ISSN:
1432-0770
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Computer Science
,
Physics
Notes:
Abstract When a subject is presented with a visual target moving between two fixed points in a periodic square wave motion, the delay of eye tracking saccades can gradually decrease until the eyes lock on the target or even precede it. For symmetrical target motions (equal duration of the two phases of each cycle), the response time defined as the interval between a target jump in one direction and the beginning of the corresponding saccadic response was almost the same for the two phases of each cycle. This response time was found to depend on the frequency of target motion and to reach a positive value (anticipation) of about 200 ms at about 0.5 Hz. At low and high frequencies eye movement delayed target movement, and the delay was almost that observed for saccades to unpredictable targets. For asymmetrical target motions, the response time was different for the two phases of each cycle. A shorter response delay or a greater anticipation was observed for the response to the shorter phase. The response time to both phases of target motion depended on cycle duration while the response time to the longer phase also depended on the degree of asymmetry of target motion. After a review of the experimental results, a mathematical model that can help their interpretation is presented. The model also provides a description of the interaction that might occur between the two hemispheres when eye tracking is made by saccades alternately to the right and to the left.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00356856
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