Eye movements in kyudo archers: Saito 1994 study

Two researchers at Keio University fitted an eye tracker to five people shooting the Japanese bow, to see where the gaze goes in the seconds before the release. Four were students from the university kyudo club, all with more than six years of practice; the fifth was a student with no experience at all. Each was asked to imagine a competition, take up the bow and hold kai, the full-draw aiming position, for five seconds, repeating the sequence four times.

The beginner and the experienced archers behaved differently. In the beginner the gaze stayed fixed on the target from beginning to end, before the draw, during it and after it. In the four experienced archers the gaze was on the target before they began to draw, then moved down and to the right, giving a distribution of fixation points across two levels instead of one. The shift happened during the draw, at the moment when the body takes the force of the bow, and so together with the act of lowering the breath that accompanies the draw in kyudo.

How the gaze moved varied from one experienced archer to another, but in each of them it stayed almost identical across the four repetitions, and the point where the gaze came to rest was practically the same every time. The authors take this to mean that each archer may have their own patch of retina on which they get a steadier fixation, and they suggest that the experienced archers, rather than looking at the target with central vision, take it in peripherally so as to hold the gaze still through the long moment of aiming. They write this with explicit caution: confirming it would take further experiments, and their discussion, they say, does not go beyond conjecture.

Eye movements were recorded with a Talk Eye, a head-worn eye tracker made by Takei Kiki Kogyo. There were five participants: four male students from the Keio shooting club, all with at least six years of practice, and one complete beginner. Before starting they were instructed to behave as they would in a real competition.

The measurement covered the stretch running up to just before the release, that is, up to the state in which the archer is holding the target under his eyes. Each participant performed the full sequence four times: taking up the bow, drawing, and holding kai for five seconds.

The analysis divides the sequence into three phases: before the draw begins, during the draw, and after the draw has finished. For each participant the authors plot the shift in mean fixation position between the first and third phases, and in a second figure the distribution of fixation points across the whole sequence. The comparison between the beginner and the experienced archers is made by looking at those two figures: there are no numerical measures in the text, no statistics and no scores.

This is a two-page conference communication rather than a full paper, and it reads like one. It reports no figures at all: there is no telling how many degrees the gaze moved, how long the shift took, or how much it varied between the four experienced archers. Everything that can be said comes from reading two graphs.

The sample is four experienced archers and one beginner, all male students from the same club, so there is no beginner group but a single person, and the comparison between experience and inexperience rests on one individual. The repetitions number four each. The text does not say what distance was shot, whether the target was a mato or a makiwara, or whether arrows were actually released, since the measurement stopped just before the release.

No variable of the shot itself was recorded: there are no scores and no points of impact, so the link between the shift in gaze and the outcome falls outside the study. The central interpretation, that the experienced archers use peripheral vision and that practice develops the peripheral retina, is stated by the authors themselves as a hypothesis needing confirmatory experiments. The paper is in Japanese, with only the title and names in English, and the venue does not involve peer review.

For someone who shoots, the value of this work lies in a simple observation: the four experienced practitioners did not look at the target the way the beginner did, and the change happened during the draw, not after it. The beginner kept his eyes on the centre throughout, and they did not.

It has to be read for what it is, though. Kyudo has an old teaching, yuki no metsuke, which says to fix the centre of the target with the right eye and not to blink until the arrow has gone, and the authors set out precisely from curiosity about whether archers actually follow it. They found that they do not, at least not literally, and they found it in four people without measuring anything quantitative.

The peripheral vision hypothesis is not a technical instruction and the authors do not offer it as one: they say more work is needed to support it. What holds up best is the individual repeatability, the fact that each of the four traced almost the same path with his gaze in all four trials, with a different path for each person. For anyone recording themselves with an eye tracker it suggests what to look at: not a correct pattern of gaze, but the consistency of their own.