!BİOLOGİCAL(PSYCHOLOGY(CH.13(((HUMAN(COMMUNICATION(BOur!knowledge!of!the!physiology!of!language!has!been!obtained!primarily!by!observing!the!effects!of!brain!lesions!on!people’s!verbal!behavior.!((]Another!source!of!information!about!the!physiology!of!language!comes!from!studies!using!functional!imaging!devices.!!BLanguage!is!more!than!communicating,!it!is!also!for!thinking.!!BThe!most!important!category!of!speech!disorders!is!aphasia,!a!primary!disturbance!in!the!comprehension!or!production!of!speech,!caused!by!brain!damage.!!Speech(Production(and(Comprehension:(Brain(Mechanism((1. Aphasia!Difficulty!in!producing!or!comprehending!speech!not!

caused!by!deafness!or!a!simple!motor!deficit;!caused!by!brain!damage.!(BNot!all!speech!disturbances!are!aphasias;!a!patient!must!have!difficulty!comprehending,!repeating,!or!producing!meaningful!speech,!and!this!difficulty!must!not!be!caused!by!simple!sensory!or!motor!deficits!or!by!lack!of!motivation.!For!example,!an!inability!to!speak!caused!by!deafness!or!paralysis!of!the!speech!muscles!is!not!considered!to!be!aphasia.!In!addition,!the!deficit!must!be!relatively!isolated;!that!is,!the!patient!must!appear!to!be!aware!of!what!is!happening!in!his!or!her!environment!and!to!comprehend!that!others!are!attempting!to!communicate.!!(

(Lateralization((BVerbal!behavior!is!a!lateralized!function;!most!language!disturbances!occur!after!damage!to!the!left!side!of!the!brain,!whether!people!are!leftBhanded!or!rightBhanded.!BThe!leftBhemisphere!of!approximately!90!percent!of!the!total!population!is!dominant!for!speech.!But,!if!leftBhemisphere!is!malformed!or!damaged!in!early!life,!then!language!dominance!is!very!likely!to!pass!to!the!right!hemisphere.!!BHowever,!other!hemisphere!plays!roles!in!speech.!For!example,!damage!to!the!rightBhemisphere!makes!it!difficult!for!a!person!to!read!maps,!perceive!spatial!relations,!and!recognize!complex!geometrical!forms!of!understanding!what!other!people!have!to!say!about!them.!!BThe!rightBhemisphere!also!appears!to!be!involved!in!organizing!a!narrative!–selecting!and!assembling!the!elements!of!what!we!want!to!say.!!The!rightBhemisphere!is!involved!in!the!expression!and!recognition!of!emotion!in!the!tone!of!voice.!It!is!also!involved!in!control!of!prosody!–the!normal!rhythm!and!stress!found!in!speech.!Therefore,!both!hemispheres!of!the!brain!have!contribution!to!make!to!our!language!abilities.!! !!Speech(Production((]Being!able!to!talk!–that!is,!to!produce!meaningful!speechB!requires!several!abilities.!First!the!person!must!have!something!to!talk!about.!For!example,!we!can!talk!about!something!that!is!currently!happening!or!something!that!happened!in!the!past.!In!the!first!case,!we!are!talking!about!our!perceptions:!things!we!are!seeing,!hearing,!feeling,!smelling,!and!so!on.!In!the!second!case,!we!are!talking!about!our!memories!of!what!happened!in!the!past.!!!

2. Broca’s(aphasia!A!form!of!aphasia!characterized!by!agrammatism,!anomia,!and!extreme!difficulty!in!speech!articulation.!!BDamage!to!a!region!of!the!inferior!left!frontal!lobe!(Broca’s!area)!disrupts!the!ability!to!speak.!!BBroca’s!aphasia!is!characterized!by!slow,!laborious,!and!nonfluent!speech.!!BPatients!with!Broca’s!aphasia!find!it!hard!to!resist!supplying!the!words.!!BSo,!the!posterior!part!of!the!cerebral!hemispheres!has!something!to!say,!but!the!damage!to!the!frontal!lobe!makes!it!difficult!for!the!patients!to!express!these!thoughts.!!BPeople!with!Broca’s!aphasia!can!comprehend!speech!much!better!than!they!can!produce!it.!(

3. Function(word!People!with!Broca’s!aphasia!find!it!easier!to!say!some!types!of!words!than!others.!They!have!great!difficulty!saying!the!little!words(with(grammatical(meaning,!such!as!a,!the,!some,!in,!about,!etc.,!which!words!are!called!function!words,!because!they!have!important!grammatical!functions.!(

4. Content(word!The!words!that!they!do!manage!to!say!are!almost!entirely!content!words!(they!convey!meaning,!including!nouns,!verbs,!adjectives,!adverbs,!such!as!apple,!house,!throw,!heavy)(

5. Broca’s(area!A!region!of!frontal!cortex,!located!just!rostral!to!the!base!of!the!left!primary!motor!cortex,!that!is!necessary!for!normal!speech!production.!!(

BBroca's!area!is!a!functionally!defined!structure!in!the!left!frontal!lobe!of!about!97%!of!humans!(including!a!large!majority!of!left–handers).!!

BBroca's!area!is!involved!mainly!in!the!production!of!spoken!and!written!language!and!also!in!language!processing!and!comprehension.!!!BLesions!that!produce!Broca’s!aphasia!are!certainly!centered!in!the!vicinity!of!Broca’s!area.!However,!damage!that!is!restricted!to!the!cortex!of!Broca’s!area!does!not!appear!to!produce!Broca’s!aphasia;!the!damage!must!extent!to!surrounding!regions!of!the!frontal!lobe!and!to!the!underlying!subcortical!white!matter.!!BIn!addition,!there!is!evidence!that!lesions!of!the!basal!ganglia!–especially!the!head!of!the!caudate!nucleusB!can!also!produce!a!BrocaBlike!aphasia.!!!BBroca’s!area!contains!motor!memories!–in!particular,!memories'of'the'sequences'of'muscular'movements'that'are'needed'to'articulate'words.!Talking!involves!rapid!movements!of!the!tongue,!lips,!and!jaw,!and!these!movements!must!be!coordinated!with!each!other!and!with!those!of!the!vocal!cords;!thus,!talking!requires!some!very!sophisticated!motor!control!mechanisms.!!BBecause!damage!to!the!inferior!caudal!left!frontal!lobe!(including!Broca’s!area)!disrupts!the!ability!to!articulate!words,!this!region!is!a!likely!candidate!for!the!location!of!these!“programs”.!!BThe!fact!that!this!region!is!directly!connected!to!the!part!of!the!primary!motor!cortex!that!controls!muscles!used!for!speech!certainly!supports!this!conclusion.!BThree!major!speech!deficits!are!produced!by!lesions!in!and!around!Broca’s!area:!Agrammatism,!Anomia,!and!Articulation!Difficulties.!(

(6. Agrammatism!refers!to!a!patient’s!difficulty!in!using!grammatical!

constructions,!without!any!difficulty!in!pronouncing!words.!!BOne!of!the!usual!symptoms!of!Broca’s!aphasia!is!agrammatism!that!is!difficulty!in!comprehending!or!properly!employing!grammatical!devices,!such!as!verb!endings!or!word!order.!BPeople!with!Broca’s!aphasia!rarely!use!function!words,!and!they!rarely!use!grammatical!makers!such!as!Bed!or!auxiliaries!such!as!have.!They!do!often!–ing,!perhaps!because!this!ending!converts!a!verb!into!a!noun.!!BBroca’s!area!was!activated!when!people!were!taught!an!artificial!grammar.!!BThey!cannot!understand!and!use!grammar.!!BThey!cannot!understand!difference!between!object!and!subject.!So!they!cannot!understand!whether!horse!or!cow!kick.!(

(7. Anomia(The!second!major!speech!deficit!seen!in!Broca’s!aphasia!is!

anomia!(“without!name”).!!BAnomia!is!actually!a!primary!symptom!of!all!forms!of!aphasia.!!BAnomia!is!difficulty!in!finding!(remembering)!the!appropriate!word!to!describe!an!object,!action,!or!attribute.!!(

!Speech(Comprehension(!BComprehension!of!speech!obviously!begins!in!the!auditory!system,!which!detects!and!analyzes!sounds,!but!recognizing!words!is!one!thing;!comprehending!them!–understanding!their!meaningB!is!another.!!BRecognizing!a!spoken!word!is!a!complex!perceptual!task!that!relies!on!memories!of!sequences!of!sounds.!This!task!appears!to!be!accomplished!by!neural!circuits!in!the!middle!and!posterior!portion!of!the!superior!temporal!gyrus!of!the!left!hemisphere,!a!region!that!has!come!to!be!known!as!Wernicke’s(area.!!!

