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Acta Physiologica 2011; Volume 202, Supplement 684
The Joint Conference (FAMÉ 2011) of the LXXVth Meeting of the Hungarian Physiological Society, XVIth Meeting of the Hungarian Society of Anatomists, Experimental Section of the Hungarian Society for Experimental and Clinical Pharmacology and Hungarian Society for Microcirculation and Vascular Biology
6/8/2011-6/11/2011
Pécs, Hungary
MEASUREMENT OF SIMPLE REACTION TIME TO CHECKERBOARD-PATTERNED CYCLOPEAN STIMULI
Abstract number: P24
Gyenge1 M., Miko-Barath1 E., Torok2 B., Jando1 G.
Aims:
In 1903, Worth defined three hierarchically organized stages of binocular vision: (1) simultaneous perception, (2) binocular fusion, and (3) stereopsis. Although the model, based on clinical observations, is useful in the practice, its neuronal background is far from understood. The objective of the present study was to determine the simple reaction time (RT) to different checkerboard-patterned cyclopean stimuli, i.e. Dynamic Random Dot Correlogram (DRDC), Dynamic Random Dot Stereogram (DRDS) and non-cyclopean pattern onset. Perception of DRDC requires fusion, while DRDS requires the highest stage of stereopsis.
Methods:
Fifteen young, healthy volunteers with intact binocular vision participated in the study. Stimuli were generated on a 60 Hz CRT monitor; dichoptic viewing was achieved by red-green color filters and anaglyphic channel separation. Microcontroller system was used to measure binocular RT, the image appearance and the microcontroller timer was synchronized to the monitor refresh cycle. Subjects had to respond to three different targets: 1. DRDC: appearance of a mixed correlated-anticorrelated checkerboard from a correlated background 2. DRDS: appearance of a crossed disparity checkerboard pattern from a correlated background 3. appearance of a yellow-black checkerboard from a dim yellow background. The mean luminances were 3 cd/m2 for all stimuli, while the contrast was about 80%. Within-subject RTs were compared by T-test.
Results:
Cyclopean RTs were considerably longer by about 140 ms than non-cyclopean RTs. In the majority of subjects, RTs to DRDSs were significantly shorter by about 30 ms than responses to DRDCs. There were three subjects showing an opposite result, i.e. 60 ms longer RTs to DRDS. In their ophthalmologic history significant (about 3D) anisometropy was found.
Conclusion:
Our results suggest that neuronal processing of binocular correlation and stereopsis are not serially related as the Worth's model would suggest. This technique could be a sensitive measure of minor binocular abnormalities.
To cite this abstract, please use the following information:
Acta Physiologica 2011; Volume 202, Supplement 684 :P24