BIOLOGY CHAP 1 3.doc

8/14/2019 BIOLOGY CHAP 1 3.doc

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CHAPTER 1PSYCHOLOGY: THE EVOLUTION OF A SCIENCE

1. Psychology is the scientific study of the mind and behavior

a.Today psychologists are studying perception, memory, creativity, consciousness, love,

anxiety

b.

Scientists define Mind as our private inner experience of perceptions, thoughts,

memories, and feelings.

c. Behavior is observable actions of human beings and nonhuman animals

. !ddressing the "uestions of #illiam $ames, father of modern psychology

#hat are the bases of perceptions, thoughts, memories, and feelings, our sub%ective sense of

self&

a.Previously believed that the pineal gland 'as a bridge bet'een the physical 'orld and

the psychological 'orld

b.#e no' (no' that those perceptions are represented as electrical and chemicalactivities in the brain

c. Some of the most exciting developments in psychology research focus on ho' our

thoughts, memories, and feelings are related to activity in the brain

i. )xample* The techni"ue of functional magnetic resonance imaging, or fM+,

allo's scientists to -scan a living brain and see 'hich parts are active 'hen a

person sees a face, reads a 'ord, and so forth

/. 0o' does the mind usually allo' us to function effectively in the 'orld&

a. Scientists sometimes say -form follo's function if 'e 'ant to understand ho'

sometimes 'or(s 2e.g., an engine3, 'e need to (no' 'hat is 'or(ing for 2e.g., po'ering

vehicles3 b. Psychological processes are adaptive

ii. )xample* Perceptions allo' us to recogni4e our families.

5. 6iven its adaptiveness, 'hy does the mind occasionally function so ineffectively in the 'orld&

a.The mind often trades accuracy for speed and versatility, resulting in malfunctions, or

-mind bugs

b.The influence of habit, or doing things 'ithout really thin(ing, could explain bi4arreactions of -absentminded people

c. Brea(do'ns and errors are opportunities to examine ho' things change from normal

operations, and provide path'ays to (no'ledge

I. Psychologys Roots: Th P!th to ! Sc"#c o$ th %"#&

!. Psychology7s !ncestors* The 6reat Philosophers

1.8ativism 2-nature3 the philosophical vie' that certain (inds of (no'ledge are innate orinborn

a. Supported by the 6ree( thin(er Plato

.Philosophical )mpiricism 2-nurture3 9 the philosophical vie' that all (no'ledge is ac"uiredthrough experience

b. Supported by the 6ree( thin(er !ristotle, 'ho believed that a child7s mind 'as a blan(

slate 2tabula rasa3 upon 'hich experiences are 'ritten /. These thin(ers offered great insight, but could not empirically test their theories

B. :rom the Brain to the Mind* The :rench ;onnection

1. :rench philosopher +ene


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a.


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iv. This type of experiment bro(e ne' ground, sho'ing that psychologists could

use scientific techni"ues to disentangle even subtle processes

=. Titchener brings structuralism to the Anited States

a.British9born )d'ard Titchener studied 'ith #undt for t'o years and opened a similarlab at ;ornell Aniversity

i. #hereas #undt emphasi4ed the relationship bet'een the elements of

consciousness, Titchener focused on identifying the elements themselves

b. Structuralism faded due to the lac( of replicable observations and 'hether it 'as even

possible to identify such elements solely through introspection

i. ne such s(eptic 'as #illiam $ames >. $ames and the :unctional !pproach

a. #illiam $ames ran experiments in his 0arvard course, the first at an !merican

university to dra' on the ne' experimental psychology developed by #undt andTitchener* these lectures and experiments led to $ames7s masterpiece, The Principles ofPsychology21?CD3

b. $ames disagreed 'ith the idea that consciousness could be bro(en do'n into separate

elements, instead claiming that consciousness 'as more li(e a flo'ing stream

i. 0e proposed instead :unctionalism the study of the purpose mental processes

serve in enabling people to adapt to their environment

c.$ames7s ideas 'ere inspired by ;harles


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1.0ysteria a temporary loss of cognitive or motor functions, usually as a result of emotionally

upsetting experiences

a. ;onditions described by :rench physicians $ean9Marie ;harcot and Pierre $anet

. These conditions of star(ly contrasting behavior 'ithin one individual 'ere dismissed by

