Dynamic Vision
The quality of static vision is measured by visual acuity. Under natural viewing conditions about 3 saccades are made in each second. Therefore, one has to able to see fast enough in order to keep the time order and the contents of the incoming messages apart. The perception of fast changes of the retinal image challenges a certain subsystem of large neurons, the so-called magnocellular system, which is responsible for dynamic vision.
The quality of dynamic vision can be tested in a simple way using a visual stimulus, which changes its orientation every 200 ms. At the end of a series of these stimuli the subjects has to indicate by key press, which orientation the the last stimulus was (up. Down. Right, or left). The percentage of correct responses corrected by the 25%, that can be achieved by guessing.
Results of Research
- Age development
- Developmental deficits in Dyslexia
The figures shows the changes of correct responses with age from 7 to 60 years.
Children with dyslexia exhibit developmental deficits in about 40% of the cases.
Literature:
- Fischer B. Hartnegg K (2002). Age effects in dynamic vision based on orientation identification. Exp-Brain-Res 143: 120-125 (abstract)
- Fischer B, Hartnegg K, Mokler A (2000) Dynamic vision perception of dyslexic children. Perception 29: 523-530 (abstract)
A complete list of publications is available.