Neuroscience, Genetics and Behavior. True or False? “Basic biological processes underlie all human...

Neuroscience, Genetics and Neuroscience, Genetics and BehaviorBehavior

True or False?True or False?

““Basic biological processes underlie Basic biological processes underlie all human behavior.”all human behavior.”

Various branches of psychology rest Various branches of psychology rest on this foundation.on this foundation.

Biological PsychologyBiological Psychology(or Psychobiology)(or Psychobiology)

The most significant transformation The most significant transformation in modern psychologyin modern psychology

AKA Biopsychologists, behavioral AKA Biopsychologists, behavioral neuroscientists, behavior geneticists, neuroscientists, behavior geneticists, physiological psychologists, physiological psychologists, neuropsychologists…neuropsychologists…

An intro to neuroscience…An intro to neuroscience…Explain the following…Explain the following…

1.1. ““Modern psychology views each Modern psychology views each individual as a individual as a biopsychosocialbiopsychosocial system.”system.”

2.2. ““Everything psychological is Everything psychological is simultaneously biological.”simultaneously biological.”

3.3. ““The mind is what the brain does..”The mind is what the brain does..”

4.4. ““A brain simple enough to be A brain simple enough to be understood is too simple to produce understood is too simple to produce a mind able to understand it.”a mind able to understand it.”

Introducing the Introducing the neuron…neuron…

Simple definition:Simple definition: a nerve cella nerve cell

The incredible neuron….The incredible neuron…. basic unit of information processing or,basic unit of information processing or,

… building block of the brain. (and … building block of the brain. (and nervous system)nervous system)

Affects everything we do…Affects everything we do…

A vastly complex system…A vastly complex system…

Facts about neurons:Facts about neurons: 100 billion neurons in the human brain 100 billion neurons in the human brain

and CNS! (and 400 trillion synapses!)and CNS! (and 400 trillion synapses!)

A grain of sand-size part of the human A grain of sand-size part of the human brain holds 100,000 neurons!brain holds 100,000 neurons!

Neural StructureNeural Structure

Dendrite (receives impulse)Dendrite (receives impulse) Branching extensions of a neuron / receive Branching extensions of a neuron / receive

messages / conduct impulses toward the cell bodymessages / conduct impulses toward the cell body Axon (transmits impulse)Axon (transmits impulse)

extension of a neuron, ending in branching extension of a neuron, ending in branching terminal fibers, through which messages are sent terminal fibers, through which messages are sent to other neurons or to muscles or glandsto other neurons or to muscles or glands

Remember: “Axons speak, dendrites listen…”Remember: “Axons speak, dendrites listen…” Myelin SheathMyelin Sheath (speeds impulse)(speeds impulse)

a layer of fatty cells segmentally encasing the a layer of fatty cells segmentally encasing the fibers of many neuronsfibers of many neurons

Speeds transmission of neural impulsesSpeeds transmission of neural impulses


So what happens when the myelin So what happens when the myelin sheath begins to wear out?sheath begins to wear out?Alzheimer's (impedes transmissions Alzheimer's (impedes transmissions

affecting thought process)affecting thought process)Multiple sclerosis: interferes with muscle Multiple sclerosis: interferes with muscle

control (as message to muscles is control (as message to muscles is impeded..)impeded..)

Neural CommunicationNeural Communication “an electrochemical process…” “an electrochemical process…”

““Neural communication is a Neural communication is a conversation between cells that conversation between cells that generates our thoughts, actions, generates our thoughts, actions, moods and memory.”moods and memory.”

Neural CommunicationNeural Communication Action PotentialAction Potential

a brief electrical charge that travels a brief electrical charge that travels down an axondown an axon

Stimulated when neuron receives signals Stimulated when neuron receives signals from sense receptors stimulated by heat, from sense receptors stimulated by heat, pressure or lightpressure or light

Neural CommunicationNeural Communication““What one neuron tells another neuron is simply What one neuron tells another neuron is simply

how much it is excited.”how much it is excited.”

Each neuron has a Each neuron has a thresholdthreshold…… the level of stimulation required to the level of stimulation required to

trigger an action potential (or neural trigger an action potential (or neural impulse)impulse)

Determined by Determined by excitatoryexcitatory and and inhibitoryinhibitory triggers that determine triggers that determine the action potential (neural impulse)the action potential (neural impulse)

Neural Communication…Neural Communication…

Neurotransmission = electro-Neurotransmission = electro-chemical processchemical process

The chemistry to electricity process The chemistry to electricity process involves the exchange of involves the exchange of ionsions

Ions: electrically charged atomsIons: electrically charged atoms

Ions…Ions…

Resting PotentialResting Potential Fluid inside a resting axon has negatively Fluid inside a resting axon has negatively

charged atomscharged atoms Fluid outside the axon membrane has Fluid outside the axon membrane has

positively charge atomspositively charge atoms Natural state of inside / outside ions = Natural state of inside / outside ions = resting resting

potentialpotential

Axon’s surface is Axon’s surface is selectively permeableselectively permeable (it decides what it allows in..)(it decides what it allows in..)

