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What is reality? And does any-body care? These questionspermeate the work of science-fiction writer Philip K. Dick,

whose characters’ memories and identities arefrequently products of drugs and other tech-nologies — implying that recollections, as wellas appearances, should never be trusted. Dick’sthemes have been catnip to film-makers —Blade Runner, Total Recall and Minority Reportare all based on his stories. The latest example,A Scanner Darkly, directed by Richard Lin-klater, will be released this July.

Neuroscientists often ask the same ques-tions. And one of the tools that they are usingto address them is ‘rotoscoping’, a filmingtechnique Linklater uses in Scanner and someof his earlier work to blur the distinctionbetween reality and animation. Our notions ofauthenticity, brain scientists are finding,depend as much on emotional and psycholog-ical plausibility as they do on physical accuracy— and the brain will swallow almost anything,provided it comes in the form of a story.

“Our ability to think of others as havingminds is very promiscuous, and applies itselfacross a wide range of entities,” says neuro-scientist Rebecca Saxe of the Massachusetts

Institute of Technology. Watch a crude anima-tion of a big square tracking a small one, forexample, and the word ‘chasing’ springs tomind. Art exploits this promiscuity, creatingemotional impact from strings of abstractsymbols such as the lines of letters in novels, orfrom flickering images on screens.

Studies of brain activity using functionalmagnetic resonance imaging (fMRI) showthat the brain distinguishes movements thatmight seem to have intentions from othermovements. Seeing mechanical motion, suchas that of a pendulum, involves a different partof the brain from seeing biological motion,even if it’s only that of a cartoon arm.

But how do neuroscientists know whetherour responses to such lab-based fictionsreflect the real world? “I was interested inwhether people attributed intentions to car-toon people in the same way that they com-prehend the intentions of real people, butfinding or creating videos with cartoon andreal people doing the exact same thingseemed very difficult,” says neuroscientist andkeen filmgoer Raymond Mar of the Univer-sity of Toronto in Canada. Mar struck lucky;he discovered that Linklater’s earlier roto-scope movie, Waking Life (2001) provided just

such material. In rotoscoping, conventionallyshot footage is transformed into cartoonishanimation using a combination of human ani-mators and computers; Waking Life uses thetechnique as a way of presenting a constantlyshifting world of dreams, whereas A ScannerDarkly uses it to evoke the estranged world ofdrug use. In the extras on the first movie’sDVD, Mar found clips of the video footagethat had been transformed into animation,ranging from mellow scenes of pillow talkbetween Julie Delpy and Ethan Hawke to aman tipping petrol over himself.

Fact or fiction?Mar and his colleagues showed both cartoonand video clips to subjects in an MRI scanner.They found that two areas of the cortex previ-ously associated with detecting intention, thesuperior temporal sulcus and the temporalparietal junction (TPJ) fired more strongly inresponse to the video footage than to the car-toons1. Cartoon sequences, on the other hand,produced more activity in an area called thebilateral orbitofrontal cortex, which respondsto rewarding stimuli. Mar’s team speculate thatthis region may have been more tickled by the trippy cartoon footage than the more

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There’s more to science at the movies than Lex Luthor’s attempts to synthesize kryptonite. In thefirst of two features on film, John Whitfield looks at how a cinematographic technique can provide

insights into the perception of reality. In the second, Alison Abbott meets Ben Heisenberg, adirector whose first film is a taut moral fable of laboratory life.

An MRI scanner darkly

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mundane video; it’s certainly the case thatwatching the rotoscoped dreamscapes is apeculiarly rich experience.

“It’s an elegant but challenging study,” saysSaxe. “It’s hard to imagine a more minimal con-trast that more effectively manipulates thisdimension. But the findings are mysterious.”The mystery is what the patterns of brain activ-ity in the two treatments mean. It may be thatthe lower activity in the TPJ stimulated by thecartoons reflects the fact that the animations areeasier to process into ideas about intention thanthe ‘real life’ footage. Mar, however, plumps foran alternative, although not necessarily contra-dictory explanation — that the more detailedvideo footage contains more cues of intention,ticking more of the brain’s boxes. His next planis to show subjects both a real, live hand pokinginto the scanner and a video of the same event,and see how their brains respond.

“It suggests a template-matching mecha-nism,” adds neuroscientist Kevin Pelphrey ofDuke University in Durham, North Carolina.“It may be that the more realistic stimuli portraymore intentionality, which these brain regionsprefer.” But more realistic doesn’t necessarilyjust equal more convincing. The best graphicsand robots risk toppling into what, in 1970, theJapanese roboticist Masahiro Mori dubbed theuncanny valley, where their almost-but-not-quite realness becomes creepy and repellent.

