Your Brain is a Time Machine with Dean Buonomano - StarTalk Radio Recap

Podcast: StarTalk Radio

Published: 2026-01-09

Duration: 50 minutes

Guests: Dean Buonomano

Summary

Dean Buonomano discusses how the human brain perceives time differently from man-made clocks, focusing on the brain's unique ability to remember the past and plan for the future. The episode explores whether time is a fundamental aspect of the universe or merely a human construct.

What Happened

Dean Buonomano, a professor of neurobiology and psychology at UCLA, delves into the intricate relationship between the brain and time. He explains how unlike man-made clocks that rely on oscillators, the brain uses dynamics to tell time. This involves a complex interplay of neurons that allows humans to remember the past and project into the future, a cognitive ability known as mental time travel.

The conversation touches on the evolution of timekeeping devices, from sundials to atomic clocks, and the role of time synchronization in societal development, especially during the Industrial Revolution. Dean highlights Galileo's observation of a swinging chandelier, which led to the discovery of pendulum properties, further developed by Christian Huygens into the pendulum clock.

Dean elaborates on the concept of eternalism versus presentism in physics, questioning whether the past, present, and future are equally real. He suggests that the brain's perception of time as a flowing entity might reflect a true aspect of the universe, challenging the notion that time could be merely a construct.

Neuroscience insights reveal that memory storage in the brain differs from computer memory, relying on changes in neuron connections. Dean discusses Hebbian plasticity, where neurons that fire together wire together, and associative synaptoplasticity, which helps recall names when seeing faces.

The episode also explores the biological importance of circadian rhythms, which are evident even in organisms like cyanobacteria. These rhythms help synchronize biological functions with the Earth's rotation, demonstrating time's significance at a molecular level.

Dean expresses skepticism about the potential of brain-machine interfaces to significantly enhance human abilities, contrasting this with Ray Kurzweil's idea of achieving a singularity by merging with AI. He argues that current neuroscience does not support such transformative changes.

Finally, the discussion touches on Stephen Hawking's time travel prevention conjecture and the recursive nature of neuroscience, where the brain studies itself. Dean emphasizes the role of mathematics in understanding complex phenomena, highlighting its importance in capturing non-intuitive aspects of reality.

Key Insights

• The brain tells time using dynamic interactions between neurons, unlike man-made clocks that rely on oscillators. This neuronal interplay enables humans to engage in 'mental time travel,' allowing for the recollection of past events and the anticipation of future ones.
• Circadian rhythms are crucial for synchronizing biological functions with the Earth's rotation and are present even in simple organisms like cyanobacteria. These rhythms highlight the fundamental role of time at a molecular level across diverse life forms.
• Memory storage in the brain relies on changes in neuron connections rather than a fixed location, as seen in computer memory. Hebbian plasticity, where neurons that fire together wire together, and associative synaptoplasticity facilitate the recall of related information, such as names when seeing faces.
• The concept of eternalism versus presentism in physics questions whether the past, present, and future are equally real. The brain's perception of time as flowing may reflect a true aspect of the universe, challenging the idea that time is merely a construct.