Transcript File - firestone falcons

The Human Brain
• Contains 10,000
different types of
neurons
• Contains 100 billion
neurons
• Each neuron
communicates with
5,000-200,000 other
neurons to make one
trillion neuronal
connections
BRAIN STRUCTURE
The brain can be divided into three major
regions:
• Hindbrain – includes the cerebellum
and two structures found in the lower
part of the brainstem: the medulla and
the pons
• Midbrain – is the segment of the
brainstem that lies between the
hindbrain and the forebrain
• Forebrain – is the largest and most
complex region of the brain,
encompassing a variety of structures,
including the thalamus, hypothalamus,
limbic system and cerebrum
HINDBRAIN
• Brainstem – the oldest part and central core
of the brain, beginning where the spinal cord
swells as it enters the skull responsible for automatic survival functions
• Medulla - base of the brainstem – controls
unconscious but vital functions such as
circulating blood, breathing, maintaining
muscle tone, and regulating reflexes
HINDBRAIN
• Pons – a bridge of fibers that connects the
brainstem with the cerebellum – it also
contains several clusters of cell bodies
involved with sleep and arousal.
• Cerebellum – (little brain) – critical to the
coordination of movement and to the sense of
equilibrium or physical balance. There is some
evidence that it plays a role in emotional
development and modulates sensations of
anger and pleasure.
MIDBRAIN
• Contains an area that is concerned
with integrating sensory processes,
such as vision and hearing
• An important system of dopaminereleasing neurons that projects into
various higher brain centers
originates here
CORPUS
CALLOSUM
Corpus callosum
 Corpus
Callous
 large band of
neural fibers
 connects the
two brain
hemispheres
 carries
messages
between the
hemispheres
 Plasticity
 the brain’s capacity for
modification, as evident in brain
reorganization following damage
(especially in children) and in
experiments on the effects of
experience on brain development
Limbic System
Is the center for our emotions
Responsible for emotion production and
storing of emotional memory
Controls appetite and sleep patterns
Plays an important part in motivation
Limbic System
Olfactory cortex is
responsible for the
sense of smell
Amygdala is responsible
for our feelings of fear
Hippocampus is
responsible for
declarative memory
(things we know, like
facts and figures,
names)
The Diencephalon
• Consists of the thalamus and hypothalamus
Thalamus: has a role in emotion and memory
The thalamus is an interpretation center for pain,
temperature, light touch and pressure.
Hypothalamus’: main function is homeostasis, or
maintaining the body’s equilibrium.
THALAMUS
• Thalamus – the structure in
the forebrain through which
all sensory information
(except smell) must pass to
get to the cerebral cortex
• The thalamus also appears to
play an active role in
integrating information from
various senses
HYPOTHALAMUS
 Hypothalamus
 neural structure lying
below (hypo) the
thalamus; directs several
maintenance activities
 eating
 drinking
 body temperature
 helps govern the
endocrine system via the
pituitary gland
 is linked to emotion
The Four Lobes of the Cerebral Cortex
The Cerebral Cortex
• Your cerebral cortex is an intricate covering of
interconnected neural cells that, like bark on a
tree, forms a thin surface layer on your
cerebral hemispheres.
• It is your body’s information processing center.
Lobes of the Brain
 Frontal Lobes
 involved in speaking and muscle movements and in
making plans and judgments
 Parietal Lobes
 include the sensory cortex
 Occipital Lobes
 include the visual areas, which receive visual
information from the opposite visual field
 Temporal Lobes
 include the auditory areas
Frontal Lobe
• Responsible for:
reasoning
planning
movement
attention
personality
emotions
memory
some aspects of speech
organization
problem solving
creative thought
impulse control
physical reaction
libido (sexual urges)
Occipital Lobe
Helps see light and objects
Allows us to recognize and identify things
Aids color recognition
Occipital lobe on the right interprets visual
signals from the left visual space
Damage to one occipital lobe will result in loss
of vision in the opposite visual field
Parietal Lobe
Concerned with cognition (thinking)
Information processing
Pain and touch sensation
Spatial orientation
Speech
Language and visual perception
Receives sensory information from other
areas of the brain
Uses memory to attach meaning to objects
Temporal Lobe
Assists us to tell one smell from another and
one sound from another
Has a role in auditory and visual memory
The right temporal lobe is involved in visual
memory (for pictures and faces)
The left temporal lobe is involved with verbal
memory (words and names)
Brain Damage
• Damage to occipital lobe may result in cortical
blindness.
