Transcript This is Your Brain. This Is How It Works.

This is Your Brain.
This Is How It Works.
•
Parts of the brain:
Keep in mind there are two distinct sides with different
functions
The Brainstem
(Pathway to the Body)
• Base of brain
• Unconscious work
• Autonomic functions
(survival)
The Cerebellum
(Balance)
• “little brain”
• Large in size
• 11% of brain’s
weight
• Center of balance
The brain has 4 areas called
lobes
• Frontal
• Parietal
• Temporal
• Occiptal
The Frontal Lobes
(Problem Solving)
•
•
•
•
Largest part
Move your body
Highly developed
Forms your
personality
Frontal Lobe
• The frontal lobes are responsible for allowing
you to think of the past, plan for the future,
focus your attention, solve problems, make
decisions, and have conversation with others.
This region is also responsible for thinking
creatively and analytically in a problem-solving
mode.
The Parietal Lobes
(Touching)
• Two major divisions
• Anterior and
posterior
• Senses hot and
cold, hard and soft,
and pain.
• Taste and smell
• Helps integrate the
senses
The Parietal Lobes
• The brain must always know where each part
of the body is located and its relation to it’s
surroundings. The anterior part (front) is
responsible for receiving incoming sensory
stimuli. The posterior part (rear) is
continuously analyzing to give a person a
sense of spatial awareness.
The Temporal Lobes
(Hearing)
• Process auditory
stimuli
• Subdivisions
• Wernicke’s Area
• Broca’s Area
The Temporal Lobes
• Subdivisions cope with hearing, language, and
some aspects to memory. Wernicke’s Area is
critical for speech including reading. It allows
us to comprehend or interpret speech and to
words together correctly so they make sense.
Broca’s area is behind the frontal lobes. This
area is the center of our speech. It also
relates to other language areas such as writing
and reading.
The Occipital Lobes
(Seeing)
• Located at lower
central back of brain
• Processes visual
stimuli
• This area gives a
person the ability to
see and observe.
Taking sides….two sides that is!
• Two sides or hemispheres of the brain:
LEFT and RIGHT
• We have two cerebral hemispheres
connected by the corpus callosum. This is
a bundle of nerves that allows each side
of the brain to communicate with each
other.
• Each side of the brain processes things
differently.
• It is an outdated assumption that “artsy”
type people are right-brained.
Taking sides….
how the two sides process information that is!
Left Brain
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•
•
•
•
Logical
Sequential
Rational
Analytical
Objective
Looks at parts
Right Brain
•
•
•
•
•
•
Random
Intuitive
Holistic
Synthesizing
Subjective
Looks at wholes
Left Hemisphere
• processes things more in parts and
sequentially
• recognizes positive emotions
• Identified with practicality and rationality
• Understands symbols and representations
• Processes rapid auditory information faster
than the right (crucial for separating the
sounds of speech into distinct units for
comprehension)
• is responsible for language development. It
develops slower in boys, that is why males
usually develop more language problems than
females.
Right Hemisphere
•
Recognizes negative emotions
• High level mathematicians, problem solvers,
and chess players use
• The “non-verbal” side
• Responds to touch and music (sensory)
• Intuitive
• Responsive to color and shape
Taking sides….
what information the two sides recognize!
Left Brain
Right Brain
• Letters
• Faces
• Numbers
• Places
• Words
• Objects
based on Sousa (1995, p. 88)
Taking sides….take the test!
Hemispheric Dominance Inventory Test
at
http://brain.web-us.com/brain/braindominance.htm
Then learn more at:
http://brain.web-us.com/brain/LRBrain.html
Cerebrum -The largest division of the brain.
It is
divided into two hemispheres, each of which is
divided into four lobes.
Cerebrum
Cerebrum
Cerebellum
http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif
Cerebral Cortex - The outermost layer of gray
matter making up the superficial aspect of the
cerebrum.
Cerebral Cortex
Cerebral
Cortex
http://www.bioon.com/book/biology/whole/image/1/1-6.tif.jpg
Cerebral Features:
• Gyri – Elevated ridges “winding” around the brain.