#undt and Titchener, but embraced as learning opportunities by $ames

/.! Giennese physician and student of ;harcot, Sigmund :reud, 'as also intrigued by these

observations;. :reud and Psychoanalytic Theory

1.#or(ing 'ith Breuer in Gienna, :reud developed theories to explain strange behaviors and

symptoms a. ;entral theme of explanations 'as repressed painful childhood memories

b. Anconscious the part of the mind that operates outside of conscious a'areness but

influences conscious thoughts, feelings, and actions

c. Psychoanalytic Theory an approach that emphasi4es the importance of unconscious

mental processes in shaping feelings, thoughts, and behaviors

i. +elies heavily on early sexual experiences and unconscious sexual desires

d. Psychoanalysis a therapeutic approach that focuses on bringing unconscious material

into conscious a'areness to better understand psychological disorders

e. ;arl $ung and !lfred !dler 'ere prominent in the psychoanalytic movement, but had

disagreements, and eventual fallouts, 'ith :reud

. #hile $ames 'or(ed in an academic setting and :reud 'ith clinical patients, both believed that

mental aberrations 'ere clues into the nature of mind


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i.Pavlov trained dogs to expect food follo'ing a tone 2stimulus3 and measured

salivation in response

ii. +esponse an action or physiological change elicited by a stimulus

b. Behaviorism is often referred to as -S9+ or -stimulus9response psychologyB. B.:. S(inner and the 9 or @9years old, children do not understand that the

mass of an ob%ect is retained even if it is divided in half

/.6erman psychologist Hurt Fe'in reintroduced the importance of one7s sub%ective experiencein the 'orld in predicting behavior

a. !ccording to Fe'in, it 'as not the stimulus, but rather the person7s construal of the

stimulus, that determined the person7s subse"uent behavior

b.Fe'in used topology,a (ind of mathematics, to model and predict a person7s sub%ective

experience

5.Still, most psychologists ignored mental processes until the advent of the computer in the

1C=Ds a. Psychologists no' 'ondered if the computer might be a model for the mind

b. The invention of the computer also led to rene'ed interest in mental processes, leading

to the development of ;ognitive PsychologyIthe scientific study of mental processes,including perception, thought, memory, and reasoning.

=. ;ognitive psychology 'as also energi4ed by the publication of S(inner7s boo( Verbal

Behavior21C=@3, 'hich argued that language ac"uisition unfolds according to the principles ofbehaviorism

a. !merican linguist 8oam ;homs(y blasted S(inner7s analysis, citing the need for many

mental rules for grammar, novel 'ords, and sentences


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>.These developments set the stage for the explosion of cognitive studies in the 1C>Ds

B. The Brain Meets the Mind* The +ise of ;ognitive 8euroscience

1. )rrors in behavior continue to illuminate the need to understand the hard'are of the brain in

order to understand even the simplest cognitive processes

a. Studies of damaged brains remind us that our simplest mental processes depend on

intricate operations carried out in the brain

. #atson7s student Harl Fashley follo'ed the lead of :lourens by removing parts of the brain of

an animal and loo(ing for -learning in the brain through behavioral deficits

a.Fashley discovered that removing more brain led to 'orse behavior instead of finding aspecific site in the brain for learning

b. Behavioral 8euroscience an approach to psychology that lin(s psychological

processes to activities in the nervous system and other bodily processes

i. ncludes recording electrical and chemical changes in the brain as sub%ects

perform specially constructed tas(s, or removing parts of the animal brain to see

ho' that affects performance

/. Because it is not ethical to do such research using human sub%ects, human research relied on

accidents and brain in%ury for many years, until brain9scanning techni"ues 'ere developed to

gauge brain activity during specific tas(s and behaviors 2e.g., reading and spea(ing3

5.:or example, scanning techni"ues are used to identify parts of the brain used in specificaspects of language

a.;ognitive 8euroscience a field that attempts to understand the lin(s bet'een cognitive

processes and brain activity;. The !daptive Mind* The )mergence of )volutionary Psychology

