Monday, 5 November 2012

The A - Z of Sports Vision - Brain Waves

Millions of nerve cells in our brain are being activated all the time, which means there is electrical activity in our brain, even when we are asleep. This electrical activity can be measured by an electroencephalogram, or EEG. The combination of electrical activity causes wavelike rhythms, which are recorded by the EEG as alpha, beta, gamma or delta waves according to their frequency. Alpha waves are the prominent pattern when we are awake, but relaxed with our eyes closed, and still aware of what is happening around us. Beta waves are emitted when we are alert or under stress. They also during deep REM (Rapid Eye Movement) sleep and may be associated with recalling memories. Delta and theta waves are mostly associated with sleep. However delta waves may occur when we are really concentrating hard on a difficult mental task and theta waves can occur briefly during emotional responses to events. Gamma waves are high-frequency waves that are associated with increased mental abilities, greater awareness and feelings of happiness. We’ve already seen (Olympic Countdown – Shooting) how elite marksmen exhibit more alpha and less beta and gamma activity than novice shooters, but similar findings have been made in other sports. An overall increase in alpha wave power has been found during the time that karate experts break wooden boards (Collins et al 1990). More left hemisphere alpha power has been shown in the preparatory period before putting (Crews & Landers 1993). They also found that in the last second before the putt, increased right hemisphere alpha activity was associated with more accuracy. Babilon et al found that an increase in high frequency alpha waves in the parts of the brain that controlled fine motor movements were indicative of successful putting. And Hartfield (1984) found increased alpha activity in the left hemisphere of professional basketball players just before making a winning shot. It’s likely that these alpha states occur when sportsmen are able to clear their mind of distractions, and concentrate fully on the task in hand. There are different methods to achieve this, such as the use of music and meditation. But a simple way may be to give 100% concentration on what you can see; whether it’s the precise spot of the ball you’re about to kick, or studying the defensive alignment of the opposition so you can see threats and opportunities at the earliest stage. David Donner