Serial Dependence in Visual Perception

Serial dependence occurs when the viewing of a stimulus causes subsequent stimuli to appear visually similar despite minor differences. For example, previous work has shown that, when participants viewed patches of similarly aligned gratings, reported orientation was biased towards the orientation of the patch seen on the previous trial. This effect has been found to apply to a wide range of visual stimuli, including relatively simple visual features such as numerosity and position, as well as more complex visual properties, such as facial identity.
It remains unclear whether serial dependence is a genuine perceptual effect or reflects the operation of post-perceptual decision processes. Using techniques such as decision modelling and psychophysical experiments, the mechanisms underlying this effect can be examined.
A further area of investigation is the relationship between this effect and adaptation; another perceptual phenomenon associated with repetitive viewing of stimuli, which pushes subsequent stimuli in the opposing perceptual direction, in opposition to serial dependence. It has been suggested that serial dependence might maintain stable visual elements (such as facial identity) whereas adaptation enhances sensitivity to dynamic visual features (such as facial expression). At present it is unclear whether or not these two effects arise from similar (but oppositely acting) processes