fixationrelated

Fixationrelated refers to brain activity linked to eye fixations during visual tasks, most commonly studied as fixation-related potentials (FRPs). FRPs are EEG-derived signals time-locked to fixation onset while participants view natural scenes, read text, or perform visual search. This approach complements traditional stimulus-locked ERP methods by capturing neural processing in more ecologically valid, free-viewing conditions.

In practice, researchers record EEG together with precise eye-tracking, detect fixation onsets, and segment EEG data around those events. Because fixations occur in rapid succession, FRPs often overlap in time and can be contaminated by saccade-related activity. Consequently, analysis frequently employs deconvolution or regression-based techniques to separate overlapping neural responses and to control for confounds such as fixation duration, saccade amplitude, pupil size, luminance, and viewing distance.

FRPs can reveal a range of neural components. An early posterior positivity known as the lambda response occurs around fixation onset and reflects initial visual processing. Later components may reflect higher-level processing, including face or scene recognition, reading-related processing, or semantic integration, depending on the task and stimuli. The interpretation of FRPs benefits from considering oculomotor influences and the overlap of successive fixations.

Applications of fixation-related approaches span reading, scene perception, face processing, and visual search. They offer ecological validity and insights into real-time neural dynamics during natural viewing, but require careful methodological handling, large data sets, and advanced analytical methods to address overlapping activity and oculomotor artifacts.

Terminology often uses fixation-related potentials or fixation-related brain responses; some sources refer to FRPs generically, while others prefer the unhyphenated form fixationrelated.