Transcript what is the brain?? - UPM EduTrain Interactive Learning

FEM 4100
Brain & human Behavior
Topic 1: Introduction
True or False?
 Do
we use only 10% of our
brains?
False: There is no scientific
evidence to suggest that we use
only 10% of our brains.
Where Did the 10% Myth Begin?
The 10% statement may have been
started with a misquote of Albert
Einstein or the misinterpretation of the
work of Pierre Flourens in the 1800s.
 It may have been William James who
wrote in 1908: "We are making use of
only a small part of our possible mental
and physical resources" (from The
Energies of Men, p. 12).

Where Did the 10% Myth Begin?
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Perhaps it was the work of Karl Lashley in the
1920s and 1930s that started it. Lashley
removed large areas of the cerebral cortex in
rats and found that these animals could still
relearn specific tasks.
We now know that destruction of even small
areas of the human brain can have
devastating effects on behavior.
That is one reason why neurosurgeons must
carefully map the brain before removing brain
tissue during operations for epilepsy or brain
tumors: they want to make sure that essential
areas of the brain are not damaged.
Why Does the Myth Continue?


Somehow, somewhere, someone started this
myth and the popular media keep on
repeating this false statement (see the
figures). Soon, everyone believes the
statement regardless of the evidence. I have
not been able to track down the exact source
of this myth, and I have never seen any
scientific data to support it.
According to the believers of this myth, if we
used more of our brain, then we could
perform super memory feats and have other
fantastic mental abilities - maybe we could
even move objects with a single thought.
Again, I do not know of any data that would
support any of this.
What Does it Mean to Use Only
10% of Your Brain?
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What data were used to come
up with the number - 10%?
Does this mean that you would
be just fine if 90% of your brain
was removed?
If the average human brain
weighs 1,400 grams (about 3 lb)
and 90% of it was removed, that
would leave 140 grams (about
0.3 lb) of brain tissue.
That's about the size of a
sheep's brain.
What Does it Mean to Use Only
10% of Your Brain?
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It is well known that damage to a relatively
small area of the brain, such as that caused
by a stroke, may cause devastating
disabilities.
Certain neurological disorders, such as
Parkinson's Disease, also affect only
specific areas of the brain.
The damage caused by these conditions is
far less than damage to 90% of the brain.
What Does it Mean to Use Only
10% of Your Brain?
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
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Perhaps when people use the 10% brain
statement, they mean that only one out of
every ten nerve cells is essential or used at
any one time?
How would such a measurement be made?
Even if neurons are not firing action
potentials, they may still be receiving
signals from other neurons.
True or False?
 Your
brain makes a painkiller
similar to heroin
True: Naturally produced chemicals
called endorphins are closely related
to heroin
True or False?
 Is
Laughter the Best Medicine?
True: It may be a good way for people to relax
because muscle tension is reduced after laughing.
• There are some cases when a good deep laugh
may help people with respiratory problems by
clearing mucus and aiding ventiliation.
• Perhaps laughing can also help cardiac patients
by giving the heart a bit of a workout.
• Some hospitals even have their own "Humor
Rooms," "Comedy Carts," and clown kids in
attempts to speed a patient's recovery and boost
morale.
False: However, laughter is NOT
ALWAYS good medicine.
• There are a few cases when laughing
actually CAUSED a heart attack or a
stroke.
• Also, immediately after abdominal
surgery, people should not laugh too
hard because they could tear out their
stitches accidentally.
• Care should also be used in patients
with broken ribs. So, try not to be too
funny around these people.
• Research has shown that parts of the limbic system
are involved in laughter.
• The limbic system is a primitive part of the brain that is
involved in emotions and helps us with basic functions
necessary for survival.
• Two structures in the limbic system have been shown
to play a role in laughter: the amygdala and the
hippocampus.
• Humans may be "tuned" for laughter much in the same
way that songbirds are "tuned" for song -- especially
their own specific family song. (While birdsong of one
species may sound the same to you and me, there are
subtle differences among the birds' songs.)
• Certain nerve cells in the songbird's brain "fire" in
response to hearing his song.
• Perhaps humans have specialized nerve cells that
respond to laughter.
• After all, laughter is a specialized vocalization, and we
are "tuned" to respond to vocalizations with language.
• We use our brain for many things.
• Laughter is yet another part of human behavior that
the brain regulates.
• It helps us clarify our intentions and provides an
emotional context to our conversations.
• Laughter, then, is used as a signal for being part of a
group--it signals acceptance and positive interactions.
• It clues the listener in to the emotional tone of the
conversation and the speaker's intentions.
• This may be one reason it is more difficult to interpret
the meaning of an e-mail or letter--emotional clues
about the sender's tone are missing.
Did You Know?
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Laughter is contagious.
Since 1950, TV has exploited this by adding
"laugh tracks" to sitcoms.
People laugh more readily upon hearing
others laugh.
When you hear others laugh, you actually
think the TV show is more humorous.
Babies start to laugh at about 4 months of
age.
Babies who are born blind and deaf can
laugh, so the ability to see or hear is not
required for laughter.
True or False?
 Many
things that happen to us
leave no record in memory
True: Most of the information around
us never reaches memory, and what
does reach memory often gets
distorted
True or False?
 You
are born with all the brain
cells you will ever have
False: Recent research shows that
some parts of the brain continue
producing new cells throughout life
The Brain vs. The Computer
 How
does the brain compare to
the computer??
• Some people say that the computer is better
than the brain; some people say that the
brain is better than the computer.
• Perhaps, it is best to say that the brain is
better at doing some jobs and the computer
is better at doing other jobs.
The Brain vs. The Computer
Similarity Both use electrical signals.
 Difference The brain uses chemicals to
transmit information; the computer uses
electricity. Even though electrical signals
travel at high speeds in the nervous
system, they travel even faster through the
wires in a computer.

