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Related Experiment Video

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Quantification of Visual Feature Selectivity of the Optokinetic Reflex in Mice

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Published on: June 23, 2023

Perceived spatial frequency of sinusoidal gratings.

Marco Zeppieri¹, Shaban Demirel, Kyle Kent

¹Discoveries in Sight, Devers Eye Institute, Legacy Health System, Portland, Oregon, USA. markzeppieri@hotmail.com

Optometry and Vision Science : Official Publication of the American Academy of Optometry

|May 3, 2008

Summary

The frequency-doubling illusion

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Area of Science:

Visual perception
Neuroscience
Psychophysics

Background:

The frequency-doubling effect describes the illusion where grating spatial frequency appears doubled.
This occurs when low spatial frequency gratings are flickered at high temporal frequencies.

Purpose of the Study:

To investigate how apparent spatial frequency changes with different spatiotemporal content.
To examine these changes after equalizing stimuli for detectability.

Main Methods:

Determined contrast thresholds for various spatiotemporal gratings.
Evaluated perceived spatial frequency at multiples of detection threshold.
Used matching tasks to compare stationary and flickered gratings.

Main Results:

Observed fractional match ratios for many spatiotemporal combinations.
Apparent spatial frequency varied, sometimes exceeding double the veridical frequency.
Task instructions had a small but significant effect on match ratios.

Conclusions:

Fractional spatial frequency percepts challenge the sole involvement of Y-type magnocellular cells.
Suggests a more complex neural basis for the frequency-doubling illusion.