CortexCast - A Neuroscience Podcast

What would happen if we truly understood the brain from the bottom up? Prof. Ed Boyden (MIT) explores ground truth, AI, consciousness and the technologies that could reshape neuroscience and, potentially, intelligence itself. What would it take to connect the life of the mind to the machinery of the brain? For this, we may need to look beyond thought, memory, and behaviour at the surface, and instead trace them down to the molecules, circuits, and physical laws from which they emerge. With a sufficiently precise map of this hidden architecture, neuroscience may one day move from simply observing the brain to repairing it, augmenting it, and perhaps even totally rethinking what intelligence itself can become.

In this episode, Yicheng Su, co-president of Oxford University Cortex Club, talks to Ed Boyden, Professor of Neurotechnology at MIT and one of the most influential figures in modern neuroscience. Over several years Professor Boyden has pioneered transformative tools including optogenetics and expansion microscopy, technologies that have completely reshaped how scientists observe, control, and understand the brain.

The conversation today, however, moves beyond the history of these discoveries and instead explores the deeper philosophy behind them. We discuss Boyden’s vision of ground truth in neuroscience: the search for the fundamental building blocks of the brain and the rules by which they interact. From molecularly annotated connectomes to AI-driven models of brain dynamics, from therapeutic possibilities to the ethics of augmentation and neural privacy, we ask what kind of science is needed to link molecules to minds.

Along the way, we also consider how young researchers should choose problems, how different disciplines can converge on neuroscience, and whether the future of intelligence will remain biological, become digital, or take forms we cannot yet imagine.

Why do psychedelics, dreams, and mental illnesses feel so different from everyday awareness? We unpack the Entropic Brain Hypothesis and what it tells us about flexibility, rigidity, and the architecture of conscious experience. Consciousness may not be a stable state, but a delicate balance between structure and freedom. In this episode, we explore the Entropic Brain Hypothesis - a framework proposing that the richness of conscious experience depends on how flexible and unpredictable brain activity becomes. Drawing on research into psychedelics, altered states, and psychiatric disorders, we discuss how shifts in brain entropy may underlie creativity, rigidity of thought, and therapeutic change, offering a new lens on the dynamics of the mind.

Reference: Carhart-Harris, R.L. (2018) The entropic brain – revisited, Neuropharmacology, 142, pp. 167–178. https://doi.org/10.1016/j.neuropharm.2018.03.010

If memory fades or motivation disappears, what remains of the self? In this episode, Professor Masud Husain reflects on how neurological disorders illuminate the fragile yet resilient architecture of human identity Our sense of self feels indivisible - until the brain begins to fracture it. In this episode, we are joined by Professor Masud Husain, neurologist and clinical neuroscientist at the University of Oxford, to explore how the brain’s failures can reveal its deepest workings. Drawing on his award-winning book Our Brains, Our Selves, he shares the stories of patients whose losses of words, memory and willpower challenge our understanding of identity. Along the way, we also engage in philosophical discussions about consciousness and AI. Our conversation is as much about humanity as it is about neuroscience - thoughtful, compassionate, and quietly profound.

How does the human eye transform waves of light into the vivid, detailed experience we call vision? In this episode of CortexCast, we follow photons on their journey from the moment they strike the retina to the point where visual signals begin to take shape. We explore the cascade of biochemical reactions triggered by molecules such as retinal and rhodopsin, the roles of rod and cone cells in night and colour vision, and the vulnerability of the central retina in age-related macular degeneration. We then turn to the networks of bipolar and horizontal cells, where visual information is funnelled, filtered, and sharpened into receptive fields — the brain’s earliest building blocks of images. Along the way, we uncover how a patch of neural tissue at the back of the eye becomes the gateway to our entire visual world.

In this episode, Neddy speaks with Dr. Johannes Kohl on the brain circuitry behind instinctive behaviours like parenting and shares insights for early-career researchers navigating the fast-moving world of neuroscience.