Earlier studies have indicated that the brain’smind-reading areas work harder if they believethey are perceiving a real person. Chris Frithof University College London and his col-leagues found that when a person played thegame known as paper, scissors, stone, anotherarea associated with attributing intention, theanterior paracingulate cortex, fired morestrongly if the subject thought they were play-ing a person rather than a computer — even ifhe or she was in fact playing a computer2.What we perceive can depend on what webelieve; imagining a thing produces brainactivity very similar to the genuine experience.

As well as tapping into pre-existing biases,

film and animation mould the brain, saysFrith. “The brain responds to cultural effects,and the conventions of realism are constantlychanging,” he says. Whatcounts as real, according tothese conventions, dependson technologies of repre-sentation; as technology haschanged, so has our percep-tion of the hallmarks ofreality. People once believednewsreels only if they werein black and white. Cur-rently, the mark of authen-ticity — exploited, forexample, in Paul Green-grass’s Bloody Sunday andUnited 93 — is wobblyhandheld footage. The coarseness of videostock, as used in The Blair Witch Project, is asimilar signifier of reality.

Our understanding of the social brain is stillrudimentary, Frith adds. “We know quite a lotabout which regions are involved, but almostnothing about what they’re actually doing, and

what neuronal computations are involved.”What’s needed, he says, are imaging studiesthan can reveal the timing of activity moreprecisely, showing how different brain regionsinteract, and theoretical analyses of how thebrain solves social problems. “Ultimately, in ascience-fictiony way, I’d like robots that can dotheory of mind and attribute intention.” Thiswould be beyond what even Dick imagined —in his novel Do Androids Dream of ElectricSheep?, filmed as Blade Runner, theVoight–Kampff empathy test is a way of spot-ting replicants’ emotional deficiencies.

Easily deludedThe mental state that arises when we interactwith unreality is complex. We get involved tothe extent that, say, we cry when Bambi’smother dies, but not so involved that we walkout of the cinema and strike up a conversationwith the nearest rabbit. Whatever the explana-tion is, says psychologist Richard Gerrig of theState University of New York, Stony Brook, itisn’t the much-touted suspension of disbelief,

because disbelief is not the default.“People believe everything, andone must expend effort to disbe-lieve,” says Gerrig.

The brain, it seems, has a defaultsetting of credulity, and a keenappetite for consuming and pro-ducing stories. Narrative is a cru-cial tool in our efforts tounderstand the world and somebrain areas seem specialized forprocessing it3. Information pre-sented in narrative form lowersour critical faculties, and experi-ments show that the more deeply

people become immersed in a story, the easierit is to sway their attitudes towards those advo-cated in that story4. This resonates with AScanner Darkly, when an undercover copbecomes so engrossed in his ‘fictional’ identityas a drug dealer that his police persona beginsto pursue his criminal one. Resisting our

Mind twisters: cartoon animation and real video footage seem to activate different brain areas.

Life like: a filming technique in which normal footage is transformed into cartoons is being exploited by neuroscientists to assess how the brain responds to more or less realistic scenes.

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Johannes walks across the grass to aMunich research institute on his first dayin the lab. A woman approaches him. Sheis from the secret service and she wants

him to spy on a fellow postdoc, Farid, aFrench citizen of Algerian origin, vaguely sus-pected of being a sleeper terrorist. Disgusted,Johannes refuses.

Johannes reports to his new boss, virologistProfessor Behringer, who introduces him toFarid. Behringer, an authoritarian departmenthead, wants the two young scientists to workon the same problem in molecular biologyfrom different angles. Farid’s approach isgenomics, while Johannes is studying proteins.

Through work, Farid and Johannes becomefriends — of sorts. And therein lies a tale oftrust, ambition and betrayal. By the end ofSchläfer (Sleeper), a many-layered and earnestfilm selected for the 2005 Cannes film festivaland now playing in European cinemas,Johannes will have informed on Farid. Indoing so, he will have benefited his own careerand may have won the girl.

Critics have praised this award-winning

first feature by a graduate of the Munich FilmSchool. As an art-house film addressing bigmoral issues, it will not be to everyone’s taste.But for an audience of scientists, three thingswill be remarkable.

