Carlos Makoto Miyauchi

Brain Training Game Boosts Executive Functions, Working Memory and Processing Speed in the Young Adults: A Randomized Controlled Trial

Background Do brain training games work? The beneficial effects of brain training games are expected to transfer to other cognitive functions. Yet in all honesty, beneficial transfer effects of the commercial brain training games in young adults have little scientific basis. Here we investigated the impact of the brain training game (Brain Age) on a wide range of cognitive functions in young adults. Methods We conducted a double-blind (de facto masking) randomized controlled trial using a popular brain training game (Brain Age) and a popular puzzle game (Tetris). Thirty-two volunteers were recruited through an advertisement in the local newspaper and randomly assigned to either of two game groups (Brain Age, Tetris). Participants in both the Brain Age and the Tetris groups played their game for about 15 minutes per day, at least 5 days per week, for 4 weeks. Measures of the cognitive functions were conducted before and after training. Measures of the cognitive functions fell into eight categories (fluid intelligence, executive function, working memory, short-term memory, attention, processing speed, visual ability, and reading ability). Results and Discussion Our results showed that commercial brain training game improves executive functions, working memory, and processing speed in young adults. Moreover, the popular puzzle game can engender improvement attention and visuo-spatial ability compared to playing the brain training game. The present study showed the scientific evidence which the brain training game had the beneficial effects on cognitive functions (executive functions, working memory and processing speed) in the healthy young adults. Conclusions Our results do not indicate that everyone should play brain training games. However, the commercial brain training game might be a simple and convenient means to improve some cognitive functions. We believe that our findings are highly relevant to applications in educational and clinical fields. Trial Registration UMIN Clinical Trial Registry 000005618.

Brain structural changes as vulnerability factors and acquired signs of post-earthquake stress.

Many survivors of severe disasters, even those without posttraumatic stress disorder (PTSD), need psychological support. To understand the pathogenesis of PTSD symptoms and prevent the development of PTSD, the critical issue is to distinguish neurological abnormalities as vulnerability factors from acquired signs of PTSD symptoms in the early stage of adaptation to the trauma in the normal population. The neurological underpinnings of PTSD have been well characterized, but the causal relationships with the traumatic event are still unclear. We examined 42 non-PTSD subjects to find brain morphometric changes related to the severity of PTSD symptoms in a longitudinal magnetic resonance imaging study extending through the Great East Japan Earthquake. We found that regional grey matter volume (rGMV) in the right ventral anterior cingulate cortex (ACC) before the earthquake, and decreased rGMV in the left orbitofrontal cortex (OFC) through the earthquake were negatively associated with PTSD symptoms. Our results indicate that subjects with smaller GMV in the ACC before the earthquake, and subjects with decreased GMV in the OFC through the earthquake were likely to have PTSD symptoms. As the ACC is involved in processing of fear and anxiety, our results indicate that these processing are related to vulnerability for PTSD symptoms. In addition, decreased OFC volume was induced by failing to extinct conditioned fear soon after the traumatic event. These findings provide a better understanding of posttraumatic responses in early stage of adaptation to the trauma and may contribute to the development of effective methods to prevent PTSD.

Resting state functional connectivity associated with trait emotional intelligence

Previous neuroimaging studies have suggested that trait emotional intelligence (TEI) is associated with components of the neural network involved in social cognition (SCN) and somatic marker circuitry (SMC). Our study is the first to investigate the association of TEI with resting-state functional connectivity (RSFC) between the key nodes of SCN and SMC [medial prefromtal cortex (mPFC) and bilateral anterior insula (AI), respectively] and other brain regions. We found that (a) the intrapersonal factor of TEI was negatively correlated with RSFC between mPFC and the anterior part of the right dorsolateral prefrontal cortex (DLPFC), (b) the TEI interpersonal factor score was positively correlated with RSFC between mPFC and the lingual gyrus, and (c) total TEI was positively correlated with RSFC between mPFC and the precuneus as well as (d) between the left AI and the middle part of the right DLPFC. Taken together with previous study findings, our findings can be comprehensively understood as neural mechanisms of SCN and SMC components are associated with TEI. In particular, the fluent interaction between SCNs two key nodes (mPFC and precuneus/PCC) [as well as between DMNs two key nodes] is suggested to be crucial for total TEI. Our study also indicated that (a) a clear functional separation between the two key nodes of the two major intrinsic networks, DMN and the task-positive network (mPFC and DLPFC), is important for higher intrapersonal TEI, (b) brain interactions involving vision-related areas (lingual gyrus) and the key node of SCN (mPFC) are important for interpersonal TEI, and (c) control of DLPFC over the key node of SMC (AI) is important for total TEI.

