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Neuroscience Neuroscience and Behaviorand Behavior

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Neuroscience and BehaviorNeuroscience and Behavior

Neural CommunicationNeural Communication NeuronsNeurons

How Neurons CommunicateHow Neurons Communicate

How Neurotransmitters Influence UsHow Neurotransmitters Influence Us

The Nervous SystemThe Nervous System The Peripheral Nervous SystemThe Peripheral Nervous System

The Central Nervous SystemThe Central Nervous System

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Neuroscience and BehaviorNeuroscience and Behavior

The Endocrine SystemThe Endocrine System

The BrainThe Brain The Tools of DiscoveryThe Tools of Discovery

Older Brain StructuresOlder Brain Structures

The Cerebral CortexThe Cerebral Cortex

Our Divided BrainOur Divided Brain

Left Brain-Right BrainLeft Brain-Right Brain

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History of Mind History of Mind

Plato correctly placed mind in the brain. Plato correctly placed mind in the brain. However, his student Aristotle believed However, his student Aristotle believed

that mind was in the heart.that mind was in the heart.

Ancient Conceptions About MindAncient Conceptions About Mind

Today we believe mind and brain are Today we believe mind and brain are faces of the same coin. Everything that is faces of the same coin. Everything that is

psychological is simultaneously psychological is simultaneously biological.biological.

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History of MindHistory of Mind

In 1800, Franz Gall In 1800, Franz Gall suggested that bumps suggested that bumps

of the skull of the skull represented mental represented mental abilities. His theory, abilities. His theory,

though incorrect, though incorrect, nevertheless proposed nevertheless proposed that different mental that different mental

abilities were modular.abilities were modular.

PhrenologyPhrenology

Bettm

an/ Corbis

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We are a We are a biopsychosocialbiopsychosocial system.system.

Cellular Level(Interconnected

Neurons)

Organ Level(Brain)

System Level(InformationProcessing)

Individual Level(Human Being)

Group Level(Family)

Ethnic Level(Culture)

Community Level(Society)

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Neural CommunicationNeural Communication

The body’s information system is built from The body’s information system is built from billions of interconnected cells called billions of interconnected cells called neuronsneurons..

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Neuron Neuron

A nerve cell, or a neuron, consists of A nerve cell, or a neuron, consists of many different parts.many different parts.

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Parts of a Neuron Parts of a Neuron

Cell Body:Cell Body: Life support center of the neuron.Life support center of the neuron.

Dendrites:Dendrites: Branching extensions at the cell body. Branching extensions at the cell body. Receive messages from other neurons.Receive messages from other neurons.

Axon:Axon: Long single extension of a neuron, covered Long single extension of a neuron, covered with with myelin [MY-uh-lin] sheathmyelin [MY-uh-lin] sheath to insulate and to insulate and speed up messages through neurons.speed up messages through neurons.

Terminal Branches of axon:Terminal Branches of axon: Branched endings of Branched endings of an axon that transmit messages to other neurons.an axon that transmit messages to other neurons.

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Action PotentialAction PotentialA neural impulse. A A neural impulse. A

brief electrical charge brief electrical charge that travels down an that travels down an

axon and is generated axon and is generated by the movement of by the movement of positively charged positively charged atoms in and out of atoms in and out of

channels in the axon’s channels in the axon’s membrane. membrane.

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Depolarization & Depolarization & Hyperpolarization Hyperpolarization

Depolarization: Depolarization: Depolarization occurs Depolarization occurs when positive ions enter the neuron, when positive ions enter the neuron,

making it more prone to firing an action making it more prone to firing an action potential. potential. Hyperpolarization Hyperpolarization occurs when occurs when negative ions enter the neuron, making it negative ions enter the neuron, making it

less prone to firing an action potential.less prone to firing an action potential.

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Threshold Threshold

Threshold:Threshold: Each neuron receives Each neuron receives depolarizing and hyperpolarizing currents depolarizing and hyperpolarizing currents from many neurons. When the depolarizing from many neurons. When the depolarizing

current (positive ions) minus the current (positive ions) minus the hyperpolarizing current (negative ions) hyperpolarizing current (negative ions)

exceed minimum intensity (threshold) the exceed minimum intensity (threshold) the neuron fires an action potential.neuron fires an action potential.

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Synapse Synapse

Synapse [SIN-aps]Synapse [SIN-aps] aa junction between the junction between the axon tip of the sending neuron and the axon tip of the sending neuron and the

dendrite or cell body of the receiving neuron. dendrite or cell body of the receiving neuron. This tiny gap is called the This tiny gap is called the synaptic gapsynaptic gap or or

cleft.cleft.