First, that the director chose toset a study of post-9/11 paranoiain a molecular-biology labora-tory. Second, that the laboratorysetting, and the interactionsbetween the scientists, areunusually realistic — eventhough the plot itself has nothingto do with science. And third,that the director is the grandsonof Werner Heisenberg, 1932Nobel laureate and originator ofthe uncertainty principle inquantum mechanics.

Benjamin Heisenberg wasborn in 1974, about a year beforehis grandfather died, but he is keenly aware ofhis forebear’s legacy. The German physicist wascriticized for working for the Nazi nuclear pro-gramme during the Second World War. But

Benjamin suspends judgement on Werner’sdecision to stay in Germany, asking: “How cananyone ever be sure that things turn out the waythey expect and want, and that other genera-tions won’t judge their decisions differently?”

Werner was not the onlyhigh-achiever in the family.Benjamin’s father Martin, aprofessor at the University ofWürzburg, is one of the mosthighly cited behavioural scien-tists in Germany. His maternalgrandmother was sister to CarlFriedrich von Weizsäcker,physicist turned philosopher,best known for his theories ofthe nuclear processes insidestars, and to Richard vonWeizsäcker, the popular for-mer German president. Two ofhis brothers studied sciences.

But Benjamin’s interests took him to artschool, where his interest in film awakened.

Film school was disappointingly superficial.“The philosophy of the school was to learn

In Benjamin Heisenberg’s first feature film, a molecular biologist (left) informs on hiscolleague (centre, left) to a woman from the secret service, with chilling consequences.

susceptibility to stories is a useful skill in amedia- and advertising-saturated world, saysGerrig. “We need to get kids and adults to con-struct disbelief. Because people don’t knowabout this tendency, it puts them at risk.”

“It’s not important whether you label some-thing as fiction or non-fiction,” Mar agrees.“The true distinction is between narrative andnon-narrative expository forms that don’t drawyou into their world.” It also looks as if the abil-

ity to lose yourself in a fictional world mightreflect your ability to navigate the genuinesocial world. Mar and his colleagues havefound that the more time a person spends read-ing fiction the greater his or her empathy andsocial skills; for readers of expository non-fic-tion (such as, to pick an example at random,science journalism) the correlation is negative5.I thought it would be best to keep back that par-ticular piece of reality until the end. ■

John Whitfield is a freelance writer based inLondon.

1. Mar, R. A., Kelley, W. M., Heatherton, T. F. & Macrae, C. N.(in the press).

2. Gallagher, H. L., Jack, A. I., Roepstorff, A & Frith, C. D.NeuroImage 16, 814–821 (2002).

3. Mar, R. A. Neuropsychologia 42, 1414–1434 (2004).4. Gerrig, R. J. & Rapp, D. N. Poetics Today 25, 265–281

(2004).5. Mar, R. A., Oatley, K., Hirsh, J., dela Paz, J. & Peterson, J. B.

J. Res. Pers. doi:10.1016/j.jrp.2005.08.002 (2005).

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craft, not art,” he says, recalling the scepticismsome teachers had of his earlier short films.“Their film history started with Terminator IIand they told me ‘oh no, don’t do art, no onewill watch it; it’s just a mindfuck’.” He laughs athis own audacity and earnestness.

The idea for Schläfer came to Heisenbergshortly after 11 September 2001. “I saw thatdomestic security was being tightened andthat no one was objecting,” he says. “Therewould have been mass demos if politicians hadtried to pass even a part of the new securitylaws ten years ago.” Fear, he noted, was chang-ing people’s politics. It led him to wonder: howdo fear and politics affect personal lives andrelationships? How much does it take toweaken someone’s moral convictions?

Growing up among scientists, Benjaminknew that the scientific environment had thedramatic potential for examining these ques-tions. Scientists are dedicated, driven andsometimes ruthlessly competitive. Scientificconflicts could illustrate how much pressure— or how little — it takes to break a person’sethical spine. The international nature of sci-ence was also important to the plot, because anArabic researcher would not be so unusual.Benjamin created a potentially explosive, butplausible, mix of characters: a ruthlessly ambi-tious principal investigator; and two equallyambitious, inexperienced young researcherswho collaborate, yet compete with each other.

Two events test their friendship and colle-giality. First, they fall in love with the same girl,Beate. When she chooses Farid, Johannesmakes contact with the secret service agent hehad previously spurned. But when Farid turnsmoody on Beate — he has learnt that he isbeing watched, but doesn’t know by whom —she takes temporary comfort with Johannes.Uplifted by his romantic triumph, Johannestells the secret service he will no longer speakwith them.

