What is real motion?
Actual movement of an object.
What is apparent motion?
Perceived motion from rapidly presented static images (e.g., movies, animations).
What is induced motion?
When the movement of one part of a scene makes another appear to move.
What is motion after-effect?
After viewing motion in one direction, stationary objects appear to move in the opposite direction.
What is biological motion?
Motion represented by finite points of light. (e.g., point-light displays of walking figures).
How is motion defined?
Change in position over time.
How does a motion detector work?
It detects motion by comparing activation between adjacent receptive fields over time.
What is the Reichardt motion detector?
Model that detects motion by comparing delayed input from one receptor with instantaneous input from another (Reichardt, 1961).
What is a local motion detector?
Neural circuit detecting motion in a small, localized visual region, tuned for direction and speed.
What is direction tuning?
Motion detectors respond maximally to their preferred direction and less to other directions.
What is the aperture problem?
When viewing motion through a limited window, the direction of movement becomes ambiguous.
How is the aperture problem solved?
Global motion detectors combine multiple local motion signals to compute true motion direction.
Which brain area processes global motion?
Area MT (middle temporal area).
What is self-motion?
Movement of the observer that generates optic flow across the retina.
What is the focus of expansion (FOE)?
The point in optic flow indicating the observer’s direction of movement.
What is optic flow?
Pattern of apparent motion of the visual world on the retina during self-motion.
What are the types of eye movements?
Fixation, saccades, smooth pursuit, vergence, and nystagmus.
What are fixation and microsaccades?
Fixation maintains gaze on a point; microsaccades are small involuntary movements that prevent fading.
What are saccades?
Rapid eye movements that shift gaze between targets.
What is smooth pursuit?
Slow tracking of a moving object to keep its image stable on the retina.
What is vergence?
Eyes move inward (convergence) or outward (divergence) to focus on near or far objects.
What is nystagmus?
Repetitive, involuntary eye movement involving a slow tracking phase and quick reset phase.
How many muscles control the eyes?
Six, organized in three pairs.
What do the medial and lateral rectus muscles control?
Horizontal eye movements (side to side).
