History NinetyPercentOfYourBrain / LiveActionTV

* ''Series/MyFavoriteMartian'': Cited by "Uncle Martin" as one of the reasons Martians are so much more advanced and intelligent than human beings. Martians use all of their brains, while earthlings only use a small percentage of theirs.
* ''Series/{{Alphas}}'': Stanton Parrish has a variation of this: He has the ability to consciously control every process in his brain, even those that are not consciously controlled in ordinary humans. This makes him able to instantly recover from any injury and prevents him from aging. However, it comes with several downsides: His emotional relationships with others are disrupted, making him similar to a [[TheSociopath sociopath]] and his ability to retain memories is disrupted to an extent (likely due to the fact that his brain, powerful as it is, still lacks the capacity to hold over 200 years worth of memories all at once.)

* Referred to in the {{premiere}} of ''Series/{{Heroes}}'' as an example of one way humanity might make a sudden evolutionary leap, but then mercifully dropped. Only to be brought back up in season three, in a speech by Sylar.

* ''Franchise/StargateVerse'': The idea that 90% of the brain is unused becomes a major plot point of the Ascension MythArc within both ''Series/StargateSG1'' and ''Series/StargateAtlantis''. To be able to AscendToAHigherPlaneOfExistence without the aid of an already-Ascended being, the brain must become fully active. As the human brain activates an increasing percentage of the brain, they begin to develop special abilities, such as the ability to [[HealingHands heal with a touch]], or [[{{Telepathy}} read minds]] or [[MindOverMatter move objects with the mind]]. Usually, such a human will only develop a single ability, but as they get closer to the threshold for Ascension, they begin to display multiple abilities. In ''SG-1'', the Goa'uld are ever in search of powerful hosts to parasitise, so a rare few have experimented with technology to force humans to develop these abilities or even to actually be capable of taking a Goa'uld into Ascension. ''Atlantis'' expands on ''SG-1'' when an ancient technological device is found that's supposed to help people artificially reach Ascension by forcibly and gradually awakening the inactive 90%. The catch is that this isn't how the brain is supposed to naturally function and it therefore brings the modified human to the point of permanent seizure. The machine therefore forces the modified human to either Ascend or die.[[note]]The Ancients were a group of humans who'd evolved to have these mental abilities and eventually figured out Ascension. But this was a natural evolution over millions of years, meaning that the Ancients' brains were biologically different from those of modern humans in order to withstand using said powers. The "Ascension machine" forcibly unlocks the abilities in a brain that's ''not'' biologically adapted to them, making it the brain equivalent of permanent UninhibitedMusclePower.[[/note]]

* ''Series/JohnDoe'' actually acknowledges that only about 10% is in use at any given time but implies that tapping into the other 90% at the same time is what allows some of the characters to use their psychic abilities.
* In ''Series/{{Seinfeld}}'', when George stopped having sex, his brain was free to do other things, accounting for his sudden burst of knowledge. Jerry compared George's brain to a cabbage, with a tiny leaf being the part he normally devoted to anything that wasn't sex. This seems to work the opposite way for women (as shown with Elaine's sudden stupidity), by which Jerry meant that most of men's brainpower is normally invested toward obtaining sex, while a woman always has men available to take care of her sexual needs ''for'' her and never has to think about it herself; therefore a celibate man becomes super-intelligent since his brain is freed up, while a celibate woman becomes super-stupid since she loses all her brainpower into thinking about sex.
* In ''Series/{{Fringe}}'', the 10% fallacy is averted only to be replaced with a different (even more absurd) rationalization. [[spoiler:A MadScientist several decades in the past developed a drug that prevents babies from losing the natural potential they have at birth.]] In a DoubleSubversion the MadScientist in question fails completely in clinical trials only to be proven right when [[spoiler:Olivia]] develops psychic powers. Maybe.
** Another subversion on that show: The reason Walter is mentally askew is that [[spoiler:10% of his physical brain was removed and implanted in other people's brains, giving them all bits and pieces of a complex design, in a bit of Lego brain surgery. Getting back that 10% puts him on track to solving an important puzzle]].