1. )xperiments by $ohn 6arcia sho'ed that rats learn to associate smells 'ith food more "uic(ly

than other modalities 2i.e., visual stimuli3 a. Fearning from the rat7s ancestors 'as being represented in the present

. )volutionary Psychology a psychological approach that explains mind and behavior in terms

of the adaptive value of abilities that are preserved over time by natural selection

a. ! central theme of the approach is that the brain is not an -all9purpose computer, but

'as built to do some things very 'ell and not others 2i.e., it comes 'ith a small suite of

built9in applications3

/. )volutionary psychologists 'ould explain the existence of human traits 'e have today by

saying that these traits have served and continue to serve an adaptive function for example,

%ealousy

5. ;ritics of evolutionary psychology argue that some traits that aid people and animals no'

probably evolved initially for different functions 2e.g., feathers 'ere probably for temperature

regulation, not flight, initially3

=.Testing evolutionary psychology is difficult because of the lac( of existing records for pastevents, thoughts, feelings, and actions

a. ne approach is to study traits across multiple cultures

b. !nother approach is to examine the issue through reproductive success


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compared to riding alone, that is, the presence of other people affected performance

/. .!. The 6ro'ing +ole of #omen and Minorities

1.riginally all 'hite men, the !P! is no' roughly half 'omen and increasingly diverse in

minority representation . )arly pioneers bla4ed the trail

a. Mary ;al(ins became the first 'oman to serve as !P! president in 1CD=

/. Today 'omen play leading roles in all aspects of psychology


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5. $ust as there 'ere no 'omen at the first !P! meeting, so 'ere there no non either

a. Henneth ;lar( became the first minority member to serve as !P! president in 1C@D

i. ;lar( studied 'ith :rancis Sumner, the first !frican !merican to receive a Ph. The other important property of a good measurement is reliability

a.+eliabilityIthe tendency of a measure to produce the same result 'henever it is used

to measure the same thing

b. The flip side of reliability is Po'erIthe tendency for a measure to produce different

results 'hen it is used to measure different things

c. +eliable and po'erful measures are those that detect the conditions specified by an

operational definition 'hen they happen, and only'hen they happen

@. Galidity, reliability, and po'er are prere"uisites for accurate measurement

a. The next step is to find something to measure, using these, and psychologists have

developed techni"ues for doing this too

B. Samples 1. Sometimes individuals do remar(able things that deserve close study by psychologists

a.;ase Method a method of gathering scientific (no'ledge by studying a single

individual

i. )xample* liver Sachs described his observations of a brain9damaged patient

'ho made certain (inds of mista(es and these observations 'ere 'orth

ma(ing because they 'ere unusual mista(es for a man to ma(e

b. t is 'orth studying an exceptional or unusual individual because it might provide

insight about a psychological phenomenon

. But most often, psychologists are interested in explaining 'hy unexceptional 2i.e.,-ordinary3 people do 'hat they do

a.t is impossible to observe the entire PopulationIthe complete collection of ob%ectsor events that might be measured

b.Therefore, psychologists observe a SampleIa partial collection of ob%ects or eventsthat is measured

c. f the sample is 'ell9chosen and relatively large, then the behavior of individuals in

the sample should be representative of the larger population

d. :or more on sampling techni"ues, see the !ppendix.

;.


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.ne 'ay for psychologists to avoid demand characteristics is to observe people 'ithouttheir (no'ledge

a. 8aturalistic bservation a method of gathering scientific (no'ledge by

unobtrusively observing people in their natural environments

i. )xample* 0ungry shoppers buy the most impulse items at the grocery store

/.

There are t'o reasons 'hy naturalistic observations doesn7t solve demand characteristic

problems*

a. Some of the things that psychologists 'ant to observe do not occur naturally

i. )xample* f 'e 'anted to find out 'hether people 'ho have undergone

sensory deprivation perform poorly on motor tas(s, 'e 'ould have to 'ait a

long time for a fe' do4en blindfolded people 'ith earplugs to 'ander by andstart typing

b.Some of the things psychologists 'ant to observe can only be gathered from directinteraction of a person

i.

