Gestures of the face have a relatively limited presence in scholarly gesture discourses. The use of facial movements as intentional communication has been historically undermined in facial behavior research. The face has been primarily studied as expressions of emotion, traditionally theorized as involuntary signs of internal affective states. Emotion expressions are differentiated from facial movements that serve conversational functions in face-to-face dialogue. The facial gestures presented in this chapter illustrate the flexibility and diversity of meanings conveyed by facial communicative actions. Gestures can refer to affective events not present in the immediate here and now, communicate understanding of another individual’s affective experience, and convey information about a target referent. Other facial gestures have counterparts in hand gestures with similar pragmatic and semantic functions. The study of facial gestural components of linguistic communicative events is important to the construction of a comprehensive model of language.

Montages are specific arrangements of channels; a channel is a pair of electrodes. Waveforms result from cerebral potentials; each montage allows the reader to appreciate the same waveform through a distinct point of view. Bipolar montages consist of channels with adjacent electrode pairs. Referential montages consist of channels with nonadjacent electrode pairs. One electrode is located closer to the cerebral activity (active), while the other is intended as a distant reference (inactive). Common bipolar montages include the longitudinal bipolar (double banana) and transverse bipolar. Common referential montages include contralateral and ipsilateral ear reference, central reference (vertex), or average reference. Bipolar montages are less prone to artifact and best appreciate focal potentials. Referential montages are more prone to artifact and best appreciate broad or generalized potentials. An active reference results when the reference which is intended to be neutral is very active. The reader must use both types of montages to evaluate the same waveform. Digital displays make it easy to switch between montages.