Unit 2 Notes--Walker

mumpsimuspreviousAI and Robotics

Oct 25, 2013 (3 years and 7 months ago)

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Unit 2: The Biological Basis of Behavior


3A: Neural Processing and the Endocrine System




Everything psychological is simultaneously biological
.



1800s: Franz Gall invented
phrenology
, which is the study of the bumps on your head (apparently, the bumps
could
reveal our mental abilities and our character traits



Biological psychologist

(a branch of psychology concerned with the links between biology and behavior)



Bottom up: nerve cells to the brain to environment


Neural Communication



All animals are made
of essentially the same tissues and brains are similar from species to species (including
humans)



A lot of research from this unit was actually completed on animals since their brains are essentially the same as ours


Neurons

Question: What are neurons, an
d how do they transmit information?



Neurons (nerve cell)

o

Sensory neurons

(carry incoming information from the sensory receptors to the brain and spinal cord)

o

Information then sent out to the rest of the body (
motor neurons
: neurons that carry outgoing info
rmation
from the brain and spinal cord to the muscle and glands)

o

Interneurons

(neurons within the brain and spinal cord that communicate internally and intervene between
the sensory inputs and motor outputs)



All neurons are the same

o

Cell body

o

Dendrites

(bu
shy, branching extensions of a neuron that receive messages and conduct impulses toward the
cell body)



short

o

Axon

(the extension of the neuron, ending in branching terminal fibers through which messages pass to
other neurons or to muscles or glands)



Often

long



AXONS SPEAK; DENDRITES LISTEN



Insulated with the
myelin sheath

(a layer of fatty tissue segmentally encasing the fibers of many
neurons, enables vastly greater transmission speed of neural impulses as the impulses hops from
one node to the next)



Incr
eases until about age of 25

neural efficiency



Degeneration: multiple sclerosis


movement becomes more and more difficult



Produced by glia cells and makes communication more efficient



Nodes of Ranvier spaces between the myelin sheath and axon

o

Transmit mes
sages when stimulated by signals from other senses or when triggered by chemicals



Message is an impulse called
action potential

(a neural impulse; a brief electrical charge that travels
down an axon)



Neurons transmit electricity

process involves exchange o
f
ion

(electrically charged ions)

o

Ions have a charge, either positive or negative

when these particles move, they
create electricity (action potential)



Resting potential

o

Fluid interior of resting axon has an exceeds of negatively charged ions

o

Fluid outside

of the axon has more positively charged ions

o

Natural tendency for materials to move from a more crowded situation to a less
crowded situation; neuron is packed with negatively charged ions, with the
positively charged ions potion on the outside of the cel
l



Axon’s surface is
selectively
-
permeable

(blocks the sodium from coming which are positively
charged ions)

o

Normally impermeable so nothing gets through, but NT weakens it



When the neurons fire, it depolarizes the axon, which opens up the channels and allo
ws the
positively charged ions in

think domino effect

o

Sodium potassium pump is what allows the movement in and out positively charged
ions come in and then are sent back out



Once it has fired, it must rest during a refractory period and sends the positivel
y charged
ions back outside



http://education
-
portal.com/academy/lesson/the
-
structure
-
and
-
function
-
of
-
neurons.html




Demonstration: Modeling a Neuron and
Using Dominoes to Illustrate the Action Potential



Action potential is similar to the flushing toilet



All or none: strength of each flush

depress the lever, flush I the same each time



Threshold: softer push of the lever will not create a flush at all since
it did not reach
threshold



Refractory Period: in order to flush, the tank must be full so two flushes cannot occur in a
row without time to refill



Most signals
excitatory

(increase the messages) some
inhibitory

(don’t pass messages along)



If there is enoug
h excitatory to outnumber the inhibitory for a certain threshold (level of stimulation
required to trigger a neural impulse) it will trigger



Sending the message is an all
-
or
-
none response (squeezing the trigger harder won’t make the bullet
move faster)


H
ow Neurons Communicate

Question: How do nerve cells communicate with other nerve cells?