)xample* f 'e 'anted to (no' ho' often people 'orried about dying,

simply observing them 'ould not do the tric( 5. Psychologists use several tric(s for avoiding demand characteristics

a. They allo' sub%ects to respond anonymously

b. They measure behaviors that are not susceptible to demand characteristics

i. )xample* Pupil dilation in response to excitement

c. They retain lac( of relationship information bet'een demand and behavior 2i.e., (eep

the participant blindto the purpose of the study3

=. But the best 'ay to avoid demand characteristics is to (eep the people being observed from

(no'ing the true purpose of the observation

a.#hen participants are (ept blind to the observer7s expectations, they cannot strive

to meet those expectations.

>. 0o'ever, people are curious, and so try to figure out 'hy they are being observed

a. So psychologists sometimes use coverstories,or misleading explanations that are

meant to (eep participants from seeing the true purpose of an observation

b.r they may usefiller items, or pointless measures that are meant to mas( the true

purpose of the observation


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b.Many modern studies are carried out by the 'orld7s blindest experimenter* acomputer

III. Th Sc"#c o$ E/0l!#!t"o#: S!y"#g 4hy

!lthough the careful measurement of properties is important, the ultimate goal of scientific research isto discover the causal relationships bet'een properties

i. )xample* Measurement can tell you ho' much happiness and altruism occur

in a particular sample, but it cannot tell you 'hether t'o properties arerelated, or, if so, 'hether their relationship is causal

!. ;orrelation and ;ausation

1.!fter collecting some data, you may notice that t'o properties tend to occur together more

often than not

a. #hen t'o properties occur together, 'e often say they are ;orrelated the value of

one is systematically related to the value of the other

b. #hen the value of altruism is high, then the value of happiness tends to be high, too.

Correlationis short for co%relationship

. But that t'o GariablesIproperties 'hose values can vary across individuals or over timeI

are present does not necessarily mean that one causes the other

/.:or example, the more television violence a child sees 2variable&3, the more aggressive thatchild is li(ely to be 2variable '3

a. But it may not mean that seeing violence causes aggression

i. )xample* ;hildren 'ho are naturally aggressive may en%oy TG violence more

than those 'ho aren7t and therefore may see( opportunities to 'atch it

5. To complicate matters even more, it may be that a third variable 2(3 causes children to both

be aggressive and to 'atch TG violence

a.

The relation bet'een aggressiveness and TG violence may be caused by Third9

variable correlationIin 'hich t'o variables are correlated only because each iscausally related to a third variable

i. )xample* Fac( of adult supervision 2(3 may allo' children to get a'ay 'ithbullying other children and to get a'ay 'ith 'atching TG sho's not normally

permitted by adults thus, 'atching TG violence 2&)and behaving

aggressively 2'3 may not be causally related but be the independent effects of

a lac( of adult supervision 2(3

B. Matched Samples and Matched Pairs

1.

The most straightfor'ard 'ay to determine 'hether a third variable 2(3 causes children to

'atch TG violence 2&3 and behave aggressively 2'3 is to eliminate differences in adult

supervision 2()among a sample of children and see if the correlation bet'een TG violence2&3 and aggressiveness 2'3 remains

a. Kou could observe children using the Matched Samples Techni"ueIa techni"ue

'hereby the participants in t'o samples are identical in terms of a third variable

b. r you could observe them using the Matched Pairs Techni"ueIa techni"ue

'hereby each participant in a sample is identical to one other participant in that

sample in terms of a third variable

c. +egardless of 'hich techni"ue you use, you 'ould (no' that children 'ho do or


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don7t 'atch TG violence have e"ual amounts of adult supervision on average assuch, if those 'ho 'atch a lot of TG violence have more aggression than those 'ho

don7t, then lac( of adult supervision can not be the cause

. )ven so, neither matched samples nor matched pairs techni"ues 'ould be enough to dismiss

aparticularthird variable li(e adult supervision, so you could not use them to dismiss all

third variables

/. The reason is that there is an infinite number of third variables and thus an infinite number ofreasons 'hy&and 'might be correlated

a. The Third Gariable ProblemIrefers to the fact that a causal relationship bet'een t'o

variables cannot be inferred from the naturally occurring correlation bet'een them

