Journey to the Center of the Mind



""Come along if you care

Come along if you dare

Take a ride to the land inside of your mind""

- The Amboy Dukes, "Journey to the Center of the Mind"

"You lock the door

And throw away the key

There's someone in my head but it's not me"

- Pink Floyd, "Brain Damage"

A relative to Fantastic Voyage Plot, except instead of traveling into another character's physical body via Applied Phlebotinum, they enter their mind. The problem this is supposed to solve can range from recurring nightmares to memory loss to psychological disorders, and even the odd Convenient Coma. Expect to see some psychological aspects of the character manifested as physical beings, a la Herman's Head (See Ghost in The Machine and Enemy Without). Since it lays bare all the innermost thoughts and feelings of a character, it can be used as an extreme case of the Big Ego, Hidden Depths or In Another Man's Shoes.

Often the justification for a Mind Screw episode.

A closely related plot is the one where the main characters enter the dreams of their sleeping cast mates or the Happy Place of comatose friends. If there's Mind Control involved, expect a Battle in The Center of The Mind to free their friend in an Orphean Rescue.

Oddly, rarely shown as a malicious act when done by the heroes, despite being deeply personally invasive and usually without consent. This may be justifiable, however, if the owner of the mind would otherwise get/remain crazy/in a coma, or, in short, when serious issues are at stake. Less justifiable when done to solve minor issues.

Compare the malicious version, Mind Probe, or a single person variant, the Vision Quest.

Anime & Manga

 * In one episode of Irresponsible Captain Tylor, a typically strange turn of events leads to Yuriko and Azalyn entering the mind of a comatose Tylor.
 * Interesting variation on the trope: Instead of one character doing this to another, the audience takes a Journey to The Center of The Mind into the protagonist's head in the final episode(s) of Neon Genesis Evangelion.
 * Yu-Gi-Oh: Shadi goes into Yugi's mind to investigate why he has a Millennium Item. He's understandably surprised to find not one but two minds there!
 * "By the way, have you ever seen Labyrinth?"
 * Yu-Gi-Oh GX: During Jim's duel with Judai while he's possessed by Haou, Jim uses his magic replacement eye to take a trip into Judai's mind to figure out what's going on with him. He finds the former Ace surrounded by images of his dead friends and listening to to a repetitive loop of Hannibal Lectures from that season's villains, sinking deeper into despair and farther out of reach.
 * In episode 12 of Pani Poni Dash, alien technology causes Rebecca's class to get stuck in Himeko's dreamscape, where they encounter all matter of weirdness, including Idiot Hair on everything, a restaurant that serves nothing but crabs, and a fat thug who claims to be the Archangel Michael guarding the door to Himeko's heart.
 * In the X 1999 anime and manga, the Taoist mystic Subaru takes a trip Within . He first used this technique in Tokyo Babylon, where he entered the mind of a rape victim to help her deal with the trauma.
 * The ending of Darker Than Black turns into a Neon Genesis Evangelion-esque Journey to The Center of The Mind for
 * It isn't the first time something similar happened, either. This is the problem with being in an Eldritch Location with an Amplifier Artifact near someone who and doesn't know it; Psychoactive Powers tend to ensue.
 * With the help of a stray Unown, the Pokémon anime's heroes go into a Larvitar's mind to find out what exactly went wrong to make him so untrusting of humans: an incident involving poachers that left its Tyranitar mother injured and the two separated when it was still in its egg!
 * Utilized for psychotherapy via Dream Land in Paprika.
 * There is a machine that allows people to do this in Chrono Crusade. They call it Diving, and the user undergoes an Out-of-Clothes Experience while visiting the patient's psyche.
 * In the Fullmetal Alchemist movie, Noa, who has a talent for reading minds, takes the liberty of looking into Edward's past while he's asleep. In doing this she learns about his home and his brother.
 * Happens throughout Kaiba with the help of a small machine. People's minds are all libraries of various kinds, with their memories as books.
 * Happens frequently in Ergo Proxy, as this is the Proxies' preferred method of combat.
 * If Road from D Gray Man is not stabbing your eyes out for the hell of it, she enters your mind so that she can start raping it. did not enjoy the little tour of his own subconscious fears and insecurities.
 * At one point in the series Sailor Moon and the other senshi enter Chibiusa's mind to help her.
 * Whenever it's done in Mahou Sensei Negima (via magic, of course), it involves an Out-of-Clothes Experience.
 * In Seikimatsu Occult Gakuin, the school activities include a Flatline Plotline. The Spirit World is depicted as this trope.
 * An interrogation technique in Naruto takes the form of this. The interrogators project themselves into their victim's head, often needing to fight through layers of protective genjutsu, until they reach the core mind. From there they can access and view memories.
 * The seal on the Kyuubi takes a form of this for Naruto. In the first part he needed to make a long trek through a maze of flooded corridors to communicate with the Kyuubi; by the second part the distance between their minds had been greatly reduced.
 * In Ciel the Last Autumn Story, one of the main characters falls into a coma after overusing her magic powers, and her closest friend and love interest have to pull one of these in order for them all to wake up safely.

