Perceptual Learning Reduces Crowding in Amblyopia and in the Normal Periphery
| Autor: | Zahra Hussain, Andrew T. Astle, Ben S. Webb, Paul V. McGraw |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Adult
Male medicine.medical_specialty Visual acuity Adolescent genetic structures Visual Physiology Audiology Amblyopia Article 050105 experimental psychology Young Adult 03 medical and health sciences 0302 clinical medicine Perceptual learning medicine Humans Learning 0501 psychology and cognitive sciences Physical Therapy Modalities Aged Crowding in General Neuroscience 05 social sciences Middle Aged Crowding eye diseases Visual field Pattern Recognition Visual Central vision Female medicine.symptom Psychology Social psychology 030217 neurology & neurosurgery |
| Zdroj: | Journal of Neuroscience Journal of Neuroscience; Vol 32 |
| ISSN: | 1529-2401 0270-6474 |
| DOI: | 10.1523/jneurosci.3845-11.2012 |
| Popis: | Amblyopia is a developmental visual disorder of cortical origin, characterized by crowding and poor acuity in central vision of the affected eye. Crowding refers to the adverse effects of surrounding items on object identification, common only in normal peripheral but not central vision. We trained a group of adult human amblyopes on a crowded letter identification task to assess whether the crowding problem can be ameliorated. Letter size was fixed well above the acuity limit, and letter spacing was varied to obtain spacing thresholds for central target identification. Normally sighted observers practiced the same task in their lower peripheral visual field. Independent measures of acuity were taken in flanked and unflanked conditions before and after training to measure crowding ratios at three fixed letter separations. Practice improved the letter spacing thresholds of both groups on the training task, and crowding ratios were reduced after posttest. The reductions in crowding in amblyopes were associated with improvements in standard measures of visual acuity. Thus, perceptual learning reduced the deleterious effects of crowding in amblyopia and in the normal periphery. The results support the effectiveness of plasticity-based approaches for improving vision in adult amblyopes and suggest experience-dependent effects on the cortical substrates of crowding. |
| Databáze: | OpenAIRE |
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