The Experts below are selected from a list of 8964 Experts worldwide ranked by ideXlab platform
Masao Aihara - One of the best experts on this subject based on the ideXlab platform.
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Prefrontal Lobe Growth Disturbance in a Patient with Frontal Absence Seizures
Journal of Pediatric Epilepsy, 2016Co-Authors: Hideaki Kanemura, Tetsuo Ohyama, Kanji Sugita, Sonoko Mizorogi, Masao AiharaAbstract:Absence seizures sometimes present in patients with frontal Lobe epilepsy. Cognitive and behavioral problems in patients with absence seizures may be correlated with frontal Lobe dysfunction. We report a 15-year-old female patient with absence seizures. She showed learning and behavioral problems such as inattention and impulsivity. We studied serial changes in frontal and Prefrontal Lobe volume to clarify such correlations among three-dimensional magnetic resonance imaging (MRI). We compared frontal and Prefrontal Lobe volumes between this patient, the childhood absence epilepsy group ( n = 4, age 8–11 y), and controls ( n = 10, age 6–15 y). Three-dimensional MRI was performed four times in the case (at worsening of absence seizures and 1, 2, and 4 y later) and three times in the childhood absence epilepsy group (at onset and 1 and 2 y later). Even after the complete cessation of seizures, frontal and Prefrontal Lobe volumes were lower in the case than in patients with childhood absence epilepsy and control subjects. Also, Prefrontal-to-frontal Lobe volume ratio increased over time in the childhood absence epilepsy and control subjects, whereas its increase was slight in the case. Patients presenting with frontal absence may show Prefrontal Lobe growth disturbance, which may manifest as poor frontal Lobe function.
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Neurobiological effects of CSWS on brain growth: A magnetic resonance imaging volumetric study
Journal of Pediatric Epilepsy, 2015Co-Authors: Hideaki Kanemura, Masao AiharaAbstract:Epilepsy with continuous spike-waves during slow sleep (CSWS) is characterized by impairment of neuropsychological abilities, frequently associated with behavioral disorders. These manifestations strongly correlate with frontal Lobe dysfunctions. CSWS in childhood may affect the Prefrontal cortex and leave residual mental and behavioral abnormalities as profound and permanent as the loss of speech in Landau-Kleffner syndrome. In our previous volumetric studies, frontal and Prefrontal Lobe volumes revealed growth disturbance in all CSWS patients compared with those of normal subjects. These studies also revealed that in the patients with shorter seizure durations and CSWS periods, developmental abnormalities of the Prefrontal Lobes were soon restored to a more normal growth ratio, whereas growth disturbances of the Prefrontal Lobes were persistent in the patients with longer seizure durations and CSWS periods. These findings suggest that seizure and the duration of paroxysmal anomalies may be associated with Prefrontal Lobe growth abnormalities, which are associated with neuropsychological problems. Thus, the duration of CSWS period seems to be a significant prognostic factor. The urgent suppression of this electroencephalography abnormality may be necessary to prevent the progression of neuropsychological impairments. The best treatment options may be required to remit seizures and electroencephalography abnormalities as soon as possible to achieve optimal prognosis in CSWS.
