The effect of age on visual decisions and consequences for models of bi-stable visual perception

We studied the effect of age on visual perceptual decisions of bi-stable stimuli. We used two different stimuli: bi-stable rotating spheres and a binocular rivalry stimulus. At onset, both stimuli can evoke two different percepts: for the sphere clockwise or anti-clockwise rotation and for the binocular rivalry stimulus a percept that switches between the stimuli in the two eyes. The stimuli were presented intermittently for 1 second with a range of inter-stimulus intervals (0.1 – 2 seconds). Subjects ranged between 18 and 73 years old and were instructed to indicate which of the two percepts dominate at each onset of the bi-stable stimulus. Our results show that perceptual choices are more stable for older subjects for the binocular rivalry stimulus and not for the bi-stable rotating spheres. The results will be discussed in the context of current models for bi-stable visual perception.