The relation of decision time to brain wave frequency and to age

Strong evidence was obtained for the proposition that subjects with slow brain waves require more time to decide between two alternatives than subjects with fast brain waves, suggesting that EEG frequency is the factor behind the age-associated drop in information capacity of the central nervous system.

Abstract

An experiment was performed to determine whether the time taken to decide between two alternatives is related to period of the EEG. In addition, the relation of decision time to subject's age was investigated, and the role of EEG period in this relationship was determined. Simple reaction time and disjunctive reaction time, in which the subject was required to respond to only one of two alternative stimuli, were determined for 54 subjects ranging in age from 34–92 years. EEGs were recorded, and for both tasks the average period of the EEG was determined from the tracings obtained in the interval of time between stimulus and response. Strong evidence was obtained for the proposition that subjects with slow brain waves require more time to decide between two alternatives than subjects with fast brain waves. This finding was discussed with reference to information theory, and it was concluded that the information capacity of the central nervous system is a function of EEG period. A low but statistically significant positive correlation was found between decision time and age. This correlation completely vanished when brain wave period was partialled out, suggesting that EEG frequency is the factor behind the age-associated drop in information capacity of the central nervous system.