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sequential Prefrontal Lobe volume changes and cognitive dysfunctions in children with panayiotopoulos syndrome presenting with status epilepticus
Epilepsy Research, 2015Co-Authors: Hideaki Kanemura, Kakuro Aoyagi, Fumikazu Sano, Tetsuo Ohyama, Kanji Sugita, Masao AiharaAbstract:Summary Panayiotopoulos syndrome (PS) is usually not associated with neurodevelopmental problems. However, neuropsychological impairments may also be present in at least some of the patients with PS. On the other hand, several degrees of neuronal damage due to status epilepticus (SE) may occur in the cortex. We prospectively measured frontal and Prefrontal Lobe volumes using three-dimensional magnetic resonance imaging (3D-MRI)-based volumetry in patients with PS with and without SE. Moreover, the neuropsychological outcome in relation to the presence of SE in children with PS is also discussed. We studied six patients with a final diagnosis of PS, including three cases with SE and cognitive impairments/behavioral problems (SE group) and three cases without SE (non-SE group). Serial 3D-MRI studies were performed five times (at onset of clinical symptoms and 1–4 years after onset) in both the SE and non-SE patients. All patients were studied with a set of Wechsler Intelligence Scale for Children, version III (WISC-III) or Wechsler Preschool and Primary Scale of Intelligence tests and the Kaufman Assessment Battery for Children (K-ABC). Growth of the frontal and Prefrontal Lobes was slightly decreased for some time after SE episodes in the SE patients. Moreover, the Prefrontal-to-frontal Lobe volume ratio was stagnant for some time after SE in the SE patients. The scores on the neuropsychological tests were decreased in the SE patients. Moreover, the average WISC and K-ABC scores in the SE group remained low and did not reach the levels of the initial examinations. Occurrence of SE in patients with PS at least in some patients may be associated with retarded Prefrontal Lobe growth, which was related to neuropsychological problems and ultimately, neuropsychological outcomes. Treatment management may be required to prevent SE as much as possible to achieve optimal prognosis in PS at least in some patients.
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Asymmetry of the Prefrontal Lobe in patients with attention deficit hyperactivity disorder: A three-dimensional volumetric magnetic resonance imaging study
Journal of pediatric neurology, 2014Co-Authors: Hideaki Kanemura, Fumikazu Sano, Tetsuo Ohyama, Kanji Sugita, Hiromi Hosaka, Masao AiharaAbstract:Asymmetries have been reported in several regions of the brain of patients with developmental disorders such as autism, developmental language disorder, and attention deficit hyperactivity disorder (ADHD). This study focused on age-related anatomical asymmetries of the Prefrontal Lobe, which can be manifestations of regional specialization of systems organization where there are functional differences between the left and right hemispheres, in children with ADHD. Subjects were 7 right-handed boys with ADHD aged 6–12 years and 5 age-matched controls. Exclusion criteria were full-scale intelligence quotient less than 80, comorbid learning disorder or developmental delay, evidence of medical or neurological disease on examination or by history, or Tourette's syndrome. No subjects met criteria for conduct disorder or oppositional disorder. Volume of the frontal and Prefrontal Lobes was determined using a workstation and the Prefrontal-to-frontal Lobe and left-to-right volume ratios were calculated. Both control and ADHD groups had a larger aggregate volume of left frontal and Prefrontal Lobes than of right frontal and Prefrontal Lobes. The leftward bias of the frontal Lobe was significantly pronounced in ADHD subjects than in control subjects (P = 0.026). In addition, the leftward bias of the Prefrontal Lobe was more pronounced in ADHD subjects than in control subjects (P = 0.0041). The left-to-right volume ratio of the Prefrontal Lobe increased with age in both groups. The left-to-right volume ratio of the frontal Lobe was more pronounced in ADHD (r = 0.922, P = 0.0014) than control group (r = 0.521, P = 0.414). In addition, the left-to-right volume ratio of the Prefrontal Lobe was more pronounced in ADHD (r = 0.903, P = 0.0029) than control group (r = 0.701, P = 0.219). These findings support the argument that right-sided Prefrontal structural anomalies may occur disproportionately in ADHD.
