Physiological Psychology – Physiological Psychology – Module 3Module 3Genetic Influences – Module 5 Genetic Influences – Module 5

General Psych 2General Psych 2

Februaty 3, 2004Februaty 3, 2004Class #3Class #3

Biological Roots of Biological Roots of BehaviorBehavior

Franz Gall (1758-1828) – Austrian Franz Gall (1758-1828) – Austrian physicist who invented phrenology physicist who invented phrenology

He felt that bumps on the skull could He felt that bumps on the skull could reveal our mental abilities and reveal our mental abilities and character traitscharacter traits

Introduced as being scientific but its Introduced as being scientific but its use was exploited by quacks on use was exploited by quacks on gullible individualsgullible individuals

PhrenologyPhrenology

Became similar to that of astrology, Became similar to that of astrology, palm-reading and tarotpalm-reading and tarot

Although, ill-fated theory was Although, ill-fated theory was laughed at by scientific community of laughed at by scientific community of that day – it may have had some that day – it may have had some validityvalidity

Localization of brain functions Localization of brain functions somehow hit the marksomehow hit the mark

The Nervous SystemThe Nervous System

Electrochemical communication system that Electrochemical communication system that enables us to think, feel, and behaveenables us to think, feel, and behave Complex beyond comprehensionComplex beyond comprehension

Although, human brains are more complex Although, human brains are more complex our nervous systems and those of animals our nervous systems and those of animals operate in a similar fashionoperate in a similar fashion Allows researchers to study simple animals such Allows researchers to study simple animals such

as squids and sea slugs to help us better as squids and sea slugs to help us better understand the organization of our own brainsunderstand the organization of our own brains

Advantage of this is experimentationAdvantage of this is experimentation

Divisions of the Nervous Divisions of the Nervous SystemSystem

Consists of two systemsConsists of two systems Central Nervous System (CNS) (brain Central Nervous System (CNS) (brain

and spinal cord)and spinal cord) Peripheral Nervous System (PNS) which Peripheral Nervous System (PNS) which

connects the CNS to the rest of the bodyconnects the CNS to the rest of the body

Organization of the Nervous Organization of the Nervous SystemSystem

Organization of the Nervous Organization of the Nervous SystemSystem

Peripheral Nervous Peripheral Nervous SystemSystem

Two components:Two components: Somatic Nervous SystemSomatic Nervous System

Transmits sensory input to the CNS Transmits sensory input to the CNS from the outside world and directs from the outside world and directs motor outputmotor output

Autonomic Nervous SystemAutonomic Nervous System Controls glands and muscles of our Controls glands and muscles of our

internal organsinternal organs ““automatic pilot”automatic pilot”

Autonomic Nervous Autonomic Nervous SystemSystem

Dual system:Dual system: Sympathetic Nervous System Sympathetic Nervous System

Arouses the bodyArouses the body Parasympathetic Nervous System Parasympathetic Nervous System

Calms us downCalms us down

NeuronsNeurons

Nerve cells (building blocks) Nerve cells (building blocks) Ours are essentially identical to animalsOurs are essentially identical to animals Small samples of brain tissue from a Small samples of brain tissue from a

person and a monkey are basically person and a monkey are basically indistinguishableindistinguishable

Neural CommunicationNeural Communication

How does a neuron communicate with other cells How does a neuron communicate with other cells to influence our behavior?to influence our behavior?

In a complicated process a neuron fires an impulse In a complicated process a neuron fires an impulse when it receives signals from sense receptors…when it receives signals from sense receptors…

The impulse is called the action potential which is The impulse is called the action potential which is a brief electrical charge that travels down the a brief electrical charge that travels down the axon which pass messages away from the cell axon which pass messages away from the cell body to other neurons, muscles, or glandsbody to other neurons, muscles, or glands Neurons are like batteries in that they generate electricity Neurons are like batteries in that they generate electricity

from chemical eventsfrom chemical events This process involves the exchange of electrically charged This process involves the exchange of electrically charged

atoms called ionsatoms called ions

Neural CommunicationNeural Communication

When the action potential reaches the When the action potential reaches the terminals at an axon’s end, it triggers the terminals at an axon’s end, it triggers the release of chemical messengers release of chemical messengers (neurotransmitters) some of which are then (neurotransmitters) some of which are then sent to different parts of the brain while sent to different parts of the brain while others are reabsorbed by the sending others are reabsorbed by the sending neuron in a process called reuptakeneuron in a process called reuptake See pages 46-49 in the text for a more detailed See pages 46-49 in the text for a more detailed

description of this processdescription of this process

NeurotransmittersNeurotransmitters

Neurotransmitters are chemicals made by Neurotransmitters are chemicals made by neurons and used by them to transmit neurons and used by them to transmit signals to the other neuronssignals to the other neurons

