[Purpose] The purpose of this study is to assess the influence of tool holding on brain activities during motor imagery in two tasks: imagining the movement of writing the alphabet while holding a pen and without holding the pen. [Subjects and Methods] Eleven healthy right-handed adults performed two tasks, holding a pen and not holding the pen during imagining the movement of writing the alphabet using a pen. Regions of targets were Brodmann areas 6 which were a motor-related region, 44/45 and 39/40 which taken on the role of forming the body schema. Change of the oxygenation state of hemoglobin associated with brain activity were acquired using a near-infrared spectroscopy. [Results] When using their dominant right hands, task-related increases in oxy-Hb were prominent in Brodmann areas 44/45 and 39/40 when imagining writing while actually holding the pen than when not. When using the non-dominant left hands, there were no significant differences between the two conditions in the same areas. [Conclusion] These results suggest that the tool held can be incorporated into the body schema in the motor imagery of an automated tool use task. Therefore, tool holding during motor imagery might be more effectively influence during rehabilitation.
Purpose: The purpose of this study was to investigate changes in the functional connectivity of the default mode network (DMN) in normal aging and in children with autistic spectrum disorder (ASD) by using resting-state functional magnetic resonance imaging (rsfMRI) and independent component analysis. Methods: Thirty-one healthy controls (HC) in four age groups (1-3, 4-8, 20-29, and 50-59 years) and 14 childhood ASD cases (1-8 years of age) were examined by rsfMRI echo-planar imaging on a clinical 3-T MRI scanner. Imaging of all children (1-8 years) was conducted under sedation, while adults were scanned in the awake state with eyes closed. Results: The regions of DMN functional connectivity in the bilateral inferior parietal lobule and posterior cingulate cortex were smaller in HC children than in HC adults, and smaller in the ASD group than in the HC children. Conclusion: It is possible to observe developmental and pathological changes in the DMN by rsfMRI. Reduced DMN functional connectivity in children may be a useful biomarker for ASD diagnosis. J. Med. Invest. 63: 204-208, August, 2016
Humans perceive their body posture, size, and position in space even when they do not look at their body. The ability to perceive the body correctly is essential to move accurately in space. The purpose of this review is to introduce the reader to the latest views on the role of peripheral afferent signals in the generation and alteration of perception of the body. First, the contribution of proprioceptive and cutaneous signals to perception of the body is introduced. Common methods to investigate these signals are muscle vibration, skin stretch, or electrical stimulation. These methods provide evidence that the perception of the body is flexible. Second, effects of multisensory integration on perception of the body are described. The combination of visual, tactile, proprioceptive, and auditory signals alter the perception of the body, suggesting that multiple sensory signals contribute to perception of the body. Third, the distortion of perception of the body after the loss of sensory signals is reviewed. Anesthesia or amputation of limbs, as well as experimentally-induced disintegration of sensory signals drastically alter the perception of the body. Fourth, neural mechanisms underlying the generation, or alteration, of perception of the body is described. The premotor and parietal cortices play a key role in perception of the body, as they are involved in multisensory integration. In the final section of the review, implications of the ways sensory information shapes perception of our body are discussed for athletic performance.