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Frontal Lobe Growth Retardation and Dysfunctions in Children with Epilepsy: A 3-D MRI Volumetric Study
Pediatrics & Therapeutics, 2013Co-Authors: Hideaki Kanemura, Masao AiharaAbstract:Behavioral abnormalities have been noted in specific epilepsy syndromes involving the frontal Lobe. Epilepsies that involve the frontal Lobe, such as frontal Lobe epilepsy (FLE), atypical evolution of benign childhood epilepsy with centrotemporal spikes (BCECTS), and epilepsy with continuous spike-waves during slow sleep (CSWS), are characterized by impairment of neuropsychological abilities, frequently associated with behavioral disorders. These manifestations correlate strongly with frontal Lobe dysfunction. Accordingly, epilepsies in childhood may affect the Prefrontal cortex and leave residual mental and behavioral abnormalities. Brain volumetry has shown that frontal and Prefrontal Lobe volumes show a growth disturbance in patients with FLE, atypical evolution of BCECTS, and CSWS compared with those of normal subjects. These studies also showed that seizures and the duration of paroxysmal anomalies may be associated with Prefrontal Lobe growth abnormalities, which are associated with neuropsychological problems. Moreover, these studies also showed that the Prefrontal Lobe appears more highly vulnerable to repeated seizures than other cortical regions. The urgent suppression of these seizure and EEG abnormalities may be necessary to prevent the progression of neuropsychological impairments. Treatment options to remit seizures and EEG abnormalities as soon as possible may be required to achieve the optimal prognosis in frontal Lobe epilepsies. Of the new AEDs, levetiracetam (LEV) may be an important addition to the treatments available for refractory childhood epilepsies with cognitive and behavioral problems.
Satoshi Kumagai - One of the best experts on this subject based on the ideXlab platform.
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discrimination of verbal visuospatial memory retrieval processes by measuring Prefrontal Lobe blood volume with functional near infrared spectrometry
IEEE Access, 2020Co-Authors: Yosuke Kurihara, Takashi Kaburagi, Keita Nishio, Yuri Hamada, Toshiyuki Matsumoto, Satoshi KumagaiAbstract:In cognitive task execution, retrieval processes transfer memories from long-term storage to working memory, comprising three short-term memories—phonological loop, visuospatial sketchpad, and episodic buffer—controlled by a short-term-memory central executive. The phonological loop and visuospatial sketchpad are prominent in verbal and visuospatial information processing, respectively. Individuals differ in how they retrieve the same information. Discrimination between verbal or visuospatial memory retrieval by monitoring central executive activation is useful. Functional near-infrared spectroscopy (fNIRS) was used to assess blood volume and Prefrontal Lobe brain activation. Using a novel approach, blood volume during memory retrieval was obtained using fNIRS. To eliminate other factors not related to the central executive activation, a base period was observed. Dynamic range was calculated for both memory retrieval and base periods, and differences obtained at ten positions within the Prefrontal Lobe were used as features to discriminate between verbal and visuospatial retrieval. For discrimination, k-nearest neighbor (kNN) and support vector machine (SVM) with different kernels were applied. Our method was tested on participants in verbal/visuospatial memory retrieval experiments. As the result, accuracy, positive predictive values, and negative predictive values of kNN and SVM were 1, which indicated that the proposed method successfully discriminated between verbal/visuospatial memory retrieval through Prefrontal Lobe blood volume observation.
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Discrimination of Verbal/Visuospatial Memory Retrieval Processes by Measuring Prefrontal Lobe Blood Volume With Functional Near-Infrared Spectrometry
IEEE Access, 2020Co-Authors: Yosuke Kurihara, Takashi Kaburagi, Keita Nishio, Yuri Hamada, Toshiyuki Matsumoto, Satoshi KumagaiAbstract:In cognitive task execution, retrieval processes transfer memories from long-term storage to working memory, comprising three short-term memories—phonological loop, visuospatial sketchpad, and episodic buffer—controlled by a short-term-memory central executive. The phonological loop and visuospatial sketchpad are prominent in verbal and visuospatial information processing, respectively. Individuals differ in how they retrieve the same information. Discrimination between verbal or visuospatial memory retrieval by monitoring central executive activation is useful. Functional near-infrared spectroscopy (fNIRS) was used to assess blood volume and Prefrontal Lobe brain activation. Using a novel approach, blood volume during memory retrieval was obtained using fNIRS. To eliminate other factors not related to the central executive activation, a base period was observed. Dynamic range was calculated for both memory retrieval and base periods, and differences obtained at ten positions within the Prefrontal Lobe were used as features to discriminate between verbal and visuospatial retrieval. For discrimination, k-nearest neighbor (kNN) and support vector machine (SVM) with different kernels were applied. Our method was tested on participants in verbal/visuospatial memory retrieval experiments. As the result, accuracy, positive predictive values, and negative predictive values of kNN and SVM were 1, which indicated that the proposed method successfully discriminated between verbal/visuospatial memory retrieval through Prefrontal Lobe blood volume observation.