The Brain vs. The Computer
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Similarity Both transmit information.
Difference A computer uses switches that are either
on or off ("binary"). In a way, neurons in the brain
are either on or off by either firing an action potential
or not firing an action potential. However, neurons
are more than just on or off because the "excitability"
of a neuron is always changing. This is because a
neuron is constantly getting information from other
cells through synaptic contacts. Information traveling
across a synapse does NOT always result in a
action potential. Rather, this information alters the
chance that an action potential will be produced by
raising or lowering the threshold of the neuron.
The Brain vs. The Computer
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Similarity Both have a memory that can grow.
Difference Computer memory grows by adding
computer chips. Memories in the brain grow by
stronger synaptic connections.
The Brain vs. The Computer
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Similarity Both can adapt and learn.
Difference It is much easier and faster for the brain
to learn new things. Yet, the computer can do many
complex tasks at the same time ("multitasking") that
are difficult for the brain. For example, try counting
backwards and multiplying 2 numbers at the same
time. However, the brain also does some
multitasking using the autonomic nervous system.
For example, the brain controls breathing, heart rate
and blood pressure at the same time it performs a
mental task.
The Brain vs. The Computer
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Similarity Both need energy.
Difference The brain needs nutrients like oxygen and
sugar for power; the computer needs electricity to keep
working.
 Similarity Both can be damaged.
 Difference It is easier to fix a computer - just get new parts.
There are no new or used parts for the brain. However, some
work is being done with transplantation of nerve cells for
certain neurological disorders such as Parkinson's disease.
Both a computer and a brain can get "sick" - a computer can
get a "virus" and there are many diseases that affect the
brain. The brain has "built-in back up systems" in some
cases. If one pathway in the brain is damaged, there is often
another pathway that will take over this function of the
damaged pathway.
True or False?
Both center patches are the same shade of gray
True: The patch on the right appeared darker
due to perceptual contrast with its background
True: The patch on the right appeared darker
due to perceptual contrast with its background
True or False?
 Intelligence
is a purely genetic
trait that does not change
throughout a person’s life
False: Intelligence is the result of both
heredity and environment, and may
change throughout your life
True or False?
 Repeated
exposure to the same
face leads us to like it less
False: Familiar people (and their
faces) are generally liked more than
less familiar people
Four Major Themes
 Why
study the brain?
 History of brain study
 Disciplines of neuroscience (study of
the brain)
 Clinical implications
Why study the brain?
“The more you use your brain, the more
brain you will have to use.”
 George
A. Dorsey
“Brain: an apparatus with which we think we
think.”
 Ambrose
Bierce
Why study the brain?

The human brain is packed solid with
billions of nerve cells each communicating
with thousands of preselected listeners
over miles and miles of living wires (the
nervous system) which operates the
whole body
History of brain study
WHAT IS
THE
BRAIN??

Analysis by analogy
 Explore
the mind
problem
 The roots of dualism
 The pneuma theory
 Descardes & the brain

The scientific method
 The
rise of
experimentation in
psychology
 Exploring the nervous
system
 Brain-behavior relation
Analysis by analogy
ancient wondered – why can a thought / an emotion
be experienced but not seen or touched
 The
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Found that inanimate was attributable to a spirit of vital
force that could be neither seen or understood (known as
animism today)
People view themselves in the dualistic term, with mind
traditionally seen as an entity distinct from the physical
world of matter and governed by entirely separate sets of
principles
Roots of dualisme – writing of the Greek philosopher
Anaxagoras
Plato elaborate on the concept, maintaining that the mind,
or soul – the instrument with which knowledge is pursued
– superior to the physical body & sense
Analysis by analogy
 The
Pneuma Theory

Aristotle explained various animal functions, including
movement, as being the result of "pneuma," a spiritual
breath (literally) that was carried to the various organs to
activate them, and that caused the limbs to move

