Let’s Build a Brain

A closer look at Let’s Build a Brain

What Let’s Build a Brain is

This is an interactive article by Aatish Bhatia and Arkarup Banerjee that shows how very simple neural circuits can produce different behaviors. It builds tiny virtual creatures called sparks and explains how connecting sensory and motor neurons in different ways changes their motion.

What you can do on the page

You can follow step‑by‑step explanations of circuits: a one‑eye spark, two‑eye versions, crossed wiring, and excitatory versus inhibitory connections. The page includes graphics where you can move the light to watch sparks react, and it describes how changing connection strengths produces different preferences among sparks.

The article links to the authors and their work: Arkarup Banerjee’s lab research is mentioned, and Aatish Bhatia’s newsletter and other interactive explanations are promoted.

Who will find this useful

Anyone curious about how simple neuron networks produce behavior - students, educators, or readers who like visual, mechanistic explanations of brains - will find the walkthrough clear and concrete.

The article is also relevant to readers interested in the historical idea behind the sparks: it draws on Valentino Braitenberg’s thought experiments from his book Vehicles: Experiments in Synthetic Psychology.

Questions people ask about Let’s Build a Brain

Can I interact with the simulation?

Yes - the article includes graphics where you can move the light and watch the sparks react.

Does the piece explain why sparks sometimes avoid or attack the light?

Yes - it shows how wiring (crossed connections) and connection type (excitatory versus inhibitory) produce behaviors like turning away from or slowing near the light.

Who wrote the article and where do they work?

The article is by Aatish Bhatia, a science journalist with a Ph.D. in physics, and Arkarup Banerjee, an associate professor of neuroscience at Cold Spring Harbor Laboratory.

Let’s Build a Brain was shared on NexURLs by Nexis on November 4, 2026, in Learning & Books.