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Anxiety Level Estimation from Weighted Frontal Lobe Area Laterality Index at Rest using NIRS
Proceedings of the 44th International Academic Conference Vienna, 2018Co-Authors: Tomoki Kobayashi, Toshiyuki Matsumoto, Takashi Kaburagi, Satoshi Kumagai, Yosuke KuriharaAbstract:Recently, the number of persons who suffer from mental illnesses that can be caused by excessive stress, such as depression and schizophrenia, has been increasing year by year. To detect and treat these illnesses earlier, it is important to assess the anxiety state of the patients as accurately as possible. In general, the State-Trait Anxiety Inventory (STAI) score is utilized to determine the anxiety state. However, since the STAI is a subjective questionnaire, some patients would intentionally not provide honest answers to the questions. Hence, it is difficult to grasp the patients? anxiety state accurately. To address this, some studies have proposed an estimation method for the STAI score by utilizing the cerebral blood volume, which cannot be intentionally controlled by the patient. In previous studies, the STAI score was estimated from the cerebral blood volume measured in a small area of the Prefrontal Lobe. To improve the estimation accuracy, we have proposed an estimation method based on the cerebral blood volume measured in a larger area of the Prefrontal Lobe. In this study, we not only utilize the cerebral blood volume measured in a larger area, but also aim to improve the estimation accuracy of the STAI score by applying a weight to each area of the Prefrontal Lobe. We introduce the weighted-multi-channel Laterality Index at Rest (wmc-LIR), which is calculated based on the oxyhemoglobin concentrations measured by near-infrared spectroscopy (NIRS) with n channels. These are located at measurement points in the Prefrontal Lobe defined by the international 10-20 system. The weight for each area represents the activity level of the brain in that area. To confirm the applicability of the proposed method, we validated wmc-LIR using NIRS recordings of 24 subjects. The average absolute error of the proposed method was 4.01. In contrast, the average absolute error of the method proposed in the previous study without assigning weights to brain areas in the same setting was 5.08.
Hideaki Kanemura - One of the best experts on this subject based on the ideXlab platform.
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Prefrontal Lobe Growth Disturbance in a Patient with Frontal Absence Seizures
Journal of Pediatric Epilepsy, 2016Co-Authors: Hideaki Kanemura, Tetsuo Ohyama, Kanji Sugita, Sonoko Mizorogi, Masao AiharaAbstract:Absence seizures sometimes present in patients with frontal Lobe epilepsy. Cognitive and behavioral problems in patients with absence seizures may be correlated with frontal Lobe dysfunction. We report a 15-year-old female patient with absence seizures. She showed learning and behavioral problems such as inattention and impulsivity. We studied serial changes in frontal and Prefrontal Lobe volume to clarify such correlations among three-dimensional magnetic resonance imaging (MRI). We compared frontal and Prefrontal Lobe volumes between this patient, the childhood absence epilepsy group ( n = 4, age 8–11 y), and controls ( n = 10, age 6–15 y). Three-dimensional MRI was performed four times in the case (at worsening of absence seizures and 1, 2, and 4 y later) and three times in the childhood absence epilepsy group (at onset and 1 and 2 y later). Even after the complete cessation of seizures, frontal and Prefrontal Lobe volumes were lower in the case than in patients with childhood absence epilepsy and control subjects. Also, Prefrontal-to-frontal Lobe volume ratio increased over time in the childhood absence epilepsy and control subjects, whereas its increase was slight in the case. Patients presenting with frontal absence may show Prefrontal Lobe growth disturbance, which may manifest as poor frontal Lobe function.
