by April Irwin
Image courtesy Wikipedia: https://en.wikipedia.org/wiki/Event-related_potential
Tavakoli and Campbell describe ERPs as, “a change in the ongoing electrical activity of the brain associated with either an external physical stimulus or an internal psychological ‘event’” (2015, p. 89). ERP components are the positive and negative deflections that can be seen in the ERP form. Exogenous, or sensory evoked components, are sensitive to the physical properties of a stimulus while the endogenous, or cognitively evoked components, are subject to more psychological properties such as decision-making or meaningfulness. We generally know more about the sources of the exogenous components, but are still working on being able to isolate the general causes of the various endogenous components. Understanding the cultural and social contexts in which these exogenous components occur would be a great way to put this method to use in the field, especially if we’re thinking about cross-cultural anthropology. Perhaps the sociocultural context would even help us be able to isolate sources of the cognitively-evoked components as well? One point that the authors make is that isolating the sources of components can be difficult, especially when a physical property is changed during the revision of a psychological property. The authors’ focus of this paper is simply to explain how stimulus presentation and ERP data is collected, so their lack of consideration for ERPs as a cost-effective neuroscientific method that may be used outside of psychology isn’t surprising. This leaves me wondering how anthropology’s current methods would be able to help us understand how ERP components work in a more complete way.
The authors also mention that in order to be able to isolate ERP components, researchers need to describe in detail the physical characteristics and timing of the stimulus presentation as well as the participant is expected to do in response to the stimulus. These two descriptions could serve the anthropological community well in that descriptions and responses to stimuli are two things that ethnographic research does really well. One shortcoming may be in the careful timing of each stimulus presentation and the milliseconds afterwards when the ERP components are evoked.
Overall, this article describes the basics of the ERP method very well using language that can be understood across disciplines. Although there may be many challenges when attempting to incorporate this particular method into anthropological and educational research, it may be worth it just to know more about ERPs and some of the principles behind the method.
Tavakoli, P., & Campbell, K. (2015). The recording and quantification of event-related potentials: I. Stimulus presentation and data acquisition. The Quantitative Methods for Psychology, 11(2), 89–97.