Does the benefit of time for working memory arise at encoding or retrieval?

Area of Science:

• Cognitive Psychology
• Neuroscience

Background:

• Extended free time between list items enhances immediate serial-order memory.
• Previous research indicates this effect is mainly proactive, benefiting later-presented items.

Purpose of the Study:

• To investigate if changing test order (forward vs. random recall) affects the proactive and retroactive benefits of extended inter-item intervals.
• To examine the relationship between free-time duration, item serial position, and recall order.

Main Methods:

• Participants performed serial recall tasks with varying inter-item interval durations.
• Recall order was manipulated between forward and random sequences.
• Analysis focused on item position and the impact of interval length on recall accuracy.

Main Results:

• Findings largely replicated the proactive benefit of extended intervals, with memory improvement increasing with item serial position.
• Additional retroactive benefits (improved memory for earlier items) were observed in specific conditions.
• Retroactive benefits were more pronounced in random order recall, particularly when participants anticipated this testing format.

Conclusions:

• Extended inter-item intervals offer primarily proactive benefits for serial-order memory, but retroactive benefits can emerge.
• The recall testing procedure significantly influences the manifestation of these temporal benefits.
• Randomized testing, especially when anticipated, can enhance retroactive memory benefits.