• Sulci – Small grooves dividing the gyri
– Central Sulcus – Divides the Frontal Lobe from the Parietal
Lobe
• Fissures – Deep grooves, generally dividing large
regions/lobes of the brain
– Longitudinal Fissure – Divides the two Cerebral Hemispheres
– Transverse Fissure – Separates the Cerebrum from the
Cerebellum
– Sylvian/Lateral Fissure – Divides the Temporal Lobe from the
Frontal and Parietal Lobes
Gyri (ridge)
Sulci
(groove)
Fissure
(deep groove)
http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif
Specific Sulci/Fissures:
Central Sulcus
Longitudinal Fissure
Sylvian/Lateral
Fissure
Transverse Fissure
http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
http://www.dalbsoutss.eq.edu.au/Sheepbrains_Me/human_brain.gif
Further Investigation
Phineas Gage:
Phineas Gage was a railroad worker in the 19th century living in
Cavendish, Vermont. One of his jobs was to set off explosive charges in large rock in
order to break them into smaller pieces. On one of these instances, the detonation
occurred prior to his expectations, resulting in a 42 inch long, 1.2 inch wide, metal rod
to be blown right up through his skull and out the top. The rod entered his skull below
his left cheek bone and exited after passing through the anterior frontal lobe of his
brain.
Frontal
Remarkably, Gage never lost consciousness, or quickly regained it (there is still some
debate), suffered little to no pain, and was awake and alert when he reached a doctor
approximately 45 minutes later. He had a normal pulse and normal vision, and
following a short period of rest, returned to work several days later. However, he was
not unaffected by this accident.
http://www.sruweb.com/~walsh/gage5.jpg
Learn more about Phineas Gage: http://en.wikipedia.org/wiki/Phineas_Gage
Frontal
Neurons
s Three main parts:
– Dendrites
– Receive messages
from other neurons
– Cell body
– Contains the
genetic information
determining cell
function
– Axons
– Conducts electrical
impulses
Neurons: Structure
© 2011 The McGraw-Hill
Companies, Inc.
Synapses and
Neurotransmitters
© 2011 The McGraw-Hill
Companies, Inc.
Synapse
• The synapse is the junction between an axon
terminal and an adjacent dendrite or cell
body.
• Neurotransmitter (NT) molecules are released
from the axon terminal into the synapse when
the action potential arrives at the axon
terminal.
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN
ACTION, 7E
Neurotransmitters
Neurotransmitters
carry information
across the synaptic
gap to next
neuron.
© 2011 The McGraw-Hill Companies, Inc.
Neurotransmitters
Glutamate
– excitatory
– learning & memory
– involved in many psychological disorders
Norepinephrine
– stress and mania: ↑ norepinephrine levels
– depression: ↓ norepinephrine levels
– regulates sleep states in conjunction with ACh
© 2011 The McGraw-Hill
Companies, Inc.
Neurotransmitters
Dopamine
– voluntary movement
– reward anticipation
– stimulant drugs: activate dopamine
receptors
– Parkinson’s disease: ↓ dopamine levels
– schizophrenia: ↑ dopamine levels
© 2011 The McGraw-Hill
Companies, Inc.
Neurotransmitters
Serotonin
– regulation of sleep, mood, attention, learning
– depression: ↓ serotonin levels
– prozac: ↑ serotonin levels
Endorphins
– natural opiates
– mediate feelings of pleasure and pain
© 2011 The McGraw-Hill
Companies, Inc.
Glial Cells
s Surround neurons and hold them in place
s Manufacture nutrient chemicals neurons
need
s Absorb toxins and waste materials
Nerve Conduction: The
Myelin Sheath
s Insulation layer
covers axons in
the brain and
spinal cord.
s Allows for highspeed conduction.