Comicbooks

 * Nightmask of The New Universe had the ability to enter anyone's dreams, which he used to assist in psychotherapy.
 * In a villainous example, one story arc of the Sleepwalker comics had the Thought Police enter the mind of Sleepwalker's human host in an attempt to capture him.
 * The final arc of Spider-Girl has the titular heroine journeying into both her own mind and the mind of her father, the original Spider-Man. The first version is a typical Mind Screw, but the latter is much more serious, as May struggles to save her dad from being possessed by the Green Goblin.
 * The Don Rosa Scrooge McDuck story "The Dream of a Lifetime" has the Beagle Boys using an invention stolen from Gyro Gearloose to enter Scrooge's mind, where they end up reliving some of his many adventures. Donald Duck ends up going in after them, to try and wake them up before Scrooge wakes up with disastrous consequences for him and the Beagle Boys.
 * Done in Paul Jenkins' run on Incredible Hulk. Bruce Banner travels into his own mind to try and strike a deal with his Hulk personalities, each of which represents a different aspect of Bruce.
 * Grant Morrison's run on New X-Men featured a trippy, one-issue-long sequence with no dialogue (save one line on the last page), in which telepaths Jean Grey and Emma Frost travel into Cassandra Nova's mind in order to rescue Professor Xavier. In a later issue, when Jean discovers, the confrontation takes place in Emma's mind.
 * In Wolverine
 * There was an issue of The Brave and The Bold (#31 of the revived series) that had The Atom literally shrinking down inside of the Joker's brain at the request of some scientists. He is given a tour through Joker's childhood after accidentally walking through the wrong synapses and absorbing some memories.
 * Doctor Strange does this quite a bit. A person's mind seems act as a sort of pocket dimension, with all associated imagery.
 * In a Justice League of America Fill-in issue by J.M. Dematteis, Martian Manhunter decides to show The Spectre that there is good in everyone by taking him, along with the rest of the League, into the mind of an "evil" person.

Films

 * This is the entire premise of Being John Malkovich. Even Malkovich goes into his own mind, and the resulting surrealistic horror might qualify as Nightmare Fuel if it weren't so goddamn funny.
 * This is the whole point of the movie The Cell, where in trying to connect to those who are in a comatose state, this normally therapeutic tool then gets used as a Mind Probe on a serial killer by the police and
 * Fight Club: "Slide!"
 * Inception:
 * Zardoz. Much mirror-maze self confrontation/realization with a loin-clothed Sean Connery and a Omnipotent Computer Brain.
 * The Imaginarium of Doctor Parnassus has it happen again and again; the Imaginarium is kinda-sorta its title character's mind combined with the explorers' imagination(s).
 * Dreamscape revolves around government agents entering people's dreams for various purposes.

