In this paper, we analyze the relationship between brain activity and accuracy of replicating actions in the process of embodied knowledge acquisition. Subjects learned a series of actions as fundamental embodied knowledge as a experiment. Remembering and executing the actions, oxy hemoglobin increase in dorsolateral prefrontal area and decrease in

. Subjects watched a video crip of a working procedure, and executed the same series of actions as another experiment.. We conducted this experiment twice. After the first experiment, we set up three practice terms. In the observation task, oxy hemoglobin stabilize at a low level in dorsolateral prefrontal area and with elevation of accuracy of replicating actions. In the execution task, oxy hemoglobin increase in dorsolateral prefrontal area and decrease in with elevation of accuracy of replicating actions. These results suggest relate self body imaging and dorsolateral prefrontal area relate working memory, and activity in these areas changes during the process of embodied knowledge acquisition.

抄録全体を表示

In this paper, we analyze the relationship between brain activity and repeatability of actions in the process of embodied knowledge acquisition. Subjects learnt a series of actions as fundamental embodied knowledge as a experiment. Remembering and executing the actions, oxy hemoglobin increase in dorsolateral prefrontal area and decrease in . Subjects watched a video crip of a working process, and executed the same series of actions. We conducted same experiments twice. After the 1st experiment, we set up three practice terms. In the observation task, oxy hemoglobin stabilize at a low level in dorsolateral prefrontal area and with elevation of repeatability. In the execution task, oxy hemoglobin increase in dorsolateral prefrontal area and decrease in with elevation of repeatability. These results suggest relate self body imaging and dorsolateral prefrontal area relate working memory.

抄録全体を表示

The occurrence of serious traffic accidents due to driving error has recently become a social issue. The decline in cognitive functions is considered a factor particularly among elderly drivers, for which some corrective measures are urgently needed. Currently, as a measure dealing with elderly drivers, drivers aged 75 years are required by law to examine their cognitive functions when they renew their driver’s license. This examination is conducted to measure memory and power of judgment. In the present study, we used a device that allows simple measurements and attached electrodes to the

, where it is easy to attach; measure electroencephalograms for the cognitive functions of memory, mental calculations (thinking), and memory recall; and examine the changes in the power spectra to determine how they vary in young and elderly individuals.

抄録全体を表示

The morphometric anatomy of the superficial cerebral veins in relation to cerebral gyri was studied in 244 cadaveric cerebral hemispheres. Our morphometry revealed that the position of the central sulcus and that of the parieto-occipital sulcus near the superior sagittal sinus were at 55% and 83.6% respectively of the half-perimeter running from the to the occipital pole (FO) . The drainage position of the central sulcal vein (of Rolando) into the superior sagittal sinus was about 65% of the FO half-perimeter on each side. The three main drainage veins among the superficial cerebral veins are classified into four types: (1) left predominant, (2) right predominant, (3) no laterality, and (4) absent. No laterality predominance was observed regarding the superficial middle cerebral vein (of Sylvius) . The inferior anastomotic vein (of Labbe), however, was predominant on the left hemisphere. The superior anastomotic vein (of Trolard) was observed with similar frequency in each type. In conclusion, the superficial cerebral veins can be classified into eight different types according to venous drainages.

抄録全体を表示

We used dance video game (DVG) training as a mean of improving elderly's cognitive function and investigated whether the elderly with MCI could overcome the once affected cognitive function via continuous DVG training. Nine elderly participated in 6-weeks of DVG training for almost 3 months on 2015 and 2016 with 6 months break. Their cognitive ability (MoCA-J scores) and the prefrontal activity during DVG play were evaluated throughout the intervention. The cognitive ability and the performance of the DVG showed improvement especially in the elderly with MCI. The prefrontal activity showed increase through initial training of DVG and decrease at the end of the intervention, suggesting the cognitive load required for DVG play. Our results suggest that DVG is a promising intervention for elderly people with MCI to maintain their cognitive ability, and that we can utilize the prefrontal activity during DVG play to determine an appropriate difficulty of the DVG training.

