The heterogeneity of attention‐deficit/hyperactivity disorder symptoms and conduct problems: Cognitive inhibition,emotion regulation,emotionality, and disorganized attachment

This study examined the contributions of several important domains of functioning to attention‐deficit/hyperactivity disorder (ADHD) symptoms and conduct problems. Specifically, we investigated whether cognitive inhibition, emotion regulation, emotionality, and disorganized attachment made independent and specific contributions to these externalizing behaviour problems from a multiple pathways perspective. The study included laboratory measures of cognitive inhibition and disorganized attachment in 184 typically developing children (M age = 6 years, 10 months, SD = 1.7). Parental ratings provided measures of emotion regulation, emotionality, and externalizing behaviour problems. Results revealed that cognitive inhibition, regulation of positive emotion, and positive emotionality were independently and specifically related to ADHD symptoms. Disorganized attachment and negative emotionality formed independent and specific relations to conduct problems. Our findings support the multiple pathways perspective on ADHD, with poor regulation of positive emotion and high positive emotionality making distinct contributions to ADHD symptoms. More specifically, our results support the proposal of a temperamentally based pathway to ADHD symptoms. The findings also indicate that disorganized attachment and negative emotionality constitute pathways specific to conduct problems rather than to ADHD symptoms.     

Assessment of retrieval strategy in incidental, intentional, and inclusion tests with word-fragment cues

The purpose of this study was to assess retrieval strategy in incidental, intentional, and inclusion tests with word-fragment cues following a levels-of-processing manipulation at study. The results of Exp. 1 showed small levels-of-processing effects in incidental tests, and most subjects reported involuntary rather than voluntary retrieval of study-list words. In an intentional test, although levels of processing had a much greater effect, quite a few subjects also reported involuntary rather than voluntary retrieval of study-list words, and these subjects showed a smaller effect of levels of processing than subjects reporting voluntary retrieval. These results suggest that subjects given instructions for both voluntary and involuntary retrieval of study-list words in an inclusion test might not in fact attempt voluntary retrieval at all, but simply adopt an involuntary retrieval strategy. The results of Exp. 2 provided evidence to support this suggestion. The general implication is that where test contamination refers to subjects' failure to use retrieval strategies in accordance with test instructions, inclusion tests can be contaminated, as well as incidental or intentional tests, and that it is always necessary to obtain converging evidence about the actual strategies subjects use.     

Stability, growth, and decline in adult life span development of declarative memory: cross-sectional and longitudinal data from a population-based study

Five-year changes in episodic and semantic memory were examined in a sample of 829 participants (35-80 years). A cohort-matched sample (N=967) was assessed to control for practice effects. For episodic memory, cross-sectional analyses indicated gradual age-related decrements, whereas the longitudinal data revealed no decrements before age 60, even when practice effects were adjusted for. Longitudinally, semantic memory showed minor increments until age 55, with smaller decrements in old age as compared with episodic memory. Cohort differences in educational attainment appear to account for the discrepancies between cross-sectional and longitudinal data. Collectively, the results show that age trajectories for episodic and semantic memory differ and underscore the need to control for cohort and retest effects in cross-sectional and longitudinal studies, respectively.     

Selective sex differences in declarative memory

Sex invariance of a six-factor, higher order model of declarative memory (two second-order factors: episodic and semantic memory; and four first-order factors: recall, recognition, fluency, and knowledge) was established for 1,796 participants (35-85 years). Metric invariance of first- and second-order factor loadings across sex was demonstrated. At the second-order level, a female advantage was observed for both episodic and semantic memory. At the first-order level, sex differences in episodic memory were apparent for both recall and recognition, whereas the differences in semantic memory were driven by a female superiority in fluency. Additional tests of sex differences in three age groups (35-50, 55-65, and 70-85 years of age) indicated that the female superiority in declarative memory diminished with advancing age. The factor-specific sex differences are discussed in relation to sex differences in hippocampal function.     