because of the ever9present possibility of third9variable correlation

;. )xperimentation

1. To learn about causal relationships, 'e have to find another method

. )xperiment a techni"ue for establishing the causal relationship bet'een variables

a. Kou already (no' about experiments because 'e have been doing them all your life

i. )xample* f you are surfing the #eb on a laptop that uses a 'ireless

connection and suddenly the connection stops 'or(ing, you might suspectyour roommate7s ne' cordless phone has interfered 'ith your connection, andthen you might observe and measure carefully, noting 'hether your

connection 'or(s 'hen you roommate uses his cordless

ii. )ven if you observe a correlation bet'een the failure to connect and your

roommate7s phone usage, the third9variable problem 'ould prevent you from

dra'ing a causal conclusion for example, perhaps your roommate calls hismom 'hen there is an electrical storm because such storms terrify him, and

thus it is the storm that interrupts your connection

iii. Then the storm 2()is the cause of both your roommate7s phone calls 2&3 and

your laptop7s failure to connect to the internet 2') /. To solve the third9variable problem, you could try to createa correlation

i. )xample* Kou can intentionally s'itch your roommate7s phone on and off a

fe' times and at the same time observe changes in your laptop7s connection

ii. f you notice that 'hen he phone is on the connection failure occurs more

often than not, then you 'ould conclude your roommate7s phone is the causeof your failed connection

5.To solve scientific problems, psychologists use the same techni"ue that you intuitively did tosolve your connection problem

i. )xample* Kou can determine 'hy there is a correlation bet'een

aggressiveness and TG violence by manipulating ho' much TG violence a

child 'atches

ii. Kou could, for example, find a sample of children, expose half of them to

hours of TG violence every day for a month, and ma(e sure the other half sa'

no TG violence during the same period

iii. !t the end of a month, you could measure the aggressiveness in each group

you 'ould essentially be computing the correction bet'een a variable youmeasured 2aggressiveness3 and a variable you manipulated 2TG violence3 and

in so doing you 'ill have solved the third9variable problem7


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=. ndependent Gariable the variable that is manipulated in an experiment

)xperimental 6roup the group of people that are treated in a particular 'ay

;ontrol 6roup the group of people that are not treated in a particular 'ay

.True random sampling is extremely difficult and thus is never really done and so nonrandomsampling is used instead

@. There are three reasons 'hy nonrandom samples are o(ay

i. Sometimes generality does not matter it often doesn7t matter if everyone does

something as long assomeonedoes it99as an experimental result can beilluminating even 'hen its generality is severely limited


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ii. Sometimes generality can be determined for example, if the results of an

experiment can be replicated in other nonrandom samples, 'e can be more

confident that the results 'ould generali4e to the 'hole population

iii. Sometimes generality can be assumed thus many participants in samples

share enough in common 'ith other people in other places to assume that the

effects found in one study 'ould occur again in another study

IV. Th Eth"cs o$ Sc"#c: S!y"#g Pl!s !#& Th!# Yo(

1.Psychologists are bound by a strict code of ethics to treat participants fairly, and to ensure

their safety and 'ell9being

a. nformed ;onsent a 'ritten agreement to participate in a study made by a

person 'ho has been informed of all the ris(s that participation may entail

b. :reedom from ;oercion99psychologists may not coerce 2e.g., physically,

psychologically, or monetarily3 participation from potential sub%ects

c. Protection from 0arm* psychologists should al'ays use the safer of t'o

methods 'hen available, and if no safe method is available, the study must

not be conducted

d. +is(9benefit !nalysis* Participants must not be as(ed to ta(e ris(s beyond

those that they 'ould ordinarily, and re"uests for small ris(s must be sho'nto provide ne' social benefits as a result of the study

e.


