Masahiro Hirai

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In order to clarify the neural dynamics involved in the perception of biological motion, we recorded event-related potentials from 12 subjects. The subjects were shown biological motion or scrambled motion as a control stimulus. In the scrambled motion, each point had the same velocity vector as in the biological motion, but the initial starting positions(More)
The purpose of this study was to measure event-related potentials (ERPs) to clarify how attention affects neural activity during the visual perception of biological motion (BM). Thirteen healthy subjects observed BM or scrambled motion (SM). For SM, each point had the same velocity vector as in BM, but the initial starting positions were randomized. Each BM(More)
To investigate developmental changes in the neural responses to a biological motion stimulus, we measured event-related potentials (ERPs) in 50 children aged from 7 to 14 years, and 10 adults. Two kinds of visual stimuli were presented: a point-light walker (PLW) stimulus and a scrambled point-light walker (sPLW) stimulus as a control. The sPLW stimulus had(More)
To clarify the dynamical processing aspect of biological motion (BM) perception from a developmental point of view, we measured event-related potentials (ERPs) in 8-month-old infants during the perception of BM or a scrambled motion (SM; randomization of BM's spatial structure). We found that activation of the right hemisphere in 8-month-old infants was(More)
Primary somatosensory cortex (SI) and posterior parietal cortex (PPC) are activated by noxious stimulation. In neurophysiological studies using magnetoencephalography (MEG), however, it has been difficult to separate the activity in SI from that in PPC following stimulation of the upper limb, since the hand area of SI is very close to PPC. Therefore, we(More)
The presence of information in a visual display does not guarantee its use by the visual system. Studies of inversion effects in both face recognition and biological-motion perception have shown that the same information may be used by observers when it is presented in an upright display but not used when the display is inverted. In our study, we tested the(More)
We investigated how the spatiotemporal structure of animations of biological motion (BM) affects brain activity. We measured event-related potentials (ERPs) during the perception of BM under four conditions: normal spatial and temporal structure; scrambled spatial and normal temporal structure; normal spatial and scrambled temporal structure; and scrambled(More)
Do we perceive humanoid robots as human beings? Recent neuroimaging studies have reported similarity in the neural processing of human and robot actions in the superior temporal sulcus area but a differential neural response in the premotor area. These studies suggest that the neural activity of the occipitotemporal region would not be affected by(More)
To investigate the neural response to detection of biological motion (BM) surrounded by distractors, event-related potentials (ERPs) were recorded. Scrambled motion with the same velocity vector as the BM but randomized initial starting points was used as the distractor. The number of distractors was varied to control the difficulty of the task. The(More)