• Parietal Lobe damage can result in disorders
of perception such as:
– Apraxia – inability to identify objects
– Hemisomatognosia – unawareness of the
opposite side of the body to the damage
– Phantom limb – sensations still present from an
amputated limb
Brain Damage
• Damage to the Temporal Lobe such as
Wernicke’s Aphasia
– People with this disorder loss their ability to
understand language
– They may be able to speak clearly, but the words
make no sense – “word salad”
– However, people with Wenicke’s aphasia are able
to comprehend non-verbal sounds and respond
appropriately
Absolute Threshold
• In neuroscience and psychophysics, an
absolute threshold is the smallest detectable
level of a stimulus.
• The absolute threshold can be influenced by
several different factors such as the subject's
motivations and expectations, cognitive
processes, and whether the subject is adapted
to the stimulus
Vision
• The absolute threshold for vision was assessed in a landmark
experiment by Hecht, Shlaer and Pirenne in 1942.
• Vision The amount of light present if someone held up a single
candle 30 mi (48 km) away from us, if our eyes were used to the
dark. If a person in front of you held up a candle and began backing
up at the rate of one foot (30 cm) per second, that person would
have to back up for 44 hours before the flame became invisible.
Hearing
• The absolute threshold of hearing is the
minimum sound level of a pure tone that an
average ear with normal hearing can hear
with no other sound present. The absolute
threshold relates to the sound that can just
be heard by the organism.
• Hearing The ticking of a watch in a quiet
environment at 20 ft (6 m).
Sense of Taste
• The absolute threshold for taste would be the
minimum amount of the flavor that can be
detected. For example: sweet, sour, and
bitterness.
• Some people have more sensitivity to various
flavors and this determines in some cases
their likes and dislikes of certain foods.
•
•
•
•
Factors that influence taste:
Temperature
Description or presentation
Smell
• Five Basic Sensations of Taste
•
•
•
•
•
Sweet
Sour
Salty
Bitter
Umami
Taste
Sense of Touch
• One test that has been done with the
absolute threshold for touch is to allow
very small items to fall on a person’s
cheek.
• For most the lowest sense of touch that
was observed was a bee’s wing dropped
from the height of ½ inch.
• This value will vary considerably
depending on the part of the body
involved.
Sense of Smell
• Absolute threshold studies
using sense of smell usually
involve a scent, such as
perfume per the size of the
room.
• The smallest detectable scent is
usually one drop of perfume for
a six room apartment.
Broca’s Area
• This area of the brain controls language
expression- an area of the frontal lobe, usually
in the left hemisphere, that directs the muscle
movements in speech.
Wernicke’s Area
• This area controls language reception.
• A brain area involved in language
comprehension and expression, usually in the
left temporal lobe.
How We Use Language
When you read aloud the words:
1. Register the visual area.
2. Are relayed to the angular gyrus, which
tranforms the words into auditory code.
3. It is received and understood in Wernicke’s
area.
4. Sent to Broca’s area
5. Motor cortex produces the sound.
Aphasia
• Aphasia is impairment of language, usually
caused by damage to the left hemisphere,
either to Broca’s area or to Wernicke’s area.
• The nervous system is an
organ system containing a
network of specialized
cells called neurons that
coordinate the actions of
an animal and transmit
signals between different
parts of its body. In most
animals the nervous
system consists of two
parts, central and
peripheral.
• The central nervous system
of vertebrates (such as
humans) contains the
brain, spinal cord, and
retina.
• The peripheral nervous
system consists of sensory
neurons, clusters of
neurons called ganglia, and
nerves connecting them to
each other and to the
central nervous system.
These regions are all
interconnected by means
of complex neural
pathways.
Nervous Systems
• Peripheral Nervous System (PNS) – is
made up of all those nerves that lie
outside the brain and spinal cord
• Nerves – bundles of neuron fibers that
are routed together in the PNS
• Somatic Nervous system (SNS) – is
made up of nerves that connect to
voluntary skeletal muscles and to
sensory receptors.
Autonomic Nervous System
• Autonomic Nervous System (ANS) – is made
up of nerves that connect to the heart, blood
vessels, smooth muscles, and glands
• Sympathetic Division – is the branch of the
ANS that mobilizes the body’s resources for
emergencies.
• Parasympathetic Division – is the branch of
the ANS that generally conserves bodily
resources.
Neurons
• Neurons send signals to
other cells as
electrochemical waves
travelling along thin fibers
called axons, which cause
chemicals called
neurotransmitters to be
released at junctions called
synapses.
• A cell that receives a
synaptic signal may be
excited, inhibited, or
otherwise modulated.
• Motor neurons, situated either in the central
nervous system or in peripheral ganglia, connect
the nervous system to muscles or other effector
organs.
• The interactions
of all these types
of neurons form
neural circuits
that generate an
organism's
perception of the
world and
determine its
behavior.