Synapse (junction between the axon tip of the sending neuron and the dendrite or ell body of the receive neuron

gap called synaptic gap or cleft)



When action potentials

reach the end of the axon, they reach the axon terminal trigger neurotransmitters (chemical
messengers that cross the synaptic gaps between neurons; when released by the sending neuron, NT travel across
the synapse and bind to receptor sites on the receiv
ing neuron influencing whether it will fire or not)



Extra NT is reabsorbed (reuptake)



More than one NT may be in a neuron

simplified picture for understanding


How Neurotransmitters Influence Us

Question: How do neurotransmitters influence behavior, and ho
w do drugs and other chemicals affect
neurotransmission?



Neurotransmitters affect motions and emotions

o

Acetylcholine (ACh)


messenger at junctions between two motor neurons and skeletal muscles



When released
to muscle cell receptors, muscles contract



If
it is blocked

paralysis



Table 3A.1
-
diffeernt types of NT and their effects



Body produces endorphins (morphine within

natural, opiatelike neurotransmitters linked to pain control and to
pleasure)



Neurotransmitters (NT) are they key component for all behavio
r and mental processes; carry messages for all that
we do; send messages to be happy or sad, to move or stay still; can function differently depending on where they
are located in the nervous syste
m
; TIP OF ICEBERG



the function of the NT depends on which
part of the bran it acts upon

o

if NT acting upon the brainstem, it affects basic functions like breathing and heartbeat

o

if acts on midbrain, memory and
emotions

o

cortex, high functions like memory integration, problem solving, and perception


How Drugs

and O
ther Chemicals Alter Neurotransmission



If we flood the brain with opiate drugs (heroine and morphine), brain may stop producing own opiates

o

Brain goes through withdrawal and extreme discomfort



Brain chemistry can be changed at synapses

use of drugs and oth
er chemicals

REVIEW THIS

o

Agonist
-
similar enough to NT that is mimics the effects


opiates produces “highs” by enhancing normal
sensations of arousal or pleasure or venom of black widow spider floods effects of ACh leading to
convulsions

o

Antagonists
-
bind a
nd blocks NT functioning

botulin blocks the effects of ACh; curare paralyzes animals in
hunting by blocking the ACh



Table 3A.1
discusses similar drugs

o

Additions: dopamine similar to cocaine

o

Serotonin similar to LSD and ecstasy



Our body produces painkillers (endorphins) as well as chemicals necessary to energy, euphoria, and
hallucinations; in healthy people, these chemicals are balanced to produce normal experiences;
however, taking illegal or non
-
prescribed drugs disrupts this
balance, causing abnormal levels of
energy, emotion, and sensory experiences.



Substance P: body’s pain NT

o

Works in opposition with endorphins to regulate pain; signals that the body is in pain and endorphins
triggered to inhibit the pain signal.



In ord
er for drugs to have an effect on the body, the brain must have an accompanying receptor site on a neuron
that matches the structure of the rug; introduction of drugs inhibits our natural chemicals;

o

Not all substances can make its way through the blood
-
br
ain barrier, which protects the brain from
pathogens and
harmful

substances

Parkinson’s p
atients must take L
-
Dopa rather than dopamine, let’s the
body break down the dopamine


Test Yourself: How do neurons communicate with one another?


The Nervous System

Question: What are the functions of the nervous system’s main divisions?



Nervous system (the body’s speedy, electrochemical communication network, consisting of all the nerve cells of the
peripheral and central nervous systems)

o

Central nervous system

(CNS)

(the brain and spinal cord)

o

Peripheral Nervous system (PNS)
(the sensory and motor neuron that connect the central nervous system
with the rest of the body

o

the two systems work together seamlessly even though we separate them to understand/teach them

The
Peripheral Nervous System



Two part
s

o

Somatic

Nervous System

(the division of the PNS that controls the body’s skeletal muscles)



Voluntary control

o

Autonomic

Nervous System

(the part of the PNS that controls the glands and the muscles of the internal
organs)



