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Research proposal · 2025

Synaptic performance of biological neurons

Omer Faizan · M.S. Data Science, Montclair State University

1 Question

Real synapses change with timing, recent activity and noise. Which of these behaviours do artificial spiking models leave out, and does it matter for learning?

2 Why it matters

The STDP rules used in machine learning are simplified biology. The missing pieces might explain why deeper STDP layers learn so little.

~86 Bneurons in the human brain
~1 msone spike, a ~100 mV swing
<1%of cortical neurons strongly active at once

3 Timing: STDP

Weight change vs. spike timing (shape after Bi & Poo, 1998)

-50-252550strengthenweakenΔt, ms (post − pre)

input before output input after output

4 Recent activity: depression

Response to a 20 Hz spike train (Tsodyks–Markram model, illustrative parameters)

spike 18−45%

5 Reference points

PropertyTypical
STDP time constants~10 ms
Depression window (neocortex)often wider than potentiation
Brain power budget~20 W

6 Biology vs. my model

BehaviourBiologyMy model
Timing-dependent plasticity✓✓
Short-term depression✓not yet
Facilitation✓not yet
Noise / variability✓not yet

7 What I expect

  • Short-term dynamics change which features a spiking layer learns.
  • A little biological noise helps more than it hurts.