On January 26, 2022, Alex White, assistant professor of neuroscience, published new research in the Journal of Neurophysiology, alongside two co-authors. The research, titled “Oculomotor freezing indicates conscious detection free of decision bias,” examines the oculomotor system, which keeps the human eyes steady in expectation of visual events. The authors investigate “oculomotor freezing,” which is triggered only by stimuli that the observer reports seeing. The study establishes whether this event is linked to observers’ sensory experiences or their decision that a stimulus was present.
To detect a difference in oculomotor freezing occurrences, the researchers manipulated decision criterion through monetary rewards and stimulus probability in a detection task. The manipulations shifted the observer’s decision criteria but did not impact the degree to which microsaccades, or small, jerk-like, involuntary eye movements, were inhibited by presence of a stimulus. The results indicate that the sensory threshold for oculomotor freezing is independent of decision bias, causing the authors to conclude that oculomotor freezing is an implicit indicator of sensory awareness.