Electroencephalographic Changes after Eye Opening and Visual Stimulation *

In 1930 Berger2 reported that visual stimulation by opening of the eyes in a lighted room blocked the occipital brain waves, while opening of the eyes in a dark room did not alter the occipital rhythm. The effect of visual stimulation on the so-called alpha rhythm was subsequently described by many authors, including Adrian and Matthews,' Fischer,4 Gibbs and Gibbs,5 Golla, Hutton, and Walter,7 Jasper and Cruikshank,8 Loomis,"1 Rheinberger and Jasper,'5 Rubin and Cohen,1" Travis,"7 and Williams.20 Adrian and Matthews' believed that "patterned vision" (i.e., differentiated perception of objects) blocked the occipital cortical activity and thus disorganized the occipital electrical discharges. Jasper and Cruikshank8 pointed to the increase in frequency of the waves after stimulation with light but mentioned that sometimes the opening of the eyes in the dark was also effective. Golla, Hutton, and Walter,7 after observations on 60 subjects, related alpha rhythm to visual imagery. Persons who showed no alpha rhythm with eyes open or closed have predominant visual imagery (M for minus type). Persons with predominantly kinesthetic and auditory imagery have alpha rhythm with eyes open and closed (P for permanent type). Between these extremes are those in whom closing of the eyes would produce alpha rhythm and who were able to make use of their visual images (R for responsive type). Berger,2 Gibbs and Gibbs,5 Travis and Hall,'8 Travis,'7 and Williams20 showed that not only visual stimulation but other procedures, which stimulated the attention of the subject, result in a change of the occipital rhythm. Loomis" noted that eye opening in a blind person did not result in any change. Lemere'0 claimed that no change of the alpha rhythm occurred in blind persons after visual stimulation while changes could be observed in all patients with alpha rhythm in malingered or hysterical blindness. In the present study, the effect of various methods of eye opening and closing in relation to visual stimulation were observed in