Related Experiment Video
Updated: Jun 28, 2026
14:38
Creating Objects and Object Categories for Studying Perception and Perceptual Learning
Published on: November 2, 2012
Outlined objects in a Mach pattern create illusions: further evidence of a frequency code for size.
Ted Jaeger1, Stephen Long, Jessica Lang
1Department of Psychology, 501 Westminster Avenue, Westminster College, Fulton, MO 65251, USA. Ted.Jaeger@westminster-mo.edu
Perceptual and Motor Skills
|November 7, 2008
Summary
New visual illusions demonstrate how object size perception is distorted by Mach patterns. Objects at inflection points appear smaller on the
Area of Science:
- Visual Perception
- Neuroscience
- Psychophysics
Background:
- Mach patterns are known to influence visual perception.
- Previous research has explored size illusions, but novel stimuli are needed.
Purpose of the Study:
- To create and investigate new size illusions using Mach patterns.
- To understand how object size is perceived within these patterns.
Main Methods:
- Experiments utilized stimuli composed of everyday objects (trees, pens, etc.) arranged in Mach patterns.
- Participants judged the size of objects at specific points within the patterns.
- Isolated objects were compared to objects within Mach stimuli.
Main Results:
- Objects at the inflection point of Mach patterns were perceived as smallest on the 'small' side and largest on the 'large' side.
- Pens and otoscopes at the 'small' side of the pattern were underestimated, while those on the 'large' side were overestimated.
- These illusions are comparable to existing Mach lines illusions.
Conclusions:
- Size illusions can be induced by Mach patterns with complex objects.
- The findings suggest that visual neurons encode object size via response frequency.
- These illusions provide insights into the neural mechanisms of size perception.
Related Concept Videos
01:06Fixed Action Patterns
A fixed action pattern (FAP) is a specific, hard-wired sequence of behaviors that occurs in response to an external stimulus, called a sign stimulus. The behavior is “fixed” because it is essentially unchangeable—proceeding similarly across individuals of a species every time it occurs.
02:19Morphogenesis
Plant morphogenesis—the development of a plant’s form and structure—involves several overlapping developmental processes, including growth and cell differentiation. Precursor cells differentiate into specific cell types, which are organized into the tissues and organ systems that make up the functional plant.
01:21Plastic Deformations of Members with a Single Plane of Symmetry
When a structural member undergoes plastic deformation due to bending, it is crucial to understand the position of the neutral axis and the stress distribution. This member, characterized by a single plane of symmetry, exhibits a uniform stress distribution, with negative stress above the neutral axis and positive stress below. Notably, the neutral axis does not align with the centroid of the cross-section. This misalignment is typical in cases where the cross-section is not rectangular or...