Monday, August 4, 2014

Alpha waves

Alpha waves

Alpha waves are neural oscillations in the frequency range of 7.5-12.5 Hz arising from synchronous and coherent (in phase or constructive) electrical activity of thalamic pacemaker cells in humans. They are also called Berger's wave in memory of the founder of EEG.

Alpha waves are one type of brain waves detected either by electroencephalography (EEG) or magnetoencephalography (MEG) and predominantly originate from the occipital lobe during wakeful relaxation with closed eyes. Alpha waves are reduced with open eyes, drowsiness and sleep. Historically, they were thought to represent the activity of the visual cortex in an idle state. More recent papers have argued that they inhibit areas of the cortex not in use, or alternatively that they play an active role in network coordination and communication. Occipital alpha waves during periods of eyes closed are the strongest EEG brain signals.

An alpha-like variant called mu (μ) can be found over the motor cortex (central scalp) that is reduced with movement, or the intention to move. Alpha waves do not start to appear until three years of age.

Biofeedback training

Given the alpha wave's connection with relaxed mental states, many people have latched onto the idea of utilizing this state through a technique called biofeedback training. This technique utilizes EEG to indicate to a subject or trainer when the subject is in an alpha wave state, which the subject is then instructed to remain in.

There are several different prospects of this training that are currently being explored. Arguably, the most popular one is the use of this training in meditation. Zen-trained meditation masters produce noticeably more alpha waves during meditation. This fact has led to a popular trend of biofeedback training programs for everyday stress relief.

Psychologists are hoping to use this technique to help people overcome phobias, calm down hyperactive children, and help children with stuttering problems to relax enough to practice regular speech.

There are other uses of biofeedback training beyond therapy. Defense Department researchers are exploring biofeedback as a way of getting captured soldiers to create alpha waves, potentially foiling enemy lie detectors. Biofeedback training has also been receiving attention as a possible way of monitoring attention. It has been theorized that teaching machines could use biofeedback as a way of monitoring children's attention, with the appearance of alpha waves signaling a lapse of attention.

Following this lapse-of-attention line of thought, a recent study indicates that alpha waves may be used to predict mistakes. In it, MEGs measured increases of up to 25% in alpha brain wave activity before mistakes occurred. This study used common sense: alpha waves indicate idleness, and mistakes are often made when a person is doing something automatically, or "on auto-pilot", and not paying attention to the task they are performing. After the mistake was noticed by the subject, there was a decrease in alpha waves as the subject began paying more attention. This study hopes to promote the use of wireless EEG technology on employees in high-risk fields, such as air traffic controlling, to monitor alpha wave activity and gauge the attention level of the employee.

Alpha waves for restoration and concentracion