Serial Dependence As a Function of Spatial Memory Quality
As light reflects onto our retina, a process of those lights begins to paint a picture that closely resembles the real-world environment in our brain. These pictures allow us to navigate through the physical world, although it is a noisy replica that could be biased. One such bias is the phenomenon of serial dependence, in which our perception of visual stimuli is influenced by previously presented stimuli. Serial dependence was thought to be a mechanism that helps us maintain a stable representation of the world because of the temporal continuity of our physical environment. The Bayesian theory of perception suggests that our brain makes decisions with not only the visual information itself but also the precision of that visual information. Therefore, serial dependence might occur as previously presented visual information that is more precise being weighted more over the current information. The current study aimed to replicate the serial dependence effect with a memory-guided saccade task in which participants were asked to remember either one or two spatial locations on a screen, after some delay, participants were instructed to report either one of the cued locations or a chosen location that they believe they remembered the best with a saccade towards the location. We replicated the serial dependence effect, and the amplitude of serial dependence is bigger when working memories of the previous trial are more precise. Which suggests that serial dependence might be a result of a readout mechanism that takes the precision of visual information into account.