Archers' brains while aiming: Kim 2014 study

Forty people simulated aiming in a functional MRI scanner: 12 Olympic-level archers (all women, mean age 33.5, 17.83 years of archery, medallists at the Olympics, Asian Games or World Championships), 14 university archers (6 men and 8 women, aged 22.9, 11.9 years of archery) and 14 people who had never shot (7 men and 7 women, aged 26.4). Facing a target sized as one at 70 metres, they had to imagine the whole shot and press a button at the moment they felt ready and imagined the release. The analysis looks at exactly that instant.

Within each group, the Olympic-level archers activated the supplementary motor area and the primary motor cortex, temporoparietal and somatosensory areas, the thalamus, the basal ganglia, the anterior cingulate and the dentate nucleus of the cerebellum. The university archers mainly activated the dorsolateral premotor cortex, the precuneus, temporoparietal and temporo-occipital areas, the secondary visual cortex and the cerebellum. The beginners activated a wider set, including frontal areas, the ventrolateral premotor cortex and the anterior cingulate.

Between groups, the Olympic-level archers showed more activity than the others in the supplementary motor area, the middle frontal cortex, the temporoparietal areas and the cerebellum; the university archers only in the right temporoparietal area and the right somatosensory cortex; the beginners in many frontal areas, the posterior cingulate, the basal ganglia and the cerebellum. In the two archer groups the change in cerebellar signal correlated with best score (r = 0.544, p = 0.006). The scores given are 342 out of 360 for the Olympic-level archers and 320 for the university archers.

Before the scan the participants practised on a laptop. In the scanner they had to go through the six phases of the shot in their mind (bow hold, draw, full draw, aim, release, follow-through) and press the button with the right hand, as quickly as possible within 10 seconds, when they felt ready and imagined letting go of the string; the press started the next trial. There were 18 trials, about 3 minutes in all. The target was a photograph projected through goggles at the apparent size of one at 70 metres. After the scan everyone said they had aimed, not just looked.

The scanner was a 3 tesla GE EXCITE with an eight-element head coil, with 60 volumes of 31 slices of 4 millimetres. The analysis, in SPM5, is locked to the instant of the button press, with no control condition, and leaves out what happens before and after. The group maps use a threshold of p < 0.05 corrected for multiple comparisons; the comparison of the three groups is an analysis of covariance with age as a covariate, at a corrected p < 0.005. The authors repeated it without covariates and by splitting the Olympic-level group at random into two halves, with the same results. No measure of performance on the task was collected.

The beginners had never shot: they were imagining a movement they did not know, so the difference from the archers is also about being able to imagine the shot, not only about shooting well. The Olympic-level archers were all women and older than the others; the authors repeated the comparison with and without age and sex as covariates and report that it did not change, but the details are only in the supplementary material.

The correlation with score combines two different measures, best score at a national competition for the Olympic-level archers and best score in training for the university archers, and with two groups so far apart (342 against 320) it may reflect the difference between groups rather than a relationship along a scale. There are only 18 trials, with no control condition. The paper's abstract says the only region active in the university archers was the superior frontal one, while the results speak of the right temporoparietal area and the right somatosensory cortex. The differences between Olympic-level and university archers run against the idea of neural efficiency (more activity in the former), and the authors acknowledge it. The anterior cingulate, which in the same group's 2008 study was active only in the experts, here appears in the Olympic-level archers and the beginners but not in the university archers.

The most useful point for anyone who shoots concerns a common idea, that of the champion who switches the mind off at the moment of the shot. In this study the Olympic-level archers, at the instant they imagined the release, had more activity than good university archers in motor planning areas and the cerebellum, not less. Compared with the beginners their brains were more selective; compared with the university archers, they were not. The picture of a silent brain is therefore too simple.

The link between the cerebellum and score is interesting, since the cerebellum has to do with the coordination and timing of movement, but with these measures and these groups it is a weak lead. The study gives no guidance on training: it describes differences between levels during an imagined shot, lying in a scanner, without knowing how those arrows would have gone.