The effect of spacing on item-context associative interference
Creators: name: Murty, Vishnu
name: Yiwen Zhang
name: Cowan, Emily T
name: Rottman, Benjamin
Publisher: name: Open Science Framework
Year: 2026
Subjects: subject: Social and Behavioral Sciences
subject: Psychology
subject: FOS: Psychology

description: We rely on our memories of the past to help guide our behaviors. As such, it is critical that we can accurately bring to mind specific memories when needed. Yet our memory systems are prone to ‘interference’, in which other memories compete with, and inhibit, associative recall. For example, imagine you are at the grocery store trying to remember what you need to buy, but instead you keep recalling items purchased in the past. Research has shown that that interference increases as more information is associated with a given item, a phenomenon known as the ‘fan effect’ (Anderson, 1974; Anderson and Reder, 1999). Because these overlapping associates share a common item, they are more likely to interfere with one another, reducing accuracy in memory. Yet, at the same time, much research has demonstrated instances in which learning results in accurate retention for the long term. For example, reports suggest spacing or ‘distributing’ repeated learning sessions over time, compared to compressing repeated learning into one session, leads to improved long-term memory (Cepeda et al., 2006; Litman and Davachi, 2008). It’s thought the spacing effect may benefit long-term retention because it provides a chance for new memories to be stabilized through a process known as memory consolidation. During offline periods following learning, such as sleep, neural mechanisms facilitate interactions across brain regions, allowing new memories to be strengthened and transformed so they can be incorporated into long-term memory stores (McClelland et al., 1995; Rasch and Born, 2013). As a result, spacing learning over a delay may reinforce consolidated memories. Yet, surprisingly little work has sought to examine how spacing affects the buildup of interference for overlapping information. In the present experiment, we will test if spacing learning of overlapping information mitigates the deleterious effects of interference described by the fan effect. Further, we designed the experiment to provide a systematic manipulation of the spacing between encoding sessions, allowing us to investigate how differential spacing lengths facilitate resistance to forgetting. In addition to testing the effects of spacing, using this design we can also interrogate why repeated exposure to information benefits memory. It’s been hypothesized that memory is improved over repeating learning episodes because each time the memory is learned with slight differences, or greater ‘encoding variability’, resulting from factors like the slow drift in background context (Melton 1970). At the same time, other research suggests that, rather than encoding variability, repeated learning reactivates and strengthens the same memory trace with each episode (Xue et al., 2010). Leveraging our multi-learning session design, we can compare memory following learning episodes that introduce variability versus involve exact repetition to adjudicate between these hypotheses.