Artificial intelligence can now craft award-winning essays and help doctors detect disease with impressive accuracy. Yet when it comes to true mental flexibility, living brains still have the clear advantage.
Humans can adjust to new situations and information with remarkable ease. Learning unfamiliar computer software, trying a new recipe, or figuring out the rules of a new game often happens quickly for people, while AI systems typically struggle to adapt in real time and to learn effectively "on the fly."
In a new study, neuroscientists at Princeton University identify one key reason for this difference. The human brain repeatedly reuses the same cognitive "blocks" across many different situations, combining and recombining them to form new patterns of behavior.
"State-of-the-art AI models can reach human, or even super-human, performance on individual tasks. But they struggle to learn and perform many different tasks," said Tim Buschman, Ph.D., senior author of the study and associate director of the Princeton Neuroscience Institute. "We found that the brain is flexible because it can reuse components of cognition in many different tasks. By snapping together these 'cognitive Legos,' the brain is able to build new tasks."
The research was published on November 26 in the journal Nature.
Compositionality: reusing skills in new situations
If someone already knows how to tune a bicycle, learning to repair a motorcycle can feel more straightforward. That ability to build a new skill out of simpler, familiar ones drawn from related experiences is known as compositionality.
"If you already know how to bake bread, you can use this ability to bake a cake without relearning how to bake from scratch," said Sina Tafazoli, Ph.D., a postdoctoral researcher in the Buschman lab at Princeton and lead author of the new study. "You repurpose existing skills -- using an oven, measuring ingredients, kneading dough -- and combine them with new ones, like whipping batter and making frosting, to create something entirely different."
Until now, evidence for exactly how the brain supports this kind of flexible, compositional thinking has been limited and sometimes conflicting.
To get a clearer picture, Tafazoli trained two male rhesus macaques to carry out three related tasks while recording activity across their brains.
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