The theory which attributed the functions of mind to invisible
spirits, emerged during the rise of Greek civilization
Hippocrates (5 century, B.C.) theorized that the brain was the
controlling mechanism of all mental & emotional faculties
Galen, Greek physician (129–201 A.D.)
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recognized that muscles were responsible for movement in both humans
and animals
suggested that the inability to vocalize is a proof of the relationship
between the nervous system & behavior (based on research on a pig’s
larynx)
Analysis by analogy
 The
Pneuma Theory
 Leonardo
da Vinci (1452–1519) discarded
Aristotle's pneuma theory of motive force; he
clearly understood that muscles were activated
by nerves that ramified through them and caused
them to contract, pulling the tendons and
attached bones

Luigi Galvani, Italian physician (1790) – discovered
that electric current applied to the muscle of a frog
produce muscle movement, correctly theorized that
the nerves are capable of conducting electricity
(identified that the nature of pneuma was a unique
substances he called animal electricity)
Analysis by analogy
 Rene
Descartes (1596-1650) & the
brain
Rejected the Greek notion that
human fate is subject to the whim
of invisible & unknowable force
 Theorize that many behaviors
formerly thought to be beyond the
scope of conventional scientific
investigation
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eg. Basic sensory experiences – could
be explained mechanistically, the
same way you might explain the
working of a complicated machine
What is the effect of Descartes
thoughts on British empirism –
John Locke, David Hume, etc??
Evolution of The Scientific Method
Behaviorism (John Watson)
 Structuralism (Wundt)

 Identify
the building blocks of consciousness
 Used introspection

Functionalism (James)
 Identify
the ways the mind adapts to the world
 Influenced by Darwin’s ideas

Gestalt psychology (Wertheimer)
 The
whole is greater than the sum of its parts
Evolution of The Scientific Method

Psychodynamic theory (Freud)
 We
are influenced by the unconscious mind
 We may try to suppress urges
 Psychoanalysis
Disciplines of Neuroscience

Neuroanatomy
 Structure

Neurochemistry
 Chemical

of the nervous system
bases of neural activity
Neuroendocrinology
 Interactions
between the nervous system and the
endocrine system

Neuropathology
 Nervous

system disorders
Neuropharmacology
 Effects
of drugs on neural activity
Disciplines of Neuroscience

Neurophysiology
 Functions

and activities of the nervous system
Neuroscience
 Interdisciplinary
field that focuses on the brain
and its role in psychological processes

Biopsychology
 The
specialty in psychology that studies the
interaction of biology, behavior, and the
environment
 Physiological Physiology

Understanding the human consciousness
What is Biopsychology?
“the scientific study of the biology of
behavior”
 psychobiology, behavioral biology,
behavioral neuroscience
 psychology: the scientific study of behavior
 Hebb (1949) proposed that psychological
phenomena might be produced by brain
activity

Biopsychology is an integrative
discipline
Knowledge from other disciplines of
neuroscience is applied to the study of
behavior
 Each discipline studies a different aspect
of the nervous system that informs our
understanding of what produces and
controls behavior

Biopsychological Research
Human and nonhuman
subjects
 Experiments and
nonexperiments
 Pure and applied research

Human and nonhuman subjects
Why use nonhumans?
 Simpler brains makes it more likely that
brain-behavior interactions will be revealed
 Comparative approach – gain insight by
making comparisons with other species
 Fewer ethical restrictions

Divisions of Biopsychology
Six major divisions
 Each has a different approach, but there is
much overlap
 Physiological psychology,
psychopharmacology, neuropsychology,
psychophysiology, cognitive neuroscience,
comparative psychology

Divisions of Biopsychology
Physiological psychology
Neural mechanisms of behavior
Direct manipulation of the brain
 Psychopharmacology
Effects of drugs on the brain
 Neuropsychology
Brain damage in humans

Divisions of Biopsychology

Psychophysiology
 Relation
between physiological activity and
psychological processes

Cognitive neuroscience
 Neural

bases of cognition
Comparative psychology
 Comparing
different species to understand
evolution, genetics, and adaptiveness of
behavior

Figure 1.6
(summary)
Converging Operations: revelations
from brain damages
Using multiple approaches to address a
single question
 Korsakoff’s syndrome – a condition
characterized by severe memory loss and
most commonly seen in alcoholics
 Is Korsakoff’s the result of the toxic effects
of alcohol on the brain?

