Brain of elite archers imagining a shot: Chang 2010

Using functional magnetic resonance imaging, the authors looked at which brain areas become active while people imagine shooting, comparing 18 elite Korean archers with 18 people who had never competed in archery. In the non-archers, imagining the shot lit up a wide network: primary motor cortex, premotor areas, supplementary motor area, inferior parietal cortex on both sides, left inferior frontal cortex, basal ganglia and cerebellum. In the archers, significant activation was confined to the supplementary motor area, more marked on the left.

In the direct comparison between groups, the non-archers showed greater activation in the primary motor cortex, premotor area, inferior parietal cortex, precuneus, basal ganglia and cerebellum; no area was more active in the archers. The perceived difficulty of the imagery task, measured with a questionnaire on a scale of 1 to 7, was similar: 2.45 for the non-archers and 2.37 for the archers, with no significant difference. The authors read the result as a form of economy: someone who has known the movement for years plans it with a narrower network, while the cerebellum and basal ganglia, involved in motor learning, work harder in people who do not know the movement.

The archers were 6 men and 12 women from the Korean university archery association, five of them on the national team, with more than ten years in the sport; the non-archers were 8 men and 10 women. Mean age was 27.2 years for the archers and 24.0 for the non-archers, with the same level of education; all were right-handed. Before the test everyone watched a 10-minute video on shooting and practised the task for 20 minutes.

In the scanner, with eyes closed, participants switched between two tasks on a voice cue: imagining their own shot in the first person, feeling it in the body, through six phases (bow hold, draw, full draw, aiming, release and follow-through), one cycle every 7 to 8 seconds; or imagining themselves at rest, sitting on a beach for example. Each condition was repeated four times in a session of about 4 minutes. The images, taken on a 3 tesla scanner, were analysed by comparing the imagined shot with the imagined rest, first within each group and then between groups, with a correction for multiple comparisons.

The comparison is between people imagining a movement they have made for years and people imagining a movement they have never made, after half an hour of video and practice. The difference may therefore come from familiarity with the movement rather than from a "more efficient" organisation of the brain, and the idea that a narrower network needs less energy is the authors' interpretation. Nobody can check what someone in the scanner is imagining at that moment: the authors rely on an interview after the test.

The authors themselves point out that muscle activity was not recorded during the imagery, that the control task was not a motor one and that the imposed pace of one shot every 7 to 8 seconds is not the pace of training. There is no link to scores: the archers had official scores, but the paper does not use them. The discussion mentions areas, such as the superior parietal cortex, that do not appear in the table comparing the groups. The sample is small and unbalanced by sex, and the archers' discipline is not stated.

The study does not say whether imagining the shot improves scores, or how to do it: it only describes what happens in an expert archer's brain while they picture their own shot, compared with people who do not know it. The picture fits the idea, which the authors take from studies on rifle shooting and golf, that with experience planning the movement involves fewer areas. Anyone who uses visualisation in their routine can read it as a sign that, for an expert archer, imagining the shot engages the areas that prepare the movement; it is not evidence that visualisation done in a particular way pays off more.

One caution: a "less active" brain is not something to train for. It is the result of years of practice, observed in a comparison with people who do not know the movement.