s Multiple sclerosis
occurs when
immune system
attacks the sheath
The Nervous System
s Three types of neurons:
– Sensory: Carry input messages from the
sense organs to the spinal cord and brain
– Motor: Transmit impulses from the brain and
spinal cord to the muscles and organs
– Interneurons: Perform connective or
associative functions in the nervous system
The Nervous System
s Central Nervous System (CNS)
– Brain and Spinal Cord
s Peripheral Nervous System (PNS)
– Connects the CNS with the muscles, glands,
and sensory receptors
The Peripheral Nervous System
s Subdivided into:
– Somatic nervous system: Consists of sensory and
motor neurons that bind together to create nerves to
transmit messages to sensory receptors
– Autonomic nervous system: Controls glands and
smooth muscles in bodily organs
• Sympathetic nervous system: arouses the body
• Parasympathetic nervous system: slows down
body processes
Brain Structures:
Thalamus and Hypothalamus
s Thalamus: Routes sensory
information to higher brain
structures
s Hypothalamus:
– Major role in motivation
and emotions
– Connects with the
endocrine system
– Involved in pain/pleasure
The Limbic System
s Helps to coordinate
behaviors needed to
satisfy motivational
and emotional urges
arising in the
hypothalamus
s Also involved in
memory
Studying the Brain:
Brain Imaging
s CT Scans: Beam of X-rays takes pictures
of narrow slices of the brain
s PET Scans: Measures brain activity,
including metabolism, blood flow, and
neurotransmitter activity
s MRI: Used to study brain structure and
activity
– FMRI allows for studying brain function as
people perform various tasks
Genetic Influences
s Twin Studies
Compare:
– Monozygotic (MZ)
twins are genetically
identical
– Dizygotic (DZ) twins
share 50% of genetic
endowment
s Adoption Studies: Twins
separated at birth
– Compare twin with both
adoptive and biological
parent
– Helps determine
heritability of traits
The Endocrine System
Endocrine System
• One of the body’s
two communication
systems
• A set of glands that
produce
hormones—
chemical
messengers that
circulate in the
blood
Hormone
• Chemical messengers produced by the
endocrine glands and circulated in the
blood
• Similar to neurotransmitters in that they
are also messengers
• Slower communication system, but with
longer lasting effects
Pituitary Gland
• The endocrine system’s gland that, in
conjunction with the brain, controls the
other endocrine glands
• Called the “master gland”
• Located at the base of the brain and
connects to the hypothalamus
Endocrine System – Pituitary
Gland
Thyroid Gland
• Endocrine gland that
helps regulate the
energy level in the body
• Located in the neck
– Metabolism: the
speed at which the
body operates or the
speed at which the
body uses energy.
Adrenal Gland
• Endocrine glands that help to arouse the body
in times of stress
• Located just above the kidneys
• Release epinephrine (adrenaline) and
norepinephrine (noradrenaline)
– Adrenaline: chemicals that prepares the
body for emergency activity by increasing
blood pressure, breathing rat, and energy
level
Endocrine System – Adrenal Gland
Pancreatic Gland
• Regulates the
level of blood
sugar in the blood
Sex Glands (Gonads)
• Ovaries (females) and testes (males) are
the glands that influence emotion and
physical development.
• Testosterone – primary males hormone
• Estrogen – primary female hormone
• Males and females have both estrogen
and testosterone in their systems.
Endocrine System – Sex Glands
Sensation
and
Perception
 Sensation
 a process by which our sensory receptors
and nervous system receive and
represent stimulus energy
 Perception
 a process of organizing and interpreting
sensory information, enabling us to
recognize meaningful objects and events
Sensation
 Our sensory and perceptual processes work
together to help us sort out complex
processes
Sensation- Thresholds
 Absolute Threshold
 The level of sensory stimulation necessary for
sensation to occur.
 minimum stimulation needed to detect a
particular stimulus 50% of the time
 Difference Threshold
 minimum difference between two stimuli
required for detection 50% of the time
 just noticeable difference (JND)
Sensation- Thresholds
 Subliminal
100
Percentage
of correct
detections
75
50
Subliminal
stimuli
25
0
Low
Absolute
threshold
Intensity of stimulus
Medium
 When stimuli
are below
one’s absolute
threshold for
conscious
awareness
Sensation- Thresholds
 Weber’s Law- to perceive as different, two
stimuli must differ by a constant minimum
percentage
 light intensity- 8%
 weight- 2%
 tone frequency- 0.3%
 Sensory adaptation- diminished sensitivity
as a consequence of constant stimulation
Vision- Stabilized Images on the
Retina
Light
• White light: light as it originates from
the sun or a bulb before in is broken
into different frequencies.
