Radiolab – "Song of the Cerebellum" (January 30, 2026)

Episode Overview

This episode, hosted by Lulu Miller and Latif Nasser, follows science journalist Rachel Gross’s journey after an unexpected stroke damaged her cerebellum. Initially dismissed as a “motor coordination” issue by doctors, Gross’s subsequent struggles—and her deep dive into neuroscience—reveal a revolutionary understanding of the cerebellum. The episode explores how this “little brain,” long considered responsible only for movement, actually plays a much vaster and more intimate role in shaping our cognition, emotions, and very sense of self.

Key Discussion Points and Insights

1. Rachel Gross’s Story: The Personal Becomes Universal

• The Incident ([01:15]–[04:31])

  • Rachel Gross describes losing her ability to sing karaoke and feeling off in other physical and cognitive ways. She recounts her stroke, the diagnosis of a cerebellar cavernoma, and subsequent surgery.
    • “The notes weren’t translating from my brain to my vocal cords.” — Rachel Gross [02:51]
    • Struggles included slurred speech, illegible handwriting, trouble running, and an inability to fill out her hospital admission form.

• Dismissal of Cerebellar Damage ([05:12]–[06:07])

  • Surgeons reassured her the cerebellum was “redundant” or even “practically vestigial,” likening its removal to losing an appendix.
    • “You can actually take out, like, a third of it, and people don’t even notice.” — Neurosurgeon (via Rachel Gross) [05:41]
  • Despite reassurances, Rachel experienced ongoing issues: slurred speech, timing problems, emotional dysregulation, and changes in her sense of self.

2. Cerebellum Science: From Motor Control to Cognition

• Traditional View ([09:25]–[12:41])

  • The cerebellum (Latin for “little brain”), long considered merely a movement-coordination center, was ignored in most recent neuroscience, often even cropped out of MRIs.
    • “There are MRI machines that don’t cover the cerebellum.” — Rachel Gross [12:19]

• A Paradigm Shift ([12:41]–[16:47])

  • Neurologist Jeremy Schmahmann describes a “complete paradigm shift” in cerebellum science, sparked in part by findings that links exist between cerebellum and upstairs (“thinky”) portions of the brain.
    • “Where we are now is a complete paradigm shift. There’s been a revolution in our thinking about the cerebellum.” — Jeremy Schmahmann [12:57]

• The Human Connection ([16:47]–[19:27])

  • Evolutionary biologist Robert Barton reveals that, evolutionarily, the cerebellum expanded disproportionately in apes and humans compared to other primates.
    • “In the human brain today, although [the cerebellum] is a lot smaller than the neocortex, it has about four times more neurons.” — Robert Barton [18:44]
    • “The cerebellum has about 80% of the brain cells that we have.” — Jeremy Schmahmann [18:58]

• What’s It Really Doing? ([19:55]–[28:57])

  • The cerebellum isn’t just moving muscles—it organizes, sequences, and fine-tunes everything, from grabbing a coffee cup to constructing sentences and regulating emotion.
    • “The cerebellum is also the invisible conductor of your thinking.” — Rachel Gross [27:19]
    • It helps regulate emotional “overshoot and undershoot”—both the physical clumsiness and social/emotional gaffes can emerge from cerebellar damage.
    • Rachel personally attests: “I have to manually do all these things that used to be unconscious and in the background.” [29:24]

3. Rethinking Brain and Identity

• Movement, Thinking, and the Self ([30:07]–[31:18])

  • The Western idea that “thinking” and “moving” are separate is deeply outdated.
    • “Thinking is intrinsically related to the way we move around in the world. … They’re continuous with each other.” — Robert Barton [30:07]

• Cerebellum as the Unseen, Underappreciated Hero ([31:18])

  • “I think of the cerebellum as the Cinderella of brain structures… Well, it’s time Cerebella came to the ball.” — Robert Barton [31:18]

• Rachel’s Emotional Response ([32:00])

  • Knowing the science brings both comfort and grief: “It’s kind of forcing me to dwell on what I have lost, which is this effortless, like, fluidity that I didn’t even realize I had.” — Rachel Gross [32:00]

4. The Plastic Brain: Learning, Recovery, and Motivation

• The Importance of Motivation for Neuroplasticity ([33:41]–[34:29])

  • Neuroscientist David Eagleman emphasizes motivation as the key to brain recovery: “You need the right cocktail of neurotransmitters there for plasticity to happen, and that generally maps onto motivation.” — David Eagleman [34:08]
  • For Rachel, this means karaoke, not tuba: “What I realized was I’m already doing this with karaoke … I practiced at home. I recorded myself. I took voice lessons.” [34:29]