Anatomical correlates of quality of life: Evidence from voxel-based morphometry

Quality of life (QOL) has been defined in many ways, and these definitions usually emphasize happiness and satisfaction with life. Health‐related problems are known to cause lower QOL. However, the neural mechanisms underlying individual differences in QOL measured by questionnaire (QOLMQ) in young healthy subjects are unknown. QOL is essential to our well‐being, and investigation of the neural mechanisms underlying QOL in uncompromised subjects is obviously of great scientific and social interest. We used voxel‐based morphometry to investigate the association between regional gray matter volume (rGMV) and QOLMQ across the brain in healthy young adults (age, 21.4 ± 1.8 years) men (n = 88) and women (n = 68) in humans. We found significant negative relationships between QOLMQ and rGMV in a region in the left rostrolateral prefrontal cortex and regions in the dorsal part of the anterior cingulate gyrus and contingent cingulate regions. These findings show that structural variations in regions associated with processing of negative emotions such as fear and anger as well as those associated with evaluation of internally generated information are associated with QOLMQ. These findings suggest that these processes might be related to QOLMQ in healthy young adults. Hum Brain Mapp 35:1834–1846, 2014.

Rhythm information represented in the fronto-parieto-cerebellar motor system

Rhythm is an essential element of human culture, particularly in language and music. To acquire language or music, we have to perceive the sensory inputs, organize them into structured sequences as rhythms, actively hold the rhythm information in mind, and use the information when we reproduce or mimic the same rhythm. Previous brain imaging studies have elucidated brain regions related to the perception and production of rhythms. However, the neural substrates involved in the working memory of rhythm remain unclear. In addition, little is known about the processing of rhythm information from non-auditory inputs (visual or tactile). Therefore, we measured brain activity by functional magnetic resonance imaging while healthy subjects memorized and reproduced auditory and visual rhythmic information. The inferior parietal lobule, inferior frontal gyrus, supplementary motor area, and cerebellum exhibited significant activations during both encoding and retrieving rhythm information. In addition, most of these areas exhibited significant activation also during the maintenance of rhythm information. All of these regions functioned in the processing of auditory and visual rhythms. The bilateral inferior parietal lobule, inferior frontal gyrus, supplementary motor area, and cerebellum are thought to be essential for motor control. When we listen to a certain rhythm, we are often stimulated to move our body, which suggests the existence of a strong interaction between rhythm processing and the motor system. Here, we propose that rhythm information may be represented and retained as information about bodily movements in the supra-modal motor brain system.

A voxel-based morphometry study of gray and white matter correlates of a need for uniqueness.

People appear to derive intrinsic satisfaction from the perception that they are unique, special, and separable from the masses, which is referred to as a need for uniqueness (NFU). NFU is a universal human trait, along with a tendency to conform to the beliefs and attitudes of others and social norms. We used voxel-based morphometry and a questionnaire to determine individual NFU and its association with brain structures in healthy men (94) and women (91; age, 21.3 ± 1.9 years). Individual NFU was associated with smaller gray matter volume of a cluster that included areas in (a) the left middle temporal gyrus, left superior temporal gyrus, and left superior temporal sulcus (STS); (b) the dorsal part of the anterior cingulate gyrus and the anterior part of the middle cingulate gyrus; and (c) the right inferior frontal gyrus and the ventral part of the precentral gyrus. Individual NFU was also associated with larger white matter concentration of a cluster that mainly included the body of the corpus callosum. These findings demonstrated that variations in NFU reflect the gray and white matter structures of focal regions. These findings suggest a biological basis for individual NFU, distributed across different gray and white matter areas of the brain.

Association between resting-state functional connectivity and empathizing/systemizing.

