APPSYCHUnit3B.1MethodsofStudyingtheBrain&Older

BrainStructures1.  Dothepreservedbrainsofdeadpeoplehaveanythinggoingoninthere?IsthereanymoreofthatpersonleGinthere?Couldwetakethebrainofadyingpersonandpreserveitforever?

2.  HowdoneuroscienKstsstudythebrain’sconnecKonstobehaviorandmind?

3.  WhatarethefuncKonsofimportantlower-levelbrainstructures?

TheToolofDiscovery:HavingOurHeadExamined

•  Studyeffectsofaccidents/braindamage–  Strokes–  TraumaKcInjury–  Tumor

•  Lesion:KssuedestrucKoninbrain.–  Canoccurnaturallyorcanbecausedbyanexperiment.

–  DamagetooneareainrathypothalamusreducesorsKmulateseaKngdependingonwherethelesionis

RecordingtheBrain’sElectricalAcKvityElectroencephalograph(EEG)

•  Electrodesmeasureelectricalwavessweepingacrosssurfaceofthebrain,displaysbrainacKvity,recordsthebrainselectricalacKvity

NeuroimagingTechniques/BrainScans

Lookinginsidethebrain:•  CT(CAT)Scan•  PET•  MRI•  fMRI

CT(CAT)ScanComputerizedTomography

•  Cross-secKonX-raypicturesofthebrain•  Canrevealbraindamage

PETScan-PositronEmissionTomography

•  Injectedwithlow&harmlessdoseofglucose.

•  Mapsthebrainatwork•  ShowsbrainsconsumpKonofglucose,findswherebrainacKvityisbasedonlocaKngtheradioacKvity,or“hotspots”

MRIMagneKcResonanceImaging

•  HeadputinstrongmagneKcfield.Alignsatomsinbrain,thendisorientsthem,measuresdetectablesignalsastheymovebackintoplace

•  Can’tcheckfuncKonofbrain•  GivesdetailedpictureofsoGKssues,heavyneuralareasintheleG

brainofmusicians,orlightneuralareasorfluid-filledareasinschizophrenics

fMRIFuncKonalMRI

•  CanrevealfuncKoningaswellasstructure

•  AcKvepartofbrain=morebloodthere

•  ThosepartslightupduringcertainmentalfuncKons

•  Watchingvideo,backofbrainlightsup(occipitallobearea)

•  Givesinsightintohowbraindividesjobsamongdifferentpartsofbrain

Older Brain Structures •  Lowest:basicsurvival

Older brain structures: The Brainstem

•  Brainstem: Oldest & innermost region –  Responsible for some

automatic survival functions

–  Coordinates brain's messages

•  Medulla: Heartbeat, breathing, hunger / thirst

•  Pons: Helps coordinate movements

Older brain structures: The Brainstem •  Reticular formation: Nerve

network and cross-wiring area, filters and relays info from body to brain –  Responsible for Arousal – wake

& sleep •  Experiment: Electrical

stimulation of cat’s reticular formation – could instantly wake a sleeping cat

•  Severed reticular formation in a cat experiment – fell into a coma but stayed alive

The Thalamus •  Thalamus: Sensory

switchboard, hub –  All the senses

EXCEPT smell send & receive messages through here & travel to other, higher parts of the brain & body

–  Reticular Formation vs. Thalamus

•  RF ->sleep, Thalamus -> mostly other senses, but both are similar

The Cerebellum •  Cerebellum

–  “Little brain” –  2 lobes –  Coordination –  Balance –  Moving muscles in a

coordinated way –  Walking, talking

Alcohol hurts coordination, but sober and great athletes have a great cerebellum

The Limbic System •  LimbicSystem:Survivaltechniques,self-preservaKon,eaKng&thirst,sexdrive,emoKons,fear,aggression,reproducKon

•  “Animalbrain”–similartobasicfuncKonsofanimals

•  InjuriesassociatedwithitcandrasKcallychangepeople

The Limbic System •  Amygdala: Aggression & fear

–  Fight or flight •  (Review - teams up with

which nervous and endocrine functions?)

–  Responsible for anxiety –  Experiments –stimulation in one

spot of amygdala can make fierce animals mellow or another spot can make relaxed animals violent

The Limbic System •  Hypothalamus

–  Regulates the pituitary gland (master gland) for hormone release

–  Hunger, thirst, body temp, sexual behavior –  Experiments with “Reward Centers” in rats, hormone release

that rewards for pleasuring oneself –  Reward deficiency syndrome and drug abuse – constantly

crave things

The Limbic System •  Hippocampus

–  Long term memory –  “file cabinet” –  Alzheimer’s – can’t

form new memories, so hippocampus plays a role

Memorizethis!