健常成人の摂食中の上肢動作に対する視線の関与―～スプーンで摂食するジュース量の違いからの検討～

Contribution to the visual axis by upper extremity motion during eating in healthy humans: Examining varying amounts of juice on a spoon while eating

要旨：本研究の目的は，摂食中の上肢動作に対する視線の関与を明らかにすることであった．方法は，被験者が異なる容量のジュースを口元へ運ぶ時，視線がスプーンボールから外れた位置（Critical Visual Point；以下，CVP），眼球からCVPまでの距離（以下，CVP距離）と所要時間を求めた．対象は健常成人20～34歳の19名とした．測定は眼球運動計測装置と，ビデオカメラを用いた．84％の被験者は容量増加によってCVP距離は変化せず，95％の被験者で所要時間は長くなった．また，増量によりCVP前の所要時間は長くなった．CVPまでの視線が，摂食動作における上肢動作の調節精度をモニターするための機能的意義を持つことを示唆する．

　This study was designed to analyze the contribution of upper extremity motion on the visual axis during eating in healthy humans. When each subject sipped various amounts of juice from a spoon, the time of their spoon movement from the plate on the surface of the table was measured along with the change of position of the visual axis from the cup and the spoon (CVP). The nineteen participating subjects (15 female, 4 male) were 20-34 years old. Exploratory eye movements were recorded using an eye-mark recorder. Eating motions were recorded from the sagittal plane using a digital video camera. In 84％ of the subjects, the distances of CVP were unchanged when the amount of juice in the spoon (spoon content) was increased. When the spoon content was increased, 95％ of the subjects exhibited an increase in spoon movement times. Spoon movement times with increased juice content were significantly longer before CVP than after CVP. Results show that spoon content did not affect CVP distance, but it affected spoon movement time. These findings suggest that CVP has functional significance for upper extremity movement velocity control during eating.