Related Experiment Video
Updated: Oct 6, 2026

Investigating the Deployment of Visual Attention Before Accurate and Averaging Saccades via Eye Tracking and Assessment of Visual Sensitivity
Published on: March 18, 2019
The influence of stimulus shape on orientation acuity
D W Heeley1, H M Buchanan-Smith
1School of Psychology, University of St. Andrews, Scotland, UK. dwh@st-and.ac.uk
Abstract:
Orientation acuity was estimated for vertical and oblique bar stimuli. Discrimination thresholds were affected by changes in the length and width of the targets, falling as bar length was increased and, conversely, rising as the bars were made wider. These changes are complimentary, in that overall discrimination performance can be predicted by a single measure of the orientation "entropy" of the target, namely the height-to-width ratio. The data provide support for a model of orientation coding where discrimination performance is not simply a reflection of the signal-to-noise ratio in single cells in the striate cortex.
Related Concept Videos
Vision
Anatomy of the Eyeball
Gestalt Principles of Perception
Factors Affecting Perception
An illustrative example of a perceptual set is the scenario where an airline pilot told...