* The main plot line for an episode of ''Series/HoneyIShrunkTheKids''. To make matters sillier, accessing the other 90% gave the character in question godlike powers. All this was caused by a device that was established in a previous episode to be used for [[FreakyFridayFlip brain-swapping]].
* In ''Series/StarTrekDeepSpaceNine'', this is cited as why Dr. Bashir can lose a portion of his brain and be completely fine (this was before Bashir was {{Retcon}}ned to be super-intelligent.) It's absolutely not true and is in fact one of the ways we know the 10% thing is a myth; there is almost no part of the brain we can lose without suffering loss of ability.
* Spoofed in an Italian RealTrailerFakeMovie parody of ''Limitless'', mercilessly titled ''Italiano Medio'' (''[[SelfDeprecation Average Italian]]'').
-->'''Protagonist's friend:''' You know that story, that we use only twenty percent of our brain? ''[hands him pill]''\\
'''Protagonist:''' OK, I'll try it just out of curiosity. ''[swallows pill]''\\
'''Protagonist's friend:''' With this, you'll only use ''two percent''.
* Disproven on ''Series/{{Mythbusters}}'', Tory's brain scans showed him using 15-30% of his brain, depending on what he was doing.
* Referenced in episode 5 of ''Series/AlmostHuman'' where an alleged [[ISeeDeadPeople spirit medium]] says her powers are the result of the Cerebellux procedure, which enhances use of brain pathways.
* Referenced in the first episode of ''Series/TwelveMonkeys'', when scans of Cole's brain reveal that he's using the entirety of his brain. In a twist, the researchers point out that this ''should'' be a Grand Mal seizure, except it's somehow organized and controlled, turning him into a human computer calculating something obscenely complex. They don't know what he's calculating, but the audience knows that he's a time traveler who has been modified to survive the journey, implying that this is part of the process.
* {{Defied|Trope}} on ''Series/AgentsOfSHIELD'', where Dr. Holden Radcliff explains that it's a myth that we only use 10% of our brains.
* ''Series/NightMan'': When Johnny Domino gets struck by lightning and starts hearing other people's thoughts, this is the explanation offered by the medical consultant on psychic phenomena--who's apparently been spearheading our side of an ESP race with the Soviet Union.
* ''Series/BirdsOfPrey2002'': Barbara claims that ordinary humans use only five percent of their brains, but metahumans far more. Dinah uses fifty percent, her scans reveal.
* {{Discussed|Trope}} and {{defied|Trope}} in ''Series/{{Limitless}}''. [[spoiler:Brian attends a party where everyone there is on low-grade NZT.]] He hears someone saying that you only use ten percent of your brain and that the pill works by allowing you to use more. Brian responds by pointing out that it's a myth.
* Surprisingly played straight in the episode "[[Recap/BlackMirrorBlackMuseum Black Museum]]" of ''Series/BlackMirror''. In the second segment, a man is informed that human beings use only 40% of their brains, so they could [[BrainUploading upload]] the consciousness of his comatose girlfriend into the "empty space" of his own brain, allowing her mind to "take the passenger's seat" on his mind. It [[GoneHorriblyWrong ends badly]].

* ''Franchise/StargateVerse'': The idea that 90% of the brain is unused becomes a major plot point of the Ascension MythArc within both ''Series/StargateSG1'' and ''Series/StargateAtlantis''. To be able to AscendToAHigherPlaneOfExistence without the aid of an already-Ascended being, the brain must become fully active. As the human brain activates an increasing percentage of the brain, they begin to develop special abilities, such as the ability to [[HealingHands heal with a touch]], or [[{{Telepathy}} read minds]] or [[MindOverMatter move objects with the mind]]. Usually, such a human will only develop a single ability, but as they get closer to the threshold for Ascension, they begin to display multiple abilities. In ''SG-1'', the Goa'uld are ever in search of powerful hosts to parasitise, so a rare few have experimented with technology to force humans to develop these abilities or even to actually be capable of taking a Goa'uld into Ascension. ''Atlantis'' expands on ''SG-1'' when an ancient technological device is found that's supposed to help people artificially reach Ascension by forcibly and gradually awakening the inactive 90%. The catch is that this isn't how the brain is supposed to naturally function and it therefore brings the modified human to the point of permanent seizure. The machine therefore forces the modified human to either Ascend or die.

* Discussed and defied in ''Series/{{Limitless}}''. [[spoiler:Brian attends a party where everyone there is on low-grade NZT]]. He hears someone saying that you only use ten percent of your brain and that the pill works by allowing you to use more. Brian responds by pointing out that it's a myth.
* Surprisingly played straight in the episode "[[Recap/BlackMirrorBlackMuseum Black Museum]]" of ''Series/BlackMirror''. In the second segment, a man is informed that human beings use only 40% of their brains, so they could [[BrainUploading upload]] the consciousness of his comatose girlfriend into the "empty space" of his own brain, allowing her mind to "take the passenger's seat" on his mind. It [[GoneHorriblyWrong ends badly]].