Brain activation patterns in major depressive disorder and work stress-related long-term sick leave among Swedish females

Deficits in executive functioning and working memory associated with frontal lobe dysfunction are prominent in depression and work-related long-term sick leave (LTSL). This study used functional magnetic resonance imaging (fMRI) to investigate potential differences in brain activation patterns in these conditions. In addition, the function of the hypothalamic-pituitary-adrenal (HPA) axis was examined and compared between groups. Since there is a clear overrepresentation of women in these diagnostic groups, and to ensure a more homogenous sample population, only women were included. To examine the neural correlates of relevant cognitive processes in patients on sick leave >90 days due to work-related LTSL, recently diagnosed patients with major depression Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV criteria, untreated), and healthy controls (n?=?10, each group), a 2-back working memory task and a visual long-term memory task were administered during fMRI scanning. HPA axis functioning was investigated using a diurnal curve of saliva cortisol and a dexamethasone suppression test. Task performance was comparable among the three groups. Multivariate image analysis revealed that both memory tasks engaged a similar brain network in all three groups, including the prefrontal and parietal cortex. During the 2-back task, LTSL patients had significant frontal hypoactivation compared to controls and patients with depression. Saliva cortisol measurements showed a flattening of the diurnal rythmicity in LTSL patients compared to patients with depression and healthy contols. Taken together, these findings indicate that work stress-related LTSL and major depression are dissociable in terms of frontal activation and diurnal cortisol rhythmicity.     

Executive process training in young and old adults

There is a growing body of research on the modifiability of executive functions in different stages of life. Previous studies demonstrate robust training effects but limited transfer in younger and particularly in older adults. The aim of the present study was to investigate whether a theoretically derived intervention for executive functioning, addressing several basic processes (updating, shifting, and inhibition), can induce transfer effects in early and late adulthood. Fifty-nine healthy adults, 29 young and 30 older adults, were randomly assigned to either training or no-contact control groups. The training groups received 15 sessions of executive process training for about 45 min/session during 5 weeks. A test battery including a criterion task and near, intermediate, and far transfer tasks was administered before and after training. Results showed pronounced age-equivalent gains on the criterion task. Near transfer was seen to non-trained updating and inhibition tasks for the young and older trained participants. However, only the young adults showed intermediate transfer to two complex working memory tasks. No far transfer effects were seen for either age group. These findings provide additional evidence for age-related constraints in the ability to generalize acquired executive skills, and specifically show that training of multiple executive processes is not sufficient to foster transfer beyond the very near in older adults.     

Imaging Episodic Memory: Implications for Cognitive Theories and Phenomena

Functional neuroimaging studies are beginning to identify neuroanatomical correlates of various cognitive functions. This paper presents results relevant to several theories and phenomena of episodic memory, including component processes of episodic retrieval, encoding specificity, inhibition, item versus source memory, encoding-retrieval overlap, and the picture-superiority effect. Overall, by revealing specific activation patterns, the results provide support for existing theoretical views and they add some unique information which may be important to consider in future attempts to develop cognitive theories of episodic memory.     

EDITORIAL

The aim of the present study was to evaluate the usefulness of Barkley’s (1997a) model of inhibition and executive functioning in describing the deficits associated with Attention Deficit Hyperactivity Disorder (ADHD). Besides group differences, the present study addressed the question of independent effects of inhibition and the other executive functions in discriminating between children with ADHD and controls and how well, in terms of sensitivity and specificity, these measures can classify the children into the correct group. The results showed that children with ADHD differed significantly from controls with regard to measures of inhibition as well as all other executive function measures, except repetition of hand movements. In logistic regression models, three different measures tapping inhibition, working memory and emotion regulation were shown to be significant independent predictors of group membership. The sensitivity for these three variables as a set was 76.2, the specificity was 90.5, with a total of 86% of the sample correctly classified. When excluding the parental rating of emotion regulation, the overall classification rate decreased some, but was still relatively high in comparison with previous studies within this area of research.     

Cognitive and Non-Cognitive Factors Contributing to the Longitudinal Identification of Successful Older Adults in the Betula Study

ABSTRACT

Studies of successful aging have typically defined elderly who fall in the upper end of a distribution of test scores as successful. A different definition of successful aging requires that older adults fall at or above the mean level of younger adults and maintain this level over time. Here we examined this definition of successful aging in a sample of 1463 individuals between the ages of 50 of 85. Based on principal coordinate analysis of cognitive and non-cognitive variables, we identified a group of 55 (8.3%) 70–85 years olds that were high functioning. This group of elderly showed elevated performance on a range of cognitive tasks. Non-cognitive factors that characterized this group included education and subjective health. The participants were retested 5 years later and the same type of analysis was repeated. Of the remaining individuals who initially were classified as high functioning, 18 (35%) remained high functioning and thus met the definition for successful aging. Years of education was a significant predictor of who remained successful over time.