Decoding Complex Behaviors
Before we head over to the algorithm, we need to talk about the ants first.
The behavior of an ant community resembles the organization of neurons into a functioning brain, Hölldobler said. “Each neuron is relatively dumb, but if you take billions of neurons, they interact in a way that we have only scratched the surface of understanding.”
Reference: The remarkable self-organization of ants | The Guardians
Q: How simple individual interactions can give rise to complex group behaviors?
A: There are three key elements transform simple interactions among individual worker ants into complex group behaviors: Epigenetic Rules, Stigmergy, Self-Organization.
1. Epigenetic Rules
You can think of it as a social algorithm that individual ants follow based on their sensory inputs and interactions with their environment. These rules could consist of binary decision points that determine an ant’s behavior in response to specific stimuli or conditions.
These genetically inherited rules play active role of decentralized, but complex group behaviors in ant colonies. For instance, one binary algorithm with three successive decision points has only eight outcomes. But seven such algorithms in combination have over 2 million outcomes.
Then you might think ants are mere automatons blindly following genetic rules. But that’s not true. Ants can also learn from experience through a process called Stigmergy.
2. Stigmergy
It is a mechanism of indirect coordination in social insect colonies, where individual agents’ actions modify the environment, leaving cues or “signs” that influence the behavior of other agents. This feedback loop between action and environment drives collective behavior and self-organization.
3. Self-Organization
It refers to the spontaneous emergence of complex, coordinated behavior from the interactions of individual agents without centralized control. This is the result of epigenetic rules and stigmergy which shows problem-solving and strong adaptation in ant colony.
Wait, but what if we can manipulate their genetics and reprogram their epigenetic rules?
Complex Behaviors into Algorithms
1. Noise Wavetable Synthesis
Just as many worker ants come together to form a large colony, I wanted to use the concept of multiple simple sound elements coming together to create a complex soundscape.
First, I created a short, single-cycle noise waveform consisting of 512 samples. The value of each sample changes based on parameters such as offset and scale.
Each sample can be seen as analogous to an individual ant, where their combined movement forms a dynamic, ever-evolving waveform that resembles an active ant colony. The way these samples interact and move according to the parameters reflects the concept of Epigenetic Rules.
This patch is stolen from inspired by Umut Eldem’s Procedural Wavetable Synthesis Tutorial from his YouTube Channel.
2. Trpoical Additive Synthesis
Tropical Additive Synthesis is distinct in that each voice influences the others.
Unlike traditional additive synthesis, where signals are simply summed together, this approach calculates the minimum value between two signals at a time. The result is then successively combined with the next signal, continually calculating the minimum value in a chain-like process.
This unique process not only creates interesting texture of sound, but also mirrors the concept of Stigmergy by having each voice influence the subsequent ones through a chain of minimum calculations, akin to how individual actions leave traces that guide the behavior of others.
I used procedural wavetable synthesis for each voice, multiplying the fundamental frequency by 2, 3, 5, and 7 to create interesting combinations of partials.
This method is devised by Giorgio Sancristoforo. Here is his academic paper, and YouTube Video.
