Human Vertical Fusional Response Under Open and Closed Loop Stimulation to Predictable and Unpredictable Disparity Presentations

Vertical fusional response was evaluated under open and closed loop viewing conditions for predictable and unpredictable stimulus disparity presentations. The gain was found to be greater than I for small disparities under open and closed loop conditions for both predictable and unpredictable disparity presentations. The gain and phase lag were larger under open loop conditions. 2.0 Hz was the maximum frequency at which the subject was able to fuse the sinusoidal stimulus disparity under closed loop. No significant difference was found between the phase lags for predictable and unpredictable disparities under both conditions, ruling out the presence of a predictor.