8. Wernicke’s(Area!A!region!of!the!auditory!association!cortex!on!the!left!temporal!lobe!of!humans,!which!is!important!in!the!comprehension!of!words!and!the!production!of!meaningful!speech.(

9. Wernicke’s(aphasia!A!form!of!aphasia!characterized!by!poor!speech!comprehension!and!fluent!but!meaningless!speech.!!!

Wernicke’s(Aphasia:(Description!BThe!primary!characteristics!of!Wernicke’s!aphasia!are!poor!speech!comprehension!and!production!of!meaningless!speech.!!BUnlike!Broca’s!aphasia,!Wernicke’s!aphasia!is!fluent!and!unlabored;!this!person!does!not!strain!to!articulate!words!and!does!not!appear!to!be!searching!for!them.!!BWhen!you!listen!to!the!speech!of!a!person!with!Wernicke’s!aphasia,!it!appears!to!be!grammatical.!!BHowever,!the!person!uses!few!content!words,!and!the!words!that!he!or!she!strings!together!just!do!not!make!sense.!!Wernicke’s(Aphasia:(Analysis((BBecause!the!superior!temporal!gyrus!is!a!region!of!the!auditory!association!cortex!and!because!a!comprehension!deficit!is!so!prominent!in!Wernicke’s!aphasia,!this!disorder!has!been!characterized!as!a!receptive!aphasia.!!BWernicke!claimed!that!the!Wernicke’s!area!is!the'location'of'memories'of'the'sequences'of'sounds'that'constitute'words.!!BThe!auditory!association!cortex!of!the!superior!temporal!gyrus!recognize!the!sounds!of!words,!just!as!the!visual!association!cortex!of!the!inferior!temporal!gyrus!recognize!the!sight!of!objects.!!BBut!why!should!damage!to!an!area!that!is!responsible!for!the!ability!to!recognize!spoken!words!disrupt!people’s!ability!to!speak?!In!fact!it!does!not;!Wernicke’s!aphasia,!like!Broca’s!aphasia,!actually!appears!to!consist!of!several!deficits.!The!abilities!that!are!disrupted!include!recognition'of'spoken'words,'comprehension'of'the'meaning'of'the'words,'and'the'ability'to'convert'thoughts'into'words.!'Recognition:(1.(Pure(Word(Deafness(BRecognizing!a!word!in!not!the!same!as!comprehending!it.!If!you!hear!a!foreign!word!several!times,!you!will!learn!to!recognize!it,!but!unless!someone!tells!you!what!it!means,!you!will!not!comprehend!it.!!BRecognition!is!a!perceptual!task;!comprehension!involves!retrieval!of!additional!information!from!memory.!!BDamage!to!the!left!temporal!lobe!can!produce!a!disorder!of!auditory!word!recognition,!uncontaminated!by!other!problems.!This!syndrome!called!pure(word(deafness.!!10. Pure(word(deafness!The!ability!to!hear,!to!speak,!and!(usually)!to!

read!and!write!without!being!able!to!comprehend!the!meaning!of!speech;!caused!by!damage!to!Wernicke’s!area!or!disruption!of!auditory!input!to!this!region.!!BAlthough,!people!with!pure!word!deafness!are!not!deaf,!they!cannot!understand!speech.!As!one!patient!expressed!that,!“I!can!hear!you!talking,!I!just!can’t!understand!speech.”!BThese!patients!can!recognize!nonspeech!sounds!such!as!the!barking!of!a!dog,!the!sound!of!a!doorbell,!and!the!honking!of!a!horn.!!BOften,!they!can!recognize!the!emotion!expressed!by!the!intonation!of!speech!even!though!they!cannot!understand!what!is!being!said.!!BMore!significantly,!their!own!speech!is!unimpaired.!!BThey!can!often!understand!what!other!people!are!saying!by!reading!their!lips.!!BThey!can!also!read!and!write,!and!they!sometimes!ask!people!to!communicate!with!them!in!writing.!!BClearly,!pure!word!deafness!is!not!an!inability!to!comprehend!the!meaning!of!words.!!BThey!know!what!car!is,!but!they!just!cannot!understand!difference!between!the!linguistic!sounds!of!car!and!cat.!!BTwo!types!of!brain!injury!can!cause!pure!word!deafness:!disruption!of!auditory!input!to!Wernicke’s!area!or!damage!to!Wernicke’s!area!itself.!Either!type!of!damage!disrupts!the!analysis!of!the!sounds!of!words!and!hence!prevents!people!from!recognizing!other!people’s!speech.!(

]Primary(auditory(cortex(or(connection(between(primary(auditory(cortex(and(Wernicke’s(area(lesions(cause(pure(word(deafness.((

BOur!brains!contain!circuits!of!mirror!neurons!–neurons!activated!either!when!we!perform!an!action!or!see!another!person!performing!particular!grasping,!holding,!or!manipulating!movements!or!when!we!perform!these!movements!ourselves.!!BFeedback!from!these!neurons!may!help!us!to!understand!the!intent!of!the!actions!of!others.!!BAlthough!speech!recognition!is!clearly!an!auditory!event,!research!indicates!that!hearing!words!automatically!engages!brain!mechanisms!that!control!speech.!In!other!words,!these!mechanisms!appear!also!to!contain!mirror!neurons!that!are!activated!by!the!sounds!of!words.!!BThe!investigators!found!that!the!excitability!of!the!subjects’!tongue!muscles!was!increased!only!when!they!heard!words!that!involved!tongue!movements.!Such!as,!the!word!beer!requires!tongue!movements,!but!the!word!buffo!does!not.!!BA!functional!imaging!study!found!that!the!auditory!cortex!is!strongly!activated!when!people!speak!out!loud!but!not!when!they!whisper.!The!investigators!suggest!that!this!region!is!involved!in!selfBmonitoring!of!speech.!Presumably,!auditory!feedback!from!our!own!voices!helps!to!regulate!our!speech.!!Extra!Notes:!BJapanese!children!until!4!years!old,!they!can!differentiate!r!and!l,!but!after!that!time,!they!get!used!to!Japanese!rules!that!there!is!no!difference!r!and!l.!!!Comprehension:(2.(Transcortical(Sensory(Aphasia((BThe!other!symptoms!of!Wernicke’s!aphasia!–failure!to!comprehend!the!meaning!of!words!and!inability!to!express!thoughts!in!meaningful!speechB!appear!to!be!produced!by!damage!that!extends!beyond!Wernicke’s!area!into!the!region!that!surrounds!the!posterior!part!of!the!lateral!fissure,!near!the!junction!of!the!temporal,!occipital!and!parietal!lobes.!For!want!of!better!term,!this!region!is!the!posterior'language'area.!!!BThe!posterior!language!area!appears!to!serve!as!a!place!for!interchanging!information!between!the!auditory!representation!of!words!and!the!meanings!of!these!words,!stored!as!memories!in!the!rest!of!the!sensory!association!cortex.!!BDamage!to!the!posterior!language!area,!which!isolates!Wernicke’s!area!from!the!rest!of!the!posterior!language!area,!produces!a!disorder!known!as!transcortical(sensory(aphasia.!!

