Bio vs Artificial neuron
Description
Understanding the fundamental difference between biological neurons (inspired by the brain) and artificial neurons (used in deep learning) is crucial to grasp how neural networks operate.
A biological neuron is a cell in the human nervous system that transmits information through electrical and chemical signals. In contrast, an artificial neuron is a mathematical model designed to mimic the behavior of its biological counterpart but in a simplified manner.
Artificial neurons use weighted sums and activation functions to simulate the decision-making process of biological neurons in a computational context.
Here's how they compare:
- Biological Neuron: Receives input via dendrites, processes it in the soma, and sends output through the axon.
- Artificial Neuron: Receives input values, applies weights, sums them, passes the result through an activation function, and outputs a value.

A diagram of a biological neuron

An abstract representation of an artificial neuron
Examples
This example demonstrates how an artificial neuron processes input using weights, bias, and an activation function:
import numpy as np
# Sigmoid activation function
def sigmoid(x):
return 1 / (1 + np.exp(-x))
# Artificial neuron computation
def artificial_neuron(inputs, weights, bias):
weighted_sum = np.dot(inputs, weights) + bias
return sigmoid(weighted_sum)
# Example inputs
inputs = np.array([0.7, 0.3])
weights = np.array([0.6, 0.4])
bias = 0.1
output = artificial_neuron(inputs, weights, bias)
print("Neuron Output:", output)
This code performs the following:
- Computes a weighted sum of the input features
- Adds a bias term
- Applies a sigmoid activation function
This simplified artificial neuron is the foundation of deeper layers in neural networks.
Real-World Applications
Brain-Inspired Computing
Understanding biological neurons has inspired developments in neuromorphic chips and brain-computer interfaces.
Neural Networks in AI
Artificial neurons are the core units of deep learning models used in speech recognition, computer vision, and NLP.
Medical Imaging
Artificial neurons help mimic visual cortex behavior to detect anomalies in radiological scans like X-rays and MRIs.
Resources
Recommended Books
- Deep Learning by Ian Goodfellow
- Neuronal Dynamics by Wulfram Gerstner
Interview Questions
What is a biological neuron?
A biological neuron is a cell in the brain that transmits electrical signals. It consists of dendrites (input), soma (cell body), and axon (output).
What is an artificial neuron?
An artificial neuron is a mathematical model that receives input, applies weights and bias, sums them, and passes the result through an activation function to produce output.
How do artificial neurons simulate biological neurons?
They mimic the signal processing of biological neurons through the use of weighted inputs, non-linear activation, and output signals. The key difference is simplification for computational feasibility.
Why are activation functions important in artificial neurons?
Activation functions introduce non-linearity, enabling the network to learn complex mappings between inputs and outputs. Without them, networks would behave like linear regressors.