Literature

 * The Greg Bear novel Queen of Angels has a climactic trip into "the country of the mind" of a killer.
 * The Japanese novel Paprika (and the 2006 anime movie based on the novel) revolves around a device that lets the user enter another person's dreams, and what happens when said device falls into the wrong hands.
 * The sixth novel in the Young Wizards series, A Wizard Alone, has Nita and Kit travel into the mind of an autistic wizard.
 * And, of course, The Dream Master by Roger Zelazny.
 * This also happened during A Hat Full of Sky by Terry Pratchett. The Nac Mac Feegles entered Tiffany's mind in order to
 * There are also some short scenes in Thud! which show Sam Vimes' mind as a permanently rainy, yet apparently empty city.
 * In Timewyrm: Revelation, one of the very first Doctor Who New Adventures novels, Ace gets pulled into the Seventh Doctor's psyche by the titular Timewyrm.
 * In Simon Spurrier's Warhammer 40000 Night Lords novel Lord of the Night, the eldar trap Sahaal in his own mind. The psyker Mita is caught with him and at first thinks it's a daemon world. She explains the situation, he persuades her, and she frees him.
 * The protagonist of Norman Spinrad's Carcinoma Angels goes on a journey into his own mind to attempt to cure his cancer. It works, but in a twist ending
 * In Andreas D. Hesse's Schatten über Fraterna (lit. "Shadows above Fraterna"), almost the whole story takes place in the protagonist's sister's mind, after his sister literally fell into a coma and he himself got hit by a truck. As every person his sister knows has an alter ego in her mind, equipped with power according to the relationship to her, he slips into the body of the duke of Fraterna, only to notice that the personification of his evil side has just stolen the most vital artifact in the whole world (the reason for his sister's coma). He is assigned by the queen (the representation of his sister) to retrieve said artifact.
 * The protagonists of James Morrow's Blameless in Abaddon enter the mind of God Himself, where they converse with Biblical characters and dinosaurs playing Scrabble. They discover that God is a Platonist, and hence everything they encounter is the Idea/Essence of that thing. They also learn some counter-arguments to the best theodicies ; they intend to use them in the prosecution of an upcoming trial against… God Himself.
 * This trope is a typical day at work for a soulscaper in Burying the Shadow. They heal injuries and illnesses of the mind from the inside.

Live-Action TV
"House: God, I hate Beer brand beer!"
 * In a Star Trek the Next Generation episode, Counselor Troi enlists the aid of a powerful alien telepath to enter the mind of her comatose mother.
 * In another, Picard and company attach Data's brain to the holodeck to enter his dreams so they can learn what he doesn't know that he knows.
 * In Deep Space Nine, O'Brien and Bashir interrogate a special agent this way. He turns the tables on them by.
 * Red Dwarf: "Terrorform," the gang has to rescue Rimmer from his personal demons as manifested on a moon that has transformed itself into a manifestation of his psyche. In "Gunmen of the Apocalypse," the crew link a virtual reality machine up to Kryten's brain and enter his subconscious to help him fight off a computer virus that he had contracted in order to come up with an antidote.
 * Natch, there's a Buffy example. When Buffy goes catatonic in "Weight of the World," Willow uses magic to enter her mind.
 * Likewise in the Angel episode "Orpheus," the eponymous drug traps both Angelus and Faith inside his memories until his soul is restored.
 * In a Supernatural dream episode, Bobby was trying to get killed by his dead wife (who he killed), Dean fought and killed a doppelganger personifying his massive ball of self-loathing and Sam was tied down in a Christ-pose and used his psychic powers(?) to kill the Big Bad of the episode by bringing back his Abusive Dad.
 * In the 6th season's finale,.
 * And again in the 7th season mid-season finale, when.
 * In Heroes, Matt Parkman was forever going inside peoples' minds and dreams for various reasons. This came back to haunt him in Volume Five when.
 * In the season four (two part) finale of House, Chase attempts to use medical hypnotism to unlock House's memories of a bus-crash. We can see both the inside of the bar he visited beforehand, and the bus he rode on. Most details are obscured or not present.


