Primary process cognition and hemispheric asymmetry

Several theorists have hypothesized that the right hemisphere operates in a primary process manner, whereas the left hemisphere operates in a secondary process manner. Evidence for this hypothesis, though supportive, has been indirect. In two experiments, we applied a validated content-analytic measure of primary process cognition to verbal material produced by subjects while right-hemisphere and left-hemisphere alpha-wave amplitude was monitored. Both experiments indicated that amount of primary process content in language is related to basal or long-term hemispheric asymmetry (high levels of right-hemisphere activation, as compared to left-hemisphere activation), and that the relation with asymmetry is stronger than that with absolute levels of either right-hemisphere or left-hemisphere activation. Both experiments showed that primary process content is not closely related to momentary asymmetry. The second experiment indicated that within subjects, momentary asymmetry is in fact weakly related to primary process content in the direction opposite to that predicted.