Journal
JOURNAL OF NEUROSCIENCE
Volume 37, Issue 1, Pages 83-96Publisher
SOC NEUROSCIENCE
DOI: 10.1523/JNEUROSCI.1989-16.2016
Keywords
Hebbian plasticity; primacy; recency; short-term potentiation; word list learning; working memory
Categories
Funding
- Swedish Science Council Grant Vetenskapradet [VR-621-2009-3807]
- VINNOVA (Swedish Governmental Agency for Innovation Systems)
- VR through the Stockholm Brain Institute
- SeRC (Swedish e-science Research Center)
- EuroSPIN Erasmus Mundus doctoral programme
Ask authors/readers for more resources
A dominant theory of working memory (WM), referred to as the persistent activity hypothesis, holds that recurrently connected neural networks, presumably located in the prefrontal cortex, encode and maintain WM memory items through sustained elevated activity. Reexamination of experimental data has shown that prefrontal cortex activity in single units during delay periods is much more variable than predicted by such a theory and associated computational models. Alternative models of WM maintenance based on synaptic plasticity, such as short-term nonassociative (non-Hebbian) synaptic facilitation, have been suggested but cannot account for encoding of novel associations. Here we test the hypothesis that a recently identified fast-expressing form of Hebbian synaptic plasticity (associative short-term potentiation) is a possible mechanism for WM encoding and maintenance. Our simulations using a spiking neural network model of cortex reproduce a range of cognitive memory effects in the classical multi-item WM task of encoding and immediate free recall of word lists. Memory reactivation in the model occurs in discrete oscillatory bursts rather than as sustained activity. We relate dynamic network activity as well as key synaptic characteristics to electrophysiological measurements. Our findings support the hypothesis that fast Hebbian short-term potentiation is a key WM mechanism.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available