 * In Smallville, Clark Kent does one of these to get some data from Lex Luthor's head and save his Brought Down to Normal cousin Kara. It should be noted that the machine used for the trip had killed everyone who tried to use it before, but, well, it IS Superman. Inside Lex's head he found 2 Lexes, the adult, ruthless Lex, and a child one, referred to as Alexander, who is good and helps Clark on the trip, while fearing the other one will attack him. Said kid coincidentally serves to revive Clark's faith that Lex can be redeemed. For a while, at least.
 * Then there was other one, when one of the criminals from the Phantom Zone tries to take over Clark's body, trapping him in a imaginary world where he is a schizophrenic patient who has hallucinated every bit of the series so far (The Phantom Zone is a book on a shelf, Jor-El is a brand of shampoo, and so on). It is the Martian Manhunter who enters his mind to save him.
 * In the Fraggle Rock episode "Boober's Dream," Boober goes on a Journey to The Center of The Mind to confront his fun-loving and irresponsible alter-ego Sidebottom, who has gotten out of control. When this fails, he enlists the rest of the Five-Man Band to journey with him and put a stop to Sidebottom's antics.
 * Played with in Taken. Several characters enter a crashed alien spacecraft, and see visions from their minds - a soldier sees his mother and her delicious cookies; one sees cockroaches, his greatest fear; one of the main characters sees her dead grandfather that she never met, who claims to be how she views him in her mind. In the end,
 * One of the episodes of Disney Channel's So Weird had this as it's plot. Fi, Jack, and Clu end up going inside a young boy's dreams to find out why he's having nightmares. The nightmare-creature (represented by a huge mass of black mist) is constantly chasing them, and will only be defeated when the child stands up and faces his fears. What's he afraid of?
 * The episode "Numbskulls of the Beast" from The Legend of Dick and Dom sees the heroes use magic to get inside the head of the Big Bad, to find where he has hidden the MacGuffin; They aren't particularly interested in why his wrath is represented as giant red teddy bears, or what's with his mind having security guards (who are flying Brooklyn-accented penguins) and cable cars.
 * In an episode of Fringe, Peter and Walter enter Olivia's mind in order to retrieve her conciousness after she is possessed by.

Music

 * Ayreon's 'The Human Equation': the protagonist, while comatose has a rather lengthy discussion with his emotions.
 * Similarly, "The Trial" from Pink Floyd's The Wall, which has Pink being confronted with his issues.

Radio

 * In one episode of And Sometimes Y, the hosts travel into the mind of a CBC Radio listener.

Tabletop Games

 * In the French roleplaying game La Méthode du Docteur Chestel, the PCs are sent into the mind of a psychiatric patient in order to investigate his inner world and try to solve his mental problems. Gamemasters are encouraged to be creative with the (unfortunate) consequences of the therapy.
 * This is the fundamental premise of Dreamwalker.
 * In the surrealistic indie rpg Lacuna Part I. The Creation of the Mystery and the Girl from Blue City the players are agents of an unidentified organization dedicated to curing anti-social (i.e. criminal) behavior by entering a shared subconscious space with the criminal/patient.
 * They basically took the idea of the collective unconscious and turned it into a semi-tangible dream world where nothing is guaranteed to make sense, and it's populated with the unconscious, unwitting minds of everyone on the planet. Needless to say, there's a lot of strange symbolism to be had.

Theater

 * The song "Amazing Journey" from Tommy: "Sickness can surely take the mind where minds can't usually go/Come on the amazing journey and learn all you should know..."