Vision
 Transduction
 conversion of one form of energy to
another
 in sensation, transforming of stimulus
energies into neural impulses
 Wavelength
 the distance from the peak of one wave to
the peak of the next
Vision
 Hue
 dimension of color determined by
wavelength of light
 Intensity
 amount of energy in a wave determined
by amplitude
 brightness
 loudness
The spectrum
of
electromagne
tic energy
Vision- Physical Properties of
Waves
Short wavelength=high frequency
(bluish colors, high-pitched sounds)
Great amplitude
(bright colors, loud sounds)
Long wavelength=low frequency
(reddish colors, low-pitched sounds)
Small amplitude
(dull colors, soft sounds)
Vision
 Pupil- adjustable opening in the center of the eye
 Iris- a ring of muscle that forms the colored portion
of the eye around the pupil and controls the size of
the pupil opening
 Lens- transparent structure behind pupil that
changes shape to focus images on the retina
Vision
Vision
 Accommodation- the process by which the
eye’s lens changes shape to help focus near
or far objects on the retina
 Retina- the light-sensitive inner surface of the
eye, containing receptor rods and cones plus
layers of neurons that begin the processing of
visual information
Retina’s Reaction to LightReceptors
 Rods
 peripheral retina
 detect black, white and gray
 twilight or low light
 Cones
 near center of retina
 fine detail and color vision
 daylight or well-lit conditions
Retina’s Reaction to Light
 Optic nerve- nerve that carries neural impulses from
the eye to the brain
 Blind Spot- point at which the optic nerve leaves the
eye, creating a “blind spot” because there are no
receptor cells located there
 Fovea- central point in the retina, around which the
eye’s cones cluster
Pathways from the Eyes to the
Visual Cortex
Color-Deficient Vision
 People who suffer
red-green blindness
have trouble
perceiving the
number within the
design
Opponent Process- Afterimage Effect
Image that
remains after
stimulation of the
retina has ended.
Cones not used
fire to bring the
visual systems
back in balance
Audition (Hearing)
 Audition
 the sense of hearing
 Frequency
 the number of complete wavelengths that
pass a point in a given time
 Pitch
 a tone’s highness or lowness
 depends on frequency
Audition (Hearing)
 Timbre
 The complexity of sound
 Intensity
 How loud a sound is
 Decibels
 a measure of how loud the sound is
The Intensity
of Some
Common
Sounds
Audition- The Ear
 Middle Ear
 chamber between eardrum and cochlea
containing three tiny bones (hammer, anvil,
stirrup) that concentrate the vibrations of the
eardrum on the cochlea’s oval window
 Inner Ear
 innermost part of the ear, contining the cochlea,
semicurcular canals, and vestibular sacs
 Cochlea
 coiled, bony, fluid-filled tube in the inner ear
through which
Touch
 Skin Sensations
 pressure
 only skin
sensation with
identifiable
receptors
 warmth
 cold
 pain
Taste
 Taste Sensations




sweet
sour
salty
bitter
 Sensory Interaction
 the principle that one sense may influence
another
 as when the smell of food influences its taste
Smell (Olfaction)
Olfactory Olfactory
nerve
bulb
Nasal
passage
Receptor cells in
olfactory
membrane
Perception
Perception
– The set of processes by which we recognize,
organize, and make sense of the sensations we
receive from environmental stimuli
• Percept
– Complex mental representation integrating
particular sensational aspects of a figure
Perceptual experience involves four
elements:
–
Distal (far) stimulus
• The object in the external world
– Informational medium
• Reflected light, sound waves, chemical molecules, or
tactile information coming from the environment
– Proximal (near) stimulus
• Representation of the distal stimulus in sensory
receptors (e.g. picture on the retina)
– Perceptual object
• Mental representation of the distal stimulus
Perceptual Constancies
Size constancy
– The perception that an object maintains the same
size despite changes in the size of the proximal
stimulation
• The same object at two different distances projects
different-sized images on the retina
• Size constancy can be used to elicit illusions
(e.g. Ponzo illusion or Müller-Lyer Illusion)
Color Constancy
• The ability to perceive an object as
the same color regardless of the
environment
Brightness Constancy
• The ability to keep an objects brightness
constant as the object is moved to various
enviroments.
