Advanced
Technical
IVT
pursuit initiation
The early phase of smooth pursuit eye movements when the eyes begin to track a moving target.
Full Definition
Pursuit initiation refers to the first 100-200 milliseconds of smooth pursuit eye movement when the oculomotor system begins tracking a moving visual target. This phase involves rapid acceleration of the eyes to match target velocity and requires intact function of cortical pursuit areas, particularly the middle temporal visual area (MT/V5) and medial superior temporal area. Abnormalities in pursuit initiation can indicate specific cortical or cerebellar dysfunction and are assessed during comprehensive neuro-ophthalmological examination of eye movement disorders.
Usage
Usage note: Distinct from pursuit maintenance, which involves sustained tracking.
In Context
- "The patient showed impaired pursuit initiation with normal pursuit maintenance, suggesting cortical involvement." — eye movement laboratory report
- "Pursuit initiation deficits were bilateral and symmetric following the parietal lobe lesion." — neuro-ophthalmology consultation
Also known as
pursuit onset
smooth pursuit initiation
Don't confuse with
saccadic initiation
optokinetic response