11. Transcortical(sensory(aphasia!A!speech!disorder!in!which!person!has!difficulty!comprehending!speech!and!producing!meaningful!spontaneous!speech!but!can!repeat!speech;!caused!by!damage!to!the!region!of!the!brain!posterior!to!Wernicke’s!area.!!BThe!difference!between!transcortical!sensory!aphasia!and!Wernicke’s!aphasia!is!that!patients!with!transcortical!sensory!aphasia!can!repeat!what!other!people!say!to!them;!therefore,!they!can!recognize!words.!However,!they!cannot!comprehend!the!meaning!of!what!they!hear!and!repeat,!nor!can!they!produce!meaningful!speech!of!their!own.!!BHow!can!these!people!repeat!what!they!hear?!–Because!the!posterior!language!area!is!damaged,!repetition!does!not!involve!this!part!of!the!brain.!Obviously,!there!must!be!a!direct!connection!between!Wernicke’s!area!and!Broca’s!area!that!bypasses!the!posterior!language!area.!!BTranscortical!sensory!aphasia!can!be!seen!as!Wernicke’s!aphasia!without!a!repetition!deficit.!!BThe!symptoms!of!Wernicke’s!aphasia!consist!of!those!of!pure!word!deafness!plus!those!of!transcortical!sensory!aphasia.!!WA!=!TSA!+!PWD!,!TSA!=!WA!–!PWD.!(BAnother!most!important!function!of!linguistic!is!that!referring!the!things.!!Transcortical!sensory!aphasia!don’t!know!what!refers!what.!They!don’t!know!meaning,!so!they!cannot!produce!meaningful!speech.!!

(

What(is(Meaning?(BWernicke’s!area!is!involved!in!the!analysis!of!speech!sounds!and!thus!in!the!recognition!of!words.!BDamage!to!the!posterior!language!area!does!not!disrupt!people’s!ability!to!recognize!words,!but!it!does!not!disrupt!their!ability!to!understand!words!or!to!produce!meaningful!speech!of!their!own.!!BBut!what,!exactly,!do!we!mean!by!the!word!meaning?!And!what!types!of!mechanism!are!involved?!!BWords!refer!to!objects,!actions,!or!relationships!in!the!world.!Thus!the!meaning!of!a!word!is!defined!by!particular!memories!associated!with!it.!!BFor!example,!knowing!the!meaning!of!the!word!tree!means!being!able!to!imagine!the!physical!characteristics!of!trees:!what!they!look!like,!what!the!wind!sound!likes!blowing!through!their!leaves,!what!the!bark!feels!like,!and!so!on.!It!also!means!knowing!facts!about!trees:!about!their!roots,!buds,!flowers,!nuts,!and!wood!and!the!chlorophyll!in!their!leaves.!These!memories!are!stored!not!in!the!primary!speech!areas!but!in!other!parts!of!the!brain,!especially!regions!of!the!association!cortex.!Different!categories!of!memories!may!be!stored!in!particular!regions!of!the!brain,!but!they!are!somehow!tied!together,!so!hearing!the!word!tree!activates!all!of!them.!!First,!we!must!recognize!the!sequence!of!sounds!that!constitute!the!word;!we!find!the!auditory!entry!for!the!word!in!our!“dictionary”.!This!entry!appears!in!Wernicke’s!area.!!Next,!the!memories!that!constitute!the!meaning!of!the!word!must!be!activated.!Presumably,!Wernicke’s!area!is!connected!–through!the!posterior!language!areaB!with!the!neural!circuits!that!contain!these!memories.!!Damage!to!particular!regions!of!the!sensory!association!cortex!can!damage!particular!kinds!of!information!and!thus!abolish!particular!kinds!of!meaning.!!Damage!to!part!of!the!association!cortex!of!the!left!parietal!lobe!can!produce!an!inability!to!name!the!body!parts.!This!disorder!is!called!autotopagnosia,!or!poor!knowledge!of!one’s!own!topography.!(autotopanomia,!poor!naming!of!one’s!own!topography)!!

!!?Speech'conveys'abstract'concepts,'some'of'them'quite'subtle.'Comprehension'of'the'more'subtle,'figurative'aspects'of'speech'involves'the'right'hemisphere.'Judging'the'moral'of'Aesop’s'fables'activated'regions'of'the'right'hemisphere.'Comprehension'of'metaphors'such'as'green'lung'of'the'city'(that'is,'a'park)'activated'the'right'superior'temporal'cortex.''

12. Autotopagnosia!Inability!to!name!body!parts!or!to!identify!body!parts!that!another!person!names.!!BThis!disorder!is!called!autotopagnosia!or!poor!knowledge!of!one’s!own!topography.!(poor!naming!of!one’s!own!topography)!BDamage!to!part!of!the!association!cortex!of!the!left!parietal!lobe!can!produce!an!inability!to!name!body!parts.!!BPeople!who!can!otherwise!converse!normally!cannot!reliably!point!to!their!elbow,!knee,!or!cheek!when!asked!to!do!so!and!cannot!name!body!parts!when!the!examiner!points!to!them.!!BHowever,!they!have!no!difficulty!understanding!the!meaning!of!other!words.!BThis!is!about!memory.(

!Repetition:(Conduction(Aphasia((People!with!transcortical!sensory!aphasia!can!repeat!what!they!hear!suggests!that!there!is!a!direct!connection!between!Wernicke’s!area!and!Broca’s!area!–and!there!is:!the!arcuate(fasciculus.!(

13. Arcuate(fasciculus!A!bundle!of!axons!that!connects!Wernicke’s!area!with!Broca’s!area;!damage!causes!conduction!aphasia.!!BThis!bundle!of!axons!appears!to!convey!information!about!the!sounds!of!words!but!not!their!meanings.!(

(14. Conduction(aphasia!An!aphasia!characterized!by!an!inability!to!

repeat!words!that!are!heard!but!the!ability!to!speak!normally!and!comprehend!the!speech!of!others.!!BPeople!with!conduction!aphasia!can!repeat!speech!sounds!that!they!hear!only!if!these!sounds!have!meaning.!They!are!unable!to!repeat!nonwords!such!as!blayngge.!They!could!repeat!a!meaningful!threeBword!phrase!but!not!three!unrelated!words.!!BOpposite!transcortical!sensory!aphasia.!!BWhen!you!say!car,!they!cannot!repeat,!but!they!know!what!car!is,!so!they!can!say!it!is!machine!that!people!drive!it!to!go!somewhere.!(

!!BSpeech!and!meaning!is!different!things.!!BThe!symptoms!of!transcortical'sensory'aphasia!and!conduction'aphasia!lead!to!the!conclusion!that!there!are!pathways!connecting!the!speech!mechanisms!of!the!temporal!lobe!with!those!of!the!frontal!lobe.!The!direct!pathway!though!the!arcuate!fasciculus!simply!conveys'speech'sounds!from!Wernicke’s!area!to!Broca’s!area.!We!use!this!pathway!to!repeat!unfamiliar!words!–for!example,!when!we!are!learning!a!foreign!language!or!a!new!word!in!our!own!language!or!when!we!are!trying!to!repeat!a!nonwords!such!as!blaynge.!!The!second!pathway,!between!the!posterior!language!area!and!Broca’s!area,!is!indirect!and!is!based'on'the'meaning'of'words,!not!on!the!sounds!they!make.!When!patients!with!conduction!aphasia!hear!a!word!or!a!sentence,!the!meaning!of!what!they!hear!evokes!some!sort!of!image!related!to!that!meaning.!They!are!then!able!to!describe!that!image,!just!as!they!would!put!their!own!thoughts!into!words.!Of!course,!the!words!they!choose!might!not!be!the!same!as!the!ones!used!by!the!person!who!spoke!to!them.!!!BThe!symptoms!of!conduction!aphasia!indicate!that!the!connection!between!Wernicke’s!area!and!Broca’s!area!appears!to!play!an!important!ole!in!shortBterm!memory!of!words!and!speech!sounds!that!have!just!been!heard.!Presumably,!rehearsal!of!such!information!can!be!accomplished!by!“talking!to!ourselves”!inside!our!head!without!actually!having!to!say!anything!aloud.!Imaging!ourselves!saying!the!word!activates!the!region!of!Broca’s!area,!whereas!imaging!that!we!are!hearing!it!activates!the!auditory!association!area!of!the!temporal!lobe.!These!two!regions,!connected!by!means!of!the!arcuate!fasciculus!circulate!information!back!and!forth,!keeping!the!shortBterm!memory!alive.!Baddeley!(1993)!refers!to!this!circuit!as!the!phonological!loop.!BWe!do!use!Borca’s!area!when!we!talk!to!ourselves.!!!

