Changes in hemoglobin concentration in the lateral occipital regions during shape recognition: a near-infrared spectroscopy study.
ABSTRACT By using near-infrared spectroscopy (NIRS), we measured the changes in the oxygenated and deoxygenated hemoglobin (oxy-Hb and deoxy-Hb, respectively) concentrations while performing visual tasks. We conducted experiments using two tasks: a shape recognition task and a position recognition task. It was found that the oxy-Hb concentration was substantially higher in the lateral occipital regions during shape recognition than during position recognition. The changes in the oxy-Hb concentration were considered to reflect the activation difference between the two tasks. No difference was observed in the oxy-Hb concentration during the memorization of shape and memorization of position. The deoxy-Hb concentration was different between the two tasks only when different stimuli were used but not when identical stimuli were used. In addition, it was suggested that the deoxy-Hb concentration is more sensitive to activation difference between the hemispheres and the activation at some regions. Measurements of the oxy-Hb and deoxy-Hb concentrations would reflect different aspects of cortical activations. The present results showed that measuring the oxy-Hb and deoxy-Hb concentrations separately can differentiate the activation of the regional cortical functions.
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ABSTRACT: Surgical robot has been considerable improvement in recent years, but their intuitive operability, representing user interoperability, has yet to be quantitatively evaluated. Thus, we propose a method for measuring brain activity to determine intuitive operability so as to design a robot with intuitive operability. The objective of this paper is to determine the angle and radius between the endoscope and the manipulator that allows users to perceive the manipulator as part of their body. In the experiments, subjects moved the hand controller to position the tip of the virtual slave manipulator on the target in the surgical simulator, measured the brain activity through brain imaging devices. The experiment was carried out a number of times with the virtual slave manipulator configured in a variety of ways. The results show that brain activation is significantly greater with a particular slave manipulator configuration. It concludes that the hand–eye coordination between the body image and the robot should be closely matched in the design of a robot with intuitive operability.SCIS-ISIS 2012; 11/2012
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ABSTRACT: Surgical robots have undergone considerable improve-ment in recent years. But intuitive operability, which represents user interoperability, has not been quanti-tatively evaluated. With the aim of designing a robot with intuitive operability, we thus propose a method for measuring brain activity to determine intuitive op-erability. The purpose of this paper is to clarify the master configuration against the position of the mon-itor that best allows user to perceive the manipulator as part of his own body. We assume that the master configuration provides immersive reality to user as if he puts own arm into the monitor. In our experiments, subjects controlled the hand controller to position the tip of the virtual slave manipulator on a target in the surgical simulator and we measured brain activity us-ing brain imaging devices. We carried out experiments a number of times with the master manipulator config-ured in a variety of ways and the position of the mon-itor fixed. We found that the brain was significantly activated in all subjects when the master manipulator was located behind the monitor. We concluded that the master configuration produces immersive reality through body images related to visual and somatic sen-sory feedback.Journal of Robotics and Mechatronics. 25(1):162-171.
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ABSTRACT: A cross-modal association between somatosensory tactile sensation and parietal and occipital activities during Braille reading was initially discovered in tests with blind subjects, with sighted and blindfolded healthy subjects used as controls. However, the neural background of oral stereognosis remains unclear. In the present study, we investigated whether the parietal and occipital cortices are activated during shape discrimination by the mouth using functional near-infrared spectroscopy (fNIRS). Following presentation of the test piece shape, a sham discrimination trial without the test pieces induced posterior parietal lobe (BA7), extrastriate cortex (BA18, BA19), and striate cortex (BA17) activation as compared with the rest session, while shape discrimination of the test pieces markedly activated those areas as compared with the rest session. Furthermore, shape discrimination of the test pieces specifically activated the posterior parietal cortex (precuneus/BA7), extrastriate cortex (BA18, 19), and striate cortex (BA17), as compared with sham sessions without a test piece. We concluded that oral tactile sensation is recognized through tactile/visual cross-modal substrates in the parietal and occipital cortices during shape discrimination by the mouth.PLoS ONE 01/2014; 9(10):e108685. · 3.53 Impact Factor