<p>Asymmetry is a reflection of a power differential in the brain. Asymmetry can be reflective of pathology.&nbsp; Alpha asymmetry has been studied in diagnosis of pathology. In right-handed individuals, alpha is typically higher in amplitude in the right hemisphere.&nbsp; However, when alpha frequency is slower by 1 Hz or more in one hemisphere, its can indicate a focal abnormality (Markand, 1990) warranting a neurological consult (Duffy, et al., 1989).&nbsp; Likewise, an amplitude difference in alpha between the two sides of more than 50% is considered significant (Hughes, 1994), and because in normal people alpha rhythm is usually of higher amplitude on the right side, a decrease of even 35% on the right may be significant (Duffy et al., 1989).&nbsp; Focal lesions may cause alpha to be disorganized ipsilaterally, to be of lower or higher amplitude, and may cause alpha to fail partially or totally to block following eye opening on the affected side.&nbsp; But, “in the absence of other findings, one should use caution in interpreting isolated amplitude asymmetry of the alpha rhythm, because amplitude asymmetries of the order as high as 2:3 are not uncommon in normal subjects” (Markand, 1990, p. 181, emphasis added).<br></p>