!

Memory(of(Words:(Anomic(Aphasia!BAnomia,!in!one!form!or!other,!is!a!hallmark!of!aphasia.!!BHowever,!one!category!of!aphasia!consists!of!almost!pure!anomia,!the!other!symptoms!being!inconsequential.!!BSpeech!of!patients!with!anomic!aphasia!is!fluent!and!grammatical,!and!their!comprehension!is!excellent,!but!they!have!difficulty!finding!the!appropriate!words.!!BThey!often!employ!circumlocutions!to!get!around!missing!words.!!BAnomic!aphasia!is!different!from!Wernicke’s!aphasia.!People!with!anomic!aphasia!can!understand!what!other!people!say,!and!what!those!with!anomic!aphasia!say!makes!perfect!sense,!even!if!they!often!choose!roundabout!ways!to!say!it.!!BAnomia!has!been!described!as!partial!amnesia!for!words.!It!can!be!produced!by!lesions!in!either!the!anterior!or!posterior!regions!of!the!brain,!but!only!posterior!lesions!produce!a!fluent!anomia.!!BThe!most!likely!location!of!lesions!that!produce!anomia!without!the!other!symptoms!of!aphasia,!such!as!comprehension!of!!!

15. Circumlocution!A!strategy!by!which!people!with!anomia!find!alternative!ways!to!say!something!when!they!are!unable!to!think!of!the!most!appropriate!word.!(literally,!“speaking!in!a!roundabout!way”)(

!BThe!patient!with!anomic!aphasia!seemed!to!have!more!difficulty!finding!nouns!than!other!types!of!words.!While!she!is!telling!something,!she!made!almost!no!errors!in!finding!verbs.!!BSeveral!studies!have!found!that!anomia!for!verbs!(averbia)!is!caused!by!damage!to!the!frontal!cortex,!in!and!around!Broca’s!area.!The!frontal!lobe!are!devoted!to!planning,!organizing,!and!executing!actions,!so!it!should!not!surprise!us!that!they!are!involved!in!the!task!of!remembering!the!names!of!action.!!BSeveral!functional!imaging!studies!have!confirmed!the!importance!of!Broca’s!area!and!the!region!surrounding!it!in!the!production!of!verbs.!!In!a!study,!subjects!read!verbs!that!related!to!movements!of!different!parts!of!the!body.!For!example,!bite,!slap,!kick!involve!movements!of!the!face,!arm,!leg.!The!investigators!found!that!when!the!subjects!read!a!verb,!they!saw!activation!in!the!regions!of!the!motor!cortex!that!controlled!the!relevant!part!of!the!body.!!BAnother!study!found!that!hearing!sentences!that!involved!hand!movements!(such!as!turning!the!key)!activated!the!hand!region!of!the!motor!cortex,!and!that!hearing!sentences!that!involved!foot!movements!(such!as!stepping!on!the!grass)!activated!the!foot!region.!Presumably,!thinking!about!particular!actions!activated!regions!that!control!these!actions.!!!Aphasia(in(Deaf(People!BSeveral!studies!have!found!a!linkage!between!speech!ad!hand!movements,!which!supports!the!suggestion!that!the!spoken!language!of!presentBday!humans!evolved!from!hand!gestures.!!(BDeaf!community!involves!another!medium:!sign!language.!Sign!language!is!expressed!manually,!by!movements!of!the!hands.!!BBroca’s!area!was!activated!when!people!observed!and!imitated!finger!movements.!!BDeaf!people!use!Broca’s!area!while!using!their!sign!language!(hand!movements!etc).!!BBut!in!normal!people!body!movements!or!hand!movements!is!controlled!by!motor!cortex.!!BAs!it!mentioned!earlier,!mirror!neurons!become!active!when!we!see!or!perform!particular!grasping,!holding,!or!manipulating!movements.!Some!of!these!neurons!are!found!in!Broca’s!area.!Presumably,!these!neurons!plan!an!important!role!in!learning!to!mimic!another!people’s!hand!movement.!!BWhen!the!experimenter!grasped!a!large!object,!the!subjects!opened!their!mouths!more!and!said!the!syllable!more!loudly!than!when!he!grasped!small!one.!These!results!suggest!that!the!region!of!the!brain!that!control!grasping!is!also!involved!in!controlling!speech!movements.!!BBecause!Broca’s!area!is!also!responsible!meaningful!movements!of!body!parts,!when!we!see!a!person!grasping!large!object,!our!mouth!will!open!largely,!and!if!we!see!a!person!grasping!small!object,!our!mouth!will!open!small.!!BDeaf!signers!produced!meaningful!signs;!increased!activity!was!seen!in!the!left!inferior!frontal!cortex!–the!region!of!Broca’s!area.!When!these!subjects!viewed!signs!made!by!others,!they!showed!increased!activity!in!the!left!superior!temporal!cortex.!Therefore,!sign!language,!like!auditory!and!written!language,!appears!to!rely!primarily!on!the!left!hemisphere!for!comprehension!and!expression.!A!study!had!both!deaf!and!hearing!subjects!sign!or!say!the!names!of!objects!they!were!shown.!Activation!was!seen!in!the!primary!visual!cortex!and!visual!association!cortex!(inferior!temporal!cortex)!and!in!Broca’s!area!in!both!deaf!and!hearing!subjects.!In!addition,!two!regions!of!the!parietal!cortex!were!specifically!activated!in!deaf!signers,!presumably!because!of!the!spatiallyBoriented!movements!these!subjects!made.!!

Prosody:(Rhythm,(Tone,(and(Emphasis(in(Speech((BWhen!we!speak,!we!do!not!merely!utter!words.!Our!speech!has!a!regular!rhythm!and!cadence;!we!give!some!words!stress,!and!we!vary!the!pitch!of!our!voice!to!indicate!phrasing!and!to!distinguish!between!assertions!and!questions.!!BIn!addition!we!can!impart!information!about!our!emotional!state!through!the!rhythm,!emphasis,!and!the!tone!of!our!speech.!These!rhythmic,!emphatic,!and!melodic!aspects!of!speech!are!referred!to!as!prosody.!!

16. Prosody!The!use!of!changes!in!intonation!and!emphasis!to!convey!meaning!in!speech!besides!that!specified!by!the!particular!words;!an!important!means!of!communication!of!emotion.!(

BJust!as!the!lesions!that!produce!Broca’s!aphasia!destroy!grammar,!they!also!severely!disrupt!prosody.!In!patients!with!Broca’s!aphasia,!articulation!is!so!labored!and!words!are!uttered!so!slowly!that!there!is!little!opportunity!for!the!patient!to!demonstrate!and!rhythmic!elements;!and!because!of!the!relative!lack!of!function!words,!there!is!little!variation!in!stress!or!pitch!of!voice.!!BProsody!is!a!special!function!of!the!right!hemisphere.!This!function!is!undoubtedly!related!to!the!more!general!role!of!this!hemisphere!in!musical!skills!and!the!expression!and!recognition!of!emotions:!Production!of!prosody!is!rather!like!singing,!and!prosody!often!serves!as!a!vehicle!for!conveying!emotion.!!BThe!meaningful!components!of!speech!primarily!activated!the!left!hemisphere.!The!prosodic!components!primarily!activated!the!right!hemisphere.!!(Stuttering((Kekeleme)!BStuttering!is!a!speech!disorder!characterized!by!frequent!pauses,!prolongations!of!sounds,!or!repetitions!of!sounds,!syllables,!or!words!that!disrupt!the!normal!flow!of!speech.!!BStuttering!which!appears!to!be!influenced!by!genetic!factors,!affects!approximately!1!percent!of!the!population!and!is!three!times!more!prevalent!in!men!than!women.!!BPeople!usually!start!stuttering!at!the!beginning!of!the!word/sentence.!The!reason!might!be!they!are!grammatically!planning,!it!is!about!planning.!!This!fact!suggests!that!stuttering!in!a!disorder!of!“selection,!initiation,!and!execution!of!motor!sequences!necessary!for!fluent!speech!production”.!BStuttering!is!not!a!result!of!abnormalities!in!the!neural!circuits!that!contain!the!motor!programs!for!speech.!!BFor!example,!stuttering!is!reduced!or!eliminated!when!a!person!reads!aloud!with!another!speaker,!signs,!or!reads!in!cadence!with!a!rhythmic!stimulus!!BThe!source!of!problem!may!be!faulty!auditory!feedback!from!sounds!of!the!stutterers’!own!speech.!Disruptions!in!the!normal!timing!of!activation!of!brain!regions!involved!in!speech!production.!!BDelayed!auditory!feedback!interferes!with!the!speech!of!most!fluent!speakers!but!actually!facilitates!the!speech!of!many!people!who!stutter.!!BDelayed!auditory!feedback!is!a!procedure!in!which!person!wearing!headphones!tries!to!speak!normally!while!hearing!his!or!her!own!voice,!which!has!been!electronically!delayed,!usually!by!50B200msec.!!!Effects!of!Therapy!for!Stuttering!!!