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Neurobiological effects of CSWS on brain growth: A magnetic resonance imaging volumetric study
Journal of Pediatric Epilepsy, 2015Co-Authors: Hideaki Kanemura, Masao AiharaAbstract:Epilepsy with continuous spike-waves during slow sleep (CSWS) is characterized by impairment of neuropsychological abilities, frequently associated with behavioral disorders. These manifestations strongly correlate with frontal Lobe dysfunctions. CSWS in childhood may affect the Prefrontal cortex and leave residual mental and behavioral abnormalities as profound and permanent as the loss of speech in Landau-Kleffner syndrome. In our previous volumetric studies, frontal and Prefrontal Lobe volumes revealed growth disturbance in all CSWS patients compared with those of normal subjects. These studies also revealed that in the patients with shorter seizure durations and CSWS periods, developmental abnormalities of the Prefrontal Lobes were soon restored to a more normal growth ratio, whereas growth disturbances of the Prefrontal Lobes were persistent in the patients with longer seizure durations and CSWS periods. These findings suggest that seizure and the duration of paroxysmal anomalies may be associated with Prefrontal Lobe growth abnormalities, which are associated with neuropsychological problems. Thus, the duration of CSWS period seems to be a significant prognostic factor. The urgent suppression of this electroencephalography abnormality may be necessary to prevent the progression of neuropsychological impairments. The best treatment options may be required to remit seizures and electroencephalography abnormalities as soon as possible to achieve optimal prognosis in CSWS.
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sequential Prefrontal Lobe volume changes and cognitive dysfunctions in children with panayiotopoulos syndrome presenting with status epilepticus
Epilepsy Research, 2015Co-Authors: Hideaki Kanemura, Kakuro Aoyagi, Fumikazu Sano, Tetsuo Ohyama, Kanji Sugita, Masao AiharaAbstract:Summary Panayiotopoulos syndrome (PS) is usually not associated with neurodevelopmental problems. However, neuropsychological impairments may also be present in at least some of the patients with PS. On the other hand, several degrees of neuronal damage due to status epilepticus (SE) may occur in the cortex. We prospectively measured frontal and Prefrontal Lobe volumes using three-dimensional magnetic resonance imaging (3D-MRI)-based volumetry in patients with PS with and without SE. Moreover, the neuropsychological outcome in relation to the presence of SE in children with PS is also discussed. We studied six patients with a final diagnosis of PS, including three cases with SE and cognitive impairments/behavioral problems (SE group) and three cases without SE (non-SE group). Serial 3D-MRI studies were performed five times (at onset of clinical symptoms and 1–4 years after onset) in both the SE and non-SE patients. All patients were studied with a set of Wechsler Intelligence Scale for Children, version III (WISC-III) or Wechsler Preschool and Primary Scale of Intelligence tests and the Kaufman Assessment Battery for Children (K-ABC). Growth of the frontal and Prefrontal Lobes was slightly decreased for some time after SE episodes in the SE patients. Moreover, the Prefrontal-to-frontal Lobe volume ratio was stagnant for some time after SE in the SE patients. The scores on the neuropsychological tests were decreased in the SE patients. Moreover, the average WISC and K-ABC scores in the SE group remained low and did not reach the levels of the initial examinations. Occurrence of SE in patients with PS at least in some patients may be associated with retarded Prefrontal Lobe growth, which was related to neuropsychological problems and ultimately, neuropsychological outcomes. Treatment management may be required to prevent SE as much as possible to achieve optimal prognosis in PS at least in some patients.
