• PNF and Movement
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• v.7 no.4
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• pp.45-53
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• 2009

Purpose : The purpose of this article was to review the literature on mirror neuron system with reference to its functional diversity in stroke rehabilitation.. Method : This review outlines scientific findings regarding different neurophysiological properties in mirror neurons, and discusses their involvement in process of stroke rehabilitation. Result & Conclusions : Mirror neurons were first discovered in macaque monkey. These neurons, like most neurons in F5 areas in premotor cortex, fired when an individual performs an action, as well as when he/she observes a similar action done by another individual, although originally fired only during action execution. Mirror neurons form a network for motor planning and initiating of motor action. Thus, in stroke rehabilitation based on the mirror neuron-action observation, motor imagery, observation with intent to imitate and imitation-may help activate mirror neuron system for improved outcome of physical therapy. These studies provide a scientific theoretical basis and discuss for the use of mirror neuron system as a complement to clinical physical therapy in stroke rehabilitation.

• PNF and Movement
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• v.13 no.1
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• pp.17-23
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• 2015

Purpose: This study aims to identify changes in the mirror neuron system in normal people through mu rhythm during action observation of occupation-based intervention, purposeful activity and prepare a method of intervention form of occupation using occupation and activity. Methods: TThis study aims to identify changes in the mirror neuron system in normal people through mu rhythm during action observation of occupation-based intervention, purposeful activity and prepare a method of intervention form of occupation using occupation and activity. The activation of the mirror neuron system was compaired among 3 condition by oneway ANOVA. Results: The result of analysis showed mu suppression in all conditions. Although all conditions showed mu suppression, there was no significant difference among the conditions. Conclusion: The results suggest that the mirror neuron system is activated during action observation to be able to occupational therapy but the mirror neuron system is not separately activated among the conditions.

• PNF and Movement
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• v.9 no.4
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• pp.33-40
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• 2011

Purpose : The aims of this study was to identify changes mu rhythm according to familiarity with a stimulus in people with stroke. Methods : Seventeen right-handed participants were asked to observe 2 different stimulus; a non-familiarity stimulus condition (NFSC), and a familiarity stimulus condition (FSC). Electroencephalogram (EEG) signals from electrodes on the participant's scalp were recorded during action observation. The activation of the mirror neuron system was compaired between FSC and NFSC by a paired t-test. An independent t-test was used to compare the difference between right and left hemispheres for the activation of the mirror neuron system during action observation of performing a task with the right hand. Results : The result of paired t-test showed no significantly difference between NFSC and FSC in the activation of the mirror neuron system. The Result of independent t-test also showed no significantly difference in the activation of mirror neuron system between the right and left hemispheres. Conclusion : The familiarity with a stimulus had no signigicant effect on the activation of the mirror neuron system according to the familiarity and in either the right or left hemispheres in people with chronic stroke.

• Journal of the Korean Society of Physical Medicine
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• v.6 no.3
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• pp.361-368
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• 2011

Purpose : The aims of this study was to identify the activation of the mirror neuron system during action observation in people with stroke and the difference between left hemisphere and right hemisphere and to provide possibility of the use of action observation as a clinical method for improving motor function after stroke. Methods : Seventeen participants were asked to observe 3 different stimulation conditions for 80 seconds. A 30 second rest period was given between stimulations. Electroencephalogram(EEG) signals from electrodes on the participant's scalp were recorded during action observation. The activation of the mirror neuron system(MNS) between the picture observation condition and action observation condition was compared with a paired t-test. An independent t-test was used to compare difference between C3 and C4 on the activation of the mirror neuron system in the action observation condition. Results : Result of paired t-test showed a significantly decreased log ratio in the activation of the mirror neuron system in the action observation condition compared to the picture observation condition. Result of the independent t-test indicated no significant differences in the activation of the mirror neuron system in the right and left hemisphere. Conclusion : The mirror neuron system showed greater activation in the action observation condition than in the picture observation condition and activation in the both hemisphere during action observation. We conclude that these findings suggest that this may possibly be an efficient clinical intervention method for improving motor function.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.6
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• pp.565-570
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• 2013

The mirror neuron regions which are distributed in cortical area handled a functionality of intention recognition on the basis of imitative learning of an observed action which is acquired from visual-information of a goal-directed action. In this paper an automated intention recognition system is proposed by applying computational model of mirror neuron system to the human-robot interaction system. The computational model of mirror neuron system is designed by using dynamic neural networks which have model input which includes sequential feature vector set from the behaviors from the target object and actor and produce results as a form of motor data which can be used to perform the corresponding intentional action through the imitative learning and estimation procedures of the proposed computational model. The intention recognition framework is designed by a system which has a model input from KINECT sensor and has a model output by calculating the corresponding motor data within a virtual robot simulation environment on the basis of intention-related scenario with the limited experimental space and specified target object.