Converging Operations
Jimmie G. – an alcoholic with Korsakoff’s
 Korsakoff’s is also seen in malnourished
persons who had little or no alcohol
 Thiamine-deficient rats exhibit memory
deficits
 Alcohol accelerates the development of
brain-damage in thiamine-deficient rats

Converging Operations
 By
exploring the possible causes of
Korsakoff’s using multiple
approaches, converging operations,
findings are more accurate
 Korsakoff’s syndrome is the result of
thiamine deficiency, but the damage
is accelerated by alcohol
Scientific Inference
 The
empirical method that
biopsychologists use to study the
unobservable
 Scientists measure what they can
observe and use these measures as
a basis for inferring what they can’t
observe
Critical Thinking
The ability to evaluate scientific claims by
identifying potential omissions or
weaknesses in the evidence
 Morgan’s Canon – when several
explanations are possible, give
precedence to the simplest one

At what level of analysis would it be
easiest to gain the best insight into
Tiger Woods’ success?
A.
B.
C.
D.
Level of the brain
Level of the person
Level of the group
All three levels would need to be
analyzed.
Levels of Analysis
The brain
The person
The group
 The
Nature of Physiological
Psychology
Generalization
 A type of scientific explanation; a general
conclusion based on many observations of
similar phenomena.
Reduction
 A type of scientific explanation; a
phenomena is described in terms of the
more elementary processes that underlie it.
 The
Nature of Physiological
Psychology
Biological
roots of physiological
psychology
Reflex
 An
automatic, stereotyped movement
produced as the direct result of a stimulus.
Model
 A mathematical or physical analogy for a
physiological process; for example, computers
have been used as models for various
functions of the brain.
 Understanding
Human
Consciousness
Corpus callosum
 The largest commissure of the brain;
interconnecting the areas of the neocortex on
each side of the brain.
Split-brain operation
 Brain surgery that is occasionally performed
to treat a form of epilepsy; the surgeon cuts
the corpus callosum, which connects the two
hemispheres.
 Understanding
Human
Consciousness
Cerebral hemispheres
 The two symmetrical halves of the brain;
constitute the major part of the brain.
 The
Nature of Physiological
Psychology
Biological
roots of physiological
psychology
Doctrine

of specific nerve energies
Muller’s conclusion that because all nerve fibers
carry the same type of message, sensory
information must be specified by the particular
nerve fibers that are active.
 The
Nature of Physiological
Psychology
Biological
roots of physiological
psychology
Experimental ablation

The research method in which the function
of a part of the brain is inferred by observing the
behaviors an animal can no longer perform after
that part of the brain is damaged.
 The
Nature of Physiological
Psychology
Biological
roots of physiological
psychology
Experimental

ablation
The research method in which the function
of a part of the brain is inferred by observing the
behaviors an animal can no longer perform after
that part of the brain is damaged.
 Natural
Selection and Evolution
Functionalism
and the inheritance of
traits
 Functionalism

The principle that the best way to understand a biological
phenomenon (a behavior or a physiological process) is to
try to understand its useful functions for the organism.
 Natural

selection
The process by which inherited traits that confer
a selective advantage (increase an animal’s
likelihood to live and reproduce) become more
prevalent in a population.
Functionalism
and the inheritance of
traits

Mutation
•
•
•
•

A change in the genetic information contained in
the chromosomes of sperm or eggs which can be
passed on to an organism’s offspring; provides
genetic variability.
Selective advantage
•
•
•
A characteristic of an organism that permits it to
produce more than the average number of offspring
of its species.
How Are Genes and
Behavior Linked?
Evolution has fundamentally
shaped psychological
processes because it favors
genetic variations that
produce adaptive behavior
How Are Genes and
Behavior Linked?
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Innate –
Inborn; present at birth; part of the organism’s
biological heritage
Evolution –
The gradual process of biological change that occurs
in a species as it adapts to its environment
Natural selection –
The driving force behind evolution, by which the
environment “selects” the fittest organisms
How Natural Selection Works
Environmental pressure
(changes in the environment)
Competition
(for resources)
Selection of fittest phenotype
(from among a variety of phenotypes)
Reproductive success
(genotype corresponding to fittest
phenotypes passed to next generation)
Frequency of that genotype increases
(in next generation)
Natural
Selection and Evolution
 Evolution
of the human species
 Evolution
A
gradual change in the structure and physiology
of a plant and animal species, generally
producing more complex organisms, as a result
of natural selection.
 Natural
Selection and Evolution
Evolution
of the human species
Evolution

A gradual change in the structure and physiology
of a plant and animal species, generally producing
more complex organisms, as a result of natural
selection.
 The
Nature of Physiological
Psychology
Evolution
of large brains
Neoteny
 A slowing of the process of maturation,
allowing more time for growth; an important
factor in the development of large brains.
 The
Nature of Physiological
Psychology
Evolution
of large brains
Neoteny

A slowing of the process of maturation, allowing
more
time for growth; an important factor in the
development
of large brains.
 The
Nature of Physiological
Psychology
Evolution
of large brains
Neoteny

A slowing of the process of maturation, allowing
more
time for growth; an important factor in the
development
of large brains.