Videogames

 * This is the central premise of Tim Schafer's Psychonauts-- traveling into the minds of others and sorting out their emotional baggage (literally) and psychological problems.
 * Likewise, the action-adventure Alundra, in which we discover that people's dreams and subconscious minds contain a lot of block puzzles.
 * And the PS 2 action-RPG Dual Hearts, which sadly got lost in the shuffle of case of many games with "Hearts" in the title coming out around the same time.
 * Dual Hearts and Alundra are created by the same development team. DH is practically a Spiritual Successor.
 * The "Dive To The Heart" segments from several Kingdom Hearts games. They generally take place early on and represent the player character's Keyblade powers awakening / resurfacing.
 * In Quest for Glory IV it's possible to see into the mind of a powerful enchantress in your dreams, by sleeping at certain places that have been touched by her magic. The dreams tell the hero what happened to her, foreshadow the climax of the game, and can vary slightly from character class to character class (characters who play as Paladins receive more information about what to do, while characters who have some magical ability have some dreams with a more romantic bent.)
 * In the Hitchhiker's game, Arthur Dent travels inside his own mind. He's looking for his common sense. It's pretty tiny, so it takes a while to find.
 * Max Payne featured several labyrinthine dream sequences including one in which you are injected with about three lethal doses of a psychotic drug, and get a phone call from your dead wife who screams "WAKE UP MAX, YOU'RE IN A COMPUTER GAME!!"
 * Breath of Fire uses this quite a bit. Every game in the series had a mental dungeon or two.
 * The surreal dreamworld side quest in Oblivion. It's the side quest where you help a comatose man wake up by retrieving parts of his sanity and reason to make him realize that it is All Just a Dream.
 * One of the scenarios in Osu! Tatakae! Ouendan 2 involves the Ouendan entering the dreams of a six-year-old boy to help him with his bed-wetting problem.
 * In the dating sim/RPG Ar Tonelico, part of wooing the girls involves journeying into their minds. This also unlocks new costumes and abilities for them.
 * Final Fantasy VII: Tifa has to venture into the mind of her friend Cloud when he becomes mentally-quadriplegic and sits 'almost' silently in a wheelchair, unable to do anything, after falling into the Lifestream. She, then Cid, become the main characters until Cloud comes round thanks to her help.
 * The third Sly Cooper game sees Sly entering the mind of a trance-bound Panda King with a little help from the Guru. Once inside, he finds the Panda King locked in their Boss Battle from the first game, continuously reliving the moment of his ultimate failure.
 * Magicant.
 * Happens in Drakengard 2, in which the protagonist, through sheer force of will, enters Manah's mind to cleanse it of Demonic Possession, ending in a rather creepy Battle in The Center of The Mind against lots of shadowy clones of Manah's younger self. But with only red eyes.
 * That hurt like hell
 * In Shin Megami Tensei I, you have to enter the mind of the heroine to eradicate a demon that is devouring her from the inside.
 * One of the Quests in Romancing Sa ga 3 had you go into a character's mind and save her from the being conjured by the poison she drank
 * At least two examples in City of Villains.
 * Neverwinter Nights 2: Mask of the Betrayer features sequences where you enter your own and other people's dreams (and fight inside them, and Your Mind Makes It Real if you die...), and the game ends with an extended where you enter your soul and have to prevent the Enemy Within from literally devouring your memories, and then banish him.
 * Gann can also wander around in your dream sequences, as can Kaelyn, Safiya, and Okku if you have enough influence with them at the end.
 * Used as a character upgrade in La Pucelle, which is the prequel to Disgaea. Complete with split personalities, Evil Is Sexy, laser swords and all wrapped up inside the mind of a rebellious princess.
 * Featured heavily in Disgaea 3, where it's called Mao's "heart" instead of his mind. Much of the plot revolves around Mao trying to defeat his psychological demons and "open his heart" by repeated trips inside his own psyche. In the end,.
 * American McGee's Alice assumes the theory that Lewis Carroll's Wonderland was all a representation of Alice's subconscious mind, and in the game Alice retreats to Wonderland after her parents die in a fire, only to find Wonderland twisted beyond recognition by her own guilt and trauma, and takes it upon herself to defeat her inner demons and set Wonderland right once again.
 * Hellgate: London has your character literally open a portal to Hell through Techsmith 314's mind - after you have him face-raped by a demonic monkey, of course. (Played with for laughs, if it's any consolation.)
 * In Pokémon Mystery Dungeon Explorers of Time/Darkness, the player and partner are sent into Azurill's nightmare to find out why he won't wake up.
 * In the Xenosaga series, there is a machine called the Encephalon which does this. In the entire trilogy, there have been three of these uses - once when retrieving KOS-MOS's memory banks from a black box in Episode I, and in Episode II, the crew has to dive into MOMO's head to figure out what the hell Albedo did to her back during the Mind Rape of the previous game. The third incident is in Episode III, where the crew dives into Shion's subconscious  without even knowing they had done so. All three of them were pretty much Mind Screws, especially the KOS-MOS one (where it doesn't even use KOS-MOS's memories, instead an amalgamation of Shion and Jr.'s).
 * In Lunar: Eternal Blue, Ronfar goes into Mauri's mind to free her from Zophar's influence.
 * Final Fantasy VI does this. There's a side quest where you can go into Cyan's mind and help him overcome his (justified) angst.
 * Baldurs Gate 2 has several dream sequences where the Player Character wanders around a recreation of their childhood home floating in a void, while Irenicus, Imoen and their Super-Powered Evil Side spout cryptic foreshadowing at them.
 * In Ar Tonelico I and II the main character can 'dive' into the 'cosmosphere' of the Reyvatails in your party, which is directly similar into exploring a person's inner mind and consciousness. It is a major game play mechanic as not only does it give you an intriguing look at their inner-selves, but is a requirement to unlock more powerful song magic for the Reyvatail you are diving into.
 * Silent Hill can be seen as this, with each game an examination of a particular character's psyche.
 * Silent Hill 2 being the most obvious.
 * This happens multiple times in Batman Arkham Asylum, thanks to The Scarecrow's fear toxins. They typically involve a lot of Mind Screw, some Fission Mailed, and oh yeah, a Kaiju-sized Scarecrow trying to drive you permanently insane.
 * In World of Warcraft, the Old God Yogg-Saron will forcibly bring the players into his mind. There, they will bear witness of some acts that took place in the lore (or are currently taking place) in the form of illusions that they must shatter to access the brain, which must be damaged enough to remove Yogg-Saron's invulnerability. However, if they remain inside the Mind's Eye for too long, their Sanity Meter will instantly drop to zero, thus falling into the Old God's control
 * In the Wailing Caverns dungeon, the player is literally fighting creatures summoned by a sleeping druid. The final boss is essentially his mental jailer--when you kill it, he wakes up.
 * In No More Heroes 2: Desperate Struggle, It's a relative Big Lipped Alligator Moment in the game, and coming from this game, that's saying a lot.
 * However, it's implied that
 * It's strongly implied that this is what the Dream World represents in Yume Nikki,but...then again...
 * This is shaping up to be a major plot element in the King's Quest Fan Sequel The Silver Lining.
 * Classic RPG Wasteland contains a boss fight where a character has to fight his/her way though the mind of an insane robot.
 * There's an educational game called Journey into the Brain.
 * In Solatorobo, the main hero undergoes one of these to unlock the repressed memories of his origins.
 * Skyrim has a sidequest where you find Sheogorath taking a vacation in the mind of the deceased, criminally insane Emperor Pelagius III's mind, which he finds to be a nice vacation spot. To get Sheogorath to leave, and tend to his Daedric realm, you have to treat Pelagius' mental illness using Sheogorath's Daedric artifact.
 * Red from Solatorobo takes one after the game's midpoint thanks to a Virtual Training Simulation. He winds up having to face his greatest fear, which is

