Table of Contents
What is smooth pursuit eye tracking?
Smooth pursuit movements are much slower tracking movements of the eyes designed to keep a moving stimulus on the fovea. Such movements are under voluntary control in the sense that the observer can choose whether or not to track a moving stimulus (Figure 20.5).
What causes abnormal smooth pursuit?
Abstract. Smooth pursuit eye movement (SPEM) abnormalities are commonly seen in Parkinson’s disease (PD). Both reduced speed and saccades seen during SPEM, also known as saccadic pursuit (SP), have been studied in PD. A comprehensive literature review analyzed 26 studies of SPEM and PD.
What is a pursuit eye movement?
Smooth pursuit eye movements (SPEMs) are tracking eye movements used to stabilize the image of a moving object of interest on the fovea.
How do smooth pursuit eye movements help us perceive moving objects?
During tracking of a moving object, smooth pursuit eye movements (pursuit for short) are used to reduce motion blur by minimizing the object movement on the retina.
What is deficient smooth pursuit eye movement?
A deficiency of smooth pursuit means that the eyes do not follow a moving target with the appropriate speed and/or accuracy. For example, the eyes may have trouble “keeping up” with the target (i.e. a low pursuit gain).
What is pursuit eye movement?
The eyes move smoothly instead of in jumps. They are called pursuit because this type of eye movement is made when the eyes follow an object. Therefore, to make a pursuit movement, look at your forefinger, at arms length and then move your arm left and right while fixating your finger tip.
Which part of the cortex detects motion so that a pursuit movement can be initiated?
A region of cortex in the frontal lobe, known as the frontal pursuit area, responds to particular vectors of pursuit, and can be electrically stimulated to induce pursuit movements. Recent evidence suggests that the superior colliculus also responds during smooth pursuit eye movement.
How do you know if you have a lack of smooth pursuit?
Lack of smooth pursuit is present when the eyes move in a jagged motion like a dry windshield wiper moving over a dry windshield. The officer assesses two clues if he sees lack of smooth pursuit in each eye. The second test to detect nystagmus is called Distinct Nystagmus at Maximum Deviation.
How can I improve my visual tracking?
Activities to promote eye tracking:
- Complete puzzles.
- Draw or paint pictures.
- Find as many things as you can see of a certain shape (circle, square, rectangle, triangle) in the room.
- Imitate a series of motor movements made by someone else.
- Perform dot-to-dot pictures.
What causes VGN?
The presence of this type of nystagmus is associated with a high dose of a CNS Depressant (including alcohol), an Inhalant, or a Dissociative Anesthetic in a particular individual. The drugs which cause VGN also cause HGN. VGN will not be present without HGN.
How can I improve my smooth pursuit?
Activities to improve visual pursuits
- Relaxing breathing eye stretches- This visual tracking activity is a way to work on smooth pursuits in a very mindful way.
- Flashlight Tag- Use a flashlight to help kids follow a target in various directions.