抄録全体を表示

Background and Purpose: We analyzed the ability of a machine learning approach that uses diffusion tensor imaging (DTI) structural connectomes to determine lateralization of epileptogenicity in temporal lobe epilepsy (TLE).
Materials and Methods: We analyzed diffusion tensor and 3-dimensional (3D) T₁-weighted images of 44 patients with TLE (right, 15, left, 29; mean age, 33.0 ± 11.6 years) and 14 age-matched controls. We constructed a whole brain structural connectome for each subject, calculated graph theoretical network measures, and used a support vector machine (SVM) for classification among 3 groups (right TLE versus controls, left TLE versus controls, and right TLE versus left TLE) following a feature reduction process with sparse linear regression.
Results: In left TLE, we found a significant decrease in local efficiency and the clustering coefficient in several brain regions, including the left posterior cingulate gyrus, left cuneus, and both hippocampi. In right TLE, the right hippocampus showed reduced nodal degree, clustering coefficient, and local efficiency. With use of the leave-one-out cross-validation strategy, the SVM classifier achieved accuracy of 75.9 to 89.7% for right TLE versus controls, 74.4 to 86.0% for left TLE versus controls, and 72.7 to 86.4% for left TLE versus right TLE.
Conclusion: Machine learning of graph theoretical measures from the DTI structural connectome may give support to lateralization of the TLE focus. The present good discrimination between left and right TLE suggests that, with further refinement, the classifier should improve presurgical diagnostic confidence.

抄録全体を表示

Purpose: We used functional magnetic resonance imaging (fMRI) to investigate the change in brain regional activity during gum chewing when edentulous subjects switched from mandibular complete dentures to implant-supported removable overdentures.
Methods: Four edentulous patients (3 males and 1 female, aged 64 to 79 years) participated in the study. All subjects received a set of new maxillary and mandibular complete dentures (CD), followed by a maxillary complete denture and a new mandibular implant-supported removable overdentures (IOD). A 3-T fMRI scanner produced images of the regional brain activity for each subject that showed changes in the blood-oxygenation-level-dependent (BOLD) contrast in the axial orientation during gum-chewing with CD and IOD.
Results: Region-of-interest analysis showed that IOD treatment significantly suppressed chewing-induced brain activity in the prefrontal cortex. The chewing-induced brain activities in the primary sensorimotor cortex and cerebellum tended to decrease with IOD treatment, however they did not reach to significance level. There was no change in brain activity in the supplementary motor area, thalamus and insula between gum chewing with CD and IOD. Group comparison using statistical parametrical mapping further showed that, within the prefrontal cortex, the neural activity of the significantly decreased during gum-chewing with IOD when compared to that with CD (P < 0.05).
Conclusion: Despite the limitation of a small sample size, these results suggest that the gum-chewing task in elderly edentulous patients resulted in differential neural activity in the within the prefrontal cortex between the 2 prosthodontic therapies—mandibular CD and IOD.

抄録全体を表示

Remarkable progress in cognitive neuroscience has revealed the involvement of the prefrontal cortex and the orbitofrontal cortex in human working memory, but the orbitofrontal cortex is still one of the least understood regions in the human brain. To elucidate the contribution of the orbitofrontal cortex to human working memory, we studied EEG P300 activity in n-back task. We elicited early P3 around 300 ms and late P3 around 360 ms of P300 components in n-back ERP. The amplitudes of the respective peaks changed depending on the working memory load (0-back, 1-back, 2-back, 3-back). We used source analysis to evaluate the orbitofrontal cortex in P3 components. A source model was constructed with the sources seeded from fMRI meta-analysis of n-back task and additional sources in the orbitofrontal cortex and the visual cortex estimated with P100 and late P3 components in the n-back ERP. This source model had more than 99% of GOF (goodness of fit) in n-back ERP. It gave us an insight of brain activity at the positions where sources existed. Early P3 was mainly produced by the dorsolateral prefrontal cortex, the ventrolateral prefrontal cortex, the inferior parietal lobule, the medial posterior parietal and the visual cortex. Late P3 was mainly produced by the medial premotor, the lateral premotor, the and the orbitofrontal cortex. The contribution of the and the orbitofrontal cortex had peaks around 390 ms which were later than late P3 component. In this study, the method to evaluate the orbitofrontal cortex activity in n-back ERP was provided. Our results elicited the involvement of the orbitofrontal cortex in late P3 component of n-back ERP.

