WHY: Synaptic strength controls how much one neuron's signal affects another. A strong excitatory synapse triples the effect. An inhibitory synapse flips it negative. That scaling IS scalar multiplication.

A scalar is just a single number. When you multiply a vector by a scalar, you multiply every component by that number:

• Strong synapse (×3): [2, 1] → [6, 3] — signal amplified
• Weak synapse (×0.1): [2, 1] → [0.2, 0.1] — signal dampened
• Inhibitory neuron (×−1): [2, 1] → [−2, −1] — signal flipped

What changes and what doesn't:

✅ Length changes (stronger or weaker)
✅ Direction flips if the scalar is negative (inhibition)
❌ Direction does NOT change for positive scalars

import numpy as np

retinal_signal = np.array([2, 1])  # firing rates

print(3 * retinal_signal)          # [6, 3]  — strong synapse
print(-1 * retinal_signal)         # [-2, -1] — inhibitory
print(0.5 * retinal_signal)        # [1.0, 0.5] — weak synapse