Abstract
Introduction: The transilient inducer changes lead to the transient disappearance of large target figures such as a 14 degree diameter filled circle (VSS2011-26:413). We devised the improved inducer which repeated the continuous transilience so that the disappearance lasted while the inducer was changing (CTIB). We investigated the disappearance of the large annulus and the triangle sectors which extended from close to the fixation point to the far periphery. They were the most difficult targets to disappear. The targets were uniformly filled or filled with lines which were either parallel or perpendicular to the inducer edge. The other curious issue was how much extent close to the fovea could be possible the CTIB.
Methods: On the black (0.341cd) background, the white (110cd) stationary annulus target with 12.25 and 8.75 degree of outer and inner radius was presented. The inducer was the inner and outer six concentric circles which appeared one by one at the edge of the target and expanded or shrank over 7 degree. They were separated at 0.875 degree each other. The first circle was gray (5.15cd), and the consecutive circle colors were changed to black in linear manner. All of them reached at 7 degree in or out then disappeared. The inducing sequence completed in 790ms. After the inducer was OFF the target remained ON up to 2000ms. The whole sequence repeated indefinitely. For the triangle sector target, the methods were similar except the geometry.
Results: For either annulus or sectors, we found that the filled targets were difficult to disappear. The targets filled with lines, however, were fairly easy to disappear. The typical optimum disappearance ratio was more than 50%. The targets at very near to the fixation point up to 0.5 degree also disappeared.
Conclusions: We extended MIB. The results suggested novel conditions for disappearance.
Meeting abstract presented at VSS 2012