Kiichiro Morita

Kurume University, Куруме, Fukuoka, Japan

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Publications (47)64.79 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: In the present study, the P300 component of the emotion-loaded visual event related potential in response to photographs of babies' crying or smiling was measured to evaluate cognitive function in elderly subjects, including those with dementia. The subjects were 48 elderly people who consulted a memory disorder clinic. The visual event-related potential was measured using oddball tasks. Brain waves were recorded from 4 sites. We analyzed the P300 amplitude and latency. Subjects were divided into three groups (dementia with Alzheimer's disease group: AD, intermediate group: MG, healthy group: HG) based on HDS-R, MMSE scores and CDR. For all subjects, there was a significant positive correlation between P300 latency and Z-score of VSRAD for crying or smiling faces. There was a negative correlation between P300 amplitude and Z-score for crying face. MG subjects were divided into two groups (high risk: HRMG, low risk: LRMG) based on Z-scores (HRMG≧2.0). The P300 amplitude of AD was significantly smaller than that of HG, and the P300 latency of AD was significantly longer than those of other groups for crying or smiling faces. The P300 latency of HRMG was significantly longer than that of LRMG for smiling face. Furthermore, the P300 latency when for crying face was significantly shorter than that for smiling face in HG and AD. These findings suggest that analysis of P300 components of the emotion-loaded visual event-related potential may be a useful neuropsychological index for the diagnosis of AD and high-risk subjects.
    Psychiatry and Clinical Neurosciences 01/2014; · 2.04 Impact Factor
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    ABSTRACT: Objective: Previous eye-tracking studies using an eye mark recorder have reported that disturbances in exploratory eye movements in adult schizophrenic patients are associated with social functioning. The current study sought to determine whether exploratory eye-movement disturbances are present in children with Asperger's syndrome (AS) compared with typically developing (TD) children. Materials/Participants: The participants were 23 children with AS and 23 age-matched TD children. We measured exploratory eye movements using an EMR-8B eye mark recorder and an exploratory eye movement-measuring device. Method: Eye movements were recorded while participants freely observed a geometric figure (free viewing task), and while they complied with the instructions of an experimenter (repeat-comparison task). We assessed eye fixation points (EFPs) and total eye scanning length (TESL) in all tasks, and measured the responsive search score (RSS) in the repeat-comparison task. Results: In the free viewing task, children with AS exhibited significantly shorter TESL compared with TD children. In the repeat-comparison task, children with AS exhibited significantly lower RSS. Autism Spectrum Screening Questionnaire scores were negatively correlated with both EFP and TESL, but not RSS. Conclusion: The current results revealed that children with AS exhibited dysfunction in exploratory eye movements. Thus, assessing exploratory eye movements in a repeat-comparison task may be useful for detecting social impairment among children with AS.
    Brain & development 05/2013; · 1.74 Impact Factor
  • Seishin shinkeigaku zasshi = Psychiatria et neurologia Japonica 01/2013; 115(1):3-9.
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    ABSTRACT: Neared infrared spectroscopy (NIRS) is one of the recently developed methodologies which can measure cerebral blood volumes to determine the blood hemoglobin (Hb) concentration simultaneously at multiple points with marked time resolution. Monitoring the changes in the Hb concentration yields site-specific readings on blood flow and, thus, on neural activities. The aim of this study was to examine the characteristics of a single event-related oxyhemoglobin concentration [oxy-Hb] changes in patients with schizophrenia using multi-channel NIRS during a word generation task, Japanese 'Shiritori', and single-word generation task in an emotionally charged state induced by three facial expressions of "crying", "neutral", and "smiling" babies' photographs. Thirty-four patients with schizophrenia and 34 age-matched healthy controls participated in the present study after giving consent. In healthy controls, [oxy-Hb] changes when viewing the "crying" baby's photograph were significantly larger than when viewing the "smiling" baby's photograph. On the other hand, in patients with schizophrenia, [oxy-Hb] changes when viewing the "smiling" baby's photograph were significantly larger than when viewing the "crying" baby's photograph. These results suggest that cautions/execution functions in patients with schizophrenia during the single event word "Shiritori" task measured by multi-channel NIRS were impaired. It was also suggested that, in patients with schizophrenia, the affective reaction influenced by each photograph may be different from healthy controls (mismatch). Multi-channel NIRS can be a useful tool for research and clinical purposes in psychiatry.
    Seishin shinkeigaku zasshi = Psychiatria et neurologia Japonica 01/2013; 115(8):853-62.