Heartbeat, digestion

automatic



Key player for emotions, stress, and health



Fight or flight response governed and this response plays a role I how we respond to stress
or environmental cues



Therapies use knowledge of this system to make them more effective



Sympathetic Nervous System
(the division of the autonomic nervous system that arouses the body,
mobilizing its energy in stressful situations)



Initiates flight or fight response



Parasympathetic

Nervous System
(the division of the autonomic nervous system t
hat calms the
body, conserving its energy)



Brings
body back down once the stress subsides



Work together to bring body back to a normal internal state

opponent process systems (work in
opposition of each other, with one system performing one role and the ot
her system performing the
eat opposite role) opposition creates homeostasis (balance) in the body


The Central Nervous System



Brain’s cluster into work groups called
neural networks



Spinal cord

is information highway connecting peripheral nervous
system to

brain

o

Sensory neurons connect to the spinal cord d
orsally, or in the back. Motor neurons

connect

in the anterior
of the spinal cord, or the front. Therefore, it is possible to lose feeling in lower portions of the body in a
spinal cord injury, but retain the ability to move if the spinal cord is not completely severed



Reflexes

(a simple, automatic
r
esponse

to a sensory stimulus
such

as the knee jerk response)

o

Interneuron
s

make reflexes happen

o

But what happens when we think: activity in circle



Mnemonics to help

o

CNS: brain and spinal cord are located in the
center

part of the body

o

PNS: fingers and toe
s lie in the outermost areas of the body from the center or the
periphery
of the body

o

Somatic NS: volunteer work is done by choice, so the body’s or soma’s voluntary actions are controlled by
this nervous system

o

Autonomic NS: sounds similar to
automatic
,

a
nd the body’s automatic actions
(
breathing, heartbeat, etc) are
controlled by this nervous syste
m


Test Yourself: How does information flow through your nervous
system

as you pick up a fork? Can you summarize
this process?


The Endocrine System

Question:
How does the endocrine system

the body’s slower information system

transmit its messages?




Connected to the nervous system, but slower than it

o

Endocrine system (the
body’s


slow


chemical communication system a set of glands that
secrete

hormones

into the bloodstream)



Secretion of hormones (chemical
messengers

that are manufactured by the endocrine glands, travel
through the

blood

stream, and

affect other tissue



Influence sex, hunger, and
aggression



Nervous System vs. Endocrine System

o

Neurotransmi
tters vs. Hormones (some are chemically the same)

o

Everywhere in the body vs. bloodstream



NT and hormones are the same. Only different based on where they are manufactured and located
in the body. NT are manufactured in the neurons and other nervous syste
m cells and located in the
nervous system, and hormones are manufactured by glands and based in the body and the blood
stream.

o

Quick (email) vs. Slower (snail mail)

o

Quick to fade vs. takes longer to get over



Autonomic nervous system tells adrenal glands
(pair of
glands

that sit above the kidneys an secret
hormones

(
epinephrine

and
norepinephrine
) that help arouse the body in
times

of stress
) and takes
longer to “simmer down”



Changes to body: increase heart rate, blood pressure ,and blood sugar providing e
nergy



Pituitary gland: most influential (under the influence of the hypothalamus, the pituitary regulates growth and
controls other endocrine glands)

o

Feedback system (brain

pituitary

other glands

hormones

brain)


o

Other glands:



Anterior pituitary gland (gro
wth hormone: too much
-
gigantism
, too little dwarfism)



Posterior pituitary gland (vasopressin:
constricting

blood vessels and raising blood pressure;
and
oxytocin sparks labor in pregnant women )



Thyroid (release thyroxine and triiodothyronine increasing
metabolic rates,
gr
o
w
t
h, and

maturation



Parathyroids (parathyroid hormones, increasing blood calcium and decreasing potassium)



Pancreas (secretes insulin, regulating the level of sugar in the blood stream)



Ovaries (secretes estrogen and promotes ovulation
and female sexual characteristics)



Testes (releases androgens, promoting sperm production and male sexual characteristics)



Disorder of the endocrine syste
m:

o

Diabetes, hypo
-

and hyper
-
thyroidism


Test Yourself: Why is the pituitary gland called the “master
gland”?