Disorder( Ares(of(Lesion((Spontaneous(

Speech(Comprehension( Repetition(Naming(

Broca’s!Aphasia!

Frontal!cortex!rostral!to!base!of!primary!motor!cortex!(Broca’s!are)!

Non!Bfluent!

Good! Poor! Poor!

Wernicke’s!Aphasia!

Posterior!portion!of!superior!temporal!gyrus!(Wernicke’s!area)!and!posterior!language!area!

Fluent! Poor! Poor! Poor!

Transcortical!Sensory!Aphasia!!

Posterior!language!area!Fluent! Poor! Good! Poor!

Pure!Word!Deafness!

Wernicke’s!area!or!its!connection!with!primary!auditory!cortex!

Fluent! Poor! Poor! Good!

Conduction!Aphasia!!

White!matter!beneath!parietal!lobe!superior!to!lateral!fissure!(arcuate!fasciculus)!

Fluent! Good! Poor! Good!

Anomic!Aphasia!

Various!parts!of!parietal!and!temporal!lobes!

Fluent! Good! Good! Poor!

Summary(! Two!regions!of!the!brain!are!especially!important!in!understanding!and!producing!speech.!Broca’s!area,!in!the!left!frontal!lobe!just!rostral!to!the!region!of!the!primary!motor!cortex!that!controls!the!muscles!of!speech,!is!involved!with!speech!production.!This!region!contains!memories!of!the!sequences!of!muscular!movements!that!produce!words,!each!of!which!is!connected!with!its!auditory!counterpart!in!the!posterior!part!of!the!brain.!Broca’s!aphasia!–which!is!caused!by!damage!to!Broca’s!area,!adjacent!regions!of!the!frontal!cortex,!and!underlying!white!matterB!consists!of!varying!degrees!of!agrammatism,!anomia,!and!articulation!difficulties.!! Wernicke’s!area,!in!the!posterior!superior!temporal!lobe,!is!involved!with!speech!perception.!The!region!just!adjacent!to!Wernicke’s!area,!which!I!have!called!the!posterior!language!area,!is!necessary!for!speech!comprehension!and!the!translation!of!thoughts!into!words.!Presumably,!Wernicke’s!area!contains!memories!of!the!sounds!of!words,!each!of!which!is!connected!through!the!posterior!language!area!with!circuits!that!contain!memories!about!the!properties!of!the!things!the!words!denote!and!with!circuits!that!are!responsible!for!pronouncing!the!words.!!! Damage!restricted!to!Wernicke’s!area!causes!pure!word!deafness!–loss!of!the!ability!to!understand!speech!without!loss!of!the!ability!to!talk,!read,!and!write.!Wernicke’s!aphasia,!caused!by!damage!to!Wernicke’s!area!and!the!posterior!language!area,!consists!of!poor!speech!comprehension,!poor!repetition,!and!production!of!fluent,!meaningless!speech.!!! Transcortical!sensory!aphasia,!caused!by!damage!to!the!posterior!speech!area,!consists!of!poor!speech!comprehension!and!production,!but!the!patients!can!repeat!what!they!hear.!Thus,!the!symptoms!of!Wernicke’s!aphasia!consist!of!those!of!transcortical!sensory!aphasia!plus!those!of!pure!word!deafness!(WA!=!TSA!+!PWD).!!! Feedback!from!mirror!neurons!that!are!activated!when!people!hear!the!speech!of!other!people!may!facilitate!speech!recognition.!The!right!hemisphere!plays!a!role!in!the!more!subtle,!figurative!aspects!of!speech.!!! The!fact!that!people!with!transcortical!sensory!aphasia!can!repeat!words!that!they!cannot!understand!suggests!that!there!s!a!direct!connection!between!Wernicke’s!area!and!Broca’s!area.!!Indeed,!there!is:!the!arcuate!fasciculus.!Damage!to!this!bundle!of!axons!produces!conduction!aphasia:!disruption!of!the!ability!to!repeat!exactly!what!was!heard!without!disruption!of!the!ability!to!comprehend!or!produce!meaningful!speech.!A!parallel!pathway,!consisting!of!an!anterior!and!a!posterior!bundle!that!connect!in!the!inferior!parietal!cortex,!may!be!responsible!for!the!ability!of!people!with!pure!conduction!aphasia!to!understand!and!paraphrase!what!they!hear.!!! The!meanings!of!words!are!our!memories!of!objects,!actions,!and!other!concepts!associated!with!them.!These!meanings!are!memories!and!are!stored!in!the!association!cortex,!not!in!the!speech!areas!themselves.!Anomic!aphasia,!caused!by!damage!to!the!temporal!or!parietal!lobes,!consists!of!difficulty!in!word!finding,!particularly!in!naming!objects.!Brain!damage!can!also!disrupt!the!“definitions”!as!well!as!the!“entries”!in!the!mental!dictionary;!damage!to!specific!regions!of!the!association!cortex!effectively!erases!some!categories!of!the!meanings!of!words.!Damage!to!Broca’s!area!and!surrounding!regions!disrupts!the!ability!to!name!actions!–to!think!of!appropriate!verbs.!The!right!hemisphere!plays!a!role!in!the!more!subtle,!figurative!aspects!of!speech.!!! The!left!hemisphere!plays!the!more!important!role!in!the!language!abilities!of!deaf!people!who!use!sign!language,!just!as!it!does!in!people!who!communicate!acoustically.!Gestural!language!may!have!been!the!precursor!to!vocal!speech;!mirror!neurons!in!Broca’s!area!are!activated!by!hand!movements.!!! Prosody!includes!changes!in!intonation,!rhythm,!and!stress!that!add!meaning,!especially!emotional!meaning,!to!the!sentences!that!we!speak.!The!neural!mechanisms!that!control!the!prosodic!elements!of!speech!appear!to!be!in!the!right!hemisphere.!!! Stuttering!appears!to!be!cause!by!abnormalities!in!neural!circuits!that!are!involved!in!feedback!and!planning!and!initiating!speech,!not!in!the!circuits!that!contain!the!motor!programs!for!articulation.!Functional!imaging!indicates!deficient!auditory!feedback!produced!by!the!stutterers’!own!voice.!Delayed!auditory!feedback,!which!impairs!the!speech!of!most!fluent!speakers,!often!facilitates!the!speech!of!stutterers.!!

DISRODERS(OF(READING(AND(WRITING!BReading!and!writing!are!closely!related!to!listening!and!talking;!thus,!oral!and!written!language!abilities!have!many!brain!mechanisms!in!common.!!