Reaching a Neuron’s Reaching a Neuron’s Threshold…Threshold…

When the neuron fires…When the neuron fires…Axon opens gates (selectively Axon opens gates (selectively

permeable) and +charged sodium ions permeable) and +charged sodium ions flood the membraneflood the membrane

+sodium ions cause depolarization+sodium ions cause depolarizationDepolarization causes reaction as axons Depolarization causes reaction as axons

pass the impulse down the chain (like pass the impulse down the chain (like dominoes)dominoes)

Opens and closes 100-1000 times Opens and closes 100-1000 times /second!/second!

Reaching a Neuron’s Reaching a Neuron’s Threshold…Threshold…

Refractory PeriodRefractory PeriodOnce impulse has been passed, the Once impulse has been passed, the

axon pumps +ions back out of axon pumps +ions back out of membrane, and thus rechargesmembrane, and thus recharges

All or none responseAll or none responseIncreased stimulus does not increase Increased stimulus does not increase

the action potential’s intensity (a gun the action potential’s intensity (a gun either fires or doesn’t)either fires or doesn’t)

Neural CommunicationNeural Communication

Cell body end of axon

Direction of neural impulse: toward axon terminals

Neural CommunicationNeural Communication Synapse (Where the action is…)Synapse (Where the action is…)

junction between the axon of the sending neuron junction between the axon of the sending neuron and the dendrite of the receiving neuronand the dendrite of the receiving neuron

synaptic gapsynaptic gap or or cleft cleft (less than a millionth of (less than a millionth of an inch!)an inch!)

NeurotransmittersNeurotransmitters chemical messengers that carry the impulse chemical messengers that carry the impulse

(“message”) from one neuron to the next(“message”) from one neuron to the next neurotransmitters bind to neurotransmitters bind to receptor sitesreceptor sites (“lock (“lock

and key”and key”

Thus ions passed on to new neuron: Thus ions passed on to new neuron: exciting or inhibiting its readiness to fire..exciting or inhibiting its readiness to fire..


ReuptakeReuptakeExcess neurotransmitters are Excess neurotransmitters are

reabsorbed by the sending neuronreabsorbed by the sending neuron

NeurotransmittersNeurotransmitters

About 75 have been discoveredAbout 75 have been discoveredWe will study 7-8We will study 7-8

NeurotransmittersNeurotransmitters(Take notes on last 2 listed)(Take notes on last 2 listed)


GABAGABA InhibitoryInhibitory

neurotransmitterneurotransmitter Undersupply = seizures, Undersupply = seizures,

tremors, insomniatremors, insomnia

GlutamateGlutamate ExcitatoryExcitatory

neurotrasmitterneurotrasmitter Involved in memoryInvolved in memory Too much = migraines, Too much = migraines,

seizuresseizures Excitotoxicity: “excite a Excitotoxicity: “excite a

neuron to death” (glial neuron to death” (glial cells help prevent…)cells help prevent…)

Chinese food- MSG Chinese food- MSG (glutamate) = (glutamate) = headachesheadaches


Acetylcholine [ah-seat-el-KO-Acetylcholine [ah-seat-el-KO-leenleen]] AChACh triggers muscle contraction triggers muscle contraction

(movement, learning, memory)(movement, learning, memory) Undersupply = Alzheirmer’sUndersupply = Alzheirmer’s


Endorphins [en-DOR-fins]Endorphins [en-DOR-fins] ““morphine within” morphine within” natural, opiate-like neurotransmittersnatural, opiate-like neurotransmitters linked to pain control and to linked to pain control and to

pleasurepleasure ““Runners high”Runners high” Opium, heroine addicts: brain stops Opium, heroine addicts: brain stops

producing natural opiates, thus producing natural opiates, thus “withdraws”“withdraws”

Neurotransmitters…Neurotransmitters…

NorepinephrineNorepinephrineMoodMoodToo much = mania / too little = Too much = mania / too little =

depressiondepressionImbalance = bipolar disorderImbalance = bipolar disorder


SerotoninSerotoninSleep, eating, moodSleep, eating, moodRelated to depressionRelated to depressionProzac (anti-depressant drug) raises Prozac (anti-depressant drug) raises

serotonin levels serotonin levels


DopamineDopaminePerceptual awareness, muscle controlPerceptual awareness, muscle controlToo much = Schizophrania (up to 6x Too much = Schizophrania (up to 6x

more dopemine)more dopemine)A Beautiful Mind / The SoloistA Beautiful Mind / The SoloistToo little = Parkinson’s Disease Too little = Parkinson’s Disease