3B: The Brain


The Tools of Discovery: Having Our Head Examined

Question: How do neuroscientists study the brain’s connections to behavior and mind?



Lesioning

(tissue destruction, a brain lesion is a naturally or experimentally caused destruction of brain tissue)

o

Damage to the hypothalamus of a rat reduces eating and causing starving unless force
-
fed; damage in other
areas causes overeating



Modern technique hav
e debunked many myths about the human brain (10% used, brain size equaling intelligence,
phrenology)


Recording the Brain’s Electrical Activity



Electroencephalogram (EEG) (an amplified recording of the waves of electrical activity that sweep
across

the brain’s
surface; measured by electrodes placed on the scalp)

o

Presentation of stimulus repeatedly; computer filters out extra “noise” to find the effect of the stimulus


Neuroimaging Techniques



Computerized Tomography scan (CT Scan): a series of X
-
Ray

photographs taken from different angles and combined
by c
omputer in
t
o

a composite representat
ion of a slice through the body

o

Reveal brain damage

o

CAT Scan (just newer name)



Positron

emission tomography scan (PET Scan): a visual display of brain activity th
at detects where a radioactive
form of
glucose

goes while th
e

brain
performs

a given t
ask

o

Drinks the radioactive glucose and then watch where it goes “food for thought”

o

Works similar to the Doppler radar



Ma
gnetic Resonance Imaging (MRI):
a technique that u
ses magnetic fields and radio waves to procures computer
generated images of soft tissue. Show brain anatomy)

o

Person is put in strong magnetic field and a
l
ign

the spinning atoms of brain molecules, radio
-
wave pulse
momentarily
disorients

the atoms, atoms
return to

their normal spin release signals
t

provide detailed
pictures of brain soft tissue



fMRI (functional MRI): a
technique

for revealing blood

flow, and therefore brain activity by
comparing

successive
MRI scans. fMRI scans show brain function

o

functi
on and structure

o

blood goes where the bran is active



Scans discussed here used to gain knowledge about most of theories in book

o

Diagnosing psychological disorders

o

Determining how drugs affect the brain and body

o

Assessing the usefulness of hypnoses

o

Examining whether unconscious processes affect
behavior

o

Exploring the interaction of sensation

an
d

perception


Older Brain Structures

Question: What are the functions of important lower
-
level brain structures?

o

When referring to “older” parts of the brain,
highlighting the parts that are shared with other mammals are
therefore the earliest parts of the brain to evolve

o

“older” structures points to the influence of evolution on ways we think about the brain



Evolution runs counter to religious or cultural belie
fs; focus discussion on ideas of how mammals
share common parts of the nervous system and has allowed us to understand better both
nonhuman animals and ourselves

o

If humans and other mammals share so many parts of the brain, what makes humans different from

other
mammals?

o

Does explaining the brain from an evolutionary standpoint make you feel more or less like other animals?
Why?

o

Indicators of the species’ capabilities come from brain structures

o

Be able to label the figures in the pictures


The Brainstem

o

Oldest and innermost region of the brain
-
brainstem

(the oldest part and central core of the bran, beginning where
the spinal cord wells as it enters the skull; the brainstem is responsible for automatic survival and functions)

o

Medulla

(the base of brainstem; controls hear
tbeat an
d

breathing)

o

Pons

(coordinate movement)

o

Reticular formation

(nerve network in the b
r
ainstem that

plays an important role in controlling arousal)



Filter and relays the

important stimuli



Not well understood in hu
mans; we think this allows us to attend to new stimuli in our environment



Some research indicates could play a role in dreaming



Activation synthesis theory of dreams proposes that dream signals originate in the brain
stem, and perhaps more specifically the

reticular formation; cortex then takes those signals
and reorganizes them into the dream story as best it can