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    ABSTRACT: Schizophrenia has been associated with a deficit of the prefrontal cortex, which is involved in attention, executive processes, and working memory. The Trail Making Test (TMT) is administered in two parts, TMT-A and TMT-B. It is suggested that the difference in performance between part A and part B reflects executive processes. In this study, we compared the characteristics of hemodynamic changes during TMT tasks between 14 outpatients with schizophrenia and 14 age- and gender-matched healthy control subjects. Using multichannel near-infrared spectroscopy, we measured relative changes in oxygenated hemoglobin concentration, which reflects brain activity of the prefrontal cortex during this task. In both tasks, patients showed significantly smaller activation than controls and, in an assessment of executive functions, a subtraction of oxygenated hemoglobin (oxy-Hb) changes during TMT-A from those of TMT-B showed a decrease in cerebral lateralization and hypoactivity in patients. There was a significant negative correlation between oxy-Hb changes and the severity of psychiatric symptoms. These findings may characterize disease-related features, suggesting the usefulness of oxy-Hb change measurement during TMT tasks for assessing functional outcomes in schizophrenic patients.
    Neuropsychiatric Disease and Treatment 01/2013; 9:675-85. · 2.00 Impact Factor
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    ABSTRACT: In the present study, we investigated the changes in P3 component in the emotionally charged visual event-related potentials (ERP) in 30 drug-naïve schizophrenic patients for up to 1 year. Visual oddball event-related potential was recorded from six recording sites for crying baby or smiling baby photographs. ERP were recorded before the treatment (session 1 [S1]), after 3 months (session 2 [S2]), and after 12 months (session 3 [S3]), as well as in 30 healthy subjects. Before taking medicine, there were no significant differences in the P300 amplitude between viewing photographs of a crying and a smiling baby. The P300 amplitude was significantly larger at S2 and S3 than at S1 for a crying baby, while there was no significant difference among sessions for a smiling baby after medication. A significant difference of the P300 amplitude was only observed between S3 and healthy subjects for a smiling baby. The P300 latency only when viewing a smiling face became significantly longer at S3 than those at S1 and S2. A significant negative correlation was obtained between the P300 amplitude changes upon viewing crying faces and negative syndrome score changes at the Pz site. The P300 amplitude induced by crying-face stimuli may be a state marker and the P300 amplitude caused by smiling-face stimuli may be a trait marker during recovery in schizophrenic patients. Atypical antipsychotic medications may be useful and may recover cognitive function reflected by the emotionally charged visual P300 components in schizophrenic patients.
    Psychiatry and Clinical Neurosciences 06/2012; 66(4):261-9. · 2.04 Impact Factor
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    ABSTRACT: Many psychophysiological tests have been widely researched in the search for a biological marker of schizophrenia. The exploratory eye movement (EEM) test involves the monitoring of eye movements while subjects freely view geometric figures. Suzuki et al. (2009) performed discriminant analysis between schizophrenia and non-schizophrenia subjects using EEM test data; consequently, clinically diagnosed schizophrenia patients were identified as having schizophrenia with high probability (73.3%). The aim of the present study was to investigate the characteristics of schizophrenia patients who were identified as having schizophrenia on EEM discriminant analysis (SPDSE) or schizophrenia patients who were identified as not having schizophrenia on EEM discriminant analysis (SPDNSE). The data for the 251 schizophrenia subjects used in the previous discriminant-analytic study were analyzed, and the demographic or symptomatic characteristics of SPDSE and SPDNSE were investigated. As for the symptomatic features, a factor analysis of the Brief Psychiatric Rating Scale (BPRS) rating from the schizophrenia subjects was carried out. Five factors were found for schizophrenia symptoms: excitement/hostility; negative symptoms; depression/anxiety; positive symptoms; and disorganization. SPDSE had significantly higher factor scores for excitement/hostility, negative symptoms and disorganization than SPDNSE. Furthermore, the BPRS total score for the SPDSE was significantly higher than that for the SPDNSE. SPDSE may be a disease subtype of schizophrenia with severe symptoms related to excitement/hostility, negative symptoms and disorganization, and EEM parameters may detect this subtype. Therefore, the EEM test may be one of the contributors to the simplification of the heterogeneity of schizophrenia.
