Time Sense and Epileptic EEG Activity

Abstract

INTRODUCTIONPreviods experiments ( I , 2) showed that flickering light, enforcing its rhythm to the whole EEG, influences in healthy man intea-vals of conditioned reflexes to time, in specific relation to flicker frequency, accordifig to the so-called rule of octaves. It was concluded from these experiments that cerebral rhythms, especially the a-rhythm, represent apparently the reference pacemaker, the "biological pendulum'' of time sense in man, for measuring time periods in the range of seconds and minutes.It is a well known fact from human pathology that alterations of cerebral rhythms occur in various kinds of epilepsy, particularly in seizures or even subclinical paroxysms characterized by slow EEG rhythms (not mentioning true paroxysms).The problem of this paper is whether in epileptics there is a correlation between the alterations of the time sense and those of the EEG rhythms. A preliminary communication already appeared (3). METHODSIn addition to our usual laboratory procedure on a 14-channelelectroencephalograph, the patient lying at rest, with several eye openings and a hyperventilation lasting 3 4 min, simultaneous testing of time sense was performed by the method of free production of intervals. According to the instruction given in advance the patient pressed the key at regular intervals during the whole procedure. The intervals had to last about 15-20 sec, their actual duration was chosen by the patient, who had to see only to their regularity. The pressing of the key was recorded simultaneously with the EEG.No special training was performed. Up to the present our work is based on 45 records from 41 patients, among them 32 epileptics (9 children), all treated with drug combinations. RBSULTSAlthough during the examination in most records (27) several prolonged intervals occurred from time to time, obviously as nonspecific reactions, e.g. to eye opening, to instruction about hyperventilation, etc., time intervals varied quite insignificantly, Epilepsia, 3 (1962) 323-328 Epilepsia, 3 (1962) 323-328