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NeurotransmittersNeurotransmitters

Neurotransmitters Neurotransmitters (chemicals) released (chemicals) released

from the sending from the sending neuron travel across neuron travel across the synapse and bind the synapse and bind to receptor sites on to receptor sites on

the receiving neuron, the receiving neuron, thereby influencing it thereby influencing it to generate an action to generate an action

potential. potential.

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ReuptakeReuptake

Neurotransmitters in Neurotransmitters in the synapse are the synapse are

reabsorbed into the reabsorbed into the sending neurons sending neurons

through the process through the process of reuptake. This of reuptake. This

process applies the process applies the brakes on brakes on

neurotransmitter neurotransmitter action.action.

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NeurotransmittersNeurotransmitters

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How Neurotransmitters How Neurotransmitters Influence Us?Influence Us?

Serotonin pathways Serotonin pathways are involved with are involved with mood regulation. mood regulation.

From Mapping the Mind, Rita Carter, © 1989 University of California Press

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Dopamine PathwaysDopamine Pathways

Dopamine Dopamine pathways are pathways are involved with involved with

diseases such as diseases such as schizophrenia and schizophrenia and

Parkinson’s Parkinson’s disease.disease.

From Mapping the Mind, Rita Carter, © 1989 University of California Press

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Lock & Key MechanismLock & Key Mechanism

Neurotransmitters bind to the receptors of the Neurotransmitters bind to the receptors of the receiving neuron in a key-lock mechanism.receiving neuron in a key-lock mechanism.

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AgonistsAgonists

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AntagonistsAntagonists

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BodyBody’’s Systemss Systems

Nervous SystemNervous System

Endocrine SystemEndocrine System

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The Endocrine SystemThe Endocrine System

The Endocrine System is the body’s “slow”

chemical communication

system. Communication is

carried out by hormones

synthesized by a set of glands.

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HormonesHormones

Hormones are chemicals synthesized by the Hormones are chemicals synthesized by the endocrine glands that are secreted in the endocrine glands that are secreted in the

bloodstream. Hormones affect the brain and bloodstream. Hormones affect the brain and many other tissues of the body.many other tissues of the body.

For example, epinephrine (adrenaline) For example, epinephrine (adrenaline) increases heart rate, blood pressure, blood increases heart rate, blood pressure, blood

sugar and feelings of excitement during sugar and feelings of excitement during emergency situations.emergency situations.

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Nervous SystemNervous System

CentralNervousSystem(CNS)

PeripheralNervousSystem(PNS)

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The Nervous SystemThe Nervous System

Nervous System: Consists of all the nerve Nervous System: Consists of all the nerve cells. It is the body’s speedy, cells. It is the body’s speedy, electrochemical communication system.electrochemical communication system.

Central Nervous System (CNS):Central Nervous System (CNS): the brain the brain and spinal cord.and spinal cord.

Peripheral Nervous System (PNS):Peripheral Nervous System (PNS): the the sensory and motor neurons that connect the sensory and motor neurons that connect the central nervous system (CNS) to the rest of central nervous system (CNS) to the rest of the body.the body.

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The Nervous SystemThe Nervous System

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Types of NeuronTypes of Neuron

Sensory neurons: Sensory neurons: carry incoming carry incoming information from the sense receptors to the CNSinformation from the sense receptors to the CNS

Motor Neurons: carry outgoing information from Motor Neurons: carry outgoing information from the CNS to muscles and glandsthe CNS to muscles and glands

Interneurons: connect neuronsInterneurons: connect neurons

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Peripheral Nervous SystemPeripheral Nervous System

Somatic Nervous System:Somatic Nervous System: The division of the The division of the peripheral nervous system that controls the peripheral nervous system that controls the body’s skeletal muscles.body’s skeletal muscles.

Autonomic Nervous System:Autonomic Nervous System: Part of the PNS Part of the PNS that controls the glands and other muscles.that controls the glands and other muscles.

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Autonomic Nervous System Autonomic Nervous System (ANS)(ANS)

Sympathetic Nervous System:Sympathetic Nervous System: Division of Division of the ANS that arouses the body, mobilizing the ANS that arouses the body, mobilizing its energy in stressful situations.its energy in stressful situations.

Parasympathetic Nervous System:Parasympathetic Nervous System: Division of the ANS that calms the body, Division of the ANS that calms the body, conserving its energy.conserving its energy.

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Autonomic Nervous System Autonomic Nervous System (ANS)(ANS)

Sympathetic NS Sympathetic NS ““ArousesArouses””

(fight-or-flight)(fight-or-flight)

Parasympathetic NS Parasympathetic NS ““CalmsCalms””

(rest and digest)(rest and digest)

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Central Nervous SystemCentral Nervous System

The Spinal Cord and Reflexes

Simple Reflex

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The BrainThe Brain

Techniques to Study the Brain

A brain lesionA brain lesion experimentally experimentally

destroys brain tissue to destroys brain tissue to study animal behaviors study animal behaviors after such destruction.after such destruction.

