Electroencephalographic Analysis in Communication Science: Testing Two Competing Models of Message Production

Abstract

Electroencephalographic (EEG) analysis allows measurement of electrical activity in bundles of neurons around electrodes placed at various locations on the scalp. In this essay, we provide an overview of the biological basis of EEG methodology and outline basic principles and practices of data collection. We conducted a study using EEG to test expectations from two competing cognitive theories of communication—computational theory and dynamic memory theory. Participants (N = 30) were assigned to one of two conditions—routine talk and direction-giving. EEG was used to measure the electrical activity in the dorsolateral prefrontal cortex (DLPFC), an area of the brain that is associated with message production. Results indicated that DLPFC activity was far more suggestive of dynamic memory theory. Specifically, electrical activity in the DLPFC was significantly lower during routine talk than during direction-giving. We discuss the implications of our findings and the limitations of EEG methods in communication research.

Notes

¹ There may be a subtle difference between small talk and routine talk in the context of two strangers meeting for the first time and talking about topics that spontaneously emerge during initial conversations and conditions in which participants are given specific topics to discuss. That is, in a naturally occurring situation, the conversational goal might be different from the goal of simply discussing topics. We instructed participants to discuss specific topics, which were evaluated as non-novel topics by students, to exert experimental control. Testing the hypothesis that DLPFC differences exist between novel conditions and those in which knowledge structures are supposed to be retrieved requires that we prevent novel topics from emerging in the routine talk condition. Whether subtle differences in conversational goals associated with small talk and routine talk in general would influence the results we reported is a matter for future research.

² It should be noted that there is also a subtle difference between giving directions to a specific location such as the zoo, and giving directions multiple times because initial attempts were misunderstood by the conversational partner. In the direction-giving research, cognitive load was imposed by manipulating plan failure (Berger, Knowlton, & Abrahams, 1996; Knowlton & Berger, 1997). Indeed, previous EEG research (Beatty & Heisel, 2007) has already demonstrated that devising alternative plans in the face of plan failure results in increased DLPFC activation. Our induction check indicated that giving directions to a specific location that the participants had not previously given was perceived by those participants as a comparatively novel communication task, which increased DLPFC activation. Overall, direction-giving in itself appears to impose substantial cognitive load even without feedback indicating that the directions were misunderstood.