Related Experiment Videos
Speed perception is affected by the Ebbinghaus-Titchener illusion
1Institut für Medizinische Psychologie und Verhaltensneurobiologie, MEG-Zentrum, Eberhard-Karls-Universität Tübingen, Gartenstrasse 29, D 72074 Tübingen, Germany. marina.pavlova@uni-tuebingen.de
Perception
|February 28, 2001
Summary
The apparent size of motion influences how fast we perceive objects moving. Larger apparent motion frames lead to slower perceived speeds, a phenomenon observed across various stimulus speeds.
Area of Science:
- Visual perception
- Psychophysics
- Motion perception
Background:
- The Ebbinghaus illusion demonstrates how surrounding context affects perceived size.
- Previous research suggests context can influence visual perception, but its effect on motion speed is less understood.
Purpose of the Study:
- To investigate if the apparent extent of visual motion impacts perceived speed.
- To determine the relationship between the size of inducing elements and perceived motion speed.
Main Methods:
- Participants viewed a dot moving within a central circle surrounded by either small or large inducing elements (Ebbinghaus configuration).
- Observers then adjusted the speed of a dot moving in isolation to match the perceived speed of the first stimulus.
- This was repeated for various actual stimulus speeds (1.3, 2.1, and 5.5 degrees per second).
Main Results:
- The perceived speed of the moving dot was consistently lower when presented with large inducing circles compared to small ones.
- This effect was observed across all tested stimulus speeds.
- Matched speeds were systematically less with larger apparent motion frames.
Conclusions:
- Perceived speed is dependent on the apparent extent of motion.
- Larger apparent motion frames result in slower perceived speeds, consistent with transposition effects in visual motion.
- Contextual size, as demonstrated by the Ebbinghaus configuration, modulates motion speed perception.