Hubel (1990)

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Clinical ObservationClinical ObservationClinical observations have shed light on a Clinical observations have shed light on a

number of brain disorders. Alterations in brain number of brain disorders. Alterations in brain morphology due to neurological and morphology due to neurological and

psychiatric diseases are now being catalogued.psychiatric diseases are now being catalogued.

Tom

Landers/ B

oston Globe

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Electroencephalogram Electroencephalogram (EEG)(EEG)

An amplified recording of the electrical waves An amplified recording of the electrical waves sweeping across the brain’s surface, sweeping across the brain’s surface,

measured by electrodes placed on the scalp.measured by electrodes placed on the scalp.

AJ P

hoto/ Photo R

esearchers, Inc.

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PET ScanPET Scan

PET (positron emission tomography)

Scan is a visual display of brain

activity that detects a radioactive form of glucose while the

brain performs a given task.

Courtesy of N

ational Brookhaven N

ational Laboratories

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MRI ScanMRI ScanMRI MRI (magnetic (magnetic

resonance imaging) resonance imaging) uses magnetic fields uses magnetic fields and radio waves to and radio waves to produce computer-produce computer-

generated images that generated images that distinguish among distinguish among

different types of brain different types of brain tissue. Top images tissue. Top images show ventricular show ventricular enlargement in a enlargement in a

schizophrenic patient. schizophrenic patient. Bottom image shows Bottom image shows brain regions when a brain regions when a

participants lies.participants lies.

Both photos from Daniel Weinberger, M.D., CBDB, NIMH

James Salzano/ Salzano Photo Lucy Reading/ Lucy Illustrations

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Older Brain StructuresOlder Brain Structures

TheThe BrainstemBrainstem isis the oldest part of the brain, the oldest part of the brain, beginning where the spinal cord swells and enters beginning where the spinal cord swells and enters the skull. It is responsible for automatic survival the skull. It is responsible for automatic survival

functions.functions.

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Brain StemBrain Stem

The The Medulla [muh-Medulla [muh-DUL-uh]DUL-uh] is the base is the base of the brainstem that of the brainstem that

controls heartbeat controls heartbeat and breathing.and breathing.

Reticular FormationReticular Formation isis a nerve network in a nerve network in the brainstem that the brainstem that plays an important plays an important role in controlling role in controlling

arousal.arousal.

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Brain StemBrain Stem

The The Thalamus Thalamus [THAL-uh-muss][THAL-uh-muss] is is the brain’s sensory the brain’s sensory

switchboard, located switchboard, located on top of the on top of the

brainstem. It directs brainstem. It directs messages to the messages to the

sensory areas in the sensory areas in the cortex and transmits cortex and transmits

replies to the replies to the cerebellum and cerebellum and

medulla.medulla.

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The “little brain” The “little brain” attached to the rear attached to the rear of the brainstem. It of the brainstem. It

helps coordinate helps coordinate voluntary movements voluntary movements

and balance.and balance.

CerebellumCerebellum

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The The Limbic SystemLimbic System isis a doughnut-shaped a doughnut-shaped

system of neural system of neural structures at the border structures at the border

of the brainstem and of the brainstem and cerebrum, associated cerebrum, associated with emotions such as with emotions such as fear, aggression and fear, aggression and

drives for food and sex. drives for food and sex. It includes the It includes the hippocampus, hippocampus, amygdala, and amygdala, and hypothalamus.hypothalamus.

The Limbic SystemThe Limbic System

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AmygdalaAmygdala

The Amygdala [ah-MIG-The Amygdala [ah-MIG-dah-la] consists of two dah-la] consists of two almond-shaped neural almond-shaped neural clusters linked to the clusters linked to the emotions of fear and emotions of fear and

anger.anger.

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HypothalamusHypothalamus

The Hypothalamus The Hypothalamus lies below (lies below (hypohypo) the ) the thalamus. It directs thalamus. It directs several maintenance several maintenance activities like eating, activities like eating,

drinking, body drinking, body temperature, and temperature, and

control of emotions. control of emotions. It helps govern the It helps govern the

endocrine system via endocrine system via the pituitary gland. the pituitary gland.

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The Cerebral CortexThe Cerebral Cortex

The intricate fabric of interconnected neural cells The intricate fabric of interconnected neural cells that covers the cerebral hemispheres. It is the body’s that covers the cerebral hemispheres. It is the body’s ultimate control and information processing center.ultimate control and information processing center.

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Structure of the CortexStructure of the Cortex

Each brain hemisphere Each brain hemisphere is divided into four is divided into four

lobes that are lobes that are separated by separated by

prominent fissures. prominent fissures. These lobes are the These lobes are the

frontal lobe (forehead), frontal lobe (forehead), parietal lobe (top to parietal lobe (top to rear head), occipital rear head), occipital lobe (back head) and lobe (back head) and temporal lobe (side of temporal lobe (side of

head).head).