抄録全体を表示

Optic nerve injury or blindness after head trauma has well been known since the days of Hippocrates, and has still remained one of the serious posttaumatic sequelae. Statistically about 2% of head-injured persons suffer from the visual loss and are impelled to have limited social activites³⁾. As the victims of traffic accidents are increasing every year, the studies about this problem are urgent.
Clinical manifestations of the injury of the optic nerve have been well known. The reports of many institutions have shown almost the same results. The summaries are as follows³⁾: There is a constant mode of trauma to make an injury. It occurs frequently in motorcycle accidents. Sometimes it occurs even in trivial accidents, where impact force is not always so large. The blow is usually given to the front of the head. Symptomatologically visual loss occurs immediately after the trauma and is limited usually to the eye on the ipsilateral side to the impact and spares the eye on the contralateral side. Diagnosis is guided from the loss of direct light reflex of the affected side. The fracture of the optic canal is often visualized in X-ray studies. Surgical intervention is not fully effective.
From the pathological view point, there are so many therories as to the causative factors of the injury of the optic nerve. The fracture of the optic canal, the bleeding of the sheath of the optic nerve, and the tearing of nerve fibers are prominent among them. Fracture theory seems most attractive because the fracture of the optic canal is found in 60-90% cases in X-ray studies.
So far, these clinical and pathological data have strongly suggested that mechanical factors play an important role to cause the lesion. However, there has never been a fundamental engineering study. Therefore in this paper, mechnical studies were performed to investigate the mechanism and to clarify the threshold of the impact force of the fracture of the optic canal, which is thought to be closely relevent to the ipsilateral optic nerve injury. The studies were made up of series of experiments.

抄録全体を表示

A series of children with Leigh's disease had normal hepatic pyruvate carboxylase activity, increased cerebral thiamine diphosphate, and decreased cerebral thiamine triphosphate. These thiamine esters were normal in liver. The author suggests that the histologic changes of Leigh's disease, as well as the similar changes of Wernicke's disease, could be due to a deficiency of cerebral thiamine triphosphate.

抄録全体を表示

This paper indicates the influence of evaluating impression task on cerebral activity. Conventional studies have asked subjects to evaluate impression given by stimulus to analyze the relationship between feeling impression and brain activity. But, there is possibility that the data about this activity acquired in such the experimental design is influenced by executing evaluating task. We surveyed this influence by comparing cerebral activity of subjects evaluating politeness of customer service actions and subjects not evaluating. Result showed that the concentration of oxidized hemoglobin in blood flow at near the

was increased every time subjects evaluate impression. On the other hand, there is not tendency like this in case of subjects not evaluating. The is reported that this region is associated with thinking back on making the decision by the study using monkey. It means that the data of brain activity acquired in the experimental design which subjects have to evaluate impression might be inadequate to analyze relationship between feeling impression and brain activity precisely. This paper suggests that subjects must not be given evaluation task or removal of noise caused by task from the data is need, if you analyze brain activity reacting to given impression.

抄録全体を表示

Animals including human beings get some information around them through sensory organs. However the sensory organs are never given the feedback of the information analyzed in the brain. We, human beings, actually see and feel the outside world.Accordingly, human beings need to see and feel it somewhere in the brain. The mechanism and place to see and feel the surroundings should be needed somewhere in the brain. The fact that BA10 is developed before the development of the areas behind BA10 such as BA9, 45, 46 and 47 sounds mysterious for some brain scientists. If something like a screen exists around BA10 and the frontal association area works in order to make the screen function, BA10 ought to develop before the areas behind it. Because the areas behind BA10 need the screen so as to be completed.

抄録全体を表示

1. Adult rats (Wistar King A) were used, thirty-seven animals for recording antidromic cortical responses, five for observation of the motor effect of cortical stimulation and three for histological sections of the cerebral cortex.
2. Electrical stimuli were applied to the medullary pyramidal tract in slightly anesthetized rats and the potential changes were recorded at the cortical surface and from various depths of the cortex.
3. The resultant responses of the cortex consisted of an initial sharp positive wave (P I) followed by a secondary small positive wave (P II) and a slow negative wave (N). The P I had the lowest threshold to medullary pyramid stimulation and most faithfully followed the increase in frequency of stimulation up to a frequency of 300/sec.
4. The distribution of the potential changes at various points of the cortical surface evoked with submaximal stimulation to the medullary pyramidal tract was measured. The maximal potential was recorded at a point 6.0 mm anterior from the line connecting the both ears and 3.0 mm lateral from the midline. The amplitude of the waves gradually decreased in the frontal direction from the maximal responsive point, and in the occipital direction it rapidly decreased to an immeasurably small level. The potential at the was about one sixth of the maximum. In a lateral direction, the amplitude at a point 2.0 mm lateral from the midline was slightly small than at 3.0 mm and the amplitude both at 1.0 and 4.0 mm was about a half of that at 3.0 mm.
5. The distribution of the antidromic cortical response coincided fairly well with the histological distribution of the pyramidal cell in the cerebral cortex of the rat.
6. Recording from the depths of the cortex, the P I changed its polarity into a negative deflection at about 2.0 mm below the pial surface and the P II changed into a negative potential at a depth of about 1.5 mm. The N decreased to zero and sometimes seemed to reverse into a very small positive wave at about 1.5 mm below the surface.
7. The above results suggest that the P I corresponds to antidromic impulses which invaded the large pyramidal cells in the deeper cortical layers with axons of faster conduction velocity and that the P II is composed of the antidromic impulses of the pyramidal neurons in the more superficial layers with axons of slower conduction velocity. It is considered that the N might represent the potentials of the apical dendrites of pyramidal cells conducting toward. the pial surface.
8. The studies of cortical hemisphere stimulation reveal that the functional motor area occupies a part a little anterior to a location of the antidromic cortical response and the pyramidal cells.
9. The functional significance of the pyramidal tract in the rat was discussed.

