Dopamine, working memory, and training induced plasticity: implications for developmental research

Cognitive deficits and particularly deficits in working memory (WM) capacity are common features in neuropsychiatric disorders. Understanding the underlying mechanisms through which WM capacity can be improved is therefore of great importance. Several lines of research indicate that dopamine plays an important role not only in WM function but also for improving WM capacity. For example, pharmacological interventions acting on the dopaminergic system, such as methylphenidate, improve WM performance. In addition, behavioral interventions for improving WM performance in the form of intensive computerized training have recently been associated with changes in dopamine receptor density. These two different means of improving WM performance--pharmacological and behavioral--are thus associated with similar biological mechanisms in the brain involving dopaminergic systems. This article reviews some of the evidence for the role of dopamine in WM functioning, in particular concerning the link to WM development and cognitive plasticity. Novel data are presented showing that variation in the dopamine transporter gene (DAT1) influences improvements in WM and fluid intelligence in preschool-age children following cognitive training. Our results emphasize the importance of the role of dopamine in determining cognitive plasticity.     

Effect of working memory training on working memory,arithmetic and following instructions

Mathematical ability is dependent on specific mathematical training but also associated with a range of cognitive factors, including working memory (WM) capacity. Previous studies have shown that WM training leads to improvement in non-trained WM tasks, but the results regarding transfer to mathematics are inconclusive. In the present study, 176 children with WM deficits, aged 7–15 years performed 5 weeks of WM training. During the training period, they were assessed five times with a test of complex WM (the Odd One Out), a test of remembering and following instructions and a test of arithmetic. The improvements were compared to the performance of a control group of 304 typically developing children aged 7–15 years who performed the same transfer tasks at the same time intervals, but without training. The training group improved significantly more than the control group on all three transfer tests (all p < 0.0001), after correction for baseline performance, age and sex. The effect size for mathematics was small and the effect sizes for the WM tasks were moderate to large. The transfer increased linearly with the amount of training time and correlated with the amount of improvement on the trained tasks. These results confirm previous findings of training-induced improvements in non-trained WM tasks including the ability to follow instructions, but extend previous findings by showing improvements also for arithmetic. This is encouraging regarding the potential role of cognitive training for education, but it is desirable to find paradigms that would enhance the effect of the training on mathematics. One of the future challenges for studying training effects is combining large sample sizes with high quality and compliance, to detect relevant but smaller effects of cognitive training.     

Working with Korean-American Families: Multicultural Hermeneutics in Understanding and Dealing with Marital Domestic Violence

Multicultural hermeneutics is introduced as a method of understanding and dealing with marital domestic violence. The brief review of literature covers four categories of hermeneutic tradition: (1) philosophical hermeneutics, (2) psychological hermeneutics, (3) narrative hermeneutics, and (4) multicultural hermeneutics. This paper proposes that multiple perspectives or an interdisciplinary scheme of hermeneutics help to understand the central issues of marital domestic violence. Korean women are vulnerable to Hwabyung (an anger syndrome), in the patriarchal and oppressive family context. Korean-American families are experiencing a certain degree of acculturation stress in transition as well as intergenerational conflict between first and second generations due to explicit and implicit cultural differences in the United States. One Korean-American family case is presented to show how marital domestic violence can be evaluated and treated better from the perspective of multicultural hermeneutics. A number of recommendations are also suggested to change the social and political context in which marital domestic violence occurs.     

On the Relation Between Job Characteristics and Depression: A Longitudinal Study

The current study assumes that workers actively influence the characteristics of their work environment. Not only will one's work environment (job characteristics) affect personal characteristics, such as feelings of depression; depression in turn is expected to affect the characteristics of one's work environment as well. Using a sample of 593 young Dutch workers, a longitudinal model relating feelings of depression and job characteristics to each other was tested using structural equation modeling. The results largely supported our expectations. Depressive workers were less likely to experience a job transition than non-depressive workers. If depressive workers did experience a job transition, work outcomes were less positive than for nondepressive workers. Thus, it appears that the relation between job characteristics and depression can be construed as a reciprocal relation. Implications and limitations of the study are discussed.     

Training and transfer effects of executive functions in preschool children

Executive functions, including working memory and inhibition, are of central importance to much of human behavior. Interventions intended to improve executive functions might therefore serve an important purpose. Previous studies show that working memory can be improved by training, but it is unknown if this also holds for inhibition, and whether it is possible to train executive functions in preschoolers. In the present study, preschool children received computerized training of either visuo‐spatial working memory or inhibition for 5 weeks. An active control group played commercially available computer games, and a passive control group took part in only pre‐ and posttesting. Children trained on working memory improved significantly on trained tasks; they showed training effects on non‐trained tests of spatial and verbal working memory, as well as transfer effects to attention. Children trained on inhibition showed a significant improvement over time on two out of three trained task paradigms, but no significant improvements relative to the control groups on tasks measuring working memory or attention. In neither of the two interventions were there effects on non‐trained inhibitory tasks. The results suggest that working memory training can have significant effects also among preschool children. The finding that inhibition could not be improved by either one of the two training programs might be due to the particular training program used in the present study or possibly indicate that executive functions differ in how easily they can be improved by training, which in turn might relate to differences in their underlying psychological and neural processes.     

Kant's arguments in support of the maxim “Do what is right though the world should perish”

This article takes up the challenge that the motto Do What is Right Though the World Should Perish invites for an answer to Kant's arguments in defense of the motto. His argumentation is discussed, as well as the underlying assumptions concerning the role of Providence, the rejection of moral conflict, and the prudential risks associated with abandoning moral absolutism. The first two are rejected, the third seen as only partially tenable. Finally, the question is taken up what to do about moral prohibitions in a world in which they can quite literally prevent or bring about universal perishing.     

Asian values scale: comparisons of Korean and Korean-American high school students

This study was intended to examine mean differences on the Asian Values Scale between Korean and Korean-American high school students. For 199 Korean and 217 second generation Korean-American high school students, means on emotional self-control and collectivism were significantly different. A two-sample t test on the mean scores of Korean high school students (M=4.5, SD=0.6) and second-generation Korean-American high school students (M=3.9, SD=0.5) indicated significant differences (p<.001). This present study contrasts directly with Kim, Atkinson, and Yang's past findings of no differences between first- and second-generation Asian college students.     

Gains in fluid intelligence after training non-verbal reasoning in 4-year-old children: a controlled, randomized study

Fluid intelligence (Gf) predicts performance on a wide range of cognitive activities, and children with impaired Gf often experience academic difficulties. Previous attempts to improve Gf have been hampered by poor control conditions and single outcome measures. It is thus still an open question whether Gf can be improved by training. This study included 4-year-old children (N = 101) who performed computerized training (15 min/day for 25 days) of either non-verbal reasoning, working memory, a combination of both, or a placebo version of the combined training. Compared to the placebo group, the non-verbal reasoning training group improved significantly on Gf when analysed as a latent variable of several reasoning tasks. Smaller gains on problem solving tests were seen in the combination training group. The group training working memory improved on measures of working memory, but not on problem solving tests. This study shows that it is possible to improve Gf with training, which could have implications for early interventions in children.