Journal of the Society of Biomechanisms
Print ISSN : 0285-0885
Search
Advanced search
OR
Browse
Search
Volume 31, Issue 4
Displaying 1-9 of 9 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
Reviews
Papers
  • Pupil Dilation during Learning of Sensorimotor Transformation
    Satoshi KOBORI
    2007 Volume 31 Issue 4 Pages 206-213
    Published: 2007
    Released on J-STAGE: March 02, 2009
    DOIhttps://doi.org/10.3951/sobim.31.206
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    We used visuomotor tracking as our motor task, and measured tracking performance and pupil dilation simultaneously. We have used pupil dilation as a measure of cognitive load. The diameter of the human pupil increases with task dif.culty across a wide range of cognitive tasks. Tracking trials were of 2 types, non-inverted and inverted. In inverted trials, the relation between joystick movement and subject visual cursor movement was inverted at an unpredictable time during the trial. This task requires learning a novel sensorimotor transformation. Subjects observed a circular target which moved sinusoidally across a computer screen in a horizontal direction. Subjects held a modi.ed joystick in their right hand, and moved it so that a visual cross hair cursor tracked the target as closely as possible. 12 normal subjects participated in the experiment. During 6 blocks of learning, subjects learned the task when tracking unpredictably inverted. Tracking inversion evoked pupil dilation, and the pupil dilation decreased with learning signi.cantly. Pupil measures were not correlated with tracking error on individual trials, suggesting that the inversion-evoked cognitive load re.ects changes in motor task, and is not merely a response to high errors.
    View full abstract
    Download PDF (1322K)
Short_Paper
  • Acoustic characteristics improvement of PZT ceramic sounder for sound source of artificial larynx
    Yuichi SUGIO, Ryota KANETAKE, Katsutoshi OOE
    2007 Volume 31 Issue 4 Pages 214-217
    Published: 2007
    Released on J-STAGE: March 02, 2009
    DOIhttps://doi.org/10.3951/sobim.31.214
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    We aimed to develop an easy-to-use artificial larynx with high tone quality. We focused on using a piezo speaker as the sound source because it is small, consumes less power, and is harmless to humans. Conventional piezo speakers are problematic in that they cannot generate enough sounds in the low-frequency range; thus, they cannot be used in artificial larynges. Therefore, we aimed to develop piezo speakers generating enough volume in the low-frequency range. If the resonance frequency of the speaker is lowered, it can easily generate low-pitch sounds. Therefore, we have created new diaphragms with low resonance frequency. Here, we report on the characteristic comparison of this piezo speaker. In fact, we analyzed the optimization of its structure by using finite element method computer simulations and fast Fourier transformation analysis of the generated sounds. By the result of computer simulation, we confirmed that the stiffness of the diaphragm was adjusted, and the resonance frequency was able to be lowered. By the result of analysis of the sound generated by the piezo speaker using the diaphragm, we confirmed that the resonance frequency was able to be lowered too.
    View full abstract
    Download PDF (1604K)
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top