(tremors: Muhammad Ali)(tremors: Muhammad Ali)

Drugs Affect Drugs Affect NeurotransmissionNeurotransmission

Drugs can be used to affect Drugs can be used to affect communication at the synapsecommunication at the synapseAgonistsAgonists excite, or mimic the excite, or mimic the

neurotransmittors / or block reuptake neurotransmittors / or block reuptake (drug addicts and withdraw)(drug addicts and withdraw)

AntagonistsAntagonists block, or inhibit block, or inhibit neurotransmitters signal neurotransmitters signal (examples=Botox/ botulism blocks Ach)(examples=Botox/ botulism blocks Ach)

A complicated process: Brain has A complicated process: Brain has blood-blood-brainbrain barrierbarrier that blocks out unwanted that blocks out unwanted chemicalschemicals


Serotonin Pathways Dopamine Pathways

Remember…Remember…

Communication within the neuron Communication within the neuron is…….is…….ElectricalElectrical

Communication between neurons Communication between neurons is….is….chemicalchemical

Glial cells (Glia)Glial cells (Glia)

Make up 90% of Make up 90% of brain’s cellsbrain’s cells

Protect, nourish Protect, nourish neurons neurons

Current research Current research suggests possible suggests possible action potentials, action potentials, debate as to role…debate as to role…

See p. 45: See p. 45: Alchemy Alchemy of Mindof Mind

An Alchemy of MindAn Alchemy of MindExplain fully each of the following quotes from your Explain fully each of the following quotes from your

reading.reading. ““Neurons speak an elite pidgin neither chemical Neurons speak an elite pidgin neither chemical

nor electrical but a lively buzz that joins the two, nor electrical but a lively buzz that joins the two, an electrochemical lingo all their own.”an electrochemical lingo all their own.”

““It is important to realize that what one neuron It is important to realize that what one neuron tells another neuron is simply how much it is tells another neuron is simply how much it is excited.”excited.”

It is a small liquid space, as is the air between It is a small liquid space, as is the air between two whispering lovers, yet so much life happens two whispering lovers, yet so much life happens there. Each junction is a bazaar full of commerce, there. Each junction is a bazaar full of commerce, intrigue and possibility. In the brain, everything intrigue and possibility. In the brain, everything depends on almost nothing, a lively space….”depends on almost nothing, a lively space….”

““Coexisting as they must, both neurons and glia Coexisting as they must, both neurons and glia are dependable, dependent… central to the are dependable, dependent… central to the brain’s social fabric and perpetual hum.”brain’s social fabric and perpetual hum.”

The Nervous SystemThe Nervous System Nervous SystemNervous System

the body’s speedy, electrochemical the body’s speedy, electrochemical communication system communication system

consists of all the nerve cells of the PNS consists of all the nerve cells of the PNS and CNSand CNS

Central Nervous System (CNS)Central Nervous System (CNS) the brain and spinal cord (encased in the brain and spinal cord (encased in

bone)bone) Peripheral Nervous System (PNS)Peripheral Nervous System (PNS)

connect the central CNS to the rest of connect the central CNS to the rest of the body’s sense receptorsthe body’s sense receptors

The Nervous SystemThe Nervous System

Central(brain and

spinal cord)

Nervoussystem

Autonomic (controlsautomatic action of

internal organs and glands)

Somatic (Skeletal) (controlsvoluntary movements of

skeletal muscles)

Sympathetic (arousing: flight or fight)

Parasympathetic (calming)

Peripheral

The Autonomic Nervous SystemThe Autonomic Nervous System

Autonomic Nervous SystemAutonomic Nervous System part of the PNS: controls the glands and part of the PNS: controls the glands and

the muscles of the internal organs the muscles of the internal organs (involuntary)(involuntary)

A Dual SystemA Dual System Sympathetic Nervous SystemSympathetic Nervous System

arouses the body, mobilizing its energy in arouses the body, mobilizing its energy in stressful situations (“Fight or flight”, or stressful situations (“Fight or flight”, or “sympathy in crisis”)“sympathy in crisis”)

Parasympathetic Nervous SystemParasympathetic Nervous System calms the body, conserving its energycalms the body, conserving its energy ““paramedics to calm down”- lowers heartbeat paramedics to calm down”- lowers heartbeat

etc.etc.

