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The BrainModule 4

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Q:How do neuroscientists explore theconnections among brain, mind, and

behavior?

A: Clinical observations have long revealed thegeneral efects o damage to various areas o

the brain. CT and MRI scans now reveal brainstructures, and !, "T and unctional MRIrecordings reveal brain activit#. $# surgicall#

lesioning or electricall# stimulating s%eci&c brain

areas, b# recording the brain's surace andelectrical activit#, we can better understand theconnection between brain, mind and behavior.

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How Can We Stud TheBrain?

!esions:destro#ing tissue naturall#or e(%erimentall#.

Clinical )bservation *hen one side is in+ured, the other is

numbwh#-

Mani%ulating the $rain lectricall#, chemicall# or magneticall#

stimulate the brain.

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"ccidents wor# welltoo$

ust as/ "hineas!age RR *or/er01242

Tam%ing Iron wentthrough his head.

3urvived $ut. Mood alterations

rratic behavior

3uggested thatrontal lobe damagealtered emotions mood.

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%ecording the Brain&s'lectrical "ctivit

'lectroencephalogram('')*: recording

waves o electricalactivit# on brain'ssurace.

This trac/ing is doneusing electrodes.

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+euroimaging

ComputedTomograph (CT* 50ra# %hotos

ositron 'missionTomograph ('T*

3hows consum%tion oglucose6unctioningregions

-agnetic

%esonance.maging (-%. uses magnetic &eld

/unctional -%. Ma%s blood 7ow

within the brain.

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Q: What are lower0level brainstructures, and what are their

1unctions?

A: The brainstem begins where the s%inal cordswells to orm the medulla, which controls

heartbeat and breathing. *ithin the brainstem,

the reticular ormation controls arousal. Ato% thebrainstem is the thalamus, the brain's sensor#switchboard. The cerebellum, attached to the

rear o the brainstem, coordinates musclemovement. $etween the brainstem cerebralcorte( is the limbic s#stem, which is lin/ed to

memor#, emotions and drives. )ne o its neuralcenters, the am#gdala, is involved in res%onses

o aggression and ear. Another, the

h#%othalamus, is involved in various bodil#

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Brain Structures

/orebrain0T)"

-idbrain0MI889

Hindbrain0$AC

Cerebral Cortex;%art o orebrainlittlebrain?

Coordinatesinvoluntar#movements: *al/ing, balancing

The brainstemacts on its own,

allowing thehigher brain to

do moreadvancedtas/s

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-idbrain

Coordinates sim%lemovements withsensor# inormation.

Most im%ortantstructure in Midbrainis the %eticular

/ormation: controls arousal and

abilit# to ocus ourattention.

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/orebrainThalamusHpothalamus!imbic SstemCerebral Cortex

*hat ma/es ushuman.

9argest %art o thebrain.

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Thalamus

3witchboard o thebrain.

Receives sensor#signals rom thes%inal cord andsends them to

cerebral corte(.

ver# sense

e(ce%t smell.

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The !imbic Sstem

8oughnut sha%eds#stem ostructures at the

border o thebrainstem.

Associated with: @ear, aggression,hunger, se(.

.ncludes: Hippocampus

"mgdala

Hpothalamus

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The !imbic Sstem0arts

H.3C"-6S

Memor# @ormation

"-7)8"!"

Aggression ear almond sha%ed

clusters

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The !imbic Sstem0Hpothalamus

"ossibl# the mostim%ortant structure inthe brain.

Controls andregulates:

Bod temperature Sexual "rousal Hunger Thirst 'ndocrine Sstem ituitar )land

HypoB $elow

HypothalamusBbelow the thalamus.

H th l

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Hpothalamus:The 9leasure Center o1

the Brain Research has ound

that rats will readil#

go to e(tremes totrigger their >rewardcenter? located in

the h#%othalamus.

3imilar researchsuggests that

humans would do

the same.

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Q: How do the neural networ#s withinthe cerebral cortex enable our

perceiving, thin#ing, and spea#ing?

A: ach hemis%here o the cerebralcorte(0has our geogra%hic areas:

the rontal, %arietal, occi%ital andtem%oral lobes. 3mall, well de&nedregions within these ones control

muscle movement and receivesensor# inormation. Most o the

corte( is uncommitted to suchunctions and is thereore ree to

%rocess other inormation.

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The Cerebral Cortex

Made u% o densel#%ac/ed neurons wecall >gra# matter?

2DE o brainweight

)lial Cells:

su%%ort brain cells.

*rin/les are calledfssures.

I #ou laid the brain out itwould be as big as a large

%ia

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Hemispheres

8ivided into hemis%heres.

Contralateral control:right controls let and viceversa.

!e1t Hemisphere:logic and seFuential tas/s.

%ight Hemisphere:s%atial and creative tas/s.

Corpus Calossum:bando nerves the connects the

let right hemis%heres.

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The /our !obes o1 the CerebralCortex

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!obes o1 the Brain

/%3+T"!

3%ea/ing, MuscleMovement, %lanning,

+udgment, motivation,emotion.>conscience?

"%.'T"!

Receives sensor#messages

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!obes o1 the Brain

3CC..T"!

;isual inormation

T'-3%"!

"uditor inormation

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/unctions o1 the Cortex

-3T3%

-otor Cortex:controlsvoluntar# movements

9ocated at the rear othe rontal lobes.

(%eriments: >wide awa/e? %atients

who's brains were >%robed?evo/ed motor res%onsesthe# could not sto%.

S'+S3%7

Sensor Cortex:registers and %rocesses

bod# sensations

9ocated at the ront o the%arietal lobes.

(%eriments: The more sensitive a bod#

region the greater area o thesensor# corte( devoted to it.

It's wh# we /iss with our li%sand not our toes.

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-otor < SensorCortexes

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"ssociation "reas

Areas involved in higher unctions:learning, remembering, thin/ing

s%ea/ing.

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$rain Activit# when =earing, 3eeing,and 3%ea/ing *ords

3%ecialiation and Integration in

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3%ecialiation and Integration in9anguage

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!anguage

"phasia:im%airment o languagedue to damage to the brain.

(. 3%ea/ but not read, write but notread, read but not write etc.

Broca&s "rea:controls language

e(%ression.0muscle movements involvedin s%eech.

Wernic#e&s "rea:controls language

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lasticit

lasticit:thebrain's ca%acit#or modi&cation.

%eorgani=ationnot regeneration

>%hantom limbs? $raille

Children have themost %lasticit#.

Removal ohemis%heres to%revent seiuresetc.

Q: What is a split brain and

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Q: What is a split brain, andwhat does it reveal about

brain 1unctioning?

A: A s%lit brain is one in which the twohemis%heres have been isolated b# a

surgical %rocedure that severed theconnective tissues, mainl# thecor%us callosum. 3tudies have oundthe let hemis%here is more verbal,and that the right hemis%here deals

with %erce%tion and emotion.

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3ur 8ivided Brain

!'/T H'-.SH'%'

Reading *riting 3%ea/ing Arithmetic Gnderstanding

%.)HT H'-.SH'%'

-- =arder to understand

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Split Brain atients

Cor%us Callosumhas been severed T#%icall# done to

relieve e(tremeseiures.

8r4 %oger Sperr his colleagues

were the &rst tos%lit the cor%uscallosum.

"atients are let

with two distinctmindsH

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