| Title: | Depression-Biased Reverse Plasticity Rule Is Required for Stable Learning at Top-down Connections |
| Author: |
Burbank, Kendra Stewart; Kreiman, Gabriel
Note: Order does not necessarily reflect citation order of authors. |
| Citation: | Burbank, Kendra S., and Gabriel Kreiman. 2012. Depression-biased reverse plasticity rule is required for stable learning at top-down connections. PLoS Computational Biology 8(3): e1002393. |
| Full Text & Related Files: |
3291526.pdf (1.194Mb; PDF)
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| Abstract: | Top-down synapses are ubiquitous throughout neocortex and play a central role in cognition, yet little is known about their development and specificity. During sensory experience, lower neocortical areas are activated before higher ones, causing top-down synapses to experience a preponderance of post-synaptic activity preceding pre-synaptic activity. This timing pattern is the opposite of that experienced by bottom-up synapses, which suggests that different versions of spike-timing dependent synaptic plasticity (STDP) rules may be required at top-down synapses. We consider a two-layer neural network model and investigate which STDP rules can lead to a distribution of top-down synaptic weights that is stable, diverse and avoids strong loops. We introduce a temporally reversed rule (rSTDP) where top-down synapses are potentiated if post-synaptic activity precedes pre-synaptic activity. Combining analytical work and integrate-and-fire simulations, we show that only depression-biased rSTDP (and not classical STDP) produces stable and diverse top-down weights. The conclusions did not change upon addition of homeostatic mechanisms, multiplicative STDP rules or weak external input to the top neurons. Our prediction for rSTDP at top-down synapses, which are distally located, is supported by recent neurophysiological evidence showing the existence of temporally reversed STDP in synapses that are distal to the post-synaptic cell body. |
| Published Version: | doi:10.1371/journal.pcbi.1002393 |
| Other Sources: | http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3291526/pdf/ |
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| Citable link to this page: | http://nrs.harvard.edu/urn-3:HUL.InstRepos:9637989 |
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