The Nervous SystemThe Nervous System

The Peripheral Nervous SystemThe Peripheral Nervous System

Links CNS to body’s sense receptorsLinks CNS to body’s sense receptorsFor each of the following, identify it as a For each of the following, identify it as a

function of the Somatic or Autonomic function of the Somatic or Autonomic Nervous System.Nervous System.SneezingSneezingTurning the pageTurning the pageScratching your headScratching your headBreathingBreathingKissing your dateKissing your dateDigesting your foodDigesting your food

Communication in the Nervous Communication in the Nervous SystemSystem

NervesNerves neural “cables” containing millions of neural “cables” containing millions of

axonsaxons part of the PNS (carry PNS info)part of the PNS (carry PNS info) connect the CNS with muscles, glands, connect the CNS with muscles, glands,

and sense organsand sense organs Extend through the bodyExtend through the body

Communication in the Nervous Communication in the Nervous SystemSystem

3 neurons that carry info in the 3 neurons that carry info in the nervous systemnervous system Sensory NeuronsSensory Neurons (afferent: millions!) (afferent: millions!)

neurons that carry incoming information from neurons that carry incoming information from the sense receptors to the central nervous the sense receptors to the central nervous systemsystem

Motor Motor Neurons (efferent: millions)Neurons (efferent: millions) carry outgoing information from the CNS to carry outgoing information from the CNS to

muscles and glandsmuscles and glands Interneurons (billions!)Interneurons (billions!)

CNS neurons that internally communicate / CNS neurons that internally communicate / process sensory and motor neurons (most process sensory and motor neurons (most complex)complex)

The Central Nervous SystemThe Central Nervous System

““The motherboard of our The motherboard of our humanity…”humanity…”

10’s of billions of neurons10’s of billions of neuronsBrain and spinal cordBrain and spinal cordSpinal cord: Information highway Spinal cord: Information highway

connecting PNS to the brainconnecting PNS to the brain

ReflexesReflexesSpinal ReflexSpinal Reflex: : Autonomic response to Autonomic response to

stimuli (Single sensory neuron, single stimuli (Single sensory neuron, single motor neuron, interneuron:…..Brain’s not motor neuron, interneuron:…..Brain’s not involved!)involved!)

Pain ReflexPain Reflex Sensory neuron, interneuron, motor neuronSensory neuron, interneuron, motor neuron

a simple, automatic, inborn response to a sensory stimulusa simple, automatic, inborn response to a sensory stimulus

The BrainThe Brain Center for all sensory information and Center for all sensory information and

voluntary movement (receives, interprets, voluntary movement (receives, interprets, decides…)decides…)

Without the brain…no pain or pleasure, no Without the brain…no pain or pleasure, no voluntary movementvoluntary movement

Neural NetworksNeural NetworksA Complex Mystery…A Complex Mystery…

Neural NetworksNeural Networks interconnected interconnected

neural cells neural cells with experience, with experience,

networks can learn, networks can learn, as feedback as feedback strengthens or strengthens or inhibits connections inhibits connections that produce certain that produce certain results results

computer simulations computer simulations of neural networks of neural networks show analogous show analogous learninglearning

Inputs Outputs

Neurons in the brain connect with one

another to form networks

The brain learns by modifyingcertain connections in response to feedback

In other words…In other words…

““Neurons that fire together... wire Neurons that fire together... wire together.”together.”

The Endocrine SystemThe Endocrine SystemThe body’s 2The body’s 2ndnd communication communication

systemsystem Interconnected with nervous systemInterconnected with nervous system

Endocrine SystemEndocrine System

ES glands produce ES glands produce hormoneshormonesHormones travel through bloodstream Hormones travel through bloodstream

to affect bodyto affect body Influences growth, mood, metabolism, Influences growth, mood, metabolism,

reproduction etc.reproduction etc.Thus ES works to keep body in balance Thus ES works to keep body in balance

in response to stress, exertion, in response to stress, exertion, thoughts etc.thoughts etc.

““Snail mail”- Much slower to process, Snail mail”- Much slower to process, several seconds, but lasts longer…several seconds, but lasts longer…

Important Glands…Important Glands…

Pituitary GlandPituitary Gland (the master gland..) (the master gland..)Pea sized, in middle of brainPea sized, in middle of brainInfluences growthInfluences growthInfluences other Endocrine glands’ Influences other Endocrine glands’

release of hormonesrelease of hormonesControlled by hypothalamus (brain) Controlled by hypothalamus (brain) Brain – pituitary – other glands – Brain – pituitary – other glands –

hormones – brain (complex system: hormones – brain (complex system: blend of Endocrine system and nervous blend of Endocrine system and nervous systems)systems)

Pituitary GlandPituitary Gland

Adrenal GlandsAdrenal Glands

Located on top of kidneysLocated on top of kidneysRelease epinephrine and Release epinephrine and

norepinephrine (adrenaline and norepinephrine (adrenaline and noradrenaline)noradrenaline)

Heart rate, blood sugar, blood Heart rate, blood sugar, blood pressure etc.pressure etc.

