lecture 8 early discoveries of brain function and localisation

8/17/2019 Lecture 8 Early Discoveries of Brain Function and Localisation

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Early discoveries of brain

function and localisation

Dr. Paul Dockree, History of Psychology: PS120, 200!


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"hat is neuro#sychology$

%&n any 'ell()ade )achine one is ignorant of )ost of the #arts* the better they 'ork the less 'e are conscious of the)+it isonly fault that dra's attention to the eistence of a)echanis) at all.- /raik, ., 1!

34 set analogy:

5aulty 34 sets:(

-no sound but intact picture -no picture but intact sound

-picture without colour (ie black & white pic)-colour without picture?


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6 3he e#eri)ental neuro#sychologist asks,%"hat #attern of behavioural dysfunctionoccurs 'hen a #articular brain region is

da)aged or lesioned$-

6 3he clinical neuro#sychologist asks, %Ho' cannor)al function be restored or co)#ensatedfor in the brain$-

6 Science(Practitioner 7odel

"hat is neuro#sychology$


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=roca9s >#hasia

In 1862, showing brain lesions in a stroke patient whocould understand language but could not speak (couldonly say "tan"), he demonstrated that the left frontallobe was responsible for articulation of speech

How did the feld evolve?


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"ernicke9s >#hasia?ike =roca, "ernicke investigated a si)ilar stroke victi).=ut this ti)e the #atient could s#eak but )ade no sense. 3he da)aged area 'as around 'here the te)#oral and#arietal lobes )eet in the #osterior #art of the lefthe)is#here. His


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S#eech content of a =roca9s and"ernicke9s a#hasic

6 3o )ean: @3he dog needs to go out so & 'ill

take hi) for a 'alk.%6 a "ernicke9s a#hasic #atient says:

%You know that smoodle pinkered and that Iwant to get him round and take care o him like ou want beore!"

6 an =roca9s a#hasic #atient says:%#alk dog!"



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5unction A: s#eech articulation5unction B: s#eechco)#rehensionBrain

functionStructures to be Lesioned

Area A

=roca9s areaArea B

"ernicke9sarea

Function X

S#eecharticulation

Impairment

/an9t s#eakuently

o &)#air)ent

&n uent s#eech

Function Y S#eech

co)#rehension

o &)#air)entFnderstanding

s#eech ofothers

Impairment /an9t

understandings#eech of others

>rea >: =roca9s area

>rea =: "ernicke9s area

$he logic o lesion analsis


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Brainfunction

Structures to be Lesioned

Area A

=roca9s areaArea B

"ernicke9sarea

Function X

S#eecharticulation

Impairment

/an9t s#eakuently

o &)#air)ent

&n uent s#eech

Function Y S#eech

co)#rehension

o &)#air)entFnderstanding

s#eech ofothers

Impairment /an9t

understandings#eech of others

5unction A: s#eech articulation

5unction B: s#eechco)#rehension

>rea >: =roca9s area

>rea =: "ernicke9s area


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6 Function X (articulation of speech)

depends on area A (Broca’s area) but notarea B,

6 whereas function Y (comprehending

speech) depends on area B (ernic!e’sarea) but not area A"

6 #ouble dissociation $ %old standard of

neurops&chological research



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"ilder Pen


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Sti)ulating the te)#oral lobes could he elicit)eaningful, integrated res#onses. Physical basisfor )e)ory: an @engra).-

"ilder Pen


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6 Holistic a##roach:

6 arl ?ashley 1!; * lesions )adethroughout the brain do not necessarycreate #roble)s 'hen learning a ne' taske.g., )ae learning in rats.

6 > lesioned brain is like a ne' syste), not anold syste) 'ith one #art )issing.



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6 ?ocalisation vs holistic:

> /o)#ro)ise(

6 /o)#le functions e.g., #erce#tion, )e)ory,reasoning cannot be acco)#lished by a singlebrain #rocess or brain regionI integration offunctional neuroanato)y * holistic vie'

6 evertheless, the si)#le #rocesses the)selvesthat are recruited to eercise co)#lefunctions are localised * localisation vie'

6 =rain da)age )ay reveal so)ething about theunderlying organisation of the syste).



