A 66-year-old woman experienced constant musical hallucinations of piano music, despite there being no piano playing. Doctors studied her brain activity using an fMRI scanner while her hallucinations were strong and weak. They found that listening to real music by Bach temporarily eased her hallucinations. When comparing brain activity, regions involved in music perception and memory were more active when hallucinations were louder. This supports the theory that weakened error detection from hearing loss allows faulty predictions in these brain regions to feel like real music is being heard.

1. In 2011, a 66-year-oldretiredmathteacherwalkedintoaLondonneurological clinichopingtoget
some answers.A fewyearsearlier,she explainedtothe doctors,she hadheard someone playinga
pianooutside herhouse.Butthenshe realizedtherewasno piano.
The phantompianoplayedlongerandlongermelodies,likepassagesfromRachmaninov’sPiano
Concertonumber2 in C minor,herdoctorsrecountin a recentstudyinthe journal Cortex.Bythe
time the woman — to whomthe doctorsreferonlybyher firstname,Sylvia— came to the clinic,
the musichad become hernearlyconstantcompanion.Sylviahopedthe doctorscouldexplaintoher
whatwas goingon.
Sergei Rachmaninoff - PianoConcertoNo.2inC minor,Op. 18. VideobyWolfgangAmadé Mozart
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More Matter Columns
Sylviawasexperiencingamysteriousconditionknownasmusical hallucinations.Theseare notpop
songsthat getstuck inyour head.A musical hallucinationcanconvince peoplethere isamarching
bandin the nextroom,or a full churchchoir.Nor are musical hallucinationsthe symptomsof
psychosis.People withmusical hallucinationsusuallyare psychologicallynormal — exceptforthe
songstheyare sure someone isplaying.
The doctors invitedSylviatovolunteerforastudyto betterunderstandthe condition.She agreed,
and the researchturnedoutto be an importantstepforwardinunderstandingmusical
hallucinations.The scientistswereable tocompare herbrainactivitywhenshe wasexperiencing
hallucinationsthatwere bothquietandloud — somethingthathadneverbeendone before.By
comparingthe two states,theyfoundimportantcluestohow the braingeneratesthese illusions.

2. If a broaderstudysupportsthe initial findings,itcoulddomore than help scientistsunderstandhow
the brainfallspreyto these phantomtunes.Itmayalsoshedlightonhow ourmindsmake sense of
the world.
“I thinkthisisa sweetpaperandan importantone,”saidOliverSacks,aneurologistwhose books
include “Hallucinations”and“Musicophilia.”“It’sanew way of lookingatthings.”
Dr. Sacks addedthat the conclusionsof the studycouldonlybe preliminary,because itwasbasedon
a single person.Butthe same methodmayworkon otherpeople withmusical hallucinations. “I
thinkit’sa verygoodprotocol,”Dr. Sacks said.
The study wasbasedon a simple idea.Sometimespeoplewithmusical hallucinationssaythat
hearingreal musiccan quietthe imaginarytunes.Researchershadalreadyfoundthattheycoulduse
a similarmethodtomasktinnitus,inwhichpeoplehave anaggingringinginthe ears.
“The ideacame to us,whynot try maskingmusichallucination?”saidSukhbinderKumar,astaff
scientistatNewcastle Universityandone of the study’sco-authors.
It turned outthat Sylviafoundthatmusicby Bach sometimeseasedherhallucinations.WhenDr.
Kumar andhiscolleaguesmeasuredthe effectintheirlab,theyfoundaconsistentpattern:once the
Bach stopped,Sylviahadseveral secondsof total relief fromthe hallucinations.Thenthe
hallucinatorypianograduallyreturned,reachingfull strengthaboutaminute anda half afterthe
Bach ended.
Dr. Kumar andhis colleagueswonderedwhattheywouldseeif theymeasuredherbrainactivityas
herhallucinationsrebounded.Brainscansinthe pasthave onlyyieldedmurkycluesaboutmusical
hallucinations,foravarietyof reasons.
One problemhasto do withhowthe studieshave beendesigned.Scientistscompare agroupof
people withnormal hearingwithanothergroupof people whoexperience musical hallucinationsto
see if there are any significantdifferencesintheirbrainactivity.All the variationsineachgroupmay
blurthe evidence forhowthe hallucinationsarise.Sylvia,bycontrast,offeredDr.Kumarand his
colleaguesanopportunitytoessentiallyswitchhallucinationsonandoff ina single brain.

3. For theirexperiment,Sylviaputonearphonesandsatwithher headina scanner thatdetectsthe
magneticfieldproducedbythe brain.Onthe dayof the study,she washearingselectionsfrom
GilbertandSullivan’s“H.M.S.Pinafore.”
Everyfewminutesthe scientistswouldswitchtoBachfor 30 seconds,totamp downthe
hallucination.Whenthe real musicstopped,Sylviapressednumbersonakeyboardtorate the
strengthof her hallucinationswhilethe scannerrecordedherbrainactivity.
Dr. Kumar andhis colleagueslaterporedoverthe data.TheycomparedSylvia’sbrainactivitywhen
the hallucinationswere strongestwithwhentheywere attheirweakest.Theyfoundthata few
regionsconsistentlyproducedstrongerbrainwaveswhenthe hallucinationswere louder.
It turnedoutthat theyare regionsthatwe all use whenwe listentomusic.One regionbecomes
active whenwe perceive pitch,forexample.Another regionbecomesactive whenwe recall apiece
of music.
Dr. Kumar arguesthat these resultssupportatheorydevelopedbyKarl Fristonof the Wellcome
Trust CenterforNeuroimaging.(Dr.Fristonisaco-authorof the new study.) Dr.Fristonhas
proposedthatour brainsare prediction-generatingmachines.
Our brains,Dr. Fristonargues,generate predictionsaboutwhatisgoingtohappennext,usingpast
experiencesasaguide.Whenwe heara sound,forexample — particularlymusic— ourbrainsguess
at what itis and predictwhatitwill soundlike inthe nextinstant.If the predictioniswrong — if we
mistooka teakettle foranoperasinger — ourbrainsquicklyrecognize thatwe are hearing
somethingelseandmake a newpredictiontominimize the error.

4. Scientistshave longknownthatpeoplewithmusical hallucinationsoftenhave atleastsome hearing
loss.Sylvia,forexample,neededhearingaidsaftergettingaviral infectiontwodecadesago.
Dr. Kumar’stheorycouldexplainwhysome peoplewithhearinglossdevelopmusical hallucinations.
Withfewerauditorysignalsenteringthe brain,theirerrordetectionbecomesweaker.If the music-
processingbrainregionsmake faultypredictions,thosepredictionsonlygrow strongeruntil theyfeel
like reality.“There isnothingfromthe sensestoconstrainthem,”Dr.Kumarsaid.
Dr. Kumar andhis colleaguesare nowusingtheirexperimental methodonmore peoplewithmusical
hallucinations.
If the theoryholdsupinfurtherresearch,itcouldexplainwhyreal musicprovidestemporaryrelief
for musical hallucinations:the incomingsoundsrevealthe brain’spredictionerrors.Anditmayalso
explainwhypeople are prone tohallucinatemusic,andnototherfamiliarsounds.
“Music ismore predictable,”saidDr.Kumar.“That makesit more likelyasaphenomenonfor
hallucinations.”