PT  - JOURNAL ARTICLE
AU  - Callie Federer
AU  - Joel Zylberberg
TI  - A self-organizing memory network
AID  - 10.1101/144683
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 144683
4099  - http://biorxiv.org/content/early/2017/06/04/144683.short
4100  - http://biorxiv.org/content/early/2017/06/04/144683.full
AB  - Working memory requires information about external stimuli to be represented in the brain even after those stimuli go away. This information is encoded in the activities of neurons, and neural activities change over timescales of tens of milliseconds. Information in working memory, however, is retained for tens of seconds, suggesting the question of how time-varying neural activities maintain stable representations. Prior work shows that, if the neural dynamics are in the ‘null space’ of the representation - so that changes to neural activity do not affect the downstream read-out of stimulus information - then information can be retained for periods much longer than the time-scale of individual-neuronal activities. The prior work, however, requires precisely constructed synaptic connectivity matrices, without explaining how this would arise in a biological neural network. To identify mechanisms through which biological networks can self-organize to support memory function, we derived biologically plausible synaptic plasticity rules that dynamically modify the connectivity matrix to enable information storing. Networks implementing this plasticity rule can successfully learn to store information even if only 10% of the synapses are plastic, they are robust to synaptic noise, and they can store information about multiple stimuli.