The effects of feedback and task accuracy in serial dependence to orientation

Assimilative serial dependence in perception occurs where responses about a stimulus (e.g., orientation) are biased towards previously seen perceptual information (e.g., the orientation of the stimulus shown on the previous trial). This bias may occur to perceptual information from the previous trial, or to the response or decision made on the previous trial. We asked whether providing response feedback could change the serial dependence effect on the following trial. Twenty-one participants completed a task in which they adjusted an on-screen pointer to reproduce the orientation of a briefly-presented Gabor stimulus. They received feedback about the accuracy of their response that either reflected their actual accuracy or was random. We found significant positive biases to the stimulus and response only when the participant had received positive ("correct!") feedback on that trial. When the inducer response had been incorrect, the effect was significant only to the response itself and not to the stimulus. Overall, we suggest that our participants demonstrated a bias towards the percept from the previous trial, which is better represented by the response than the stimulus for incorrect trials, and that this effect can be modulated post-perceptually by feedback.