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6 hat are the methods used in neurops&cholog&'

6 s&chometric testing 6 database of standardised scores6 /linical #atients vs. healthy controls

6 *linical obser+ation6 Diagnosis6 >ssess)ent6 Jehabilitation

6 euroanatom& :6 /onnectional studies in ani)al studies6 #roKection )a#s e.g., ?G to visual corte


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6 Lesion anal&sis

6selection of ani)als or hu)ans 'ithdiscrete brain da)age to areas thought tobe essential in a #articular #rocessing chain.

6one of the oldest )ethods for studyingbrain function in hu)ans and ani)als.

6single )ost infor)ative techniLue available

for understanding the neural bases ofbehaviour.

6htt#:MM'''.''norton.co)McollegeM#sychM#sychsci2McontentMactivitiesMch0a.as#N)ovie

hat are the methods used in neurops&cholog&'

http://www.wwnorton.com/college/psych/psychsci2/content/activities/ch04a.asphttp://www.wwnorton.com/college/psych/psychsci2/content/activities/ch04a.asphttp://www.wwnorton.com/college/psych/psychsci2/content/activities/ch04a.asphttp://www.wwnorton.com/college/psych/psychsci2/content/activities/ch04a.asp


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6 -&pes of lesions:6 cerebrovascular accidents /4>I strokeI occurs

'hen blood o' to the brain is disru#tedI



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6 -&pes of lesions:

6 penetrating head in%uries, fro) gunshot or otherincidentsI



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6 -&pes of lesions:

! ollowing traumatic brain in#ury ($%I), di&use white matter damage typicallyco'occurs with more focal lesions or hematomas (blood clots) and contusions(bruising) damaging the dense collections of cell bodies (grey matter )



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6 -&pes of lesions:

eurodegeneration' 'ides#read area oftissue death or abnor)al cell functioningdue to neuro#athology >D, PDI

healthy older

personPt with AD



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6 #eliberate lesions ( on e#eri)ental ani)als.

6 tissue ecision, 'here tissue is deliberatelyre)oved usually by as#irationI

6 tissue destruction, tissue is destroyedelectrolytically or che)ically e.g., 7P3P, ache)ical agent to create an ani)al )odel ofParkinson9s diseaseI



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6 tissue deactivation, 'here tissue isreversibly deactivated via inKections oflocal anaesthetic or through che)icalcoolingI

6 tissue disconnection, 'here brain areas areleft intact but


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6eurosurger is often conducted on hu)ans

in order to relieve conditions such as drug(resistant e#ile#sy #atient H.7., relief fro)intractable #ain or brain tu)ours.



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3he "ada test: sodiu) a)ytal

techniLue

6Sodiu) a)ytal is inKected intoone he)is#here at a ti)e

6 3he eOect is to shut do'n anylanguage andMor )e)oryfunction in that he)is#here inorder to evaluate the otherhe)is#here @half of the brain@.

6 3hen the #atient is engaged ina series of language and)e)ory related tests

ateralit


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6 =roca and a#hasia thera#y 1;6=roca concluded that the #atient,

%could recognie a 'ord as one 'ould a face orlandsca#e, the details of 'hich had never beenanalysed-

6 it deosnQt )ttaer 'aht oredr the ltteers in a 'rod are,the olny i#r)oetnt tihng is taht the frist and lsat

ltteres are at the rghit #clae. 3he rset can be a tatol)ses and you can sitll raed it 'outhit a #orbel). 3ihsis bcuseae 'e do not raed ervey lteter by it slef butthe 'rod as a 'lohe.

eurorehabilitation


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6 ""1( Ger)an rehabilitationPo##lereuter, Goldstein6 /ologne and 5rankfurt centres

6 ""&& * >leandra ?uria:theoretical #ers#ective fro)'hich to #redict recovery6 Jestoration of function via:

6 De(inhibition6 3ransfer to o##osite

he)is#here

6 Jeorganisation of the syste)6 ?uria stressed the

i)#ortance of #re)orbid#ersonality and )otivation

eurorehabilitation


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Is there an point to lesion

analses now?

6 > reading of the last


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6 ?esion analysis complements functional i)aging by identifyingnecessary and contributing co)#onents of the #rocessing chainIfunctional i)aging also allo's the identi

lecture 8 early discoveries of brain function and localisation

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