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Asymmetry of the Prefrontal Lobe in patients with attention deficit hyperactivity disorder: A three-dimensional volumetric magnetic resonance imaging study
Journal of pediatric neurology, 2014Co-Authors: Hideaki Kanemura, Fumikazu Sano, Tetsuo Ohyama, Kanji Sugita, Hiromi Hosaka, Masao AiharaAbstract:Asymmetries have been reported in several regions of the brain of patients with developmental disorders such as autism, developmental language disorder, and attention deficit hyperactivity disorder (ADHD). This study focused on age-related anatomical asymmetries of the Prefrontal Lobe, which can be manifestations of regional specialization of systems organization where there are functional differences between the left and right hemispheres, in children with ADHD. Subjects were 7 right-handed boys with ADHD aged 6–12 years and 5 age-matched controls. Exclusion criteria were full-scale intelligence quotient less than 80, comorbid learning disorder or developmental delay, evidence of medical or neurological disease on examination or by history, or Tourette's syndrome. No subjects met criteria for conduct disorder or oppositional disorder. Volume of the frontal and Prefrontal Lobes was determined using a workstation and the Prefrontal-to-frontal Lobe and left-to-right volume ratios were calculated. Both control and ADHD groups had a larger aggregate volume of left frontal and Prefrontal Lobes than of right frontal and Prefrontal Lobes. The leftward bias of the frontal Lobe was significantly pronounced in ADHD subjects than in control subjects (P = 0.026). In addition, the leftward bias of the Prefrontal Lobe was more pronounced in ADHD subjects than in control subjects (P = 0.0041). The left-to-right volume ratio of the Prefrontal Lobe increased with age in both groups. The left-to-right volume ratio of the frontal Lobe was more pronounced in ADHD (r = 0.922, P = 0.0014) than control group (r = 0.521, P = 0.414). In addition, the left-to-right volume ratio of the Prefrontal Lobe was more pronounced in ADHD (r = 0.903, P = 0.0029) than control group (r = 0.701, P = 0.219). These findings support the argument that right-sided Prefrontal structural anomalies may occur disproportionately in ADHD.
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Frontal Lobe Growth Retardation and Dysfunctions in Children with Epilepsy: A 3-D MRI Volumetric Study
Pediatrics & Therapeutics, 2013Co-Authors: Hideaki Kanemura, Masao AiharaAbstract:Behavioral abnormalities have been noted in specific epilepsy syndromes involving the frontal Lobe. Epilepsies that involve the frontal Lobe, such as frontal Lobe epilepsy (FLE), atypical evolution of benign childhood epilepsy with centrotemporal spikes (BCECTS), and epilepsy with continuous spike-waves during slow sleep (CSWS), are characterized by impairment of neuropsychological abilities, frequently associated with behavioral disorders. These manifestations correlate strongly with frontal Lobe dysfunction. Accordingly, epilepsies in childhood may affect the Prefrontal cortex and leave residual mental and behavioral abnormalities. Brain volumetry has shown that frontal and Prefrontal Lobe volumes show a growth disturbance in patients with FLE, atypical evolution of BCECTS, and CSWS compared with those of normal subjects. These studies also showed that seizures and the duration of paroxysmal anomalies may be associated with Prefrontal Lobe growth abnormalities, which are associated with neuropsychological problems. Moreover, these studies also showed that the Prefrontal Lobe appears more highly vulnerable to repeated seizures than other cortical regions. The urgent suppression of these seizure and EEG abnormalities may be necessary to prevent the progression of neuropsychological impairments. Treatment options to remit seizures and EEG abnormalities as soon as possible may be required to achieve the optimal prognosis in frontal Lobe epilepsies. Of the new AEDs, levetiracetam (LEV) may be an important addition to the treatments available for refractory childhood epilepsies with cognitive and behavioral problems.
Yosuke Kurihara - One of the best experts on this subject based on the ideXlab platform.