• Karaoke Recovery and the Many Facets of Performance ([36:07]–[37:35])

  • Speech pathologist Alison Hilger highlights the cerebellum’s vast role in singing (breath, vocal fold tension, timing, emotional nuance, audience interaction).
    • “Singing is actually the most complicated, most coordinated movement you will ever do in your body.” — Alison Hilger [36:12]
  • Rachel realizes: “It was in that fluidity and that ease that I felt in those moments that my sense of self was emerging.” [37:35]

• Loss, Adaptation, and Finding Community ([37:57]–[39:52])

  • Despite the grief of lost fluidity, Rachel finds meaning in community and acceptance—joining a choir for stroke survivors, letting go of old notions of control, and appreciating connection in whatever form is possible.

Notable Quotes & Memorable Moments

• The Beginning: Karaoke Gone Wrong ([02:20])
  • “It was really at the chorus that just, like, nothing came out of my mouth. It was just air.” — Rachel Gross
• Surprised by the Brain’s Complexity ([18:58])
  • “The cerebellum has about 80% of the brain cells that we have.” — Jeremy Schmahmann
• Paradigm Shift in Science ([12:57])
  • “Where we are now is a complete paradigm shift. There’s been a revolution in our thinking about the cerebellum.” — Jeremy Schmahmann
• Invisible Organizer ([27:19])
  • “The cerebellum is also the invisible conductor of your thinking.” — Rachel Gross
• Sense of Self and Loss ([32:00])
  • “It’s kind of forcing me to dwell on what I have lost, which is this effortless, like, fluidity that I didn’t even realize I had.” — Rachel Gross
• On the Nature of Thinking ([30:07])
  • “Thinking is intrinsically related to the way we move around in the world.” — Robert Barton
• Motivation for Recovery ([34:08])
  • “Everything is about the motivation for it.” — David Eagleman
• Fluidity and Identity ([37:35])
  • “It was in that fluidity and that ease that I felt in those moments that my sense of self was emerging.” — Rachel Gross
• Letting Go ([39:53])
  • “You do have to let go of some of that. Let go of, like, control and this image of what you should be … and just, like, live fully in the moment that you have now.” — Rachel Gross

Timestamps for Important Segments

| Timestamp | Segment & Topic | |-------------|---------------------------------------------------------------------| | 01:15–04:31 | Rachel’s initial symptoms, hospital visit, and diagnosis | | 05:12–06:07 | The cerebellum described as “redundant” and surgical reassurances | | 09:25–11:01 | History and traditional understanding of the cerebellum | | 12:41–16:47 | Jeremy Schmahmann on the new paradigm and anatomical evidence | | 17:04–19:27 | Robert Barton on cerebellum evolution and neuron counts | | 23:40–28:57 | Patients reveal cerebellar role in cognition, emotion, behavior | | 30:07–31:18 | Philosophical shift: movement, thinking, and the brain’s evolution | | 33:41–34:29 | David Eagleman: Recovery, motivation, and neuroplasticity | | 36:07–37:35 | Alison Hilger: Singing as cerebellum’s complexity | | 37:57–39:52 | Accepting loss, finding new community—Rachel’s choir for survivors | | 42:07–43:44 | Unexpected romance, karaoke brings new connection |

Episode Highlights & Closing Moments

• Serendipitous Ending ([42:07–43:44])

  • Rachel receives a message from someone who saw her perform at karaoke—her “cerebellum injury-inflected” singing caught someone’s attention, leading to a romantic connection.

• Ultimate Message

  • The cerebellum is the often-overlooked “Cinderella” of the brain—intimately tied to not just movement, but thought, emotion, and selfhood.
  • Loss and recovery are intertwined, with meaning found in both striving and acceptance.

Tone and Language

The episode balances scientific curiosity with profound empathy. Rachel Gross’s narrative is both investigative and deeply personal; hosts Lulu Miller and Latif Nasser blend playful banter with respect for the vulnerable, emotional nature of the story.

For Listeners Who Missed the Episode

“Song of the Cerebellum” captures both the marvels of neuroscience and the mysteries still unfolding within the brain. Through Rachel Gross’s journey, listeners are challenged to rethink brain function, recognize the subtle sources of selfhood, and appreciate the hidden depths within all of us—right down to the little “Cinderella” at the base of our skulls.

Recommended quote for reflection:

“Is the self a language that I can relearn? … If I keep pushing through that awkwardness and those moments of losing control, all these glitches and mistakes and kind of backtracking, will that ever feel like me?”
— Rachel Gross [38:57]

For further exploration, check out Radiolab’s episode “Damn it, Basal Ganglia,” also referenced in this show.