Electrophysiological (QEEG) Correlates of Effective Reading: Towards a Generator/Activation Theory of the Mind

Resumen

Introduction. An investigation into the relationships between Quantitative EEG (QEEG) and memory scores for reading material was conducted employing 38 normal subjects. Method. There were three conditions during which QEEG data was collected: (a) subject reading a story silently, (b) subject engaging in an immediate recall period, followed by subject’s oral recall, and (c) delayed recall assessment, followed by the same methodology of quiet recall and subsequent oral recall. The reading and recall performances were correlated with QEEG variables. Generator patterns were determined as a set of significant phase or coherence relationships, which all emanate from one location. The concept of emanate is an assumption based, in part, on previous literature of generator patterns and on the statistical need to reduce the number of variables. Degrees of activation values were determined as the differences in QEEG variables between two conditions (a relevant condition and the task condition). For the reading condition, a visual attention task served as the relevant condition, while for the recall tasks, the eyes closed served as the relevant control condition. Results. During the input (reading) condition absolute levels of F7 beta generator and T5 coherence alpha generator activity were associated with higher memory scores. Degree of activation (visual attention vs. reading) values indicated significant relationships (increased activation positively correlated with recall) between recall and eight generator patterns (coherence) in the alpha range. Immediate recall was positively associated with absolute levels of generator activity (coherence beta2, 32 to 64 Hz) from the F4 location and with the absolute level of activations in the theta frequency predominantly at frontal locations. Degree of activation (from eyes closed) analysis indicated that increased memory scores were associated with activations in the theta frequency range in diffuse locations, activations of beta frequencies at posterior locations and generator activity predominantly in the beta2 frequency from right hemisphere locations. Higher long-term recall was associated with higher absolute levels of generator activity (alpha set at .10) from right frontal locations and frontal theta activity. The higher the degree of activation (from eyes closed) of posterior beta activity and beta generator activity from several sites, the higher the long-term memory score. Discussion. The results provide a new perspective on brain functioning, which cannot be accounted for by any present day theories of brain functioning.