17. Pure(alexia!Loss!the!ability!to!read!without!loss!of!the!ability!to!write;!produced!by!brain!damage.!!BPure!alexia,!pure!word!blindness,!or!alexia!without!agraphia.!!BDejerine!(1892)!described!this!syndrome,!and!his!patient!had!lesion!in!the!visual!cortex!of!the!left!occipital!lobe!and!the!posterior!end!of!the!corpus!collosum.!!BThe!patient!could!still!write,!although!he!had!lost!the!ability!to!read.!!BIn!fact,!if!he!was!shown!some!of!his!own!writing,!he!could!not!read!it.!!BPatients!with!pure!alexia!cannot!read,!but!they!can!recognize!words!that!are!spelled!aloud!to!them,!so!they!have!not!lost!their!memories!of!the!spellings!of!words.!!BPure!alexia!is!obviously!a!perceptual!disorder;!it!is!similar!to!pure!word!deafness,!except!that!the!patient!has!difficulty!with!visual!input,!not!auditory!input.!!BThis!disorder!is!caused!by!lesions!that!prevent!visual!information!from!reaching!extrastriate!cortex!of!the!left!hemisphere.!!BFlow!of!visual!information!for!a!person!with!this!brain!damage:!Information!from!the!left!side!of!the!visual!field!is!transmitted!to!the!right!striate!cortex!(primary!visual!cortex)!and!then!to!regions!of!the!right!visual!association!cortex.!!From!there,!the!information!crosses!the!posterior!corpus!collosum!and!is!transmitted!to!the!left!visual!association!cortex,!where!it!is!analyzed!further.!!The!information!is!then!transmitted!to!speech!mechanisms!located!in!the!left!frontal!lobe.!Thus,!the!person!can!read!the!words!aloud.!!BBut,!lesion!of!the!corpus!collosum!prevents!visual!information!concerning!written!text!from!reaching!the!posterior!left!hemisphere.!Without!this!information,!the!patient!cannot!read.!!BFace!area!is!used!for!reading.!Recognizing!words.!(

((Toward(an(Understanding(of(Reading((Reading!involves!at!least!two!different!processes:!!

18. Whole]word(reading!Reading!by!recognizing!a!word!as!a!whole;!“sight!reading”.!Direct!recognition!of!the!word!as!a!whole!and!sounding!it!out!letter!by!letter.!!BWhen!we!see!a!familiar!word,!we!normally!recognize!and!pronounce!it.!This!process!is!known!as!wholeBword!reading.!(With!very!long!words,!we!might!instead!perceive!segments!of!several!letters!each).!(

19. Phonetic(reading!Reading!by!decoding!the!phonetic!significance!of!letter!strings;!“sound!reading”.!!BThe!second!method!of!reading,!which!we!use!for!unfamiliar!words,!requires!recognition!of!individual!letters!and!knowledge!of!the!sounds!they!make.!!BIf!you!did!not!recognize!the!words,!because!you!never!saw!before,!so!you!had!to!figure!out!how!to!pronounce!the!words.!!BWhen!we!see!familiar!word,!we!normally!recognize!it!as!a!whole!and!pronounce!it.!!If!we!see!unfamiliar!word!or!a!pronounceable!nonword,!we!must!try!to!read!it!phonetically.!!BGenerally!in!Turkish!and!Italian!we!commonly!use!phonetic!language,!we!spell!them!out.!!BWhen!we!read!unknown!words!we!use!phonetic!reading.!(

((

BDyslexia!means!“faulty!reading”.!Acquired!dyslexias!are!those!caused!by!damage!to!the!brains!of!people!who!already!know!how!to!read.!In!contrast,!developmental!dyslexias!refer!to!reading!difficulties!that!become!apparent!when!children!are!learning!to!read.!!!Investigators!have!reported!several!types!of!acquired!dyslexias:!Surface(dyslexia,(phonological(dyslexia,(and(direct(dyslexia.((

20. Surface(dyslexia!A!reading!disorder!in!which!a!person!can!read!words!phonetically!but!has!difficulty!reading!irregularly!spelled!words!by!the!wholeBword!method.!!BSurface!dyslexia!is!a!deficit!in!wholeBword!reading.!!BThe!term!surface!reflects!the!fact!that!people!with!this!disorder!make!errors!related!to!the!visual!appearance!of!the!words!and!to!pronunciation!rules,!not!to!the!meaning!of!the!words,!which!is!metaphorically!“deeper”!than!the!appearance.!!BBecause!patients!with!surface!dyslexia!have!difficulty!recognizing!words!as!a!whole,!they!are!obliged!to!sound!them!out.!!BThus,!they!can!easily!reads!words!with!regular!spelling!such!as!hand,!table!or!chin.!!BBut!they!have!difficulty!reading!words!with!irregular!spelling,!such!as!sew,!pint,!yacht.!–!They!read!them!yatchet!(not!as!yaat),!because!they!don’t!read!effectively,!so!they!don’t!understand!their!meanings.!!In!fact,!they!may!read!these!words!such!as!sue,!pint,!yatchet.!!BThey!have!no!difficulty!reading!pronounceable!nonwords!such!as!glab,!trisk,!and!chint.!!BBecause!people!with!surface!dyslexia!cannot!recognize!whole!words!by!their!appearance,!they!must,!in!effect,!listen!to!their!own!pronunciation!to!understand!what!they!are!reading.!!BAlso,!if!the!word!is!one!member!of!a!homophone!(eşsesli),!it!will!be!impossible!to!understand!it!unless!it!is!read!in!the!context!of!a!sentence.!For!example,!if!you!hear!the!single!word!“pair”!without!additional!information,!you!cannot!know!whether!the!speaker!is!referring!to!pair,!pear,!or!pare.!It!could!be!for!example!pair!of!apple!to!be!understood!by!people!who!with!surface!dyslexia.!!BIf!they!read!the!word!pint!and!pronounce!it!pint,!they!will!say!that!is!not!an!English!word!(which!it!is!not,!pronounced!that!way)!BEx:!Hakim.!We!use!phonological!reading!mostly!in!Turkish!because!we!not!simply!say!hakim,!we!say!actually!haaakim.!!(

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((

21. Phonological(dyslexia(A!reading!disorder!in!which!a!person!can!read!familiar!words!but!has!difficulty!reading!unfamiliar!words!or!pronounceable!nonwords.!!BThe!symptoms!of!phonological!dyslexia!are!opposite!those!of!surface!dyslexia:!People!with!this!disorder!can!read!by!the!wholeBword!method!but!cannot!sound!words!out.!!!BThus,!they!can!read!words!that!they!are!familiar!with!but!have!great!difficulty!figuring!out!how!to!read!unfamiliar!words!or!pronounceable!nonwords.!!BPeople!with!phonological!dyslexia!may!be!excellent!readers!if!they!had!already!acquired!a!good!reading!vocabulary!before!that!brain!damage!occurred.!!BAntiestamblishmentarianism!–!the!only!way!to!read!this!word,!we!have!to!use!phonological!reading.!!!BGrab,!trisk!–!the!only!way!to!read!these!nonwords,!meaningless!words,!we!have!to!use!phonological!reading!because!we!have!never!seen!them!before,!we!are!not!familiar!to!them.!But!phonological!dyslexia!cannot!read!unfamiliar!words.!(

BWholeBword!reading!and!phonological!reading!involve!different!brain!mechanisms.!!BThe!process!of!whole!word!reading!follows!the!ventral!stream!of!the!visual!system!to!the!fusiform!gyrus,!located!on!the!base!of!the!temporal!lobe.!!(

22. Visual(word]form(area((VWFA)!A!region!of!the!fusiform!gyrus!on!the!base!of!the!temporal!lobe!that!plays!a!critical!role!in!wholeBword!recognition.!!BThis!region!is!also!involved!in!the!perception!of!faces!and!other!shapes!that!require!expertise!to!distinguish,!and!certainly!recognizing!whole!words!or!kanji!symbols!requires!expertise.!!BVWFA!quickly!recognize!words!written!in!different!typestyles,!fonts!or!CASES.!This!means!that!the!VWFA!can!recognize!whole!words!with!different!shapes;!certainly!chair!and!CHAIR!do!not!look!same.!!BDamage!to!the!VWFA!produces!surface!dyslexia;!that!is,!impairment!of!wholeBword!reading.!!BFusiform!Face!Area!is!responsible!for!recognizing!faces,!but!left!side!of!this!area!most!responsible!recognizing!letters.!!BWhen!VWFA!is!damaged,!it!is!surface!dyslexia.!(

