Brain Waves

Does the study of brain waves help us distinguish experts from novices, and can brain waves be altered to improve performance?
Four types of brain wave have been identified. Alpha waves (8 – 14 Hz) are seen when we are relaxed, daydreaming or visualising. Increases in alpha waves are often associated with reduced overall activity of the brain. Beta waves (15 – 38 Hz) are associated with conscious thought, with higher frequency beta being associated with anxiety or stress. Gamma and delta waves are mostly seen in different stages of sleep.
Neurofeedback, also known as EEG biofeedback, is a strategy to enable people to alter their own brainwaves. It has been used in the treatment of ADHD (Attention-deficit hyperactivity disorder). Often the patient is using a videogame that’s linked to their EEG, and the aim is usually to increase beta waves and reduce theta waves. When the desired effect is taking place, they get some kind of encouragement in the game, such as beep or a character moving in the desired direction.
Neurofeedback has also been used to improve the balance of patients who have suffered brain injury or stroke. Significant improvements have been found after just 8 – 10 sessions, whereas ADHD treatments usually take 40 – 50 sessions.
Before trying neurofeedback to improve sporting ability, one would need to know if experts demonstrate different brainwave activity compared with lesser players. And there is actually some evidence for that. It’s hard to play rugby or football when attached to the electrodes of EEG equipment, so most of the evidence comes from aiming sports, such as archery, shooting and golf putting.
Haufler et al (2000) found that during aiming, when marksmen were compared with novice shooters, marksmen exhibited less activation (increased alpha with less beta and gamma activity) at all electrode sites on the head, but especially in the left hemisphere. Kerick et al (2001) looked at skilled marksmen during shooting. Over an 8-second period preceding the pull of the trigger, they exhibited greater alpha activity in the left temporal area compared with when they were doing a control activity. Hatfield et al (1984) also found a progressive increase in alpha power in the left temporal area during the last 7.5 seconds of aiming, with no change in the right temporal area.
These results could fit in with the idea that the left hemisphere dominates in language, and that a lot of verbal thoughts could inhibit efficient sporting performance.
Landers et al (1991) used neurofeedback to try and improve the performance of pre-elite archers. On the basis that reduced cortical activity in the left hemisphere (associated with increased alpha waves and reduced beta waves) would increase accuracy, the archers were randomly assigned to one of three groups. One group was given “correct” feedback (reduced left hemisphere activity), another “incorrect” feedback (reduced right hemisphere activity), and a control with no feedback.
They found that those trained to have reduced left temporal activity showed a significant improvement in performance, whilst those trained to have reduced right temporal activity showed a significantly worse performance. The control group showed no change.
However, there’s a problem. Examination of the participants’ EEG spectra failed to show a clear pattern of change after the test compared with beforehand. It’s as if the feedback changed something, but not what it was supposed to.
Also, the link between brain waves and sport performance turns out not to be as simple as first thought. For instance, Del Percio et al (2007) found a correlation between a reduction in alpha output in part of the right hemisphere and skilled karate performance. In contrast, Collins et al (1990) found that skilled karate performance was linked to a bilateral increase in alpha output.
Crews & Landers (1994) found that in the last second before a golf putt, increased alpha waves in the right hemisphere were associated with increased putting accuracy. This is in contrast with the increase in the left hemisphere that had been found in shooting and archery. Looking at putting novices, however, Shelley-Trembley et al (2006) found that lower beta levels in the right hemisphere correlated with accuracy.
So it seems that we need to understand brain waves rather better before we can be sure that trying to change them will improve performance. Oh well, back to practise then.

David

www.donneroptometrists.co.uk