Empathizing is the drive to identify the mental status of other individuals and respond to it with an appropriate emotion; systemizing is the drive to analyze a system. Previously, we have shown that structures associated with the default mode network (DMN) and external attention system (EAS) are associated with empathizing and systemizing, respectively. Here we investigated the association between resting-state functional connectivity (RSFC) and empathizing/systemizing in 248 healthy young adults. We considered the medial prefrontal cortex (mPFC) and bilateral dorsolateral prefrontal cortices (DLPFCs), which are key nodes of DMN and EAS, as seed regions, and investigated correlations across subjects between individual empathizing/systemizing and RSFC between each seed region and other brain regions. We found that higher empathizing was associated with larger RSFC between the mPFC and areas in (a) the dorsal anterior cingulate cortex (dACC), (b) precuneus, and (c) left superior temporal sulcus (STS). Furthermore, there was an interaction effect between sex and systemizing on RSFC between the left DLPFC and dACC: males showed positive correlations between this RSFC and systemizing, whereas females showed the opposite tendency. Thus, empathizing was associated with increased positive functional coupling with the key node and other nodes of DMN, as well as the area associated with feeling anothers pain. Systemizing was associated with increased positive functional coupling between the key nodes of EAS in males. These findings provide further support for the concept of an association between DMN/EAS and empathizing/systemizing.

Effects of multitasking-training on gray matter structure and resting state neural mechanisms

Multitasking (MT) constitutes engaging in two or more cognitive activities at the same time. MT‐training improves performance on untrained MT tasks and alters the functional activity of the brain during MT. However, the effects of MT‐training on neural mechanisms beyond MT‐related functions are not known. We investigated the effects of 4 weeks of MT‐training on regional gray matter volume (rGMV) and functional connectivity during rest (resting‐FC) in young human adults. MT‐training was associated with increased rGMV in three prefrontal cortical regions (left lateral rostral prefrontal cortex (PFC), dorsolateral PFC (DLPFC), and left inferior frontal junction), the left posterior parietal cortex, and the left temporal and lateral occipital areas as well as decreased resting‐FC between the right DLPFC and an anatomical cluster around the ventral anterior cingulate cortex (ACC). Our findings suggest that participation in MT‐training is as a whole associated with task‐irrelevant plasticity (i.e., neural changes are not limited to certain specific task conditions) in regions and the network that are assumed to play roles in MT as well as diverse higher‐order cognitive functions. We could not dissociate the effects of each task component and the diverse cognitive processes involved in MT because of the nature of the study, and these remain to be investigated. Hum Brain Mapp 35:3646–3660, 2014.

Degree centrality and fractional amplitude of low-frequency oscillations associated with Stroop interference.

Stroop paradigms are commonly used as an index of attention deficits and a tool for investigating functions of the frontal lobes and other associated structures. Here we investigated the correlation between resting-state functional magnetic imaging (fMRI) measures [degree centrality (DC)/fractional amplitude of low frequency fluctuations (fALFFs)] and Stroop interference. We examined this relationship in the brains of 958 healthy young adults. DC reflects the number of instantaneous functional connections between a region and the rest of the brain within the entire connectivity matrix of the brain (connectome), and thus how much of the node influences the entire brain areas, while fALFF is an indicator of the intensity of regional brain spontaneous activity. Reduced Stroop interference was associated with larger DC in the left lateral prefrontal cortex, left IFJ, and left inferior parietal lobule as well as larger fALFF in the areas of the dorsal attention network and the precuneus. These findings suggest that Stroop performance is reflected in resting state functional properties of these areas and the network. In addition, default brain activity of the dorsal attention network and precuneus as well as higher cognitive processes represented there, and default stronger global influence of the areas critical in executive functioning underlie better Stroop performance.

Associations among imaging measures (2): The association between gray matter concentration and task‐induced activation changes

The association between functional activation and gray matter (GM) structure has been revealed in clinical studies and studies of aging involving a small number of subjects. The purpose of this study was to investigate the association between functional activation maps and GM structures in young adults who do not show apparent GM atrophy and to investigate in detail the nature of this association using a large number of subjects. We used voxel‐by‐voxel regression analyses to investigate voxel‐by‐voxel associations between GM concentration (GMC) and contrast estimate images of brain activity during n‐back working memory tasks. Associations were assessed for each voxel after regressing out the effects of age, sex, and mean signal intensity during functional magnetic resonance imaging scanning at each voxel using data from 248 normal, right‐handed, young adult subjects. In our study, the concept of “the greater the GMC, the greater the task‐related activation increase/task‐related activation decrease (or the greater the task‐related activation change from baseline)” was true for a wide range of activated and deactivated areas. However, in some minor regions, the other pattern of “the greater the GMC, the smaller the task‐related activation increase” was observed. The first pattern is often observed at the borders of GM structures. These findings may have to be taken into consideration when group/individual differences in functional activation are investigated. Hum Brain Mapp 35:185–198, 2014.