Abstract
It is known that some amblyopes can focus their attention to the input from one eye and suppress that from the other eye at will. We explored whether a person with no amblyopia history can have such ocular based attention. Four observers with no known history of amblyopia participated in the experiment. The stimuli in each trial contained a Gabor target in one of the four possible locations (up, down, left and right) that presented to one eye and a Gabor distractor at another location either to the same or to the other eye. Other possible locations for stimulus presentation in both the left and the right eye images were filled with white noise. A cue at the center of the display indicated the location of the target. The cue was presented to only one eye to control the ocular attention of the observers. In addition, a fixation point which carried no information about target location was presented to the uncued eye. The task of the observer was to determined which one of the two locations indicated by the cue contained the target. Thus, to perform the task, the observer had to attend to the cued eye. We measured the detection threshold at 75% accuracy. The target threshold in uncued eye increased more than 3.5-fold (11.2 dB) from that in the cued eye for the dominant eye and about 3-fold (9.3 dB) for the non-dominant eye. Such suppression of the unattended eye suggests that binocular suppression can be voluntarily controlled. Hence, it is possible to build an amblyopic model among normal population.
NSC: 99-2410-H-002-081-MY3.