Shape constancy
– The perception that an object maintains the same
shape despite changes in the size of the proximal
stimulus
• Involves the perceived distance of different parts of the
object from the observer
Space Constancy
• The ability to keep objects in the environment
steady by perceiving either ourselves or
outside objects as moving
Depth Perception
• Importance of depth perception
– When you drive, you use depth to assess the
distance of an approaching automobile
– When you decide to call out to a friend walking
down the street, you determine how loudly to call,
based on how far away you perceive your friend to
be
Depth Cues
• Eleanor Gibson and her
Visual Cliff Experiment.
• If you are old enough to
crawl, you are old enough
to see depth perception.
• We see depth by using
two cues that researchers
have put in two
categories:
• Monocular Cues
• Binocular Cues
Perceptual Organization
• When we are given a cluster of sensations, we
organize them into a “gestalt” or a “whole”
• “The whole is greater than the sum of the
parts.”
• We take in sensory information and infer a
perception that makes sense to us based on
our past experiences.
Proximity
• A perceptual cue that involves grouping
together things that are near each other
• Our mind has
“Rules” for
Grouping
Similarity
• A perceptual cue
that involves
grouping like things
together
Closure
• The process of filling in the
missing details of what is viewed
Illusions
• Inaccurate perceptions
Müller-Lyer Lines
• Eye-movement theory: Arrowheads
influence extent of eye movements
• Equal lines however one looks longer
then the other.
What do you see?
Looks like President Clinton and Vice President Gore,
right?
Wrong... It's Clinton's face twice, with two different
haircuts.
What do you see?
What do
There's a face... and the word
Is the left center circle bigger?
No, they're both the same
size
It's a spiral, right?
No, these are a bunch of independent circles
Keep staring at the black dot. After a while
the gray haze around it will appear to
shrink.
Can you find the dog?
Stare at the black lightbulb for at least 30 seconds.
Then immediately stare at a white area on the screen
or at a sheet of paper. You should see a glowing light
bulb!
Do you see a couple or a skull?
Sleep
Rhythms of Waking and Sleep
• All animals produce endogenous circadian
rhythms, internal mechanisms that operate
on an approximately 24 hour cycle.
– Regulates the sleep/ wake cycle.
– Also regulates the frequency of eating and
drinking, body temperature, secretion of
hormones, volume of urination, and sensitivity
to drugs.
Fig. 9-2, p. 267
Circadian rhythms:
• Remains consistent despite lack of
environmental cues indicating the time of
day
• Can differ between people and lead to
different patterns of wakefulness and
alertness.
• Change as a function of age.
– Example: sleep patterns from childhood to late
adulthood.
Rhythms of Waking and Sleep
• Human circadian clock generates a rhythm
slightly longer than 24 hours when it has no
external cue to set it.
• Most people can adjust to 23- or 25- hour day
but not to a 22- or 28- hour day.
• Bright light late in the day can lengthen the
circadian rhythm.
Stages of Sleep And Brain Mechanisms
• Rapid eye movement sleep (REM) are
periods characterized by rapid eye
movements during sleep.
• Also known as “paradoxical sleep” because
it is deep sleep in some ways, but light
sleep in other ways.
Stages of Sleep And Brain Mechanisms
• Stages other than REM are referred to as nonREM sleep (NREM).
• When one falls asleep, they progress through
stages 1, 2, 3, and 4 in sequential order.
• After about an hour, the person begins to cycle
back through the stages from stage 4 to stages
3 and 2 and than REM.
• The sequence repeats with each cycle lasting
approximately 90 minutes.
Stages of Sleep And Brain Mechanisms
• Stage 3 and 4 sleep predominate early in the
night.
– The length of stages 3 and 4 decrease as the night
progresses.
• REM sleep is predominant later in the night.
– Length of the REM stages increases as the night
progresses.
• REM is strongly associated with dreaming, but
people also report dreaming in other stages of
sleep.
Stages of Sleep And Brain Mechanisms
• During REM sleep:
– Activity increases in the pons (triggers the
onset of REM sleep), limbic system, parietal
cortex and temporal cortex.
