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Relearning Process Not Always A 'Free Lunch'

Date:
August 21, 2008
Source:
Public Library of Science
Summary:
Researchers have helped determine why relearning a few pieces of information may or may not easily cause a recollection of other associated, previously learned information. The key, they find, is in the way in which the learned information is forgotten.
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Researchers at Sheffield University and the University of St. Andrews, United Kingdom, have helped determine why relearning a few pieces of information may or may not easily cause a recollection of other associated, previously learned information. The key, they find, is in the way in which the learned information is forgotten.

When one learns a language and then doesn't use it, one may find that relearning a few words will trigger many others to come back and be relearned. The same happens with other skills that involve mental associations. The authors term this phenomenon "free-lunch learning." Previous work has shown that "free-lunch learning" occurs both in humans and in artificial neural networks.

In this study, co-authors Jim Stone and Peter Jupp created a mathematical model to show the opposite effect, called "negative free-lunch learning." These are cases in which relearning parts of forgotten associations decreases the recall of the remaining parts. The authors find that the difference between free-lunch learning and negative free-lunch learning is due to the particular method used to induce forgetting.

If forgetting is induced by random fluctuations in the strength of synaptic connections, then free-lunch learning will be observed. However, the authors show here that if forgetting is induced by directional decay in synaptic connectivity, then negative free-lunch learning occurs.

This suggests that evolution may have selected physiological mechanisms that involve forgetting using a form of synaptic drift, as in humans we typically observe free-lunch learning.


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The above post is reprinted from materials provided by Public Library of Science. Note: Materials may be edited for content and length.


Journal Reference:

  1. Stone et al. Falling towards Forgetfulness: Synaptic Decay Prevents Spontaneous Recovery of Memory. PLoS Computational Biology, 2008; 4 (8): e1000143 DOI: 10.1371/journal.pcbi.1000143

Cite This Page:

Public Library of Science. "Relearning Process Not Always A 'Free Lunch'." ScienceDaily. ScienceDaily, 21 August 2008. <www.sciencedaily.com/releases/2008/08/080821211553.htm>.
Public Library of Science. (2008, August 21). Relearning Process Not Always A 'Free Lunch'. ScienceDaily. Retrieved July 31, 2015 from www.sciencedaily.com/releases/2008/08/080821211553.htm
Public Library of Science. "Relearning Process Not Always A 'Free Lunch'." ScienceDaily. www.sciencedaily.com/releases/2008/08/080821211553.htm (accessed July 31, 2015).

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