More information in Unit 5: States of Consciousness

o

Crossover point where most nerves to and from each side of the brain connect with the body’s
opposite side

o

The right side

of the brain controls the left side of the body; the left side of the brain controls the right side
of the body

The Midbrain



Thalamus, cerebellum, l
imbic system: divided this way
due to the functions they govern

o

Brainstem secti
ons govern basic functions like heartbeat and breathing

o

Midbrain sections govern hormones, memory processing, and sensory input

o

Less vital, but no less important


The Thalamus

o

Thalamus

(sensory switchboard; located on top of the brainstem; it direct messages to the sensory receiving areas in
the cortex and transmits replies to the cerebellum and medulla) at the top of the brainstem

sensory switchboard

o

All senses go through here except s
mell

o

Smell goes through the appropriate cortex for processing



Smell is an “old” sense on the evolutionary scale, travels to the olfactory cortex and then to the
thalamus for processing; it seems that our brains adapted other senses after smell, causing the
m to
be processed differently

o

More in Unit 4: Sensation/Perception


The Cerebellum

o

Cerebellum

(the “little brain” at the rear of the brainstem; functions include processing sensory in and out and
coordinating movement output and balance)

o

enables nonverbal
learning and memory; judge time, modulate our emotions, discriminate sounds and
textures; coordinates voluntary movements (with assistance from the pons)

o

influence of alcohol on the cerebellum (walking may lack coordination)

o

Part of the function is to tell

the brain what to expect from the body’s own movements. Blakemore and
colleagues studied why people can’t tickle themselves. Volunteers lay in a brain
-
scanning machine with
their eyes closed. A plastic rod with a piece of soft foam tickled the participa
nts’ left palms. The volunteers
were either tickling themselves or were being tickled. They concluded that the cerebellum tells the
somatosensry cortex what sensation to expect that this dampens the tickling sensation.

o

Older brain functions all occur wi
thout any conscious effort and illustrates theme: our brain processes most
information outside or awareness


The Limbic System

o

Border between older parts and cerebral
hemispheres

o

Limbic system

(doughnut
-
shaped neural system (including the
hippocampus
,
amygdale

and
hypothalamus
) located
below the cerebral hemispheres’ associated with emotions and drives

o

Hippocampus

processes memories

more in Unit 7A


Amygdala

o

Amygdala
(two lima bean=sized neural clusters in the limbic system; linked to emotion)

o

Role in rage and fear, including the perception of these
emotions

and processing of
emotional

memories

o

Not
neat
ly organized into structures that correspond to categories of behavior

o

Aggressive and fearful

involves

other are
as as well just a

link

o

More in U
nit 8
-
Emotions

o

Works closely with the frontal lobes to regulate emotional responses; the amygdale supplies the emotional
feelings while the frontal lobe makes the judgment regarding the appropriate expression of the emotion



What types of behaviors would oc
cur if these components had to work alone instead of together?


The Hypothalamus

o

Hypothalamus

(a neural structure lying below the thalamus; it directs several maintenance activities (eating,
drinking, body temperature, helps govern the endocrine system via

the pituitary gland, and it linked
to

emotion and
reward, sexual behaviors)

o

Monitors both blood chemistry and takes orders from other parts

o

(Pituitary gland=master gland from endocrine system)



Because it work with the pituitary gland, the hypothalamus
controls all aspects of behavior that are
regulated by hormones

eating, the stress response, and sexual desire

controls the body!

o

Manages the pituitary gland

o

Pleasurable reward found my Olds and Milner



Law of Effect (behaviors that are rewarded are more
li
kely

to be repeated and behaviors that are
punished are not likely to be repeated) supported physiologically by the discovery of reward centers
in the brain

o

Rewards release the Neurotransmitters Dopamine and specific areas are associated with eating, drink
ing,
and sex



Dopamine
similar to cocaine and LSD

activate reward centers, leading to eh desire to take the
drugs again, pleasurable experience of taking drugs is due to the activation of the reward center