(BPhonological!reading!appears!to!follow!the!dorsal!stream!to!the!region!around!the!junction!of!the!inferior!parietal!lobe!and!the!superior!temporal!lobe!(temporoparietal!cortex)!and!then!follows!a!fiber!bundle!from!this!region!to!the!inferior!frontal!cortex!–which!includes!Broca’s!area.!!BPhonological!reading!activates!the!left!temporoparietal!cortex!and!Broca’s!area.!!BSome!parts!of!the!visual!association!cortex!must!be!involved!in!perceiving!written!words.!For!instance,!visual!agnosia!is!a!perceptual!deficit!in!which!people!with!bilateral!damage!to!the!visual!association!cortex!cannot!recognize!objects!by!sight.!However,!people!with!visual!agnosia!can!still!read,!which!means!that!the!perceptual!analysis!of!objects!and!words!involves!at!least!some!different!brain!mechanisms.!!BCertainly,!the!ability!to!read!cannot!have!shaped!the!evolution!of!human!brain,!because!the!invention!of!writing!is!only!a!few!thousand!years!old.!Thus,!reading!and!object!recognition!use!brain!mechanisms!that!undoubtedly!existed!long!before!the!invention!of!writing.!!!!!

23. Direct(dyslexia(A!language!disorder!caused!by!brain!damage!in!which!the!person!can!read!words!aloud!without!understanding!them.!!BRecognizing!a!spoken!word!is!different!from!understanding!it.!!BFor!example,!patients!with!transcortical!sensory!aphasia!can!repeat!what!is!said!to!them!even!though!they!show!no!signs!of!understanding!what!they!hear!or!say.!!BThe!same!is!true!for!reading.!Direct!dyslexia!resembles!transcortical!sensory!aphasia,!except!that!the!words!in!question!are!written,!not!spoken.!!BPatients!with!direct!dyslexia!are!able!to!read!aloud!even!though!they!cannot!understand!the!words!they!are!saying.!(

BDyslexia!is!more!common!in!English.!!BFor!example,!a!bilingual!person!know!English!and!Japanese,!he!might!have!dyslexia!in!English!but!not!in!Japanese.!!!Subtle(Differences(in(written(words:!Unless!you!can!read!Arabic,!Hindi,!or!Mandarin,!you!will!probably!have!to!examine!these!words!carefully!to!find!the!small!differences.!However,!as!a!reader!of!English,!you!will!immediately!recognize!the!words!“car”!and!“ear”.!!Stimuli(Used(in(a(Test(of(Word(Recognition:!These!examples!of!stimuli!were!used!in!the!experiment!by!Vinckier!et!al.!Mouton!is!the!French!word!for!“sheep”.!If!we!don’t!know!Arabic,!Hindi!and!mandarin!we!cannot!differ!these!words!from!each!other,!but!if!we!are!expert!we!can!differ!them.!!If!you!cannot!differentiate!the!word!with!wholeBword!reading,!you!have!to!use!phonological!reading.!We!use!wholeBword!reading!when!we!are!expert!on!that!language.!!!BThese!words!activates!different!brain!areas.!!!BThese!findings!indicate!that!the!brain!regions!responsible!for!phonetic!reading!and!wholeBword!reading!are!each!independently!connected!with!brain!regions!responsible!for!speech.!!!Toward(an(Understanding(of(Writing((BWriting!depends!on!knowledge!of!the!words!that!are!to!be!written,!along!with!the!proper!grammatical!structure!of!the!sentences!they!are!to!form.!!BTherefore,!if!a!patient!is!unable!to!express!himB!or!herself!by!speech,!we!should!not!be!surprised!to!see!a!writing!disturbance!(dysgraphia)!as!well.!!BIn!addition,!most!cases!of!dyslexia!are!accompanied!by!dysgraphia.!!BOne!type!of!writing!disorder!involves!difficulties!in!motor!control—in!directing!the!movements!of!a!pen!or!pencil!to!form!letters!and!words.!Investigators!have!reported!surprisingly!specific!types!of!writing!disorders!that!fall!into!this!category.!!BOrganization!of!the!motor!aspects!of!writing!involved!the!dorsal!parietal!lobe!and!the!premotor!cortex.!BFor!example,!some!patients!can!write!numbers!but!not!letters,!some!can!write!uppercase!letters!but!not!lowercase!letters,!some!can!write!consonants!but!not!vowels,!some!can!write!cursively!but!cannot!print!uppercase!letters,!and!others!can!write!letters!normally!but!have!difficulty!placing!them!in!an!orderly!fashion!on!the!page.!BMany!regions!of!the!brain!are!involved!in!writing.!For!example,!damage!that!produces!various!forms!of!aphasia!will!produce!impairments!in!!writing!that!are!similar!to!those!seen!in!speech.!!BOrganization!of!the!motor!aspects!of!writing!involves!the!dorsal!parietal!lobe!and!the!premotor!cortex.!These!regions!(and!the!primary!motor!cortex,!of!course)!become!activated!when!people!engage!in!writing,!and!damage!to!these!regions!impairs!writing.!!BA!functionalBimaging!study!by!Rijntjes!et!al.!(1999)!had!people!sign!their!names!with!either!their!index!finger!or!their!big!toe.!!BIn!both!cases,!doing!so!activated!the!premotor!cortex!that!controlled!movements!of!the!hand.!!BThis!finding!suggests!that!when!we!learn!to!make!a!complex!series!of!movements,!the!relevant!information!is!stored!in!regions!of!the!motor!association!cortex!that!control!the!part!of!the!body!that!is!being!used!but!that!this!information!can!be!used!to!control!similar!movements!in!other!parts!of!the!body.!!

BLongcamp!et!al.!(2005)!found!that!simply!looking!at!alphabetical!characters!activated!the!premotor!cortex:!on!the!left!side!in!rightBhanded!people!and!on!the!right!side!in!leftB!handed!people.!!

!BA!more!basic!type!of!writing!disorder!involves!problems!in!the!ability!to!spell!words,!as!opposed!to!problems!with!making!accurate!movements!of!the!fingers.!!BLike!reading,!writing!(or,!more!specifically,!spelling)!involves!more!than!one!method.!The!first!method!is!related!to!audition.!!BWhen!children!acquire!language!skills,!they!first!learn!to!recognize!the!sounds!of!words,!then!learn!to!say!them,!then!learn!to!read,!and!then!learn!to!write!Undoubtedly,!reading!and!writing!depend!heavily!on!the!skills!that!are!learned!earlier.!!BFor!example,!to!write!most!words,!we!must!be!able!to!“sound!them!out!in!our!heads,”!!that!is,!to!hear!them!and!to!articulate!them!subvocally.!!BA!second!way!of!writing!involves!transcribing!an!image!of!what!a!particular!word!looks!like—copying!a!visual!mental!image.!!BHave!you!ever!looked!off!into!the!distance!to!picture!a!word!so!that!you!could!remember!how!to!spell!it?!!BSome!people!are!not!very!good!at!phonological!spelling!and!have!to!write!some!words!down!to!see!whether!they!look!correct.!!BThis!method!obviously!involves!visual!memories,!not!acoustical!ones.!!!BNeurological!evidence!supports!at!least!the!first!three!of!these!speculations.!Brain!damage!can!impair!the!first!of!these!methods:!phonetic!writing.!This!deficit!is!called!phonological(dysgraphia.!!