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discrimination of verbal visuospatial memory retrieval processes by measuring Prefrontal Lobe blood volume with functional near infrared spectrometry
IEEE Access, 2020Co-Authors: Yosuke Kurihara, Takashi Kaburagi, Keita Nishio, Yuri Hamada, Toshiyuki Matsumoto, Satoshi KumagaiAbstract:In cognitive task execution, retrieval processes transfer memories from long-term storage to working memory, comprising three short-term memories—phonological loop, visuospatial sketchpad, and episodic buffer—controlled by a short-term-memory central executive. The phonological loop and visuospatial sketchpad are prominent in verbal and visuospatial information processing, respectively. Individuals differ in how they retrieve the same information. Discrimination between verbal or visuospatial memory retrieval by monitoring central executive activation is useful. Functional near-infrared spectroscopy (fNIRS) was used to assess blood volume and Prefrontal Lobe brain activation. Using a novel approach, blood volume during memory retrieval was obtained using fNIRS. To eliminate other factors not related to the central executive activation, a base period was observed. Dynamic range was calculated for both memory retrieval and base periods, and differences obtained at ten positions within the Prefrontal Lobe were used as features to discriminate between verbal and visuospatial retrieval. For discrimination, k-nearest neighbor (kNN) and support vector machine (SVM) with different kernels were applied. Our method was tested on participants in verbal/visuospatial memory retrieval experiments. As the result, accuracy, positive predictive values, and negative predictive values of kNN and SVM were 1, which indicated that the proposed method successfully discriminated between verbal/visuospatial memory retrieval through Prefrontal Lobe blood volume observation.
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Discrimination of Verbal/Visuospatial Memory Retrieval Processes by Measuring Prefrontal Lobe Blood Volume With Functional Near-Infrared Spectrometry
IEEE Access, 2020Co-Authors: Yosuke Kurihara, Takashi Kaburagi, Keita Nishio, Yuri Hamada, Toshiyuki Matsumoto, Satoshi KumagaiAbstract:In cognitive task execution, retrieval processes transfer memories from long-term storage to working memory, comprising three short-term memories—phonological loop, visuospatial sketchpad, and episodic buffer—controlled by a short-term-memory central executive. The phonological loop and visuospatial sketchpad are prominent in verbal and visuospatial information processing, respectively. Individuals differ in how they retrieve the same information. Discrimination between verbal or visuospatial memory retrieval by monitoring central executive activation is useful. Functional near-infrared spectroscopy (fNIRS) was used to assess blood volume and Prefrontal Lobe brain activation. Using a novel approach, blood volume during memory retrieval was obtained using fNIRS. To eliminate other factors not related to the central executive activation, a base period was observed. Dynamic range was calculated for both memory retrieval and base periods, and differences obtained at ten positions within the Prefrontal Lobe were used as features to discriminate between verbal and visuospatial retrieval. For discrimination, k-nearest neighbor (kNN) and support vector machine (SVM) with different kernels were applied. Our method was tested on participants in verbal/visuospatial memory retrieval experiments. As the result, accuracy, positive predictive values, and negative predictive values of kNN and SVM were 1, which indicated that the proposed method successfully discriminated between verbal/visuospatial memory retrieval through Prefrontal Lobe blood volume observation.
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Anxiety Level Estimation from Weighted Frontal Lobe Area Laterality Index at Rest using NIRS
Proceedings of the 44th International Academic Conference Vienna, 2018Co-Authors: Tomoki Kobayashi, Toshiyuki Matsumoto, Takashi Kaburagi, Satoshi Kumagai, Yosuke KuriharaAbstract:Recently, the number of persons who suffer from mental illnesses that can be caused by excessive stress, such as depression and schizophrenia, has been increasing year by year. To detect and treat these illnesses earlier, it is important to assess the anxiety state of the patients as accurately as possible. In general, the State-Trait Anxiety Inventory (STAI) score is utilized to determine the anxiety state. However, since the STAI is a subjective questionnaire, some patients would intentionally not provide honest answers to the questions. Hence, it is difficult to grasp the patients? anxiety state accurately. To address this, some studies have proposed an estimation method for the STAI score by utilizing the cerebral blood volume, which cannot be intentionally controlled by the patient. In previous studies, the STAI score was estimated from the cerebral blood volume measured in a small area of the Prefrontal Lobe. To improve the estimation accuracy, we have proposed an estimation method based on the cerebral blood volume measured in a larger area of the Prefrontal Lobe. In this study, we not only utilize the cerebral blood volume measured in a larger area, but also aim to improve the estimation accuracy of the STAI score by applying a weight to each area of the Prefrontal Lobe. We introduce the weighted-multi-channel Laterality Index at Rest (wmc-LIR), which is calculated based on the oxyhemoglobin concentrations measured by near-infrared spectroscopy (NIRS) with n channels. These are located at measurement points in the Prefrontal Lobe defined by the international 10-20 system. The weight for each area represents the activity level of the brain in that area. To confirm the applicability of the proposed method, we validated wmc-LIR using NIRS recordings of 24 subjects. The average absolute error of the proposed method was 4.01. In contrast, the average absolute error of the method proposed in the previous study without assigning weights to brain areas in the same setting was 5.08.