Makes evolutionary sense: if eating, drinking, and
sex are pleasurable, they are more

likely to be
repeated and thus increasing chances of survival

o

Theory: addictive disorders (alcohol dependence, drug abuse, binge eating) may stem from a
reward
deficiency syndrome

genetically predisposed deficiency in the

nature brain systems for pleasure and well
-
being that leads people to crave whatever provide that missing pleasure or relieves negative feelings

o

More in unit 8A: Motivation

o

Studies in rats have shown that the hypothalamus can be divided into two sections: The lateral side (LH),
which controls hunger, and the ventromedial side (VMH), which controls satiety. In these studies,
stimulation to the LHG produced behaviors that led t
o seeking our food while lesions to the VMH caused
rats to overeat to the point of becoming obese

o

Hippocampus vs. Hypothalamus

o

Memory of “camp”

o

Mnemonic?


The Cerebral Cortex

Question: What functions are served by the various cerebral cortex regions?




Cer
ebrum
-
two large hemispheres that work together enabling out
perceiving
, thinking,

and speaking



Cerebral cortex

(the intricate fabric of interconnected neural cells
covering

the cerebral
hemispheres
; the body’s
ultimate control and information processing ce
nter)

o

Adaptability

if brain is
from here


Structure of the Cortex



Crumpled inside of the skull

allows a smaller space which would be about three times the size

o

Wrinkles on the brain are made by fissures and folds called gyri and sulci. Gyri (singular:
gyrus) are the
grooves in the brain. Sulci (singular: sulcus) are the humps in between the grooves.

o

Deeply convoluted surface of the brain is most strongly linked to intelligence. Only about 1/3 of the brain is
visible only the surface. Answer to get
the brain through the birth canal is to crumple it.



Glial cells

(cells in the nervous
system

that support, nourish,

and protect neurons)

o

worker bees to the neuron queen bees

o

provide nutrients and insulating myelin

o

may play a role in learning and thinking

o

proportion of glia to neurons increase with increase of intelligence



Divided into four lobes separated by
fissures

(folds)

o

Lobes of the brain are plural; there are two of each lobe (one for each hemisphere). Two frontal, parietal,
occipital, and tempora
l lobes)

o

Frontal
-
behind your forehead
, involved in speaking and muscle movements, and
making

plans and
judgments



Bordered
in the rear by the central fissure, a long gyrus going vertically down the center of the
cortex (more prominent on the left side)



Contains the motor cortex



Works with decision making to create purposeful movement

o

Parietal
-
at the top and to the rear
, receives sensory input for touch and body position



Contains

the sensory cortex



Works with the association areas to process sensory
signals for accurate perception

o

Occipital
-
at the back of your head
,
includes

areas that receive
information

from the visual fields

o

Temporal


just above your ears
, includes the auditory areas, each receive information primarily from the
opposite ear



Bordere
d
on top by the lateral fissure, along gyrus running horizontally from front to back



Two hemispheres are separated by

the longitudinal fissure, larges of the gyri. Deep fissure
separates the two hemispheres almost completely down the corpus callosum

o

Many

functions need multiple lobes even though each lobe has a “job”



Lobe Review

o

Frontal lobe controls thinking and judgment, so have students tap their foreheads like they are thinking
through a difficult decision.

o

Temporal lobes control hearing and it is l
ocated just beside the ears.

o

Occipital lobe controls vision, so have students recall a time when they’ve gotten hit in the back of the head.
Typically when this happens, people “see stars” since their visual system is momently impaired.

o

Parietal lobe co
ntrols touch and sensory processing, so have students scratch the tops of their heads like
they are washing their hair, this will help them remember that touch is controlled by that part of the head.