Webcomics
"Psycho Mantis: Once, just once, I would like to see a mind that is not a goddamn metaphor."
 * Dominic Deegan: Oracle for Hire loves this trope. Dominic adventures inside the minds of Szark Sturtz, kid brother Gregory Deegan, even his own, often fending off demons and necromancers with clear understanding and sheer strength of will.
 * 9th Elsewhere is about the journey inside the mind of a troubled teenage author with writer's block, where the voyagers are the protagonist (the aftermentioned troubled writer) and the oddball muse assigned to her by a musing organization.
 * The Last Days of Foxhound features the main cast going into Liquid's head following a Heroic BSOD starting here, and later one of Ocelot, with hilarious results:


 * We get a glimpse inside of 's mind in Hanna Is Not a Boys Name when he
 * In Nodwick, the rest of the party enters Yeagar's mind . Yeagar's intellect is represented by an avatar of Artax (the party wizard), his conscience by Piffany (the cleric), and his insecurities by Nodwick (the henchman and the brains of the outfit).
 * Soul Symphony: Pretty much the story's premise. Main character Olivia is chosen to cure high school students of negative emotions by teleporting into their "Soul Worlds" and defeat monsters.
 * We get a glimpse of a confusing world inside Nenshe's head in the fifth arc of Rumors of War.
 * Ninth Elsewhere is essentially the personification of this trope.

