An Evaluation of Its Presence Using Three Instruments

A brief suppression of the central portion of stimuli, called Intermittent Central Suppression (ICS), has been reported during binocular fusion. Hussey linked the presence of ICS to reading deficiency. The present study reports an investigation of ICS in a group of proficient readers to evaluate the sensitivity of different tests in measuring this effect. Twenty-nine college students were examined with three different tests: Poltest, Steroscope Test and Modified Borish Test. The tests revealed different sensitivities to detect suppression. The Poltest was least sensitive; the Stereoscope Test was slightly more sensitive and the Modified Borish Test produced the largest number of suppression reports. About half of the sample reported some degree of ICS. However, our results differed from those reported by Hussey; our participants reported that suppressions were of a shorter duration and were limited to one eye. This could be caused by the different samples; Hussey participants were not proficient readers, while ours were. Recommendations for future research are made.