Abstract

Studies of ‘change blindness’ have shown that motion detection is vulnerable to interruption by blinks, resulting in very poor change detection. Here we describe a form of change detection that functions with staring eyes and is not vulnerable to blinks. ‘Change-blindness’ is replaced by ‘Change salience’ when eye movements are measured and controlled so that the pre-change and changed stimuli fall on the same retinal locations. ‘Change salience’ is abolished by eye movements, and it is strongly asymmetrical: a singleton changed object is much easier to detect than an object that is the only stimulus in the image not to change. The asymmetry in ‘Change salience’ is not attributable to a reduction in the amplitude (contrast) of stimuli by adaptation because, paradoxically, a reduction in actual amplitude of the target increases, rather than decreases, target detectability. We conclude that the visual system has a specific mechanism for change detection in a stationary scene, based on the automatic attraction of attention by the transient increase in firing of detectors than have not recently been stimulated. These findings suggest a new functional role for low-level sensory adaptation, which has hitherto proved elusive.