Functions of the Cortex



Localiz
at
ion vs. diffusion of

responsibilities


Motor Functions



Motor cortex

(an area at the rear of the frontal lobes that controls voluntary movements)


Mapping the Motor Cortex



No sensory receptors (can’t feel pain) so can stimulate different areas of the brain and lead to
discoveries about
what those parts do



The amount of cortex devoted to

a body part is not proportional
to

t
hat’s part’s size, rather more tissue to sensitive
areas and to areas requiring
precise

control/ fingers more
representation

than the upper arm


Neura
l Prosthetics



Experiments with monkeys leading researchers to let the monkeys think about moving something and it moving
--
lead to monkey think, computer do

o

Speculation could be used in helping with language in humans

o

Test in 2004

human could do basic actio
ns by thinking them


Sensory Functions



Area specializes in
receiving

incoming messages from the skins senses and from movement of body parts



Front of parietal lobes,
parallel

to and

just behind the motor cortex,
sensory cortex

(area at the front of the
par
ietal

l
obes that registers and
processes

body touch and

movement
sensations
)

o

The more
sensitive the body region, the larger the sensory cortex area devoted to it



Cortex receive sensory information from more than just here:

o

Occipital lobes (back of the
brain) is visual

o

Auditory cortex in temporal lobe (above the ear)

opposite lobe takes care of the opposite ear



Auditory hallucinations people with schizophrenia experience are triggered in the brain without
external stimulation

people are actually hearing
voices

MRI shows activity in these areas


Association Areas



Non
-
committed areas are
association areas
(areas of the cerebral cortex that are not involved in primary motor or
sensory functions; rather they are involved in high mental functions such as learn
ing, remembering, thinking, and
speaking)

o

Not neatly mapped since probing doesn’t illicit responses

o

Association areas in all lobes



Frontal enable


judgment
, planning and processing of

new memories

damage can lead to lack of
fore planning

and change in pers
onalities



Phineas Gage
-
RR spike through cheek and brain; change in his behavior and moral compass
gone

let people understand how the frontal lobe works with the rest of the brain.



Brain research relies heavily on case studies to learn more about function
ing and anatomy in
humans
; most

brain research would be unethical to perform on both humans and
nonhuman animals, so researchers have to wait for naturally occurring injuries to happen in
order to learn more about how the brain works.



Parietal lobes

enab
le
mathematical

and spatial reasoning; one area lets you recognize faces
(without it you can see and explain, but you can’t actually recognize person as someone you know)



Memory, language, and attention is activity among distinct brain areas


Language

Que
stion:
What brain areas are involved in language processing?



O
ne of the most complex fields of study



Many different areas are used in language processing

o

Aphasia

(impairment of language, usually caused by left hemisphere damage to Broca’s

area (impairing
speaking) or Wenicke’s areas (impairing understanding)

o

Reading aloud
: register in visual area, relayed to second brain area (angular gyrus which transforms the
words into an auditory code), which is receive and understood in the nearby Wen
icke’s area, and
is sent o
Broca’s are which controls the motor cortex as it creases the pronounce words



Different damage to the system leads to different aphasia



In language processing
, the brain operates by dividing its mental functions

speaking, perceiving,
thinking, and remembering

into subfunctions
.



Wernick
e’s aphasia speak meaningless words



Broca’s aphasia
-
struggle to spea, but could sing familiar songs

“Tan” was the patient sinc
e it was
the only thing he could say



The mind’s subsystems are localized in particular brain regions, yet he brain acts as a unified whole

o

Specialization and integration



Be careful of the hot spot theory, that one area is just one behavior


The Brian’s Pla
sticity

Question: To what extent can a damaged brain reorganize itself?



Plasticity

(the brain’s ability to change especially during childhood, by reorganizing after damage or by building new
pathways based on experience)

o

Severed neurons do not regenerate

o

Some very specific brain functions seem preassigned to particular areas (facial recognition)

o

Some of the brain’s neural tissue can reorganize in response to damage



Constraint induced therapy
-
aims to rewire brains by restraining a fully functioning limb an
d forcing
use of the “bad hand” or the uncooperative leg

eventually the brain rewires and reteaches the bad
limb to work again

o

Brain’s plasticity allows different areas to take over for others (i.e. blind people have sense of touch in
occipital lobe)



