The Role of Peripheral Visual Information on Central Task Performance
MSc. Ieva Timrote (Department of Optometry and Optical Science UL)
Visual perception is a complex process, where information from the surrounded environment reaches the eye and is transformed from a physical stimulus into a neural impulse. Most importantly, information that has reached the Lateral Genicular Nucleus in the brain level, contains two sorts of information. P pathway consists of cells containing information about small details and accuracy to see small objects (Stein, 2001). M pathway consists of cells containing information from the periphery of the eye, therefore one is able to detect motion and notice stimulus in the periphery (Stein, 2001). Parrish et al (2005) has demonstrated that M pathway matures functionally until 3-4 years or even 7-8 years of age, although P pathway matures functionally until 3-4 or 11-12 years of age depending on the difficulty level of the psychophysical task. Nowdays, a lot of tests are used to evaluate different visual functions, although the central task is simple and does not reflect the everyday situation. For this reason, the aim of this work was to evaluate participant’s attention an peripheral visual perception when performing central task with surrounded peripheral visual information. We made a computer program that allowed us to change the central task, as well as peripheral information in near and far periphery to evaluate the role of peripheral visual information on central task performance. Our results suggest that central task performance is affected by age and letters that constructs the central task. If we add peripfehral figures in the far periphery in addition to the static noise, central task is performed less accurately. Most importantly, significant noise in the far periphery helps to perform the central task faster. What is more, moving noise in the far periphery interacts with the central task so that more time is needed to complete the central task.
References
- Stein, J., The Magnocellular Theory of Developmental Dyslexia. Dyslexia. 2001; 7: 12-36.
- Parrish, E.E., Giaschi, D.E., Boden, C., Dougherty, R., The maturation of form and motion perception in school age children. Vision Research. 2005; 45: 827-837.