Showing posts with label Brain Waves. Show all posts
Showing posts with label Brain Waves. Show all posts
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
Monday, 2 July 2012
Olympic Countdown - Shooting
Brain waves
Research has shown significant increases in left hemisphere alpha activity (8-12 Hz) during shot preparation of skilled marksmen (Hatfield et al 1994), and between the best and worst shots of elite archers (Salazar et al 1990).
Increases in alpha waves are often associated with a reduced overall activity of the brain. 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. The most pronounced differences were in the left central-temporal parietal areas.
Kerick et al (2001) looked at skilled marksmen during shooting. Over an eight-second period preceding the trigger pull, they exhibited greater alpha activity in the left temporal area compared with a control activity. Hatfield et al (1984) also found a progressive increase in alpha power during the last 7.5 seconds of aiming, whilst there no change in the right temporal area.
“So what?” I hear you say. Well, what if you could control your own brainwaves? This is what “EEG biofeedback” aims to do. It’s been used in the treatment of ADHD.
The procedure usually involves watching a video game, and when the desired effect occurs (such as reducing theta waves) they get an encouragement, such as a beep or a character moving in the desired direction.
Lander et al (1991) used EEG biofeedback to see if it could improve archery performance. Research shows that shooters have reduced cortical activity in the left temporal area when shooting. Experienced pre-elite male (16) and female (8) archers were randomly assigned to one of three treatment conditions. a) Correct feedback (i.e. greater left hemisphere low-frequency activity; b) incorrect feedback (i.e. greater right hemisphere low-frequency feedback, and c) no feedback control.
They found that those trained to shift the level of cortical activity towards more negativity in the left temporal region showed a significant improvement in performance, and those trained to shift the level of cortical activity towards more negative in the right temporal region showed significantly poorer performance. There was no change in the control group.
However, all is not as clear cut as it might seem. Examination of participants’ EEG spectra from pre- to post-training failed to reveal a clear pattern of change as a result of the training. So we’re not there yet. But one day it’s likely that shooters will be able to control the brainwaves to help them win gold.
David Donner
Wednesday, 11 August 2010
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
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
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