抄録全体を表示

In this study, the mechanism of cerebral contusion was investigated using finite element analysis. A finite element human head model was constructed and used to simulate of 9 real-world fatal cerebral contusion accident cases. In these simulations, the impact velocities of the impact objects were estimated on the basis of the available information such as the regions of skull fracture and cerebral contusion. The pressure fluctuations inside the skull and the input force durations in each case were obtained using these simulations. These results show that in case of coup contusion, a negative pressure occurs on the impact side and is directly correlated with short force durations. In contrast, in case of contrecoup contusion, negative pressure occurs on the opposite side of impact and is directly correlated with long force durations. As the result, coup contusions are caused when the input force durations are short, contrecoup contusions are caused when the input force durations are long.

抄録全体を表示

In a complex and changing environment, the validity of rules or goals might change in terms of their associated reward and cost, and we often face the necessity to make a strategic decision to adaptively shift between these behavioral rules or goals.　Such a decision entails assessment of the value (cost and benefit) of current and alternative rules or reward resources for the individual, and also for the group, in socially advanced species.　Cognitive abilities such as flexibility in adapting to a changing environment and adaptive foraging to seek a better environment might depend on such cognitive functions that enable a thorough assessment of the value of different options and a proper and timely decision to choose the most appropriate goal.　A distributed neural network involving prefrontal and medial frontal cortices regulates the use of cognitive resources to optimize exploitation of current reward resources, while minimizing the associated cost.　This is referred to as executive control of goal directed behavior.　Recent studies suggest that dorsolateral prefrontal, orbitofrontal and anterior cingulate cortices are involved in optimizing the exploitation of the current reward sources however, the most rostral part of the prefrontal cortex (frontopolar cortex) plays a crucial role in adjusting the tendency for exploitation, versus exploration of other alternative resources, by assessing the value of alternative tasks/goals and re-distribution of our cognitive resources.　Maintaining a proper balance between exploitation and exploration tendencies might be a fundamental cognitive ability necessary for foraging behavior and cognitive flexibility in adapting to environmental demands.

抄録全体を表示

We measured the lengths of some parts of the right and left hemispheres (HEs) in 70 formalin-fixed brains and on 15 computed tomography/magnetic resonance imaging (CT/MRI) images (7 left-handed and 8 right-handed cases) to clarify the morphological changes indicating which HE developed earlier and handedness. In many cases of the fixed brains, 1) the distance from the

to the occipital pole was longer in the left HE than in the right HE, 2) the distance from the middle plane to the lateral-most portion of the HE was wider in the right HE than in the left HE, 3) the left occipital pole elongated more posteriorly and covered the right occipital pole, and 4) the volume of each HE was nearly the same. The results indicate that the left HE develops and grows slightly earlier in the larger semi-cranium (half of the cranium) than the right HE which develops later in the smaller semi-cranium. The whole brain was more spherical in the female cases than in the male cases. The morphological changes in both HEs for handedness were not evident on the CT/MRI images.

抄録全体を表示

Purpose : To determine the reproducibility of corrected quantitative cerebral blood flow (qCBF) through measurement of transit flow time using multi-delay three-dimensional pseudo-continuous arterial spin labeling (pCASL) in healthy men and women and to evaluate the differences in qCBF between not only men and women, but also the follicular and luteal phases of the women’s menstrual cycle. Methods : The participants were 16 healthy volunteers (8 men and 8 women ; mean age, 25.3 years). Two MRI were conducted for all participants ; female participants were conducted in the follicular and luteal phases. The reproducibility of qCBF values was evaluated by the intraclass correlation coefficient (ICC) and differences between the two groups were estimated by voxel-based morphometry (VBM) analysis. Results : The qCBF values were lower in men than in women, and those in females were significantly different between the follicular and luteal phases (P < 0.05). In VBM analysis, the qCBF values of the lower frontal lobes were significantly higher in women than in men (P < 0.05). The qCBF values of the

were significantly higher in the follicular phase than in the luteal phase (P < 0.01). Conclusion : Multi-delay pCASL can reveal physiological and sex differences in cerebral perfusion. J. Med. Invest. 67 : 321-327, August, 2020

抄録全体を表示