The human visual system averages speed information
Related Experiment Video
Updated: Oct 21, 2026

VisualEyes: A Modular Software System for Oculomotor Experimentation
Published on: March 25, 2011
1Northwestern University, Department of Psychology, Evanston, IL 60208.
Abstract:
It has been known for many years that human observers are unable to detect modest accelerations and decelerations in moving visual stimuli. We find that human observers can integrate speeds over many dots, moving at different speeds, producing a global speed percept analogous to the global direction percept first reported by Williams, D. W. and Sekuler, R. (1984, Vision Research, 24, 55-62). We measured speed discrimination for random dot stimuli which contained many different speeds. Our results show that observers always base their discrimination on the mean speed of the stimulus; changes in other stimulus characteristics (e.g. mode) are not detected. Moreover, discrimination thresholds for the global mean speed derived from many different speeds are comparable to those obtained with stimuli in which all dots move at the same speed suggesting that the internal noise associated with the encoding of speed information is quite high.
More Related Videos
06:46Investigating the Deployment of Visual Attention Before Accurate and Averaging Saccades via Eye Tracking and Assessment of Visual Sensitivity
Published on: March 18, 2019
09:27Eye Movements in Visual Duration Perception: Disentangling Stimulus from Time in Predecisional Processes
Published on: January 19, 2024
Related Concept Videos
Vision
Average Velocity
Average and Instantaneous Velocity Vectors
Visual System
Once through the pupil, the light passes through the lens, a...
Parallel Processing
Velocity of an Object