A chemical message telling the next cell to A chemical message telling the next cell to fire or not to fire its own action potentialfire or not to fire its own action potential

More than 200 in our body all with More than 200 in our body all with different functionsdifferent functions

Lets briefly discuss some of the most Lets briefly discuss some of the most important ones…important ones…

SerotoninSerotonin

Facilitates a relaxed, sleepy feeling Facilitates a relaxed, sleepy feeling Tryptophan which is an amino acid Tryptophan which is an amino acid

found in dairy products and turkey is found in dairy products and turkey is converted into serotonin in the body converted into serotonin in the body So, insomnia sufferers may be smart to So, insomnia sufferers may be smart to

listen to grandmother’s suggestion to listen to grandmother’s suggestion to drink a warm glass of milk before going drink a warm glass of milk before going to bedto bed

Some Illnesses Associated With Some Illnesses Associated With

SerotoninSerotonin

Too low levels in depression and Too low levels in depression and anxiety sufferersanxiety sufferers

Obesity may also be associated with Obesity may also be associated with low levelslow levels

Linked to aggression as well -- low Linked to aggression as well -- low levels in the brains of suicide victimslevels in the brains of suicide victims

DopamineDopamine High levels lead to pleasureHigh levels lead to pleasure

Makes person feel happy and activeMakes person feel happy and active Dopamine raises the body's temperature Dopamine raises the body's temperature

and increases metabolic rateand increases metabolic rate Gives you euphoric feelings and allows you Gives you euphoric feelings and allows you

to be activeto be active Drug and alcohol abuse will block dopamine Drug and alcohol abuse will block dopamine

receptors and therefore a person needs to receptors and therefore a person needs to take more to get the same effecttake more to get the same effect

Illnesses Associated With Illnesses Associated With DopamineDopamine

Parkinson’s Disease – too low levelsParkinson’s Disease – too low levels Schizophrenia – too high levelsSchizophrenia – too high levels Tourette’s disorder – too high levelsTourette’s disorder – too high levels Huntington’s disease – too high Huntington’s disease – too high

levelslevels

NorepinephrineNorepinephrine

Plays a role in attention and arousalPlays a role in attention and arousal Used by sympathetic nervous system Used by sympathetic nervous system

to prepare us for actionto prepare us for action

Illnesses Associated With Illnesses Associated With NorepinephrineNorepinephrine

DepressionDepression Chronic stress depletes this Chronic stress depletes this

neurotransmitter and can lead to neurotransmitter and can lead to depressiondepression Note:Note:

Aerobic Exercise is found to protect Aerobic Exercise is found to protect the brain from this depletion – so go the brain from this depletion – so go out and run a mile or two if your out and run a mile or two if your down in the dumpsdown in the dumps

EpinephrineEpinephrine

Involved in energy and glucose Involved in energy and glucose metabolismmetabolism

Illnesses Associated With Illnesses Associated With EpinephrineEpinephrine

Depression – too low levelsDepression – too low levels

AcetylcholineAcetylcholine

Involved in voluntary movement, Involved in voluntary movement, learning, memory, and sleeplearning, memory, and sleep

Helps parasympathetic nervous Helps parasympathetic nervous system to slow our heart ratesystem to slow our heart rate

Illnesses Associated With Illnesses Associated With AcetylcholineAcetylcholine

Alzheimer’s disease – too low levelsAlzheimer’s disease – too low levels Note:Note:

Unfortunately, drugs used to increase Unfortunately, drugs used to increase acetylcholine to help restore normal acetylcholine to help restore normal levels appear to have small effects on levels appear to have small effects on improving memoryimproving memory

GABAGABA

Inhibits excitation and anxietyInhibits excitation and anxiety Appears directly related to anxiety Appears directly related to anxiety

reductionreduction

Illnesses Associated With Illnesses Associated With GABAGABA

Anxiety disorders – too low levelsAnxiety disorders – too low levels Huntington’s Disease – too low levelsHuntington’s Disease – too low levels

GABA systems aren’t working and this allows GABA systems aren’t working and this allows dopamine systems to run wilddopamine systems to run wild

Huntington's disease is a hereditary disorder Huntington's disease is a hereditary disorder characterized by memory loss, abnormal characterized by memory loss, abnormal movement and premature deathmovement and premature death It affects 1 in 10,000 people, and children with an It affects 1 in 10,000 people, and children with an

affected parent have a 50 percent chance of affected parent have a 50 percent chance of developing the diseasedeveloping the disease

Epilepsy – too low levelsEpilepsy – too low levels

GlutamateGlutamate

Main excitatory neurotransmitter in Main excitatory neurotransmitter in the brainthe brain