Adrenal GlandsAdrenal Glands

What do you know about the What do you know about the human brain?human brain?

Answer the following as true or false.Answer the following as true or false.

1.1. The larger the brain, the smarter the animal.The larger the brain, the smarter the animal.

2.2. The brain’s structure is a better indicator of The brain’s structure is a better indicator of intelligence than it’s size.intelligence than it’s size.

3.3. The right side of the brain controls the right The right side of the brain controls the right side of the body, and so on with the left.side of the body, and so on with the left.

4.4. You fall in love with your heart, not your You fall in love with your heart, not your brain.brain.

5.5. Your brain uses 20% of your body’s energy, Your brain uses 20% of your body’s energy, but makes up only 2% of your body’s weight.but makes up only 2% of your body’s weight.

What do you know about the What do you know about the human brain?human brain?

True-False continued…True-False continued…6.6. Your brain is about the size of a cantaloupe and Your brain is about the size of a cantaloupe and

is wrinkled like a walnut.is wrinkled like a walnut.7.7. Your brain feels like a ripe avocado and looks Your brain feels like a ripe avocado and looks

pink because of the blood running through it.pink because of the blood running through it.8.8. The baby’s brain grows 3x in size during its first The baby’s brain grows 3x in size during its first

year.year.9.9. At birth, the human brain weighs 4/5 of a At birth, the human brain weighs 4/5 of a

pound, while an adult’s weighs about 3 pounds.pound, while an adult’s weighs about 3 pounds.10.10. Your brain generates about 25 watts of power Your brain generates about 25 watts of power

while awake- or enough to illuminate a light while awake- or enough to illuminate a light bulb.bulb.

The typical human brain…The typical human brain…

o contains about 100 contains about 100 billion neuronsbillion neurons

o consumes about ¼ of consumes about ¼ of the body’s oxygenthe body’s oxygen

o spends most of the spends most of the bodies calories bodies calories

o Is 70% water!!!Is 70% water!!!o weighs about 3 weighs about 3

poundspounds

The BrainThe Brain

LesionLesion tissue tissue

destruction destruction a naturally or a naturally or

experimentallexperimentally caused y caused destruction of destruction of brain tissuebrain tissue

Neuroimaging TechniquesNeuroimaging Techniques

““Mapping the brain”Mapping the brain”

Electroencephalogram (EEG) Electroencephalogram (EEG) Detects Brain WavesDetects Brain Waves

Scans / measures Scans / measures electrical activity electrical activity across brain across brain

can specify can specify waves to specific waves to specific stimulusstimulus

Sleep researchSleep research

CAT (computed tomography) ScanCAT (computed tomography) Scan Multiple x-ray pictures = 3D image of brain structureMultiple x-ray pictures = 3D image of brain structure Structure only- not functionStructure only- not function Tumors, physical abnormalitiesTumors, physical abnormalities

PET (positron emission tomography) PET (positron emission tomography) Scan Scan Can measure amount and movement of Can measure amount and movement of

chemicals in the brain (glucose)chemicals in the brain (glucose) Check brain’s activity to specific tasks Check brain’s activity to specific tasks

(the more used, the more activity…)(the more used, the more activity…) Neurotransmitters and drugsNeurotransmitters and drugs

MRI (magnetic resonance imaging) MRI (magnetic resonance imaging) Like CAT, but used magnetic fields to Like CAT, but used magnetic fields to

measure density and location of brain measure density and location of brain materialmaterial

soft tissue; allows us to see structures soft tissue; allows us to see structures within the brainwithin the brain

FMRI (Functional MRI) Reveals FMRI (Functional MRI) Reveals brains’ functioning as well as its brains’ functioning as well as its structure (IOW: MRI + PET)structure (IOW: MRI + PET)

Watches brain “light up” by Watches brain “light up” by concentrations of blood flow to concentrations of blood flow to specific areasspecific areas

The Old Brain The Old Brain ((hind brainhind brain))“Parts shared with Distant Ancestors”“Parts shared with Distant Ancestors”

““Life Support System”Life Support System”

BrainstemBrainstem the oldest part and central core of the brain, the oldest part and central core of the brain,

beginning where the spinal cord swells as it beginning where the spinal cord swells as it enters the skullenters the skull

responsible for automatic survival functionsresponsible for automatic survival functions

