Time-of-day preference, pattern evoked potentials, and hemispheric asymmetries: a preliminary statement.

Summary 7 "Morning-type" and "6 Evening-type" individuals were subjected to pattern reversal steady-state Event-related Potentials (ERPs) recording to obtain data with respect to time of day, diurnal typology, and hemispheric asymmetries. A significant interaction between these factors suggested a model of hemispheric functioning much more complex than suspected.