Mirror Neurons
• A mirror neuron is a neuron that fires both when an
animal acts and when the animal observes the same
action performed by another. Thus, the neuron
"mirrors" the behavior of the other, as though the
observer were itself acting.
• It is argued that mirror neurons may be important for
understanding the actions of other people, and for
learning new skills by imitation.
How the Nervous System and
Endrocrine Systems Interact
• Hormones provide feedback to the brain to
affect neural processing.
• Reproductive hormones affect the
development of the nervous system.
• The hypothalamus controls the pituitary gland
and other endocrine glands.
•The endocrine system is the system of glands,
each of which secretes different types of hormone
directly into the bloodstream (some of which are
transported along nerve tracts to regulate the body
•Endocrine glands are glands of the endocrine
system that secrete their products, hormones,
directly into the blood rather than through a duct.
Principal functions of the
endocrine system
• Maintenance of the internal environment in
the body (maintaining the optimum
biochemical environment)
• Integration and regulation of growth and
development
• Control, maintenance and instigation of sexual
reproduction, including fertilization, fetal
growth and development and nourishment of
the newborn
Endocrine System
Hormones
• Like neurotransmitters,
they activate cells in the
body.
• They affect both internal
processes and visible
behavior.
• Are secreted directly into
the bloodstream or lymph
system.
Behavioral Endocrinology
The study of the relationship between hormones
and behavior
Hormones affect behavior and behavior feeds
back to affect hormones
Hormones
↔
Behavior
Hormones and Behavior
Hormones DO NOT act like “faucets” in
which behavior spews forth if the
hormone spigot is open.
Hormone-behavior relationships are complex.
It is NOT appropriate to say that hormones “cause”
behavior.
Rather, hormones change the probability that a
particular behavior will be displayed in the
appropriate social context – hormones simply
influence behavior.
First endocrinology experiment
Berthold’s Experiment
1) Background: Naturalistic observations of changes in
behavior and appearance of roosters with age and
season.
2) Castrated 6 roosters.
3) Re-implanted a testis in 2 roosters.
4) Transplanted a testis from another bird in 2
roosters.
5) Left 2 castrated roosters to develop into capons.
The Pituitary Gland
• A sort of master gland
• It is a cherry-sized
endocrine gland
• The hormones it
secretes affect the
growth and secretion
of other endocrine
glands
• The real boss is the
hypothalamus
ADRENAL GLANDS
The adrenal glands are the part of the body
responsible for releasing three different
classes of hormones. These hormones control
many important functions in the body, such
as:
• Maintaining metabolic processes, such as
managing blood sugar levels and regulating
inflammation
• Regulating the balance of salt and water
• Controlling the "fight or flight" response to
stress
• Maintaining pregnancy
• Initiating and controlling sexual maturation
during childhood and puberty
Fight or Flight Response
Psychological Correlates of
Physiological processes
• Fight or Flight Response –
believed to have evolved to
help our ancestors prepare for
sudden physical threats
• It prepares our bodies to either
confront a threat or run away
from it
Fight or Flight Behavior
• In the human fight or flight response in prehistoric
times, fight was manifested in aggressive, combative
behavior and flight was manifested by fleeing
potentially threatening situations, such as being
confronted by a predator.
• In current times, these responses persist, but fight
and flight responses have assumed a wider range of
behaviors.
• For example, the fight response may be manifested in
angry, argumentative behavior, and the flight
response may be manifested through social
withdrawal, substance abuse, and even television
viewing
Fight or Flight
• More alert as circulatory
system diverts blood (full of
oxygen) away from stomach
and intestines towards the
brain and skeletal muscles
• The liver releases sugar to
make more energy available
• The body releases adrenaline
which makes the heart beat
faster and stronger
Epinephrine and Cortisol
• Also known as adrenalin, epinephrine is a naturally
occurring hormone.
• During the fight-or-flight response response, the
adrenal gland releases epinephrine into the blood
stream, along with other hormones like cortisol,
-signaling the heart to pump harder,
-increasing blood pressure,
-opening airways in the lungs,
-narrowing blood vessels in the skin and intestine to
increase blood flow to major muscle groups
Fight or Flight
• Bronchioles in the lungs dilate to bring in
more oxygen
• Pupils of the eyes dilate to make vision
sharper
• Mouths become dry as we produce less saliva
• We perspire more as a means of cooling off
body as the increased arousal produces more
heat in the body
Men versus Women
• Males and females tend to deal with
stressful situations differently. Males
are more likely to respond to an
emergency situation with aggression
(fight), while females are more likely to
flee (flight), turn to others for help, or
attempt to defuse the situation.
• During stressful times, a mother is
especially likely to show protective
responses toward her offspring and
affiliate with others for shared social
responses to threat.