| Abstract: | Change blindness has been linked to comparisons over time when visual input is disturbed by a transient. This is most directly seen in “flicker” paradigms where change is invisible when introduced during a blank period between successive presentations of stimuli, and is implicit in paradigms where a stimulus is changed during a saccade. Difficulties in comparing two simultaneously present stimuli have been considered to be due to transaccadic memory limitations in tasks requiring saccades. We present here experiments that demonstrate the phenomenology of change blindness, but in tasks where two stimuli are present in the central visual field within a single fixation and where there are no transients present. These experiments are based on contrast discriminations of patterns composed of a few simple elements. We have found comparisons over space within a single fixation to be as difficult as comparisons over time. As in the more usual paradigms for change blindness, cueing makes changes easy to detect. These results suggest that a memory bottleneck is not essential to produce change blindness. |