– Activity decreases in the primary visual cortex,
the motor cortex, and the dorsolateral
prefrontal cortex.
Insomnia
• is a sleep disorder associated with inability
to fall asleep or stay asleep.
– Results in inadequate sleep.
– Caused by a number of factors including noise,
stress, pain medication.
– Can also be the result of disorders such as
epilepsy, Parkinson’s disease, depression,
anxiety or other psychiatric conditions.
– Dependence on sleeping pills and shifts in the
circadian rhythms can also result in insomnia.
Sleep apnea
• is a sleep disorder characterized by the
inability to breathe while sleeping for a
prolonged period of time.
• Consequences include sleepiness during the
day, impaired attention, depression, and
sometimes heart problems.
• Cognitive impairment can result from loss of
neurons due to insufficient oxygen levels.
• Causes include, genetics, hormones, old age,
and deterioration of the brain mechanisms
that control breathing and obesity.
Narcolepsy
• is a sleep disorder characterized by
frequent periods of sleepiness.
• Four main symptoms include:
– Gradual or sudden attack of sleepiness.
– Occasional cataplexy - muscle weakness
triggered by strong emotions.
– Sleep paralysis- inability to move while asleep
or waking up.
– Hypnagogic hallucinations- dreamlike
experiences the person has difficulty
distinguishing from reality.
Periodic Limb Movement
Disorder
• is the repeated involuntary movement of
the legs and arms while sleeping.
– Legs kick once every 20 to 30 seconds for
periods of minutes to hours.
– Usually occurs during NREM sleep.
REM Behavior Disorder
• is associated with vigorous movement
during REM sleep.
– Usually associated with acting out dreams.
– Occurs mostly in the elderly and in older men
with brain diseases such as Parkinson’s.
– Associated with damage to the pons (inhibit
the spinal neurons that control large muscle
movements).
• “Night terrors” are experiences of intense
anxiety from which a person awakens
screaming in terror.
– Usually occurs in NREM sleep.
• “Sleep talking” occurs during both REM and
NREM sleep.
• “Sleepwalking” runs in families, mostly
occurs in young children, and occurs mostly
in stage 3 or 4 sleep.
Why Sleep? Why REM? Why Dreams?
• The original function of sleep was to
probably conserve energy.
• Conservation of energy is accomplished via:
– Decrease in body temperature of about 1-2
Celsius degrees in mammals.
– Decrease in muscle activity.
Why Sleep? Why REM? Why Dreams?
• Animals also increase their sleep time
during food shortages.
– sleep is analogous to the hibernation of
animals.
• Animals sleep habits and are influenced by
particular aspects of their life including:
– how many hours they spend each day devoted
to looking for food.
– Safety from predators while they sleep
• Examples: Sleep patterns of dolphins, migratory
birds, and swifts.
Why Sleep? Why REM? Why Dreams?
• Sleep enables restorative processes in the
brain to occur.
– Proteins are rebuilt.
– Energy supplies are replenished.
• Moderate sleep deprivation results in impaired
concentration, irritability, hallucinations,
tremors, unpleasent mood, and decreased
responses of the immune system.
Why Sleep? Why REM? Why Dreams?
• People vary in their need for sleep.
– Most sleep about 8 hours.
• Prolonged sleep deprivation in laboratory
animals results in:
– Increased metabolic rate, appetite and body
temperature.
– Immune system failure and decrease in brain
activity.
Why Sleep? Why REM? Why Dreams?
• Humans spend one-third of their life asleep.
• One-fifth of sleep time is spent in REM.
• Species vary in amount of sleep time spent in
REM.
– Percentage of REM sleep is positively correlated
with the total amount of sleep in most animals.
• Among humans, those who get the most sleep
have the highest percentage of REM.
Fig. 9-18, p. 289
Why Sleep? Why REM? Why Dreams?
• REM deprivation results in the following:
– Increased attempts of the brain/ body for REM
sleep throughout the night.
– Increased time spent in REM when no longer
REM deprived.
• Subjects deprived of REM for 4 to 7 nights increased
REM by 50% when no longer REM deprived.