Brain-science study of the effects of psychological variation on human motor skill

2006 Fiscal Year Final Research Report Summary

• Project/Area Number: 16300206
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Sports science
• Research Institution: The University of Tokyo
• Principal Investigator: OHTSUKI Tatsuyuki The University of Tokyo, Department of Life Sciences, Professor, 大学院・総合文化研究科, 教授 (30093553)
• Co-Investigator(Kenkyū-buntansha): KUDO Kazutoshi The University of Tokyo, Department of Life Sciences, Assistant Professor, 大学院・総合文化研究科, 助手 (30302813) ; MURAKOSHI Takayuki The University of Tokyo, Department of Life Sciences, Associate Professor, 大学院・総合文化研究科, 助教授 (60190906)
• Project Period (FY): 2004 – 2006
• Keywords: psychological pressure / task demand / psychological variation / anxiety / fMRI / Go / NoGo task / coincident timing / motor skill

Research Abstract

This project investigated the effects of psychological variation such as stage fright, psychological pressure, anxiety about failure and modification of kinesthetic sensation on the physiological variables and performance accuracy.
In the first study, immediately before the task movement with standard load, the same movement with the different load from standard was performed. When this previous load was higher (lower) than the standard, subjects felt the standard load became smaller (larger) and the movement became faster (slower), and the agonist EMG and movement speed actually increased (decreased).
In the second study, subjects caught a moving visual target at the designated position on the display. When the task demand was intensified by telling subjects that the points won by them were nullified if they failed to meet the predetermined criterion, anxiety level and force error increased with a decrease in timing error. An fMRI study revealed that the activity of amygdala and the sup plementary motor area increased in the high-demand trials. It indicates that the enhanced psychological pressure and anxiety disturb the working memory of time in the prefrontal cortex, so that the attention to time increases and instead the attentional resource to control force decreases.
In the third study, the influence of task demand on the accuracy of judgment and quickness of reaction was examined by using Go/NoGo task. Anxiety, HR, rate of failure and EMG increased by giving failure-avoidance pressure, while antagonists' cocontraction, HR and MSR (mental sweating response) increased by giving special award if preset target score was obtained. An fMRI study revealed enhanced ACC activity in subjects who increased rate of failure and increased anxiety, while in subjects who improved performance the prefrontal activity related to inhibition of error reaction increased. From these results, in the visual judgment task, high task demand affects the brain activity responsible for stimulus cognition and motor programming.