• PNF and Movement
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• v.13 no.4
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• pp.175-180
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• 2015

Purpose: This study aimed to examine the effects of mirror-neuron-system-based action observation physical training on improvements in upper extremity functions and daily living activities in chronic stroke patients. Methods: Ten chronic stroke patients were randomly selected. As a therapeutic intervention, along with conventional occupational therapy, the patients engaged in action observation physical training through repeated imitation practices after they viewed a video. The therapeutic intervention was implemented for 20 minutes, three times each week for eight weeks. A Manual Function Test (MFT) was conducted to compare upper extremity functions before and after the therapeutic intervention, and the Modified Barthel Index (MBI) was used to compare the ability to perform daily living activities. Results: Significant improvements in upper extremity motor functions and the ability to perform daily living activities were shown after the intervention. The subjects' left upper extremity motor functions and ability to perform daily living activities showed significant improvement after the intervention. Conclusion: The study's results indicate that action observation physical training based on the mirror neuron system improves chronic stroke patients' upper extremity motor functions and their ability to perform daily living activities. Therefore, action observation training has positive effects on the functional recovery of chronic stroke patients.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.6
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• pp.606-611
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• 2014

The understanding of another's behavior is a fundamental cognitive ability for primates including humans. Recent neuro-physiological studies suggested that there is a direct matching algorithm from visual observation onto an individual's own motor repertories for interpreting cognitive ability. The mirror neurons are known as core regions and are handled as a functionality of intent recognition on the basis of imitative learning of an observed action which is acquired from visual-information of a goal-directed action. In this paper, we addressed previous works used to model the function and mechanisms of mirror neurons and proposed a computational model of a mirror neuron system which can be used in human-robot interaction environments. The major focus of the computation model is the reproduction of an individual's motor repertory with different embodiments. The model's aim is the design of a continuous process which combines sensory evidence, prior task knowledge and a goal-directed matching of action observation and execution. We also propose a biologically inspired plausible equation model.

• Journal of KIISE
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• v.42 no.3
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• pp.320-327
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• 2015

Although service robots in various fields are being commercialized, most of them have problems that depend on explicit commands by users and have difficulty to generate robust reactions of the robot in the unstable condition using insufficient sensor data. To solve these problems, we modeled mirror neuron and theory of mind systems, and applied them to a robot agent to show the usefulness. In order to implement quick and intuitive response of the mirror neuron, the proposed intention-response model utilized behavior selection networks considering external stimuli and a goal, and in order to perform reactions based on the long-term action plan of theory of mind system, we planned behaviors of the sub-goal unit using a hierarchical task network planning, and controled behavior selection network modules. Experiments with various scenarios revealed that appropriate reactions were generated according to external stimuli.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.5
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• pp.537-542
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• 2011

A mirror neuron is a neuron fires both when an animal acts and when the animal observes the same action performed by another. We propose a method of 3D reconstruction for occluded object motion tracking like Mirror Neuron System to fire in hidden condition. For modeling system that intention recognition through fire effect like Mirror Neuron System, we calculate depth information using stereo image from a stereo camera and reconstruct three dimension data. Movement direction of object is estimated by optical flow with three-dimensional image data created by three dimension reconstruction. For three dimension reconstruction that enables tracing occluded part, first, picture data was get by stereo camera. Result of optical flow is made be robust to noise by the kalman filter estimation algorithm. Image data is saved as history from reconstructed three dimension image through motion tracking of object. When whole or some part of object is disappeared form stereo camera by other objects, it is restored to bring image date form history of saved past image and track motion of object.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.3
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• pp.365-373
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• 2015

We propose a simple and compact thyristor-based neuron circuit. The thyristor exhibits bi-stable characteristics that can mimic the action potential of the biological neuron, when it is switched between its OFF-state and ON-state with the help of assist circuit. In addition, a method of inter-neuron connection with synaptic devices is proposed, using double current mirror circuit. The circuit utilizes both short-term and long-term plasticity of the synaptic devices by flowing current through them and transferring it to the post-synaptic neuron. The double current mirror circuit is capable of shielding the pre-synaptic neuron from the post synaptic-neuron while transferring the signal through it, maintaining the synaptic conductance unaffected by the change in the input voltage of the post-synaptic neuron.