Medulla [muh-DUL-uh]Medulla [muh-DUL-uh] base of the brainstembase of the brainstem controls heartbeat, blood pressure and controls heartbeat, blood pressure and

breathingbreathing

Pons: Help coordinate movement, Pons: Help coordinate movement, facial expressionsfacial expressions

Connects hindbrain with mid & Connects hindbrain with mid & forebrainforebrain

CerebellumCerebellum Cerebellum [sehr-Cerebellum [sehr-

uh-BELL-um]uh-BELL-um] the “little brain” the “little brain”

attached to the attached to the rear of the rear of the brainstembrainstem

coordinate coordinate voluntary voluntary movement and movement and balance (fine balance (fine muscle muscle movements)movements)

CerebellumCerebellum

Reticular Formation Reticular Formation ((MidbrainMidbrain))

Reticular FormationReticular Formation a nerve network in the brainstem that a nerve network in the brainstem that

plays an important role in controlling plays an important role in controlling arousal and sleep!arousal and sleep!

Explain the significance of the Explain the significance of the next slide…next slide…

The BrainThe Brain

The Forebrain The Forebrain (Thought and (Thought and Reason)Reason)

Thalamus [THAL-uh-muss] Thalamus [THAL-uh-muss] the brain’s the brain’s sensory switchboardsensory switchboard, located on top , located on top

of the brainstem (of the brainstem (all but smellall but smell)) it directs messages to the sensory receiving areas it directs messages to the sensory receiving areas

in the cortex and transmits replies to the in the cortex and transmits replies to the cerebellum and medullacerebellum and medulla

The Limbic SystemThe Limbic System Limbic SystemLimbic System

a doughnut-shaped system of neural a doughnut-shaped system of neural structures structures

at border of the brainstem and cerebral at border of the brainstem and cerebral hemisphereshemispheres

associated with emotions, drives and associated with emotions, drives and memory memory

includes the hippocampus, amygdala, includes the hippocampus, amygdala, and hypothalamus.and hypothalamus.

The Limbic SystemThe Limbic System

Amygdala [ah-MIG-dah-la] Amygdala [ah-MIG-dah-la] components of the limbic system and are components of the limbic system and are

linked to emotion (fear and aggression)linked to emotion (fear and aggression)

HippocampusHippocampus

Memory (processes new memories Memory (processes new memories and stores in cerebral cortex)and stores in cerebral cortex)

HypothalamusHypothalamus neural structure / neural structure /

below (below (hypohypo) the ) the thalamus; Basic thalamus; Basic Drives:Drives: hungerhunger thirstthirst body temperaturebody temperature Sex drive (libido)Sex drive (libido)

helps govern the helps govern the endocrine system via endocrine system via the pituitary glandthe pituitary gland

is linked to is linked to emotionemotion

The Limbic SystemThe Limbic System

Electrode Electrode implanted implanted in reward in reward centercenter

Hemispheres of the BrainHemispheres of the Brain Left:Left:

Language and logicLanguage and logic Right:Right:

Spatial, creativeSpatial, creative

Why do most strokes affect the Why do most strokes affect the right side of the body?right side of the body?

Most strokes occur in the left Most strokes occur in the left hemispherehemisphere

The Cerebral CortexThe Cerebral Cortex(Thin layer of densely packed neurons: .0039-inch)(Thin layer of densely packed neurons: .0039-inch)

Cerebral Cortex Cerebral Cortex intricate fabric of interconnected neural intricate fabric of interconnected neural

cells that covers the cerebral hemispheres cells that covers the cerebral hemispheres (20 billion nerve cells!)(20 billion nerve cells!)

body’s ultimate control and information body’s ultimate control and information processing centerprocessing center

The larger the cortex, more adaptability, The larger the cortex, more adaptability, capacity for learningcapacity for learning

Wrinkles = fissures (3 sq ft w/o them!)Wrinkles = fissures (3 sq ft w/o them!) *Perceiving, thinking, speaking**Perceiving, thinking, speaking*

Glial Cells Glial Cells cells in the nervous system that support, cells in the nervous system that support,

nourish, and protect neurons nourish, and protect neurons Aka Aka neuron nannies or glue cellsneuron nannies or glue cells

The Cerebral CortexThe Cerebral Cortex(Each hemisphere has 4 (Each hemisphere has 4

lobes)lobes) Frontal LobesFrontal Lobes

involved in speaking and muscle movements: involved in speaking and muscle movements: judgement, logic (abstract thought, emotional judgement, logic (abstract thought, emotional control)control)

Parietal LobesParietal Lobes include the sensory cortex (sensory center/ senses)include the sensory cortex (sensory center/ senses)

