) receptors containing the alpha 5 subunit have been implicated in the modulation of hippocampal-dependent learning, presumably via their tonic inhibitory influence on hippocampal glutamatergic activity. Here, we examined the expression of latent inhibition (LI)--a form of selective learning that is sensitive to a number of manipulations targeted at the hippocampal formation, in alpha 5(H105R) mutant mice with reduced levels of hippocampal alpha 5-containing GABA(A) receptors. A single pre-exposure to the taste conditioned stimulus (CS) prior to the pairing of the same CS with LiCl-induced nausea was effective in reducing the conditioned aversion against the taste CS in wild-type mice--thus constituting the LI effect. LI was however distinctly absent in male alpha 5(H105R) mutant mice. Hence, a partial loss of hippocampal alpha 5 GABA(A) receptors is sufficient to alter one major form of selective learning, albeit this was not seen in the female. This observed phenotype suggests that specific activation of these extrasynaptic GABA(A) receptors may confer therapeutic potential against the failure to show selectivity in learning by human psychotic patients.     

Exploring self‐esteem of Hong Kong Chinese adults cardiac diseases

Low self‐esteem appears to be both a vulnerability factor for cardiac diseases and a result of cardiac diseases. Thus enhancing self‐esteem might facilitate recovery and/or help to prevent recurrence. Since some evidence suggests that self‐esteem might even serve as an important gauge of cardiac rehabilitation, it is therefore important to know more of the construct of self‐esteem to enable the planning of a more promising rehabilitation process. This paper explores the source and basis of the self‐esteem of Hong Kong Chinese with cardiac diseases. One hundred and fifty‐two adults with cardiac diseases and 146 adults not suffering from any major illness participated in this study. The Adult Source of Self‐Esteem Inventory (ASSEI) (Elovson & Fleming, 1989), open‐ended questions on self‐evaluation, and interviewing were the major procedures used to identify the sources and basis of the self‐esteem of persons with and without cardiac diseases. The subjects' important life aspects were identified through interpreting their responses to open‐ended questions and interviews. Moreover, a structured questionnaire on their subjective perceptions of importance and satisfaction in different life areas was used to identify the relationships between discrete self‐concept variables. Factor analysis of their responses to the 20 ASSEI items revealed four factors, namely, Interpersonal Relationship, Personal Quality, Physical Self, and Personal Achievement. We also examined and compared the means and ranks of the ASSEI items as indicated by the subjects. Content analysis of open‐ended questions further confirmed the self‐esteem domains of persons with cardiac diseases. The discrepancy of ideal‐actual physical abilities was found to be more prominent in the cardiac group. It was also found that family is an important entity to Chinese individuals with cardiac diseases. Implications of the findings to rehabilitation of persons with cardiac diseases were also discussed.     

Sex Differences in Effectiveness of Extended-Release Stimulant Medication among Adolescents with Attention-Deficit/Hyperactivity Disorder

This study examined whether adolescent females with attention-deficit/hyperactivity disorder (ADHD) are differentially responsive than their male counterparts to extended-release stimulant medications. This investigation may bear special importance for an adolescent (as opposed to child) population, because hormonal and metabolism differences between sexes are most likely to emerge at this time. Male (n = 19) and female (n = 16) adolescents, ages 16–19 with ADHD, participated in a randomized, double-blind crossover study evaluating the effectiveness of osmotic-release methylphenidate, extended release amphetamine salts, placebo, and routine limited medication regimen. Medication efficacy was evaluated using ADHD symptom ratings from adolescent self-report and parent report, along with objective measures of inattention and hyperactivity/impulsivity during driving performance and neuropsychological tasks. Males and females were largely equivalent in impairment, and medication was similarly effective in reducing symptoms. No interactions were found between sex and medication on any measure of effectiveness or side effects. This finding suggests that the efficacy and tolerability of extended-release stimulant medications is equivalent for male and female adolescents with ADHD.     

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.     

Non‐linear structural equation models with correlated continuous and discrete data

Structural equation models (SEMs) have been widely applied to examine interrelationships among latent and observed variables in social and psychological research. Motivated by the fact that correlated discrete variables are frequently encountered in practical applications, a non‐linear SEM that accommodates covariates, and mixed continuous, ordered, and unordered categorical variables is proposed. Maximum likelihood methods for estimation and model comparison are discussed. One real‐life data set about cardiovascular disease is used to illustrate the methodologies.