Then a lab drama sets things on their final,fateful course. One day Farid barges excitedlyinto Johannes’ lab: “Nature has said ‘yes’!” Sup-pressing his annoyance that he didn’t know apaper had been submitted, Johannes is thrilled.He had, after all, helped Farid’s project byreanalysing his sequencedata and identifying twooverlooked genes thatwere key to solving theirbiological puzzle. Theycelebrate. But then helearns that the manipu-lative Behringer hasexcluded him from theauthor list. His rage isignited, with chilling con-sequences for Farid. AfterFarid is arrested for sus-pected involvement in afailed Munich bombing,Behringer replaces Farid’sname with Johannes’ onthe Nature paper.

We are never told the details of the researchproject. “People would stop listening — theyonly need to know enough to understand why a conflict has developed, andglimpse its complexity,” saysBenjamin. But any milieu has tobe convincing to make viewersbelieve in the film. This is whyBenjamin took pains to ensurethe science throughout was asreal as possible.

Enter Katarina zu Eulen-burg, Benjamin’s cousin, andan immunology PhD studentat Berlin’s Humboldt Univer-sity. She read the script andhosted the actors in her lab, teaching themhow to pipette liquids and handle animals.She was on set, ensuring that in each lab scenethe actors and extras were working appropri-ately. She even provided her gloved hands forclose-ups of detailed procedures. “It was suchfun — and I realized how similar the proce-dures of film-making are to doing a researchproject,” she says. “It is hard and disciplinedwork which you really have to believe in,

because it takes such a longtime to get the idea, write thescript, find the financing andthen make the film.”

Her and Benjamin’s effortswere rewarded when Schläferwon the 2005 Midas Prize forthe best European drama featuring science. But afterseeing the film, MartinHeisenberg told his son thatno one — not even a scientistas ruthless as Behringer —can swap names on a paperalready accepted by Nature.But Benjamin didn’t reshoot.“The dramatic moment wastoo important to the plot,

and I was sure that one incorrect detail wouldnot disturb the realism of the lab scenes.”

His father suspects he was the source ofBenjamin’s view of the importance of a Naturepaper, something he finds a little embarrass-ing: “I always tell my students that these thingsshouldn’t matter so much.” And Benjamin sayshe himself has only experienced labs with very positive atmospheres. “My portrayal of a pushy lab, whose competitive atmospherebecame poisonous, comes from what otherscientists tell me exists.”

In Schläfer, this poisonous atmosphere leadsJohannes to betray Farid, a decision we con-demn but understand. His betrayal is fore-shadowed by a scene in which Johannes kills alab mouse. “We see a parallel in Johannes’ abil-ity to coldly kill an animal, even though weknow from other scenes that he is a caring andsensitive person,” says Benjamin. “Killing ananimal for the greater good of science requiresa decision to cross an ethical border — andthen you just do it without thinking about theethics every day.” Benjamin imagines some-thing similar must happen when someonedecides to spy for the secret service.

Would the German secretservice really recruit scientistsin a public research lab? It’s notout of the question, says MartinHeisenberg, who witnessed aneast German spy in his formerlab at the institute for virologyat the University of Tübingenbefore German reunification.“He regularly went throughnotebooks and transmittedinformation.”

Alexander Kekulé, a micro-biologist at the University of Halle, Germany,says that spying on a suspected terrorist in aGerman lab today is entirely conceivable.“There have been recent scandals in Germanyabout the BND [secret service] getting jour-nalists to spy on their colleagues — therewould be even fewer scruples in spying inother professions, including science.”

With Schläfer, Benjamin says he has got thebig moral issues out of his system, at least tem-porarily. His next film is about a bank robberin Vienna.

But he knows he will come back to sciencein the future. “Mostly science in films is char-acterized by the classical mad professor, orsomeone running around saying ‘Oh my God!The organ emulator is running at 400%!’ —with no one having a clue what that couldmean.” But film-makers are becoming muchmore aware of the dramatic possibilities of science, he says: “The time of science in filmsis coming.” ■

Alison Abbott is Nature’s senior Europeancorrespondent.

The DVD of Schläfer with English subtitles isavailable from September. It can be bought from www.filmgalerie451.de.

Benjamin Heisenberg’s film Sleeper asks what ittakes to weaken a person’s moral convictions.

When Johannes decides to spy on hiscolleague, he crosses an ethical line.

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