    Psychiatry and Clinical Neurosciences 02/2012; 66(3):187-94. · 2.04 Impact Factor
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    ABSTRACT: Various functional imaging studies have demonstrated reduced lateralization of cortical activation during neurocognitive tasks in schizophrenia. -A well-known card game, "concentration" , reflects working memory (WM). We compared characteristics of hemodynamic changes in the prefrontal to temporo-parietal areas of the brain during this card game between 24 outpatients with schizophrenia and 24 age- and gender-matched healthy control subjects. Using multi-channel near-infrared spectroscopy, we measured relative changes in oxygenated hemoglobin concentration (oxy-Hb changes), which reflects brain activity during this task. Patients showed reduced lateralization in the midfrontal area, which is involved in executive functions, and in the inferior parietal area, involved in WM subcomponents. We also found a significant negative correlation between left midfrontal region oxy-Hb changes and severity of negative symptoms of schizophrenia. Our results characterized disease-related features, suggesting the usefulness of oxy-Hb change measurement during this card game for assessing functional outcome in schizophrenic patients.
    The Kurume Medical Journal 01/2012; 59(3.4):53-60.
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    ABSTRACT: The aim of the present study was to evaluate and characterize visual cognitive function and the effect of emotion in patients with schizophrenia.We recorded exploratory eye movements as biologic markers in 40 schizophrenic patients and 40 age-matched healthy controls. Total eye scanning length (TESL), total number of gaze points (TNGP), and TNGP in right (right TNGP) and left (left TNGP) visual fields on screen were calculated as subjects viewed affectively charged pictures (smiling and crying babies) with fitting sounds.TESL of patients was shorter than that of controls when viewing pictures of smiling babies while recalling pleasurable events, and significantly decreased under negative emotional loading when viewing crying babies while recalling sad events. TESL recovered to the original values after loading positive emotion again in the controls. However, TESL did not recover to the original values in schizophrenic patients. TNGP showed similar alterations in the emotional loading task. When TNGP was evaluated in left and right fields, in patients, the non-recovery of TNGP was only observed in the left side. TESL and left TNGP were negatively correlated with negative symptom scores on PANSS.Schizophrenic patients'eye movements in the left visual field screen during the emotional loading task were different from those of controls, which suggests that visual cognitive function is impaired in the right brain in schizophrenic patients. Exploratory eye movements are a useful marker of visual cognitive function, and are a useful tool to evaluate the influence of emotion in schizophrenic patients.
    The Kurume Medical Journal 01/2012; 59(1-2):17-24.
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    ABSTRACT: The relationship between mother and baby is of fundamental importance in the development of cognitive function and emotion. In this study we investigated the effects of affective photographs of a mother and baby (crying or smiling faces) and other stimuli (neutral mother or baby faces) on visual cognitive function in schizophrenic patents. We recorded exploratory eye movements in 22 healthy controls and 22 age-matched schizophrenic patients. Total number of right and left field gaze points (right TNGP, left TNGP) in the visual fields were determined using an eye-mark recorder as subjects viewed affectively charged or neutral photographs (crying, smiling or neutral faces). Left TNGP for all mother photographs (crying, smiling or neutral) were significantly larger in controls than patients, and right TNGP for neutral mother photographs were significantly larger in controls than in patients. Right TNGP for photographs of smiling babies were significantly larger in controls than patients, and left TNGP for photographs of both smiling and crying babies were significantly larger in controls than patients. Within the patient group, right TNGP were significantly larger than left TNGP for all mother photographs (crying, smiling or neutral). Left TNGP for photographs of mothers and babies correlated negatively with negative symptom scores. These results suggest that exploratory eye movements when viewing emotionally laded twin stimuli such as photographs of a mother and baby are a useful marker of visual cognitive function in both healthy controls and schizophrenic patients.
    The Kurume Medical Journal 01/2011; 58(1):27-33.
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    ABSTRACT: Shiritori is a popular Japanese word chain game that resembles verbal fluency tasks used in Western countries. Recently, shiritori has been used to determine the dominant hemisphere for language and as a rehabilitation tool. However, there are few reports of neuroimaging during shiritori. We used functional magnetic resonance imaging (fMRI) to conduct a detailed study of brain activities during shiritori and observed activation not only of the left inferior frontal gyrus (including the pars opecularis, the pars triangularis and the pars orbitalis), which is a language-related area, but also of the left superior and middle frontal gyri, the right pars orbitalis (inferior frontal gyrus), and the right cerebellar hemisphere. Shiritori is a useful tool for psychological study and rehabilitation.
    The Kurume Medical Journal 01/2011; 57(4):109-15.
