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Methods to Test Visual Attention Online
Published on: February 19, 2015
Task-determined strategies of visual process
G Geiger1, J Y Lettvin, O Zegarra-Moran
1Biophysics Sector, SISSA, Trieste, Italy.
Brain Research. Cognitive Brain Research
|June 1, 1992
Summary
Severe dyslexics show distinct visual perception strategies compared to ordinary readers, particularly in peripheral letter recognition. Training improved dyslexic visual strategies, demonstrating that these pre-cognitive visual skills are learnable.
Area of Science:
- Visual perception
- Cognitive psychology
- Neuroscience
- Reading disabilities
Background:
- Lateral masking in peripheral vision impacts letter recognition, independent of visual acuity.
- Existing models do not fully explain these peripheral visual effects.
- Dyslexia presents unique challenges in visual processing and reading.
Purpose of the Study:
- To investigate differences in peripheral letter recognition and lateral masking between ordinary readers and individuals with severe dyslexia.
- To explore the hypothesis that lateral masking distribution reflects task-dependent visual perception strategies.
- To determine if these visual strategies can be modified through targeted training.
Main Methods:
- Developed tachistoscopic letter recognition tasks to measure peripheral visual field performance.
- Compared performance of ordinary readers and severe dyslexics on these tasks.
- Implemented an active practice regimen for adult dyslexics to retrain visual strategies.
Main Results:
- Ordinary readers perform best with central visual field presentation; recognition declines in the periphery.
- Severe dyslexics exhibit enhanced peripheral recognition in the direction of reading and increased central masking.
- Post-training, dyslexics showed significant reading improvement and their visual test results shifted towards those of ordinary readers.
Conclusions:
- Visual perception employs switchable, task-determined pre-cognitive strategies.
- The distribution of lateral masking is a modifiable aspect of these visual strategies.
- These findings suggest that visual processing strategies, including those affected in dyslexia, can be learned and improved.
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