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!