Occipital LobesOccipital Lobes Vision: receive visual information from the Vision: receive visual information from the

opposite visual fieldopposite visual field Temporal LobesTemporal Lobes

Hearing, or auditory areasHearing, or auditory areas

The Cerebral CortexThe Cerebral Cortex

The Cerebral CortexThe Cerebral Cortex Motor CortexMotor Cortex

at the rear of the frontal lobes / controls at the rear of the frontal lobes / controls voluntary movements voluntary movements

What parts of body occupy most cortical space?What parts of body occupy most cortical space? Fingers and mouth (require most precise control)Fingers and mouth (require most precise control)

Sensory CortexSensory Cortex at the front of the parietal lobes / at the front of the parietal lobes /

registers and processes body sensationsregisters and processes body sensations The more sensitive the body region, the The more sensitive the body region, the

more area occupied in the sensory cortexmore area occupied in the sensory cortex


Functional Functional MRI scan MRI scan shows the shows the visual cortex visual cortex activated as activated as the subject the subject looks at faceslooks at faces

Visual and Auditory Visual and Auditory CortexCortex

Association AreasAssociation Areas More intelligent animals have increased “uncommitted” or More intelligent animals have increased “uncommitted” or

association areasassociation areas of the cortex of the cortex Association areas = 75% of cortex Association areas = 75% of cortex Interprets, integrates and acts on info processed by sensory areasInterprets, integrates and acts on info processed by sensory areas Associates sensory input with stored memories (complex mystery)Associates sensory input with stored memories (complex mystery)

Language and the BrainLanguage and the Brain Broca’s Area Broca’s Area

Location: lower left frontal lobe / Role: Location: lower left frontal lobe / Role: directs muscle movements of directs muscle movements of making making speechspeech

Wernicke’s Area Wernicke’s Area Location: left temporal lobe / Role: Location: left temporal lobe / Role:

language language comprehension and expressioncomprehension and expression Aphasia Aphasia (language impairment)(language impairment)

usually caused by left hemisphere damage usually caused by left hemisphere damage either to Broca’s area (impairing speaking) or to either to Broca’s area (impairing speaking) or to Wernicke’s area (impairing understanding)Wernicke’s area (impairing understanding)

Specialization and Specialization and IntegrationIntegration

Specialization and Specialization and IntegrationIntegration

Brain activity when hearing, seeing, and Brain activity when hearing, seeing, and speaking wordsspeaking words

Brain ReorganizationBrain Reorganization PlasticityPlasticity

brain’s capacity to modify itselfbrain’s capacity to modify itself brain reorganizes / compensates brain reorganizes / compensates

after damage, injuryafter damage, injury children have the most plasticitychildren have the most plasticity Example: blind and braille- one Example: blind and braille- one

finger used: sense of touch finger used: sense of touch invades visual cortexinvades visual cortex

Review QuestionReview Question

1.1. When stroking the face of someone who’s When stroking the face of someone who’s hand has been amputated, why did the hand has been amputated, why did the subject feel the sensation not only on his subject feel the sensation not only on his face, but also on his amputated face, but also on his amputated (“phantom”) fingers?(“phantom”) fingers?

Answer: Hand area of the sensory cortex is Answer: Hand area of the sensory cortex is no longer used, thus fibers from the facial no longer used, thus fibers from the facial sensory areas invade the space. (Note sensory areas invade the space. (Note that the hand area is between the face that the hand area is between the face and arm regions of the sensory cortex.)and arm regions of the sensory cortex.)

In other words…. Plasticity!In other words…. Plasticity!

PlasticityPlasticity

Our Divided BrainOur Divided Brain

True or False:True or False:

1. Each hemisphere shares equally in 1. Each hemisphere shares equally in performing all functions of the body.performing all functions of the body.

2. The two hemispheres can be 2. The two hemispheres can be isolated by severing the corpus isolated by severing the corpus callosum.callosum.

3. Each hemisphere of the brain has a 3. Each hemisphere of the brain has a “mind of its own.”“mind of its own.”

Our Divided BrainOur Divided Brain Corpus Corpus

CallosumCallosum large band of large band of

neural fibers: neural fibers: 200,000,000!200,000,000!

connects the connects the two brain two brain hemispheres hemispheres

carries carries messages messages between the between the hemispheres hemispheres (billion pieces of (billion pieces of info / second!)info / second!)

Corpus callosum

Our Divided BrainOur Divided Brain

The The information information highway from highway from the eye to the eye to the brainthe brain

Split BrainSplit Brain

Isolate the 2 Isolate the 2 hemispheres by cutting hemispheres by cutting the connecting fibers the connecting fibers between them (corpus between them (corpus callosum) callosum)

To remedy To remedy uncontrollable epileptic uncontrollable epileptic seizuresseizures

Testing the “split Testing the “split brain” proves specific brain” proves specific functions of each functions of each hemispherehemisphere

The Split Brain ExperimentThe Split Brain ExperimentDr. Gazzaniga- 1967Dr. Gazzaniga- 1967Stare at the DotStare at the Dot…..…..

he.arthe.art1.1. Which word would the split-brain Which word would the split-brain

patient verbalize seeing? Why?patient verbalize seeing? Why?