Yuri Hamada - One of the best experts on this subject based on the ideXlab platform.
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discrimination of verbal visuospatial memory retrieval processes by measuring Prefrontal Lobe blood volume with functional near infrared spectrometry
IEEE Access, 2020Co-Authors: Yosuke Kurihara, Takashi Kaburagi, Keita Nishio, Yuri Hamada, Toshiyuki Matsumoto, Satoshi KumagaiAbstract:In cognitive task execution, retrieval processes transfer memories from long-term storage to working memory, comprising three short-term memories—phonological loop, visuospatial sketchpad, and episodic buffer—controlled by a short-term-memory central executive. The phonological loop and visuospatial sketchpad are prominent in verbal and visuospatial information processing, respectively. Individuals differ in how they retrieve the same information. Discrimination between verbal or visuospatial memory retrieval by monitoring central executive activation is useful. Functional near-infrared spectroscopy (fNIRS) was used to assess blood volume and Prefrontal Lobe brain activation. Using a novel approach, blood volume during memory retrieval was obtained using fNIRS. To eliminate other factors not related to the central executive activation, a base period was observed. Dynamic range was calculated for both memory retrieval and base periods, and differences obtained at ten positions within the Prefrontal Lobe were used as features to discriminate between verbal and visuospatial retrieval. For discrimination, k-nearest neighbor (kNN) and support vector machine (SVM) with different kernels were applied. Our method was tested on participants in verbal/visuospatial memory retrieval experiments. As the result, accuracy, positive predictive values, and negative predictive values of kNN and SVM were 1, which indicated that the proposed method successfully discriminated between verbal/visuospatial memory retrieval through Prefrontal Lobe blood volume observation.
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Discrimination of Verbal/Visuospatial Memory Retrieval Processes by Measuring Prefrontal Lobe Blood Volume With Functional Near-Infrared Spectrometry
IEEE Access, 2020Co-Authors: Yosuke Kurihara, Takashi Kaburagi, Keita Nishio, Yuri Hamada, Toshiyuki Matsumoto, Satoshi KumagaiAbstract:In cognitive task execution, retrieval processes transfer memories from long-term storage to working memory, comprising three short-term memories—phonological loop, visuospatial sketchpad, and episodic buffer—controlled by a short-term-memory central executive. The phonological loop and visuospatial sketchpad are prominent in verbal and visuospatial information processing, respectively. Individuals differ in how they retrieve the same information. Discrimination between verbal or visuospatial memory retrieval by monitoring central executive activation is useful. Functional near-infrared spectroscopy (fNIRS) was used to assess blood volume and Prefrontal Lobe brain activation. Using a novel approach, blood volume during memory retrieval was obtained using fNIRS. To eliminate other factors not related to the central executive activation, a base period was observed. Dynamic range was calculated for both memory retrieval and base periods, and differences obtained at ten positions within the Prefrontal Lobe were used as features to discriminate between verbal and visuospatial retrieval. For discrimination, k-nearest neighbor (kNN) and support vector machine (SVM) with different kernels were applied. Our method was tested on participants in verbal/visuospatial memory retrieval experiments. As the result, accuracy, positive predictive values, and negative predictive values of kNN and SVM were 1, which indicated that the proposed method successfully discriminated between verbal/visuospatial memory retrieval through Prefrontal Lobe blood volume observation.