Decoding the Brain: How AI Models Learn to "See" Like Us EP 53

Decoding the Brain: How AI Models Learn to "See" Like Us

Have you ever wondered if the way an AI sees the world is anything like how you do? It's a fascinating question that researchers are constantly exploring, and new studies are bringing us closer to understanding the surprising similarities between advanced artificial intelligence models and the human brain.

A recent study delved deep into what factors actually make AI models develop representations of images that resemble those in our own brains. Far from being a simple imitation, this convergence offers insights into the universal principles of information processing that might be shared across all neural networks, both biological and artificial.

The AI That Learns to See: DINOv3

The researchers in this study used a cutting-edge artificial intelligence model called DINOv3, a self-supervised vision transformer, to investigate this question. Unlike some AI models that rely on vast amounts of human-labeled data, DINOv3 learns by figuring out patterns in images on its own.

To understand what makes DINOv3 "brain-like," the researchers systematically varied three key factors during its training:

• Model Size (Architecture):They trained different versions of DINOv3, from small to giant.
• Training Amount (Recipe):They observed how the model's representations changed from the very beginning of training up to extensive training steps.
• Image Type (Data):They trained models on different kinds of natural images: human-centric photos (like what we see every day), satellite images, and even biological cellular data.

To compare the AI models' "sight" to human vision, they used advanced brain imaging techniques:

• fMRI (functional Magnetic Resonance Imaging):Provided high spatial resolution to see which brain regions were active.
• MEG (Magneto-Encephalography):Offered high temporal resolution to capture the brain's activity over time.

They then measured the brain-model similarity using three metrics: overall representational similarity (encoding score), topographical organization (spatial score), and temporal dynamics (temporal score).

The Surprising Factors Shaping Brain-Like AI

The study revealed several critical insights into how AI comes to "see" the world like humans:

• All Factors Mattered:The researchers found that model size, training amount, and image type all independently and interactively influenced how brain-like the AI's representations became. This means it's not just one magic ingredient but a complex interplay.
• Bigger is (Often) Better:Larger DINOv3 models consistently achieved higher brain-similarity scores. Importantly, these larger models were particularly better at aligning with the representations in higher-level cortical areas of the brain, such as the prefrontal cortex, rather than just the basic visual areas. This suggests that more complex artificial intelligence architectures might be necessary to capture the brain's intricate processing.
• Learning Takes Time, and in Stages:One of the most striking findings was the chronological emergence of brain-like representations.

    ◦ Early in training, the AI models quickly aligned with the early representations of our sensory cortices (the parts of the brain that process basic visual input like lines and edges).

    ◦ However, aligning with the late and prefrontal representations of the brain required considerably more training data.

    ◦ This "developmental trajectory" in the AI model mirrors the biological development of the human brain, where basic sensory processing matures earlier than complex cognitive functions.

• Human-Centric Data is Key:The type of images the AI was trained on made a significant difference. Models trained on human-centric images (like photos from web posts) achieved the highest brain-similarity scores across all metrics, compared to those trained on satellite or cellular images. While non-human-centric data could still help the AI bootstrap early visual representations, human-centric data proved critical for a fuller alignment with how our brains process visual input. This highlights the importance of "ecologically valid data"—data that reflects the visual experiences our brains are naturally exposed to.

AI Models Mirroring Brain Development

Perhaps the most profound finding connects artificial intelligence development directly to human brain biology. The brain areas that the AI models aligned with last during their training were precisely those in the human brain known for:

• Greater developmental expansion(they grow more from infancy to adulthood).
• Larger cortical thickness.
• Slower intrinsic timescales(they process information more slowly).
• Lower levels of myelination(myelin helps speed up neural transmission, so less mye