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    ABSTRACT: Colors are thought to elicit various emotional effects. Red, with its high likelihood of attracting attention, is considered to have an exciting, active effect; whereas green, with its low attention value, is considered to have a relaxing, sedative effect. Colors are also thought to affect human cognition and emotion. However, there have been few studies of the influence of colors in one's surroundings (e.g., the color environment and its effect on cognitive function). In this study, we investigated the influence of differences in color environments (red, green, or darkness) on cognitive function by analyzing the P300 component of event-related potentials (ERPs) elicited by oddball visual paradigms as a measure of cognitive characteristics in patients who had sustained traumatic brain injury (TBI). In 18 patients with TBI and 18 age-matched control subjects, ERPs were recorded in response to photographs of crying babies. We found that P300 amplitudes in the red environment were significantly larger in controls than in TBI patients, while those in both the green environment and darkness showed no difference between controls and patients. P300 latencies in the red environment and in darkness were significantly longer in patients than in controls. P300 latency in the red environment was significantly shorter than that in darkness. However, P300 latency in the green environment showed no difference between controls and patients. In healthy individuals, the emotional effects of the red environment enhanced cognitive function. In patients with TBI, however, cognitive function was reduced in the red environment. Furthermore, P300 amplitude and latency were strongly correlated with the time on the Trail Making Test (TMT), and the value of the intelligence quotient of the Wechsler Adult Intelligence Scale-III (WAIS-III). These findings suggest that P300 amplitude and latency are useful indexes for the evaluation of TBI patients, and that color environments affect cognitive function.
    Journal of neurotrauma 09/2010; 27(9):1577-84. · 4.25 Impact Factor
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    ABSTRACT: To evaluate the development of human visual cognitive function in childhood, we examined exploratory eye movements in 78 healthy subjects using affective pictures. We divided them into six groups, each of which comprised 14 subjects (7 boys or men, 7 girls or women) at the indicated ages. Exploratory eye movements were recorded via gazing points using an eye-mark recorder. The total eye scanning length (TESL) of gaze points increased significantly with age, and the mean eye scanning length, in 4-6-year-olds was significantly shorter than in the others groups. The total number of gaze points (TNGP) on the left half of the screen increased significantly with age. The left TNGP in 4-6-year-olds was significantly smaller than in the other groups. The response search score (RSS) measured in 8 areas of the screen increased significantly with age. It was concluded that exploratory eye movements are useful markers to estimate the development of human visual cognitive function in childhood.
    No to hattatsu. Brain and development 09/2010; 42(5):340-5.
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    ABSTRACT: Visual cognitive dysfunction is one of the most important signs indicating the early stage of dementia. Thus, visual testing could be used as an aid to the clinical diagnosis of dementia. In the present study, exploratory eye movement was measured to evaluate visual cognitive function in elderly subjects, including those with dementia. We analyzed responsive search scores (RSS) from exploratory eye movements of 300 subjects who were examined with an eye mark recorder while viewing S shaped figures. Subjects were divided into three groups (dementia, intermediate, healthy) from the values of the Revised Hasegawa Dementia Scale (HDS-R), the Mini-Mental State Examination (MMSE) and the Clinical Dementia Rating. We further divided the intermediate groups into two subgroups, the high score and low score groups, based on RSS. In 202 subjects, Z-scores of voxel-based specific regional analysis system for Alzheimer's disease (VSRAD) were obtained from magnetic resonance imaging (MRI). RSS of the dementia group were significantly lower than those in the intermediate and healthy groups, in order: dementia < intermediate < healthy groups. RSS of the low score intermediate group was significantly lower than that of the high score intermediate group. There was no significant difference between the low score intermediate and dementia groups, or between the high score intermediate and healthy groups. No significant differences of either HSD-R or MMSE were observed between the low score and the high score intermediate groups. The Z-score of VSRAD using MRI in the low score intermediate group was significantly higher than that in the high score intermediate group. These findings suggest that RSS using an eye mark recorder is a useful psychophysiological marker to evaluate the early stage of dementia as well as at-risk elderly people.
    Psychogeriatrics 09/2010; 10(3):124-30. · 1.26 Impact Factor
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    ABSTRACT: Using optical topography (near-infrared spectroscopy: NIRS), relative changes in oxidized hemoglobin (oxy-Hb) were measured before and after the introduction of Role lettering. Tasks performed during measurements included antegrade (from the subject to other persons) and retrograde (from other persons to the subject) mental imaging and writing tasks. All subjects were junior high school students. Relative changes in oxy-Hb were measured before and 3, 6, and 12 months after the start of Role lettering. The region of interest (ROI) was determined based upon the motor cortex region of hand movement and upon relative oxy-Hb changes noted before any Role lettering. For antegrade mental tasks, oxy-Hb increased significantly in right-sided ROI after 3 months; this increase persisted at 1 year. For retrograde mental tasks, oxy-Hb significantly increased bilaterally at 3 months, an effect that also persisted at 1 year. With the antegrade writing task, no significant difference was observed throughout the study; with the retrograde writing task, oxy-Hb level decreased significantly in right lateral ROI after 6 months; the decrease persisted at 1 year. The number of words produced after Role lettering increased significantly in both antegrade and retrograde writing tasks at 1 year, compared with the number before Role lettering. Role lettering thus altered mental activity, particularly in the right hemisphere. Retrograde writing tasks, similar to those employed in the actual practice of Role lettering, reduced right hemispheric function; continuation of the task enhanced performance. Role lettering studies using NIRS may provide useful psychophysiologic indices.