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/. Fi(e cells in all organs of the body, neurons have a cell body

a.;ell Body 2Soma3 coordinates the information9processing tas(s and (eeps the cell

alive

b. . SynapseIthe %unction bet'een one neuron7s axon and another neuron7s dendrite or cell have

bet'een1DD trillion and =DD trillion synapses@. There are three types of neurons

a.Sensory neurons receive information from the external 'orld and convey this

information to the brain via the spinal cord

b.Motor neurons carry signals from the spinal cord to the muscles to produce

movement

c. nterneurons connect sensory neurons, motor neurons, and other interneurons

d. Most of the nervous system is composed of interneurons

e. nterneurons 'or( together in small circuits to perform simple tas(s

!. )lectrical Signaling* ;ommunicating nformation 'ithin a 8euron

1. ;ommunication 'ithin and bet'een neurons proceeds in t'o stages 9 conduction andtransmission, together referred to as electrochemical action

a. :irst the a signal is received and may initiate electrical conduction do'n the axon

b. Second, the signal travels chemically across the synapse to the next neuron

.;harged molecules, or ions, flo' across the cell membrane differentially to set up the resting

potential

a.!t rest there is a higher concentration of potassium 2H3 on the inside of the cell

and sodium 28a3 outside of the cell

b.The flo' of ions across the cell membrane is controlled by opening and closing smallchannels that are specific to each ion

c.This leaves the neuron 'ith fe'er positively charged molecules on the inside relativeto the outside

d.+esting PotentialIthe difference in electric charge bet'een the inside and outside ofa neuron7s cell membrane

e. The resting potential of a neuron is approximately 9@D millivolts

/.!ction Potential an electrical signal that is conducted along the length of a neuron7s axon to

the synapse

a. nput must pass a threshold to activate an action potential


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b. !ll9or9none, that is, an action potential7s strength remains the same from the

beginning to the end and is not influenced by further changes in input strength

5.The action potential occurs only 'hen there is a change in the state of the axon7s membranechannels

=. #hen an action potential is generated at the beginning of the axon, it spreads a short distance,'hich generates an action potential at a nearby location

a.+efractory period the time follo'ing an action potential during 'hich a ne' actionpotential cannot be initiated

>. Bare segments of axon bet'een sections of myelin are called the nodes of +anvier, 'hich

cause action potential to -%ump 2saltatory conduction3 and speed conduction

B. ;hemical Signaling* Synaptic Transmission bet'een 8eurons

1. Terminal ButtonsI(nobli(e structures that branch out from an axon

a.8eurotransmitters chemicals that transmit information across the synapse toreceiving neuron7s dendrites or soma

b.+eceptors parts of the cell membrane that receive neurotransmitters and initiate ane' electrical signal

c.+eceptors act li(e a loc(9and9(ey system, 'here only certain neurotransmitters canactivate certain receptors

d. The sending, or presynaptic neuron, releases neurotransmitters into the synapse that

are received by the postsynaptic neuron

.8eurotransmitters are cleared from the synapse 'hen they are finished binding to receptors viathree different processes

a.+eupta(e neurotransmitters are ta(en bac( into the presynaptic neuron throughtransporters

b.)n4ymatic


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mimic(ing the manufacture or function of neurotransmitters

a. !gonists are drugs that increase the action of a neurotransmitter

i. )xample* F9dopa increases dopamine and helps treat Par(inson7s disease

.Anexpected evidence has highlighted dopamine7s central role in regulating movement andmotor performance.

a. Six young street people 'ere diagnosed 'ith advanced Par(inson7s, but none of them

actually had Par(inson7s but they 'ere all heroin addicts

/. The six thought they 'ere ingesting a form of heroin 2MPPP3, but they had really ingested a

close derivative 2MTTP3, 'hich destroyed dopamine9producing neurons in brain area critical

for motor performance

5. ther street drugs can alter neurotransmitter function

a. !mphetamine is a strong agonist

b. ;ocaine acts through similar mechanisms to amphetamine but an overdose of

either can cause the heart to contract very rapidly, leading to fainting and sometimes

to death

c. 8orepinephrine and dopamine play a critical role in mood control an increase in

either results in euphoria, 'a(efulness, and a burst of energy

=. Pro4ac increases serotonin by bloc(ing reupta(e, 'hich helps treat symptoms of depression

II. Th O'g!#"5!t"o# o$ th N')o(s Syst-

8ervous SystemIan interacting net'or( of neurons that conveys electrochemical information

throughout the body

!.


