Supplementary eye field

Region of the brain involved in eye movement

Supplementary eye field

Part of	Frontal cortex
System	Visual system

The supplementary eye field (SEF) is a region of the frontal cortex in the brain that is involved in the control of eye movements. It is located in the medial frontal cortex, anterior to the supplementary motor area (SMA). The SEF plays a crucial role in the planning and execution of saccadic eye movements, which are rapid, simultaneous movements of both eyes in the same direction.

Anatomy

The SEF is situated in the medial frontal cortex, specifically in the superior frontal gyrus. It is part of the frontal eye fields (FEF) network, which also includes the lateral intraparietal area (LIP) and the superior colliculus (SC). The SEF is interconnected with these regions, as well as with the primary visual cortex (V1) and the dorsolateral prefrontal cortex (DLPFC).

Function

The primary function of the SEF is to coordinate and control voluntary eye movements. It is particularly involved in the generation of saccades, which are quick, simultaneous movements of both eyes that allow for rapid changes in the point of fixation. The SEF is also implicated in the control of smooth pursuit movements, which enable the eyes to closely follow a moving object.

Neurophysiology

Neurophysiological studies have shown that neurons in the SEF are active during the planning and execution of eye movements. These neurons exhibit activity that is related to the direction, amplitude, and velocity of saccades. The SEF is also involved in the cognitive aspects of eye movement control, such as decision-making and the suppression of unwanted saccades.

Clinical Significance

Damage to the SEF can result in deficits in eye movement control, such as difficulty in initiating saccades or in maintaining fixation. Such impairments can be observed in various neurological conditions, including stroke, Parkinson's disease, and Huntington's disease.

Research

Ongoing research is focused on understanding the precise role of the SEF in eye movement control and its interactions with other regions of the brain. Studies using techniques such as functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) are providing insights into the neural mechanisms underlying the SEF's functions.

See also

• Frontal eye fields
• Superior colliculus
• Saccade
• Smooth pursuit
• Primary visual cortex
• Dorsolateral prefrontal cortex