In horizontal gaze examination, his smooth pursuit was replaced by microsaccades
and his eyes were unable to perform convergence.
Even in normal adult vision, small eye drifts and microsaccades
prevent Troxler fading of high spatial frequencies.
When volunteers' rates of microsaccades
slowed down, the visual illusion faded and the snakes were more likely to stop moving.
Right before the snakes appeared to move, participants tended to produce blinks, saccades and/or microsaccades
, and right before the snakes stopped, participants' eyes tended to remain stable, researchers including Jorge Otero-Millan, Stephen Macknik and Martinez-Conde reported.
Software engineering topics include modeling V1 as a spatial frequency analyzer, the mathematics of image processing with irregularly sampled data, the relationship between super-resolution techniques and the eye movements known as tremor and microsaccades
, eye vergence and depth perception as they pertain to a robotic assisted surgery application, and motion detection algorithms.
The group's study, titled "Distinctive Features of Saccadic Intrusions and Microsaccades
in Progressive Supranuclear Palsy," used eye tracking to study eye movement abnormalities in the disease, which is often misdiagnosed as Parkinson's disease.
The results of the study showed that the rate of microsaccades - tiny, jerk-like fixational eye movements - dramatically increased when participants found Waldo.
The role of microsaccades in visual perception has been a highly debated, and vaguely understood topic among researchers, since long.
And now the findings may help explain the correlation between microsaccades and search behaviour, both in the normal brain, and in brains with visual or eye movement deficits.
Susana Martinez-Conde, who led the study at the Barrow Neurological Institute in Phoenix, came to this conclusion after testing the effect of the involuntary jerks of the eyes, scientifically known as microsaccades.
Accounting for the reaction time required to press the button, the researchers found that the illusion became more pronounced when microsaccades were happening at a faster rate.
However, that study did not take into account the effect of microsaccades because the contact lenses do not keep pace with the eye during such rapid, jerky movements.