Abstract
The visual system can adapt to optical blur, whereby the adapted image is perceived as sharp. Here we show that adaptation reduces blur-induced biases in shape perception, with repeated adaptations (perceptual learning), leading to unbiased perception upon re-exposure to blur. Observers wore a cylindrical lens of +1.00. D on one eye, thus simulating monocular astigmatism. The other eye was either masked with a translucent blurred lens (monocular) or unmasked (dichoptic). Adaptation was tested in several repeated sessions with a proximity-grouping task, using horizontally or vertically arranged dot-arrays, without feedback, before, after, and throughout the adaptation period. A robust bias in global-orientation judgment was observed with the lens, in accordance with the blur axes. After the observer wore the lens for 2. h, there was no significant change in the bias, but after 4. h, the monocular condition, but not the dichoptic, resulted in reduced bias. The adaptation effect of the monocular 4-h adaptation was preserved, and even improved, when the lens was re-applied the next day, indicating learning. After-effects were observed under all experimental conditions except for the 4-h monocular condition, where learning took place. We suggest that, with long experience, adaptation is transferred to a long-term memory that can be instantly engaged when blur is re-applied, or disengaged when blur is removed, thus leaving no after-effects. The comparison between the monocular and dichoptic conditions indicates a binocular cortical site of plasticity.
Original language | English |
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Pages (from-to) | 1550-1558 |
Number of pages | 9 |
Journal | Vision Research |
Volume | 50 |
Issue number | 16 |
DOIs | |
State | Published - 21 Jul 2010 |
Externally published | Yes |
Bibliographical note
Funding Information:This study was supported in part by the Israel Science Foundation (ISF) , the Claire & Amedee Maratier Institute for the Study of Visual Disorder and Blindness, Tel Aviv, Israel, and the Joseph Sagol Fellowship Program for Brain Research, Israel.
Funding
This study was supported in part by the Israel Science Foundation (ISF) , the Claire & Amedee Maratier Institute for the Study of Visual Disorder and Blindness, Tel Aviv, Israel, and the Joseph Sagol Fellowship Program for Brain Research, Israel.
Funders | Funder number |
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Claire & Amedee Maratier Institute | |
Joseph Sagol Fellowship Program for Brain Research, Israel | |
Israel Science Foundation |
Keywords
- Perception
- Perceptual grouping
- Perceptual learning
- Plasticity
- Visual adaptation