The Rest Is Science — "Cognitive Ghosts"
Professor Hannah Fry & Michael Stevens (Vsauce)
March 17, 2026

Episode Overview

In this thought-provoking episode, Professor Hannah Fry and science educator Michael Stevens (Vsauce) delve into the mysterious world of cognitive ghosts — the strange mental phenomena that blur the line between what we think is real and what actually is. They explore experiences like déjà vu, jamais vu, "the call of the void," and even hallucinated companions, uncovering both the latest science and the humanity behind these spectral quirks of the mind. The discussion also weaves through false memories, media-induced misconceptions, evolutionary hangovers, and how our brains fill in gaps both at the edge of consciousness and at the threshold of death.

Key Topics & Discussion Points

1. The Strangely Familiar: Inducing Artificial Déjà Vu

[00:09–06:09]

• The Word List Experiment: Hannah has Michael (and the audience) count how many words in a list start with S (none do), then quizzes him about which words appeared, including the absent "sleep."
• Artificial Déjà Vu: This triggers a sense of false familiarity; "sleep" fits the theme but wasn’t present. Experiments like this, discussed in "Awareness of Novelty for Strangely Familiar Words" (a déjà vu study), let scientists study the phenomenon in the lab.
• fMRI Findings: Real déjà vu isn't tied to memory recall (hippocampus) but to conflict-resolution (frontal cortex): "Your brain glitching, essentially saying, wait, no, have we been here before? ...This familiarity that I'm feeling is a phantom signal..." — Hannah [06:09]

Quote:
"I would have thought 'sleep' was one of them if I hadn't have been paying very close attention ...Sleep is very conspicuously absent." — Michael [04:00]

2. The Many “Vous”: Jamais Vu, Presque Vu, and More

[09:50–16:55]

• Presque Vu (Tip-of-the-Tongue): Knowing that you know something (like an actor’s name), but being unable to recall it, with the weird experience often shared contagiously by others.
• Jamais Vu: The familiar made suddenly strange, e.g., writing a common word like "door" repeatedly until it loses meaning—70% of test subjects stopped from feeling "peculiar."
• Evolutionary Function: This strangeness may be a "clever technique" for novelty and survival, breaking loops of repetition.

Quote:
"You can sort of take something quite solid and make it into something quite ghostly... take a word, write it out 30 times and it'll start to do something really strange in your brain." — Hannah [12:06]

3. Hard-to-Study Phenomena: Déjà Rêvé & Beyond

[15:35–19:05]

• Déjà Rêvé: The eerie sense that you dreamed something before it happened in real life. Little scientific study exists; most reports come from anecdotal sources.
• Confabulation of Origins: The brain’s trouble tracking where memories come from leads to stories of "past lives," such as the famous case of "Bridey Murphy" — ultimately explained by childhood exposure, not reincarnation.
• Memory as Patchwork: "Remembering is not a perfect replica... we are re-membering — Frankensteining together what happened out of pieces that are slightly different this time." — Michael [20:00]

4. Cognitive Ghosts and Perception: Blindsight

[19:05–24:54]

• Blindsight: People with certain brain injuries are legally blind yet still react to visual stimuli they’re not consciously aware of, fabricating explanations for their behavior.
• No Central Homunculus: Raises the question of whether the self is really a unified entity or a collection of semi-independent "ghostly" subsystems.

Quote:
"You then have to wonder, well who's inside the mind of that little person?... you get an infinite regress. That doesn't explain anything." — Michael [24:54]

5. Ghostly Tuggings: The Call of the Void & Cute Aggression

[25:14–31:35]

• High Place Phenomenon ("Call of the Void"): The feeling of wanting to jump from a height or throw oneself into danger is not a death wish but a confabulation to explain intense fear of falling.
• Cute Aggression: The overwhelming desire to squeeze or "eat up" something adorable is theorized as a homeostatic response—balancing excessive nurturing emotions with aggression.

Quote:
"The instinct we have to protect and...cuddle cute things is so overwhelming that...to bring itself back down to normal, it has to...encourage aggressive behaviors. ...You need to also push it away." — Michael [30:01]

6. Hypnic Jerks & Evolutionary Hangovers

[31:39–37:00]

• Hypnic Jerk: That full-body twitch before sleep, often accompanied by the feeling of falling. It may be a vestigial neural mechanism to prevent falling out of trees, a "ghost from our evolutionary past."
• Old Myths with New Forms: Rituals about salt and crystals (e.g., amethyst "preventing drunkenness") originate from practical customs but have become "ghosts" of forgotten reasons.

