In the pulse-step model, which statement describes the step component?

• A. It maintains the eye in a new position after movement.
• B. It initiates movement.
• C. It determines velocity.
• D. It terminates movement.

Answer: (A)

In the pulse-step model, movement starts with a pulse: a brief, high-frequency burst that drives the eye quickly by delivering a strong motor command. After the eye has moved, a step signal remains as a sustained, lower-level innervation to hold the eye in that new position. So the step component is the holding signal that maintains the relocated eye position, resisting the elastic pull and keeping gaze stable. It isn’t responsible for starting movement (that’s the pulse), nor does it set velocity (that’s tied to the pulse’s characteristics), and while movement ends when the pulse ceases, the step’s role is specifically to maintain the final position.