Web Originals

 * Carmilla does it to Samantha Everheart in the third 'Hive' story of the Whateley Universe when Samantha is going into a Heroic BSOD. (It's Carmilla's fault this is happening, so she has to fix it.)
 * In We Are Our Avatars, many went @Ozbourne Oz Original Character's mind, and later done with "Raven."

Western Animation

 * In The Tick episode "The Tick vs. Proto-Clown," The Tick gets literally knocked into orbit by the titular monster and goes on a journey through his own mind while the rest of the heroes have to deal with Proto-Clown.
 * In the Jimmy Neutron episode "I Dream of Jimmy," Jimmy travels into Carl's highly-illogical dream-scape to deal with his friend's recurring nightmare.
 * In an episode of Teen Titans, Cyborg and Beast Boy go into the depths of Raven's mind, where they meet embodiments of all the facets of her personality.
 * Duckman enters his own mind via hypnosis. Inside, he finds a monster made from his guilt that sabotages his ability to love women because he feels responsible for his wife's death.
 * Spongebob SquarePants did the dream version in the episode "Sleepy Time." Naturally, Spongebob managed to ruin the dreams of everyone in Bikini Bottom, and he awoke to find a group of annoyed friends and neighbors, insisting he stay out of their dreams because they get enough of him during the day.
 * The Spectacular Spider Man has.
 * The first episode of the Aardman Animations series Rex the Runt had the cast entering the mind of Cloudcuckoolander Vince in a shrunken submarine in order to cure his Random Pavarotti Disease.
 * Instead, they re-tune him to BBC Radio 4.
 * The Batman had an episode where Batman and Dr. Hugo Strange entering the mind of the Joker to find out where he hid Detective Yin before she's killed by a bomb. The latter was quickly side-tracked by trying to psycho-analyze the Joker (which he was just looking for an excuse to do) while Batman.
 * Danny Phantom has one episode where Danny's overshadowing ability extends to flying inside people's minds, specifically their dreams.
 * An opening of Arthur had the titular character enter the mind of his teacher and the mind of a classmate (later revealed to have dyslexia). The first mind was a giant homework factory, the second was a giant picture slideshow.
 * In the series finale of Mighty Orbots, when the title robots mistakenly believe they are slated to be scrapped, they decide to prove their worth by making a likely suicidal frontal assault on the series Big Bad, Umbra, a vast living computer in a Dyson Sphere called the Shadow Star. They physically penetrate Umbra's body, and find themselves literally inside his mind, doing battle with the physical manifestations of his thoughts.
 * This once happened to Beetlejuice when Lydia became trapped in his mind. She ended up helping his pathetic, wimpy "will power" defeat "Prankenstein," the part of Beetlejuice's personality that goads him into playing tricks on people.
 * In the Venture Brothers episode "Assisted Suicide" the Monarch uses a mind-control machine to go inside Dr. Venture's brain to try and kill him from the inside out; Dr. Orpheus goes in after him to save Doc from the "possessing spirit." However, it turns out that Dr. Venture's mind isn't such a pleasant place to be, and a combination of traumatic memories and Freuidan archetypes send the Monarch running away screaming.
 * Doctor Henry Killinger does this to Doctor Venture as well in the episode "The Doctor is Sin."
 * In "Memory of a Memory" of Adventure Time, the main duo Finn and Jake have to retrieve a spell from their friend Marceline's memory so that she can awaken from her slumber.
 * In the Halloween Episode of Invader Zim, Zim and Dib gets trapped in a world filled with twisted amalgamations of characters from the Crapsack World the show takes place in, evidently inside Dib's mind. Of course, when they try to escape into the real world, they find it too horrifying to bear and return back to their own (apparently less) hellish dimension.
 * The Duck Dodgers episode, "A Lame Duck Mind" has the Cadet, I.Q. High and the Villain of the Week going inside the tangled mess that is Dodger's brain. They're assisted by Dodger's Id, Super-Ego and Ego.
 * Candance, Phineas, Ferb and others go inside Candance's mind in "Monster from the Id" to retrieve a memory.

Real Life

 * There are people who have tried to do this in real life.
 * See also psychonautics, lucid dreaming, and vision quests.