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>.The sympathetic and parasympathetic nervous systems coordinate to control many bodyfunctions

a. !n example is sexual behavior in both men and 'omen, a successful sexual

experience depends on a delicate balance bet'een the t'o systems

B. ;omponents of the ;entral 8ervous System

1. The brain and spinal cord are ultimately responsible for most of 'hat 'e do

. Spinal cord coordinates breathing, pain, movement, and other functions

/.Spinal +eflexes simple path'ays in the nervous system that rapidly generate musclecontractions

5. More elaborate tas(s re"uire collaboration of the spinal cord and the brain

a.


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cerebral cortex

/. 0ypothalamus 2belo' thalamus3 regulates body temperature, hunger, thirst, and sexual

behavior :our :s of behavior* fighting, fleeing, feeding, and mating

a.;ommissures bundles of axons that ma(e possible communication bet'een parallel

areas of the cortex in each half

b. ;orpus callosumIthe largest commissure, it connects large areas of the cerebral

cortex on each side of the brain and supports communication of information acrossthe hemisphere

5. There are several other (ey subcortical structures

a.Pituitary 6land the -master gland of the body7s hormone9producing system, 'hich

releases hormones that direct the functions of many other glands in the body

b. 0ippocampusIcritical for creation and storage of ne' memories

c. !mygdalaI'hich plays a central role in many emotional processes

d. :inally, the basal ganglia is a set of structures that direct intentional

The Cerebral Corte.

1 Separation of cortex into t'o hemispheres each side is roughly symmetrical and controlsmany functions on the opposite, or contralateral, side of the body

a.;ommissures bundles of axons that ma(e possible communication bet'een parallelareas of the cortex in each half

b.;orpus callosumIthe largest commissure, it connects large areas of the cerebralcortex on each side of the brain and supports communication of information across

the hemisphere

. )ach hemisphere has four lobesIoccipital, parietal, temporal, and frontal

a. ccipital Fobe a region in the bac( of the brain that processes visual information

b.Parietal Fobe located in front of the occipital lobe and carries out functions such as

touch c.

Temporal Fobe located laterally and belo' parietal cortex, is responsible for hearing

and language

/.:rontal Fobe behind the forehead, has speciali4ed areas for movement, abstract thin(ing,

planning, memory, and %udgment

5. !ssociation !reas areas of cortex that are composed of neurons that help provide sense and

meaning to information registered in parts of the primary cortex

a.8eurons in the association areas are usually less speciali4ed and more flexible than

neurons in the primary areas

b.This means they can be shaped by learning and experience to do their %ob more

effectively a "uality calledplasticity

=.:unctions that 'ere assigned to certain areas of the brain may be capable of being reassigned

to other areas

i. )xample* f you lose your middle finger in an accident, over time that area in

the somatosensory cortex becomes responsive to stimulation of the fingers

ad%acent to the missing finger area

>. Plasticity doesn7t only occur to compensate for missing digits or limbs an extraordinary

amount of stimulation of one finger can result in that finger ta(ing over the representation ofthe part of the cortex that usually represents fingers that are ad%acent to it


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III. Th E)ol(t"o# o$ N')o(s Syst-s

!. )volutionary


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influences on behavior, there are four important "ualifications

a.0eritability is an abstract concept it tells us nothing about the specific genes

that contribute to a trait

b. 0eritability is a population concept it tells us nothing about the individual

c. 0eritability is dependent on the environment it occurs 'ithin certain contexts

d.0eritability is not fate circumstances can change the li(elihood of behaviors orpathologies

IV. I#)st"g!t"#g th ,'!"#

!. Fearning about Brain rgani4ation by Studying the


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a. ;T7s are often used to detect lesions or tumors in the brain

/. Magnetic +esonance maging 2M+3 involves images that result from brief but po'erful

magnetic pulses being applied to the brain and interpreting ho' cells in the tissue react to thepulses

5. :unctional Brain9maging allo's scientists to 'atch the brain in action during some behavior,

based on increased blood flo' in active regions

i.!n example is Positron )mission Tomography 2P)T3

ii. :unctional Magnetic +esonance maging 2fM+3is the most 'idely used

functional9brain9imaging techni"ue currently used

BIOLOGY CHAP 1 3.doc

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