electrooculograph

What Is an Electrooculograph?

An electrooculograph (EOG) records electrical activity from eye movements using electrodes near the eyes. It captures voltage changes from the corneoretinal potential — a natural voltage difference between front and back of the eye. In deception research, EOGs have been explored both as potential deception indicators and as artefact correction tools for EEG-based measurements.

Deception Detection Applications

Research has investigated whether systematic eye movement patterns carry diagnostic information about deception. The Oculomotor Deception Test uses eye-tracking to assess deceptive behaviour. These approaches remain primarily in research and are distinct from standard polygraph testing. Lateral eye movements, fixation duration, and pupillary responses have all been studied as potential indicators, but none has been validated as a standalone detection method.

Artefact Correction Role

In EEG-based deception research using ERPs, eye movements produce electrical artefacts contaminating brain signals. EOG recordings identify and subtract these artefacts, improving signal quality for P300 and other analyses. This correction function is essential for obtaining clean ERP data.

Relationship to Standard Polygraph

EOG is not a standard polygraph component. The three core channels — electrodermal, respiratory, and cardiovascular — provide the validated data for diagnostic opinions. However, some examiners note eye behaviour during behavioural observation as supplementary information, and the closed-eyes technique eliminates eye movement artefacts from the testing environment entirely.