Recall Performance Improvement in a Bio-Inspired Model of the Mammalian Hippocampus

Andreakos, Nikolas, Yue, Shigang and Cutsuridis, Vassilis (2020) Recall Performance Improvement in a Bio-Inspired Model of the Mammalian Hippocampus. In: Brein Informatics, Sept 19, 2020, Online.

Full content URL: https://doi.org/10.1007/978-3-030-59277-6_29

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Recall Performance Improvement in a Bio-Inspired Model of the Mammalian Hippocampus
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Item Type:Conference or Workshop contribution (Paper)
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Abstract

Mammalian hippocampus is involved in short-term formation of declarative memories. We employed a
bio-inspired neural model of hippocampal CA1 region consisting of a zoo of excitatory and inhibitory
cells. Cells’ firing was timed to a theta oscillation paced by two distinct neuronal populations exhibiting
highly regular bursting activity, one tightly coupled to the trough and the other to the peak of theta. To
systematically evaluate the model’s recall performance against number of stored patterns, overlaps and
‘active cells per pattern’, its cells were driven by a non-specific excitatory input to their dendrites. This
excitatory input to model excitatory cells provided context and timing information for retrieval of
previously stored memory patterns. Inhibition to excitatory cells’ dendrites acted as a non-specific global
threshold machine that removed spurious activity during recall. Out of the three models tested, ‘model 1’
recall quality was excellent across all conditions. ‘Model 2’ recall was the worst. The number of ‘active
cells per pattern’ had a massive effect on network recall quality regardless of how many patterns were
stored in it. As ‘active cells per pattern’ decreased, network’s memory capacity increased, interference
effects between stored patterns decreased, and recall quality improved. Key finding was that increased
firing rate of an inhibitory cell inhibiting a network of excitatory cells has a better success at removing
spurious activity at the network level and improving recall quality than increasing the synaptic strength of
the same inhibitory cell inhibiting the same network of excitatory cells, while keeping its firing rate fixed.

Keywords:Associative memories - Neural information processing - Brain - Inhibition
Subjects:B Subjects allied to Medicine > B140 Neuroscience
G Mathematical and Computer Sciences > G730 Neural Computing
Divisions:College of Science > School of Computer Science
ID Code:43364
Deposited On:15 Dec 2020 11:10

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