    The Kurume Medical Journal 01/2010; 57(3):51-8.
  • Clinical Neurophysiology - CLIN NEUROPHYSIOL. 01/2010; 121.
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    Psychiatry and Clinical Neurosciences 05/2009; 63(2):253-4. · 2.04 Impact Factor
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    ABSTRACT: To evaluate the development of visual cognitive function in childhood, we examined exploratory eye movements in 84 healthy subjects viewing picture-based stimuli. Age-defined groups included 4- to 6-year-olds, 7-year-olds, 10-year-olds, 14-year-olds, 16-year-olds, and adults. In each group, 7 subjects were male and 7 were female. Exploratory eye movements, recorded as gaze points using an eye-mark recorder, were analyzed in terms of the total number of gaze points (TNGP); total eye-scanning length of gaze points (TESL); total number of gaze points on the left (l TNGP) and right (r TNGP) of the screen; and responsive search score (RSS) on the left (l RSS) and right (r RSS) of the screen. Both the TESL and TNGP increased significantly with age. The TESL and TNGP of 16-year-olds and adults viewing a repeat-comparison figure were significantly greater than when viewing a comparison figure. During the repeat-comparisons, the TNGP in 4- to 6-year-olds was greater on the right than the left; the opposite was true in 16-year-olds and adults. The RSS in 4- to 10-year-olds was greater on the right than the left; 16-year-olds and adults showed the reverse findings. Thus, in the repeat-comparison task, TNGP, TESL, TNGP, and RSS differences between left and right visual fields are useful biologic markers for estimating the development of visual cognitive function.
    Brain & development 02/2009; 31(10):750-7. · 1.74 Impact Factor
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    ABSTRACT: In our previous studies, we identified that exploratory eye movement (EEM) dysfunction appears to be specific to schizophrenia. The availability of a biological marker specific to schizophrenia would be useful for clinical diagnosis of schizophrenia. Consequently, we performed the discriminant analysis between schizophrenics and non-schizophrenics on a large sample using the EEM test data and examined an application of the EEM for clinical diagnosis of schizophrenia. EEM performances were recorded in 251 schizophrenics and 389 non-schizophrenics (111 patients with mood disorders, 28 patients with neurotic disorders and 250 normal controls). The patients were recruited from eight university hospitals and three affiliated hospitals. For this study with a large sample, we developed a new digital computerized version of the EEM test, which automatically handled large amounts of data. We measured four parameters: number of eye fixations (NEF), total eye scanning length (TESL), mean eye scanning length (MESL) and responsive search score (RSS). These parameters of schizophrenics differed significantly from those of the other three groups. The stepwise regression analysis selected the TESL and the RSS as the valid parameters for discriminating between schizophrenics and non-schizophrenics. In the discriminant analysis using the RSS and TESL as prediction parameters, 184 of the 251 clinically diagnosed schizophrenics were discriminated as having schizophrenia (sensitivity 73.3%); and 308 of the 389 clinically diagnosed non-schizophrenic subjects were discriminated as non-schizophrenics (specificity 79.2%). Based on our findings we believe that the EEM measures may be useful for the clinical diagnosis of schizophrenia.
    European Archives of Psychiatry and Clinical Neuroscience 02/2009; 259(3):186-94. · 3.36 Impact Factor
  • Neuroscience Research - NEUROSCI RES. 01/2009; 65.

Publication Stats

202 Citations
64.79 Total Impact Points

Institutions

  • 1995–2013
    • Kurume University
      • • Department of Neuropsychiatry
      • • Cognitive and Molecular Research Institute of Brain Diseases
      Куруме, Fukuoka, Japan
  • 2010
    • Fukuoka Prefectural University
      Takawa, Fukuoka, Japan
  • 2003
    • Kyushu University of Health and Welfare
      Миядзаки, Miyazaki, Japan