The role of memory load and inter-item similarity on serial dependence

Abstract

The visual system often relies on the recent past to inform our representation of the present, a phenomenon known as serial dependence. Serial dependence is especially evident when faced with uncertain information, highlighting the advantage of relying on prior information for a more precise estimate. Visual working memory plays a crucial role in shaping uncertainty, given its limited resources. As the number of items stored in memory increases, the precision with which each of them is represented degrades, thereby increasing the strength of serial dependence. The current study aimed to explore whether the type of information concurrently held in working memory affects the strength of serial dependence. Seventeen participants performed an orientation adjustment task and an intermediate task of comparing circle sizes, line lengths, or line orientations. The results showed that despite more variable orientation estimates after comparing items containing orientation information, serial dependence did not differ across the three intermediate tasks. This suggests that although memory precision is influenced by the similarity of representations, the reliance on the past remains the same.