Phant
om Limb sensations occur

interaction of sensation and perception and brain trying to
compensate for it

o

Seen after serious damage

if tumor invades the left hemisphere (language skills) the right may compensate



Some evidence to suggest that when one sense i
s lost the others will compensate and become more
acute; certain functions can take over a damaged part of the brain to repurpose that part for a new
function; typically new function is related to its original purpose only it I snow used with another
sense

that has taken over like reading from vision

o

Important concept to understand; brain is resilient, figuring out ways to compensate for injury; younger on
is when the injury occurs the more functioning can be regained



Neurogenesis

(formation of new neurons
)

happens deep in the brain and migrates elsewhere

o

Lots of questions regarding this

o

Stem cells can be used for anything


Our Divided Brain

Question: What do split brains reveal about the functions of our two brain hemispheres?



La
teralization:

specialization in each hemisphere


Splitting the Brain



Speculation that seizures caused by amplification of neural communication between the two hemispheres, so what
happens if we cut the
corpus callosum

(large band of neural fibers connecting the two brains hemispheres and
carrying messages between them)

o

Seizures eliminated and people essentially “normal”

o

Intact brains, information passed simultaneously between the two hemispheres. In split brain, not t
he
case

can quiz each side separately

o

Sperry and Gazzaniga study: whatever is shown is left visual field can’t be spoken because the brain
structure for spoken language isn’t there; however, they are able to communicate the ideas through writing



Visual inf
ormation directed to each side of the brain comes from visual fields, not each eye. The left
eye doesn’t send information to the right hemispheres and vice versa

the right halves of each eye
send information to the right hemisphere and vice versa.



Specu
lation that the results of research may be due to the condition o the patients brains after
experiencing year of debilitating epilepsy. Could the organization be due to the epilepsy? Or the
specialization same in all people? Empirical research limited d
ue to ethics

o

Antagonistic behaviors between the two sides to get started



Life is only challenging for the first few months after surgery; as the time passes the “two separate
minds” begin to figure out how to work together; day to day life is not really af
fected because the
optic chiasms are not severed (this is the part that connects the brain and the eyes)

o

Left side of the brain is more verbal and the right side is more spatial and recognition of emotion



Work together to function





“Two Brain” Myth

o

There

is not activity to which only one hemisphere makes a
contribution

o

Logic is not confined to the left hemisphere

o

There

is no evidence that either creativity or
intuition

is an exclusive property of the right hemisphere

o

It is imposs
ible to educate one
hemisphere at a time

o

There is not
evidence

that people are purely “left brained” or “right brained”


Right
-
Left Differences in the Intact Brain



Left Hemisphere

o

Language centers

o

Quick, literal interpretations



Basic language processing is a left hemisphere
activity; Deaf people process sign language in

th
e

left
hemisphere.
Bu
t, right hemisphere is responsible for more complex understandings and
interpretation of language working together leads to an understanding of language



Right

o

Inferences

o

Modulate speech

to make items clear

o

Sense of self


Test Yourself: Within what brain region would damage be most likely to disrupt your ability to skip rope? Your ability
to sense tastes or sounds? IN what brain region would damage perhaps leave you in a coma? Without t
he very
breath or heartbeat of life?


The Brain and Consciousness

Question: What is the “dual processing’ being revealed by today’s cognitive neuroscience?



Consciousness

(our awareness of ourselves and our environment) is a hot button issue to study

o

Great
deal of speculation here


Cognitive Neuroscience



Cognitive neuroscience

(interdisciplinary study of the brain activity inked with cognition (including perception,
thinking, memory, and language)) trying to link brain states to conscious experiences

o

Through

scanning we learn that even though the body may not be able to move the brain may be activated
in those areas for certain activities (playing tennis example)


Dual Processing



Dual processing

(principle that information is often simultaneously processed on

separate conscious and
unconscious tracks)

o

Computers cannot process more than one piece of information at a time (serial processing)

out brain can
(parallel processing)


The Two
-
Track Mind



Processing happens in different ways when we are processing
dually



Tasks on page 91 last paragraph just before the end


Test Yourself
: What are the minds two tracks, as revealed by studies of “dual processing”?