2.2. Which word, when asked Which word, when asked to pointto point with his left hand, would he with his left hand, would he report seeing? Why?report seeing? Why?

Split BrainSplit BrainExplain the following…Explain the following…

The Split brainThe Split brain

1. If this visual was 1. If this visual was shown to the right shown to the right hemisphere of a hemisphere of a split brain patient, split brain patient, how might the how might the patient identify the patient identify the object?object?

The Split BrainThe Split BrainInteresting facts about the split brain:Interesting facts about the split brain:

Subjects can simultaneously draw Subjects can simultaneously draw different figures with the left and right different figures with the left and right hand.hand.

When the 2 hemispheres are at odds, When the 2 hemispheres are at odds, the left will rationalize reactions it the left will rationalize reactions it doesn’t understand.doesn’t understand.

The hemispheres are an “odd couple”, The hemispheres are an “odd couple”, each with “a mind of its own.”each with “a mind of its own.”

The Split BrainThe Split BrainWhich hemisphere is more active Which hemisphere is more active

with…with…Simple requestsSimple requests

Perceiving objectsPerceiving objects

Decision making Decision making (deliberative)(deliberative)

Quick intuitive responsesQuick intuitive responses

Recognizing facesRecognizing faces

Perceiving , expressing Perceiving , expressing emotionemotion

Right brainRight brain


Left brainLeft brain




Hemispheric Differences in the Intact Hemispheric Differences in the Intact BrainBrain

Hemispheric specialization = lateralizationHemispheric specialization = lateralization Blood flow, glucose, brain waves detected between Blood flow, glucose, brain waves detected between

hemispheres for perceptual tasks and speaking, hemispheres for perceptual tasks and speaking, calculating tasks (EEG, PET, FMRI)calculating tasks (EEG, PET, FMRI)

Sedative to artery to specific hemisphere: alters Sedative to artery to specific hemisphere: alters specific functions of the bodyspecific functions of the body

If left hemisphere is sedated, what functions would be If left hemisphere is sedated, what functions would be lost?lost?

Language, right side of body limpLanguage, right side of body limp If sedative to right hemisphere?If sedative to right hemisphere?

Difficulty identifying themselves in altered photo, left side Difficulty identifying themselves in altered photo, left side limplimp

Questions to consider….Questions to consider….

1. If a word is flashed to your right 1. If a word is flashed to your right hemisphere (through your left visual hemisphere (through your left visual field), why does it take you slightly field), why does it take you slightly longer to state what you see than it longer to state what you see than it would if flashed to your left hemisphere?would if flashed to your left hemisphere?

Process time through the corpus callosumProcess time through the corpus callosum

2.2. Which hemisphere would a deaf person Which hemisphere would a deaf person use for sign language?use for sign language?right (visual / spatial) or left (language)?right (visual / spatial) or left (language)?

• Left: to the brain, language is languageLeft: to the brain, language is language

HandednessHandedness What percentage of humans are right What percentage of humans are right

handed?handed? 90%90%

What ultimately makes you right or left What ultimately makes you right or left handed?handed? Genetics? Pre-natal? Social-Cultural?Genetics? Pre-natal? Social-Cultural?

What expressions can you think of that What expressions can you think of that discriminate against “lefties?”discriminate against “lefties?” Right on / right hand man / righteous / right Right on / right hand man / righteous / right

mind -- out in left field / left-handed complimentmind -- out in left field / left-handed compliment

Lefties tend to be…..Lefties tend to be…..

MusiciansMusicians

MathematiciansMathematicians

Professional baseball / cricket playersProfessional baseball / cricket players

ArchitectsArchitects

artistsartists

Disappearing Disappearing SouthpawsSouthpaws

The percentage of left-handers decreases sharply in The percentage of left-handers decreases sharply in samples of older people (adapted from Coren, 1993).samples of older people (adapted from Coren, 1993).

The percentage of lefties sharplydeclines with age

10 20 30 40 50 60 70 80 90Age in years

14%

12

10

8

6

4

2

0

Percentage ofleft-handedness

Brain Structures and Brain Structures and their Functionstheir Functions

Neuroscience, Genetics and Behavior. True or False? “Basic biological processes underlie all human...

Documents

Transcript of Neuroscience, Genetics and Behavior. True or False? “Basic biological processes underlie all human...