not exclusively restricted to the eyes-closed condition (Mulholland 1965) and an extremely large body of psychophysical literature spanning several decades has shown that α activity is inseparably linked to a host of perceptual and cognitive phenomena (Lindsley 1952; Lansing 1957; Anliker 1963, 1966; VanRullen and Koch 2003). For example, α rhythm frequency is robustly correlated with both reaction time (Surwillo 1961) and perceived simultaneity (Kristofferson 1967) and α activity is strongly linked with various aspects of long term memory (Klimesch 1996, 1999).
