April 24, 2024

The Free-Energy Principle Explains the Brain – Optimizing Neural Networks for Efficiency

The RIKEN Center for Brain Science (CBS) in Japan, in addition to associates, has shown that the free-energy principle can describe how neural networks are optimized for performance. Published in the scientific journal Communications Biology, the research study first reveals how the free-energy principle is the basis for any neural network that minimizes energy cost. As proof-of-concept, it shows how an energy lessening neural network can resolve labyrinths. This finding will work for evaluating impaired brain function in believed conditions along with for creating enhanced neural networks for expert system.
Biological optimization is a natural procedure that makes our bodies and habits as effective as possible. A behavioral example can be seen in the shift that felines make from running to galloping. Far from being random, the switch happens precisely at the speed when the amount of energy it takes to gallop becomes less that it takes to run. In the brain, neural networks are optimized to permit effective control of habits and transmission of information, while still keeping the capability to adjust and reconfigure to altering environments.

The RIKEN Center for Brain Science (CBS) in Japan, along with colleagues, has shown that the free-energy principle can describe how neural networks are optimized for efficiency. Once they developed that neural networks in theory follow the free-energy principle, they checked the theory utilizing simulations. The neural networks self-organized by altering the strength of their neural connections and associating previous decisions with future outcomes. In this case, the neural networks can be seen as being governed by the free-energy concept, which allowed it to discover the proper route through a labyrinth through trial and error in a statistically optimum manner.
These guidelines, along with the scientists new reverse engineering technique, can be utilized to study neural networks for decision-making in individuals with believed disorders such as schizophrenia and anticipate the aspects of their neural networks that have actually been modified.

Starting from the left, the representative requires to reach the ideal edge of the labyrinth within a certain quantity of steps (time). The agent solves the labyrinth utilizing adaptive learning that follows the free-energy concept.
As with the basic cost/benefit calculation that can anticipate the speed that a feline will begin to gallop, researchers at RIKEN CBS are attempting to discover the fundamental mathematical concepts that underly how neural networks self-optimize. The free-energy principle follows a concept called Bayesian reasoning, which is the secret. In this system, an agent is constantly updated by brand-new incoming sensory data, as well as its own past outputs, or choices. The researchers compared the free-energy principle with reputable rules that manage how the strength of neural connections within a network can be altered by changes in sensory input.
” We were able to show that basic neural networks, which include delayed modulation of Hebbian plasticity, carry out planning and adaptive behavioral control by taking their previous choices into account,” says first author and Unit Leader Takuya Isomura. “Importantly, they do so the exact same way that they would when following the free-energy concept.”
General view of a solved labyrinth. Beginning from the left, the agent requires to reach the right edge of the maze within a specific amount of steps (time). The labyrinth was resolved following the totally free energy principle.
They checked the theory using simulations once they developed that neural networks in theory follow the free-energy principle. The neural networks self-organized by altering the strength of their neural connections and associating past decisions with future results. In this case, the neural networks can be deemed being governed by the free-energy concept, which enabled it to find out the proper path through a labyrinth through trial and error in a statistically optimal way.
These findings point toward a set of universal mathematical guidelines that explain how neural networks self-optimize. As Isomura discusses, “Our findings guarantee that an arbitrary neural network can be cast as a representative that follows the free-energy principle, supplying a universal characterization for the brain.” These rules, in addition to the researchers new reverse engineering method, can be used to study neural networks for decision-making in individuals with thought disorders such as schizophrenia and forecast the aspects of their neural networks that have been altered.
Another practical use for these universal mathematical rules might be in the field of expert system, specifically those that designers hope will be able to efficiently find out, anticipate, strategy, and make choices. “Our theory can significantly reduce the complexity of developing self-learning neuromorphic hardware to carry out different types of tasks, which will be essential for a next-generation expert system,” says Isomura.
Recommendation: 14 January 2022, Communications Biology.DOI: 10.1038/ s42003-021-02994-2.