Guideline 2: All known sensory presentations that are intended to or may affect neural responses should be marked and annotated. Sensory presentations (including their onsets and offsets), as well as transitions between trial, performance blocks, stimulus or task condition changes, and other known or easily computed significant moments) should be given event markers. In addition to the formally designated experiment “stimuli,” dataset sensory presentations may include delivery of instructions, feedback, auxiliary stimuli including fixation points, cues, other filler images, changes in background, plus any unplanned events noted as having occurred during the recording. The role of each sensory presentation within the task and experiment, as well as a description of the sensory presentation and modality itself should be documented.

Event annotation should aim to document all that the participant experiences. At a minimum, thoughtfully detailed reporting of participant sensory experience allows analysts to regress out the influences of other sensory presentations on dynamics associated with presentations of the primary stimuli; nonlinear modes of analysis may benefit still more from this information quite possibly in ways yet undocumented.