7. Media Myths & Tropes: The Coconut Effect

[53:18–60:36]

• Ghosts in Pop Culture: Fictional tropes (e.g., electrocution "zapping," earpiece tapping, falling anvils) shape collective misconceptions.
• The Coconut Effect: When media conventions become so ingrained (like coconut clopping for horse hooves), audiences expect them even when they’re false.

Quote:
"We now need to keep the lie up because otherwise they will be confused. So the Coconut Effect is when you have to lie... just to get your point across. Because to tell the truth would be confusing because we're so divorced from it." — Michael [59:52]

8. Cognitive Ghosts Outside the Mind: Hallucinated Companions

[44:37–52:58]

• Third Man Factor: Shackleton and crew, and many mountaineers, have felt an unexplained, comforting "ghostly companion" during life-threatening endurance expeditions.
• Lab Replication: Neuroscientists in Switzerland used delayed robotic feedback to induce a sensed presence behind participants—demonstrating how sensory glitches can create the illusion of another.

Quote:
"You put someone in a room... a 500 millisecond delay... the brain can no longer reconcile... so it defaults to... there must be someone else in the room with me." — Hannah [50:42]

9. End-of-Life Dreams and Visions

[63:06–69:35]

• Common Experiences: The vast majority of dying patients report vivid dreams of deceased loved ones ("welcoming committee") or journeys.
• Brainwaves at Death: Late-stage gamma wave activity may underlie these experiences, possibly as the brain compensates for loss of sensory input or as a protective, pain-relieving mechanism.
• The Mystery Remains: While some explanations are neurological, others may be more spiritual. These "cognitive ghosts" accompany us to the end, as a source of comfort and closure.

Quote:
"There is still so much that we don't understand... the most important moments of a person's life, as they transition from being alive to being dead... There are still so many unanswered questions." — Hannah [68:43]

Notable Quotes & Moments

• Michael on Confabulation [04:00]:
  "I would have thought sleep was one of them if I hadn't...been paying very close attention...Sleep is very conspicuously absent."
• Hannah on Familiarity and Memory [09:42]:
  "Familiarity and the memory are separate. We can feel that something is familiar. We can know that we know something, but not immediately be able to recall it."
• Michael on Blindsight [22:14]:
  "A non-conscious part of their brain is receiving the visual signal and responding to it, but the awareness is not getting the message."
• Hannah on Jamais Vu [12:06]:
  "Write [a word] out 30 times and it'll start to do something really strange in your brain."
• Michael, media tropes [59:52]:
  "The coconut effect is when you have to lie in some form of communication...because to tell the truth would be confusing because we're so divorced from it."

Timeline of Important Segments

• 00:09–06:09 — The "S-word" memory test and artificial déjà vu
• 09:50–16:55 — Tip-of-tongue (presque vu) and jamais vu explained
• 19:05–24:54 — Blindsight and dissociation of self-awareness
• 25:14–31:35 — High Place phenomenon and cute aggression
• 31:39–37:00 — Hypnic jerk and evolutionary cognitive ghosts
• 44:37–52:58 — Third man factor: ghostly companions & lab studies
• 53:18–60:36 — Media tropes: dead unicorns & the coconut effect
• 63:06–69:35 — End-of-life dreams and visions, gamma brainwaves

Tone & Language

Lively banter, curiosity-driven, occasionally self-deprecating, full of infectious wonder — the episode makes complex neuroscience approachable and blends humor with philosophical depth.

For Further Exploration

• Recommended papers:
  • "Awareness of Novelty for Strangely Familiar Words"
  • "The Induction of Jamais Vu"
• Documentaries/Media referenced:
  • "The Coconut Effect" (TV Tropes)
• Notions covered:
  • Blindsight, Homunculus fallacy, High Place phenomenon (L’appel du vide), Presque vu, Jamais vu, Déjà rêvé, End-of-life visions

Final Thoughts

"Cognitive Ghosts" is a fascinating journey through the haunted halls of the mind. From blips in memory to phantom companions on mountain treks, Fry and Stevens capably show how our sense of reality is far weirder — and more fragile — than we often believe. Whether you’re hoping to understand déjà vu, laugh at media clichés, or reflect on end-of-life mysteries, this episode provides something to fire every curious mind.

"There are other versions of you, other processes separate from your awareness, that are all happening. But even at the end of life, you are certainly not alone. Your brain makes sure of it."
— Michael Stevens [69:01]