Found this study via @J3ro3nJ. I often say to students that the basics of learning and remembering is deep learning, emotion and repetition. With the latter I mean spaced repetition. Repetition does work, but a new study adds an important nuance. UC Irvine neurobiologists Zachariah Reagh and Michael Yassa have found that while repetition do enhances the factual content of memories, it can reduce the amount of detail stored with those memories. This means that with repeated recall, nuanced aspects may fade away.

From the press release:

In the study, which appears this month in Learning & Memory, student participants were asked to look at pictures either once or three times. They were then tested on their memories of those images. The researchers found that multiple views increased factual recall but actually hindered subjects’ ability to reject similar “imposter” pictures. This suggests that the details of those memories may have been shaken loose by repetition.

This discovery supports Reagh’s and Yassa’s Competitive Trace Theory – published last year inFrontiers in Behavioral Neuroscience – which posits that the details of a memory become more subjective the more they’re recalled and can compete with bits of other similar memories. The scientists hypothesize that this may even lead to false memories, akin to a brain version of the telephone game.

Yassa, an assistant professor of neurobiology & behavior, said that these findings do not discredit the practice of repetitive learning. However, he noted, pure repetition alone has limitations. For a more enriching and lasting learning experience through which nuance and detail are readily recalled, other memory techniques should be used to complement repetition.

So, bring on the cards…

Abstract of the research:

Most theories of memory assume that representations are strengthened with repetition. We recently proposed Competitive Trace Theory, building on the hippocampus’ powerful capacity to orthogonalize inputs into distinct outputs. We hypothesized that repetition elicits a similar but nonidentical memory trace, and that contextual details of traces may compete for representation over time. We designed a task in which objects were incidentally encoded either one or three times. Supporting our theory, repetition improved target recognition, but impaired rejection of similar lures. This suggests that, in contrast to past beliefs, repetition may reduce the fidelity of memory representations.