24. Phonological(dysgraphia(A!writing!disorder!in!which!the!person!cannot!sound!out!words!and!write!them!phonetically.!BPeople!with!this!disorder!are!unable!to!sound!out!words!and!write!them!phonetically.!!BThus,!they!cannot!write!unfamiliar!words!or!pronounceable!nonwords,!such!as!antiestablishmentaniarism,!trisk.!!BThey!can,!however,!visually!imagine!familiar!words!and!then!write!them.!!BPhonological!dysgraphia!appears!to!be!caused!by!damage!to!regions!of!the!brain!involved!in!phonological!processing!and!articulation.!!BDamage!to!Broca’s!area,!the!ventral!precentral!gyrus,!and!the!insula!cause!this!disorder,!and!phonological!spelling!tasks!activate!these!regions.!?Dysgraphia'refers'to'a'writing'deficit,'just'as'dyslexia'refers'to'a'reading'deficit.'!(

25. Orthographic(dysgraphia!A!writing!disorder!in!which!the!person!can!spell!regularly!spelled!words!but!not!irregularly!spelled!ones.!!BOrthographic!dysgraphia!is!just!the!opposite!of!phonological!dysgraphia:!It!is!a!disorder!of!visually!based!writing.!!BPeople!with!orthographic!dysgraphia!can!only!sound!words!out;!thus,!they!can!spell!regular!words!such!as!care!or!tree,!and!they!can!write!pronounceable!nonsense!words.!BHowever,!they!have!difficulty!spelling!irregular!words!such!as!half!or!busy;!they!may!write!haff!or!bizzy.!!BOrthographic!dysgraphia!(impaired!phonological!writing),!like!surface!dyslexia,!is!caused!by!damage!to!the!VWFA!on!the!base!of!the!temporal!lobe.!!

!26. Developmental(dyslexia(A!reading!difficulty!in!a!person!of!normal!

intelligence!and!perceptual!ability;!of!genetic!origin!or!caused!by!prenatal!or!perinatal!factors.!!BSome!children!have!great!difficulty!learning!to!read!and!never!become!fluent!readers,!even!though!they!are!otherwise!intelligent.!Specific!language!learning!disorders,!called!developmental!dyslexias,!tend!to!occur!in!families,!a!finding!that!suggests!a!genetic!(and!hence!biological)!component.!!BThe!concordance!rate!of!monozygotic!twins!ranges!from!84!percent!to!100!percent,!and!that!of!dizygotic!twins!ranges!from!20!percent!to!35!percent.!!BLinkage!studies!suggest!that!the!chromosomes!1,2,6,15!and!18!may!contain!genes!responsible!for!different!components!of!this!disorder.(

BOne!common!deficit!is!deficient!phonological!awareness.!That!is,!people!with!developmental!dyslexia!have!difficulty!blending!or!rearranging!the!!sounds!of!words!that!they!hear.!Problems!such!as!these!might!be!expected!to!impair!the!ability!to!read!phonetically.!(!BDyslexic!children!also!tend!to!have!great!difficulty!in!writing:!They!make!spelling!errors,!they!show!poor!spatial!arrangements!of!letters,!they!omit!letters,!and!their!writing!tends!to!have!weak!grammatical!development.!BFor!example,!Shaywitz!et!al.!(2002)!had!seventy!dyslexic!children!and!seventyBfour!nondyslexic!children!read!words!and!pronounceable!nonwords.!The!researchers!found!significantly!different!patterns!of!brain!activation!in!the!two!groups.!A!child’s!reading!skill!was!positively!correlated!with!activation!of!the!left!VWFA.!!Hoeft!et!al.!(2007)!found!that!dyslexics!showed!decreased!activation!in!the!left!temporoparietal!cortex!(dorsal!to!the!region!identified!by!Shaywitz!et!al.)!and!in!the!VWFA.!They!also!saw!hyperactivation!of!the!left!inferior!frontal!cortex,!including!Broca’s!area.!!BPresumably,!the!activation!of!Broca’s!area!reflected!an!effort!to!decode!the!phonology!of!the!incomplete!information!being!received!from!the!poorly!functioning!regions!of!the!more!posterior!brain!regions!involved!in!reading.!((

SUMMARY(! Brain!damage!can!produce!reading!and!writing!disorders.!Pure!alexia!is!caused!by!lesions!that!produce!blindness!in!the!right!visual!field!and!that!destroy!fibers!of!the!posterior!corpus!collosum.!!! Research!in!the!past!few!decades!has!discovered!that!acquired!reading!disorders!(dyslexias)!can!fall!into!one!of!several!categories,!and!the!study!of!these!disorders!has!provided!neuropsychologist!and!cognitive!psychologists!with!thoughtBprovoking!information!that!has!helped!them!to!understand!the!brain!mechanisms!involved!in!reading.!!! Analysis!of!written!words!appears!to!begin!in!the!left!posterior!inferior!temporal!cortex.!Phonological!information!is!then!analyzed!by!the!temporoparietal!cortex!and!Broca’s!area,!whereas!wordBform!information!is!analyzed!by!the!visual!word!form!area,!located!in!the!fusiform!cortex.!Surface!dyslexia!is!a!loss!of!wholeBword!reading!ability.!Phonological!dyslexia!is!a!loss!of!the!ability!to!read!phonetically.!Reading!of!kana!(phonetic)!and!kanji!(pictographic)!symbols!by!Japanese!people!is!equivalent!to!phonetic!and!wholeBword!reading,!and!damage!to!different!parts!of!the!brain!interfere!with!these!two!forms!of!reading.!!! Direct!dyslexia!is!analogous!to!transcortical!sensory!aphasia;!the!patients!can!read!words!aloud!but!cannot!understand!what!they!are!reading.!Some!can!read!both!real!words!and!pronounceable!nonwords,!so!both!phonetic!and!wholeBwords!reading!can!be!preserved.!!! Brain!damage!can!disrupt!writing!ability!by!impairing!people’s!ability!to!form!letters!–or!even!specific!types!of!letters,!such!as!uppercase!or!lowercase!letters!or!vowels.!!! The!dorsal!parietal!cortex!appears!to!be!the!most!critical!region!for!knowledge!of!the!movements!that!produce!letters.!Other!deficits!involve!the!ability!to!spell!words.!!!! We!normally!use!two!different!strategies!to!spell!words:!phonetic!(sounding!the!word!out),!visual!(remembering!how!it!looks!on!paper).!!! Two!types!of!dysgraphia—phonological!and!orthographic—represent!difficulties!in!implementing!phonetic!and!visual!strategies,!respectively.!The!existence!of!these!two!disorders!indicates!that!several!different!brain!mechanisms!are!involved!in!the!process!of!writing.!In!addition,!some!patients!have!a!deficit!parallel!to!direct!dyslexia:!They!can!write!words!they!can!no!longer!understand.!!!! Developmental!dyslexia!is!a!hereditary!condition!that!may!involve!abnormal!development!!of!parts!of!the!brain!that!play!a!role!in!language.!Most!developmental!dyslexics!have!difficulty!with!phonological!processing—of!spoken!words!as!well!as!written!ones.!!!! FunctionalBimaging!studies!report!decreased!activation!of!a!region!of!the!left!occipitotemporal!and!temporoparietal!cortex!and!hyperactivation!of!Broca’s!area!may!be!involved!in!developmental!dyslexia.!!!!!!!!

!! Children!who!learn!to!read!languages!that!have!writing!with!regular!correspondence!between!spelling!and!pronunciation!(such!as!Italian)!are!much!less!likely!to!become!dyslexic!than!are!those!who!learn!to!read!languages!with!irregular!spelling!(such!as!English!or!French).!A!better!understanding!of!the!components!of!reading!and!writing!may!help!us!to!develop!effective!teaching!methods!that!will!permit!people!with!dyslexia!to!take!advantage!of!the!abilities!that!they!do!have.!!!!!

Reading(Disorder(Whole]word(Reading(

Phonetic(Reading(

Remarks(

Pure!Alexia! Poor! Poor! Can!write!

Surface!Dyslexia!! Poor! Good! !

Phonological!Dyslexia!! Good!Poor! !

Direct!Dyslexia!! Good!Good! Cannot!comprehend!words!

!

Writing(Disorder(Whole]word(

Writing(

Phonetic(Writing(

Remarks(

Phonological!Dysgraphia! Good! Poor! !

Orthographic!Dysgraphia!! Poor! Good!! !

Semantic!Agraphia!!(direct!dysgraphia)! Good!

Good! Cannot!comprehend!words!

!By:!

Sbselman busraselman@std.sehir.edu.tr

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