Neuroscientists at the University of Cambridge have identified five “major epochs” of brain structure over the course of a human life, as our brains rewire to support different ways of thinking while we grow, mature, and ultimately decline.

A study led by Cambridge’s MRC Cognition and Brain Sciences Unit compared the brains of 3,802 people between zero and ninety years old using datasets of MRI diffusion scans, which map neural connections by tracking how water molecules move through brain tissue.

In a study published in Nature Communications, scientists say they detected five broad phases of brain structure in the average human life, split up by four pivotal “turning points” between birth and death when our brains reconfigure. — Read More

Something I think people continue to have poor intuition for: The space of intelligences is large and animal intelligence (the only kind we’ve ever known) is only a single point, arising from a very specific kind of optimization that is fundamentally distinct from that of our technology. — Read More

Biological brains demonstrate complex neural activity, where neural dynamics are critical to how brains process information. Most artificial neural networks ignore the complexity of individual neurons. We challenge that paradigm. By incorporating neuron-level processing and synchronization, we reintroduce neural timing as a foundational element. We present the Continuous Thought Machine (CTM), a model designed to leverage neural dynamics as its core representation. The CTM has two innovations: (1) neuron-level temporal processing, where each neuron uses unique weight parameters to process incoming histories; and (2) neural synchronization as a latent representation. The CTM aims to strike a balance between neuron abstractions and biological realism. It operates at a level of abstraction that effectively captures essential temporal dynamics while remaining computationally tractable. We demonstrate the CTM’s performance and versatility across a range of tasks, including solving 2D mazes, ImageNet-1K classification, parity computation, and more. Beyond displaying rich internal representations and offering a natural avenue for interpretation owing to its internal process, the CTM is able to perform tasks that require complex sequential reasoning. The CTM can also leverage adaptive compute, where it can stop earlier for simpler tasks, or keep computing when faced with more challenging instances. The goal of this work is to share the CTM and its associated innovations, rather than pushing for new state-of-the-art results. To that end, we believe the CTM represents a significant step toward developing more biologically plausible and powerful artificial intelligence systems. We provide an accompanying interactive online demonstration at this https URL and an extended technical report at this https URL . — Read More

#human

In October, the Roots of Progress Institute organized Progress Conference 2025 to connect people and ideas in the progress movement.

In this dispatch, medical historian Laura Mazer explores the conference’s longevity track, where researchers, economists, and entrepreneurs shared new ways to extend not just lifespan, but healthspan. 

She finds that the frontier of medicine is shifting — from fighting disease to pursuing more life itself. — Read More

In a dark MRI scanner outside Tokyo, a volunteer watches a video of someone hurling themselves off a waterfall. Nearby, a computer digests the brain activity pulsing across millions of neurons. A few moments later, the machine produces a sentence: “A person jumps over a deep water fall on a mountain ridge.”

No one typed those words. No one spoke them. They came directly from the volunteer’s brain activity.

That’s the startling premise of “mind captioning,” a new method developed by Tomoyasu Horikawa and colleagues at NTT Communication Science Laboratories in Japan. Published this week in Science Advances, the system uses a blend of brain imaging and artificial intelligence to generate textual descriptions of what people are seeing — or even visualizing with their mind’s eye — based only on their neural patterns. — Read More

As far as I’m aware, Anthropic is the only AI company with official AGI timelines^[1]: they expect AGI by early 2027. In their recommendations (from March 2025) to the OSTP for the AI action plan they say:

As our CEO Dario Amodei writes in ‘Machines of Loving Grace’, we expect powerful AI systems will emerge in late 2026 or early 2027. Powerful AI systems will have the following properties:

Intellectual capabilities matching or exceeding that of Nobel Prize winners across most disciplines—including biology, computer science, mathematics, and engineering.

They often describe this capability level as a “country of geniuses in a datacenter”. — Read More

Researchers have developed a new method for training artificial intelligence that dramatically improves its speed and energy efficiency by mimicking the structured wiring of the human brain. The approach, detailed in the journal Neurocomputing, creates AI models that can match or even exceed the accuracy of conventional networks while using a small fraction of the computational resources.

The study was motivated by a growing challenge in the field of artificial intelligence: sustainability. Modern AI systems, such as the large language models that power generative AI, have become enormous. They are built with billions of connections, and training them can require vast amounts of electricity and cost tens of millions of dollars. As these models continue to expand, their financial and environmental costs are becoming a significant concern. — Read More

Have you ever asked an AI model what’s on its mind? Or to explain how it came up with its responses? Models will sometimes answer questions like these, but it’s hard to know what to make of their answers. Can AI systems really introspect—that is, can they consider their own thoughts? Or do they just make up plausible-sounding answers when they’re asked to do so?

Understanding whether AI systems can truly introspect has important implications for their transparency and reliability. If models can accurately report on their own internal mechanisms, this could help us understand their reasoning and debug behavioral issues. Beyond these immediate practical considerations, probing for high-level cognitive capabilities like introspection can shape our understanding of what these systems are and how they work. Using interpretability techniques, we’ve started to investigate this question scientifically, and found some surprising results.

Our new research provides evidence for some degree of introspective awareness in our current Claude models, as well as a degree of control over their own internal states. We stress that this introspective capability is still highly unreliable and limited in scope: we do not have evidence that current models can introspect in the same way, or to the same extent, that humans do. Nevertheless, these findings challenge some common intuitions about what language models are capable of—and since we found that the most capable models we tested (Claude Opus 4 and 4.1) performed the best on our tests of introspection, we think it’s likely that AI models’ introspective capabilities will continue to grow more sophisticated in the future. — Read More

Reasoning, the process of devising and executing complex goal-oriented action sequences, remains a critical challenge in AI. Current large language models (LLMs) primarily employ Chain-of-Thought (CoT) techniques, which suffer from brittle task decomposition, extensive data requirements, and high latency. Inspired by the hierarchical and multi-timescale processing in the human brain, we propose the Hierarchical Reasoning Model (HRM), a novel recurrent architecture that attains significant computational depth while maintaining both training stability and efficiency. HRM executes sequential reasoning tasks in a single forward pass without explicit supervision of the intermediate process, through two interdependent recurrent modules: a high-level module responsible for slow, abstract planning, and a low-level module handling rapid, detailed computations. With only 27 million parameters, HRM achieves exceptional performance on complex reasoning tasks using only 1000 training samples. The model operates without pre-training or CoT data, yet achieves nearly perfect performance on challenging tasks including complex Sudoku puzzles and optimal path finding in large mazes. Furthermore, HRM outperforms much larger models with significantly longer context windows on the Abstraction and Reasoning Corpus (ARC), a key benchmark for measuring artificial general intelligence capabilities. These results underscore HRM’s potential as a transformative advancement toward universal computation and general-purpose reasoning systems. — Read More

#human

The hierarchical reasoning model (HRM) system is modeled on the way the human brain processes complex information, and it outperformed leading LLMs in a notoriously hard-to-beat benchmark.

Scientists have developed a new type of artificial intelligence (AI) model that can reason differently from most large language models (LLMs) like ChatGPT, resulting in much better performance in key benchmarks.

The new reasoning AI, called a hierarchical reasoning model (HRM), is inspired by the hierarchical and multi-timescale processing in the human brain — the way different brain regions integrate information over varying durations (from milliseconds to minutes). — Read More