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Functions of the CortexFunctions of the Cortex

TheThe Motor CortexMotor Cortex is the area at the rear of the is the area at the rear of the frontal lobes that control voluntary movements. frontal lobes that control voluntary movements. The The Sensory CortexSensory Cortex (parietal cortex) receives (parietal cortex) receives

information from skin surface and sense organs.information from skin surface and sense organs.

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Visual FunctionVisual Function

The functional MRI The functional MRI scan shows the visual scan shows the visual cortex is active as the cortex is active as the subject looks at faces.subject looks at faces.

Courtesy of V

.P. Clark, K

. Keill, J. M

a. M

aisog, S. Courtney, L

.G.

Ungerleider, and J.V

. Haxby,

National Institute of M

ental Health

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Auditory FunctionAuditory Function

The functional MRI The functional MRI scan shows the scan shows the

auditory cortex is auditory cortex is active in patients who active in patients who

hallucinate.hallucinate.

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LanguageLanguageAphasia is an impairment of language, Aphasia is an impairment of language,

usually caused by left hemisphere damage usually caused by left hemisphere damage either to Broca’s area (impaired speaking) either to Broca’s area (impaired speaking)

or to Wernicke’s area (impaired or to Wernicke’s area (impaired understanding).understanding).

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Specialization & Specialization & IntegrationIntegration

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

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More intelligent animals have increased More intelligent animals have increased “uncommitted” or association areas of the “uncommitted” or association areas of the

cortex.cortex.

Association AreasAssociation Areas

The most primitive area of the brain, The most primitive area of the brain, associated with the most basic associated with the most basic functions, is the:functions, is the:

a.a. cortexcortex

b.b. limbic systemlimbic system

c.c. thalamusthalamus

d.d. brainstem.brainstem.

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The brain is sculpted by our genes but also by The brain is sculpted by our genes but also by our experiences.our experiences.

PlasticityPlasticity refers to the brain’s ability to modify refers to the brain’s ability to modify itself after some type of injury or illness.itself after some type of injury or illness.

The Brain’s PlasticityThe Brain’s Plasticity

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Our Divided BrainOur Divided Brain

Our brain is divided into two hemispheres. Our brain is divided into two hemispheres.

The The left hemisphereleft hemisphere processes reading, processes reading, writing, speaking, mathematics, and writing, speaking, mathematics, and

comprehension skills. The comprehension skills. The right hemisphereright hemisphere appears to be responsible for visual-spatial appears to be responsible for visual-spatial

processing.processing.

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Hemispheric DifferencesHemispheric Differences

People with intact brains show left-right People with intact brains show left-right hemispheric differences in mental hemispheric differences in mental

abilities.abilities.

**A number of brain scan studies show **A number of brain scan studies show normal individuals engage their right normal individuals engage their right

brain when completing a perceptual task brain when completing a perceptual task and their left brain when carrying out a and their left brain when carrying out a

linguistic task. linguistic task.

**Possible personality differences are also **Possible personality differences are also being explored.being explored.

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Splitting the BrainSplitting the BrainA procedure in which the two hemispheres of the A procedure in which the two hemispheres of the brain are isolated by cutting the connecting fibers brain are isolated by cutting the connecting fibers

(mainly those of the corpus callosum) between them.(mainly those of the corpus callosum) between them.

Corpus Callosum

Ma

rtin M

. Ro

the

r

Courtesy of T

erence William

s, University of Iow

a

Need to KnowNeed to Know

1. Information from left side of body 1. Information from left side of body or left visual field projects to the or left visual field projects to the right hemisphere, opposite for right right hemisphere, opposite for right side.side.

2. Information sent from left 2. Information sent from left hemisphere of the brain is sent to hemisphere of the brain is sent to the right side of the body, opposite the right side of the body, opposite for right hemisphere. for right hemisphere.

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Split Brain PatientsSplit Brain Patients

With the corpus callosum severed, objects (apple) With the corpus callosum severed, objects (apple) presented in the right visual field can be named. presented in the right visual field can be named.

Objects (pencil) in the left visual field cannot.Objects (pencil) in the left visual field cannot.

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Divided ConsciousnessDivided Consciousness

If a picture of a banana is briefly flashed in the If a picture of a banana is briefly flashed in the left visual field of a right-handed splitbrain left visual field of a right-handed splitbrain patient, she would most likely be able to:patient, she would most likely be able to:

a.a. tell you she saw a bananatell you she saw a banana

b.b. be able to point to a banana with her left handbe able to point to a banana with her left hand

c.c. be able to point to a banana with her right be able to point to a banana with her right handhand

d.d. run from the room screaming in frustrationrun from the room screaming in frustration

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