Working Memory Training Improves Dual-Task Performance on Motor Tasks

The authors investigated whether working memory training improves motor-motor dual-task performance consisted of upper and lower limb tasks. The upper limb task was a simple reaction task and the lower limb task was an isometric knee extension task. 45 participants (age = 21.8 ± 1.6 years) were classified into a working memory training group (WM-TRG), dual-task training group, or control group. The training duration was 2 weeks (15 min, 4 times/week). Our results indicated that working memory capacity increased significantly only in the WM-TRG. Dual-task performance improved in the WM-TRG and dual-task training group. Our study provides the novel insight that working memory training improves dual-task performance without specific training on the target motor task.     

Association of maternal smoking during pregnancy and infant neurobehavioral status

The association of maternal smoking during pregnancy with neurobehavioral status was examined in 344 Japanese infants. Based on a questionnaire, their mothers were classified into three groups, Nonsmokers, Exsmokers, and Smokers. The Neonatal Behavioral Assessment Scale was administered three days after birth. Among the three groups, on the seven clusters and their 28 behavioral subscales there were no significant differences. The infants of Smokers had lower scores than those of Exsmokers and Nonsmokers on two behavioral items, general tone and peak of excitement. General tone remained significant after adjustment for covariates.     

Impaired Interpretation of Others’ Behavior is Associated with Difficulties in Recognizing Pragmatic Language in Patients with Schizophrenia

Much attention has been paid to the pragmatic language function in schizophrenia. This study of Japanese patients with schizophrenia examined the relationship between impaired interpretation of the behaviors of other people in social contexts and the ability to recognize metaphor and irony. We assessed 34 patients with schizophrenia and 34 normal subjects using first- and second-order theory of mind tasks, the Metaphor and Sarcasm Scenario Test, and the Dewey Story Test (which tests the ability to judge others’ social behaviors). We compared the performance between the groups and analyzed correlations between the tasks. All tasks revealed significant deficits in the patients compared with the controls. In the patient group, metaphor comprehension was correlated with the ability to judge normal behaviors, and irony comprehension was correlated with the ability to judge abnormal behaviors, suggesting that deficits of social cognition in schizophrenia include these two types of factors associated with pragmatic language.     

The effects of an afterschool physical activity program on working memory in preadolescent children

The present study examined the effects of a 9-month randomized control physical activity intervention aimed at improving cardiorespiratory fitness on changes in working memory performance in preadolescent children relative to a waitlist control group. Participants performed a modified Sternberg task, which manipulated working memory demands based on encoding set sizes, while task performance and the contingent negative variation (CNV) event-related brain potential were measured. Analyses revealed that the physical activity intervention led to increases in cardiorespiratory fitness and improved Sternberg task performance. Further, the beneficial effects of the physical activity intervention were greater for a task condition requiring greater working memory demands. In addition, the intervention group exhibited larger initial CNV at the frontal electrode site, relative to the waitlist group at post-test; an effect not observed during the pre-test. These results indicate that increases in cardiorespiratory fitness are associated with improvements in the cognitive control of working memory in preadolescent children.     

Full-field input generated from right visual field information for healthy participants reproduces performance simulating left unilateral spatial neglect in line bisection

Patients with left unilateral spatial neglect (USN) typically place the subjective midpoint to the right of the objective centre when bisecting a horizontal line. This pathological phenomenon may be explained as a result of greater dependence on the right endpoint in the external reference frame (Koyama et al., Brain Cogn, 35, 1997, 271; McIntosh et al., Cogn Brain Res, 25, 2005, 833). Ishiai et al. (Brain, 112, 1989, 1485) reported that once patients with USN fixated on a certain point on the right part of the presented line, they persisted with this point and marked the subjective midpoint there without leftward searches. Ishiai et al.'s interpretation was that the patients saw a totalised line representation that extended equidistantly to the right and left sides, based on the information of the attended rightward extent from the subjective midpoint. Accordingly, we used virtual reality goggles (VRG) and devised a mirror-image viewing (MV) condition that showed a full-field view based on the right visual field information to test whether healthy participants would thereby show neglect-like bisection performance. The participants were 30 healthy adults (22–37 years old; 15 women and 15 men). In this condition, 96.7% (29/30) of participants were judged to exhibit USN-like performance of line bisection, indicating the effectiveness of MV condition to simulate USN. The novelty of the present study lies in the use of a task-specific intervention of neglect-like visuospatial processing during line bisection without attempting to modify the direction of spatial attention. This approach may contribute to the understanding of the pathological visuospatial processing of USN.