Very important in learning and Very important in learning and memorymemory

Illnesses Associated With Illnesses Associated With GlutamateGlutamate

Alzheimer’s disease Alzheimer’s disease Too low levels in hippocampusToo low levels in hippocampus

Strokes Strokes Too high levels can cause neurons to dieToo high levels can cause neurons to die

ALS (Lou Gehrig’s Disease) ALS (Lou Gehrig’s Disease) Causes death in neurons in the spinal Causes death in neurons in the spinal

cord and brainstemcord and brainstem

EndorphinsEndorphins

Involved in pain reduction and Involved in pain reduction and pleasure pleasure

They enhance the release of They enhance the release of dopaminedopamine

These natural opiates are released in These natural opiates are released in response to pain and vigorous response to pain and vigorous exerciseexercise

Illnesses Associated With Illnesses Associated With EndorphinsEndorphins

Use of artificial opiates can cause Use of artificial opiates can cause body to stop manufacturing its own – body to stop manufacturing its own – this can lead to drug addictionthis can lead to drug addiction

Endocrine System: Taking the Endocrine System: Taking the Slow LaneSlow Lane

Unlike the speedy nervous system Unlike the speedy nervous system which zips messages from eyes to which zips messages from eyes to brain to hand in a fraction of a brain to hand in a fraction of a second, endocrine messages use the second, endocrine messages use the slow laneslow lane

May take several seconds or more as May take several seconds or more as bloodstream carries a hormone from bloodstream carries a hormone from an endocrine gland to its target an endocrine gland to its target tissuetissue

Endocrine SystemEndocrine System

Hormones are chemical messengersHormones are chemical messengers Influence all aspects of our lives – Influence all aspects of our lives –

growth, metabolism, reproduction, growth, metabolism, reproduction, moods, etc.moods, etc.

Strives for homeostasis (balance) by Strives for homeostasis (balance) by responding to stress, exertion, internal responding to stress, exertion, internal thoughts, etc.thoughts, etc.

Module 5: Genetic Module 5: Genetic influencesinfluences

What influences one’s behavior: What influences one’s behavior: Nature or Nurture?Nature or Nurture? The age-old debate: The age-old debate:

Is it genes or is it the environment?Is it genes or is it the environment?

Principle of GeneticsPrinciple of Genetics

23 chromosomes carried in the egg are 23 chromosomes carried in the egg are paired with 23 chromosomes brought to it paired with 23 chromosomes brought to it by the spermby the sperm

46 chromosomes – master plan for your 46 chromosomes – master plan for your bodybody

Each is composed of a molecule called Each is composed of a molecule called DNADNA

DNA is made up of thousands of DNA is made up of thousands of segments which are called genessegments which are called genes

Principle of GeneticsPrinciple of Genetics

Your sex is determined by the 23Your sex is determined by the 23rdrd pair – pair – the sex chromosomesthe sex chromosomes

From your mother always an “x”From your mother always an “x” From your father, you have a 50/50 chance From your father, you have a 50/50 chance

of receiving an x of receiving an x making you a female making you a female From your father, you have a 50/50 chance From your father, you have a 50/50 chance

of receiving an xyof receiving an xy making you a male making you a male XX = femaleXX = female XY = maleXY = male

Twin StudiesTwin Studies

MonozygoticMonozygotic: identical twins (one-egg): identical twins (one-egg) DizygoticDizygotic: not identical – resemble one : not identical – resemble one

another as much as any brother or sister another as much as any brother or sister would.would.

QuestionQuestion: Do identical twins who are : Do identical twins who are adopted by separate families act like one adopted by separate families act like one another more than say two adopted another more than say two adopted children into the same family who have no children into the same family who have no genetic influences?genetic influences?

““The Jim The Jim Twins”Twins” Thomas Bouchard’s University of Thomas Bouchard’s University of

Minnesota twin studies – Minnesota twin studies – extraordinary similarities between extraordinary similarities between Jim Springer and Jim Lewis Jim Springer and Jim Lewis (Bouchard, 1979)(Bouchard, 1979) Uncanny coincidences?Uncanny coincidences? Any limitations to this study?Any limitations to this study?

Bouchard (1979)Bouchard (1979)

Oskar Stohl and Jack Yulfe were Oskar Stohl and Jack Yulfe were raised in environments with more raised in environments with more obvious differencesobvious differences

Adoption StudiesAdoption Studies

Surprising finding from hundred’s of Surprising finding from hundred’s of studies: people who grow up together, studies: people who grow up together, whether biologically related or not – whether biologically related or not – DO DO NOTNOT much resemble one another in much resemble one another in personality…personality… Adoptee’s more similar to biological parents Adoptee’s more similar to biological parents

than adoptive parentsthan adoptive parents Developmental Psych’s big puzzle: Developmental Psych’s big puzzle:

Why are children in the same family so Why are children in the same family so different???different???