Download The Brain*s Two Hemispheres

Language and Special Abilities
 In
most people, language functions are
located primarily in the left hemisphere.
 Two particularly important language regions
of the left hemisphere are Broca’s area and
Wernicke’s area
 Broca’s
Area is located in the left frontal
lobe – directs the muscle movements
involved in speech (expressive language).
 Damage to Broca’s area, which often
happens to victims of strokes, results in
difficulty with spoken language.
 The stroke victim can form ideas but cannot
turn those ideas into coherent speech
 http://www.youtube.com/watch?v=6CJWo5T
DHLE
 http://www.youtube.com/watch?v=12dO78c
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 Wernicke’s
Area, located in the left temporal
lobe, is involved with your ability to
understand what someone else says
(receptive language).
 Damage to Wernicke’s Area might leave a
person able to hear words but unable to
comprehend the meaning of sentences
created with the words.
 For example: A person with Wernicke’s Area
damage would be able to recognize the
individual parts of a computer (monitor,
mouse, keyboard, etc.) but not understand
that these parts, together, create a
computer.
 The
right hemisphere houses most of your
brain’s spatial abilities.
 The word spatial relates to your ability to
perceive or organize things in a given space,
such as judging distance, understanding
geometric objects, or parking a car.
 The right hemisphere also provides the
insight to help us make connections among
words.
 What
word goes with painting, ring, and nail?
Our right hemisphere finds the answer:
finger.
 For a small handful of people with surgically
severed corpus callosums the differing roles
of the two hemispheres are much more
dramatic…
 The
average adult human brain weighs 1.3 to
1.4 kg (approximately 3 pounds).
 The Brain controls our mental processes and
maintains basic life functions
 Brain is not divided into sections, but certain
brain structures are specialized to perform
certain tasks, process called localization of
function
 The
brainstem is the
oldest part and
central core of the
brain. It begins
where the spinal
cord swells as it
enters the skull and
is responsible for
automatic survival
functions
 Medulla
– located at the base of the
brainstem, it controls basic life-support
functions like heartbeat and breathing
 Reticular formation – a nerve network in the
brainstem that plays an important role in
controlling wakefulness and arousal
Thalamus
Cerebellum
Midbrain
Pons
Medulla
Spinal Cord
 Thalamus
– the
brain’s sensory
switchboard,
located on top of
the brainstem. It
directs messages
to the sensory
receiving areas in
the cortex
Thalamus
Cerebellum
Midbrain
Pons
Medulla
Spinal Cord
 Cerebellum
– the
“little brain”
attached to the rear
of the brainstem. It
helps coordinate
voluntary
movements and
balance
Thalamus
Cerebellum
Midbrain
Pons
Medulla
Spinal Cord

Limbic System is a ring
of structures at the
border of the brainstem
and cerebral cortex. It
helps regulate
important functions
such as memory, fear,
aggression, hunger and
thirst, and it includes
the hypothalamus, the
hippocampus, and the
amygdala.
 Hypothalamus
– a neural structure lying
below the thalamus. It helps regulate
many of the body’s maintenance
activities, such as eating, drinking, and
body temperature, and is linked to
emotion
 Hippocampus – a neural center located in
the limbic system that wraps around the
back of the thalamus. It helps process
new memories for permanent storage
 Amygdala – an almond-shaped neural
cluster in the limbic system that controls
emotional responses, such as fear and
anger.
 The
cerebral cortex
is the intricate
fabric of
interconnected
neurons that form
the body’s ultimate
control and
informationprocessing center
Frontal lobes – the portion of the cerebral cortex
lying just behind the forehead that is involved in
planning and judgment. It includes the motor
cortex
 Parietal lobes – the portion of the cerebral
cortex lying at the top of the head and toward
the rear. It is used for processing information
 Temporal lobes – the portion of the cerebral
cortex lying roughly above the ears. It includes
the auditory (hearing) areas of the brain
 Occipital lobes – the portion of the cerebral
cortex lying at the back of the head. It includes
the primary visual processing areas of the brain

Motor Cortex
Sensory Cortex
Parietal Lobe
Frontal Lobe
Occipital
(Visual) Lobe
Temporal Lobe
Cerebellum
Medulla
Spinal Cord
 Corpus
Callosum is
the large band of
neural tissue that
connects the two
brain hemispheres and
allows them to
communicate with
each other
From a top view,
notice how the brain
is divided into two
halves, called
hemispheres.
Each hemisphere
communicates with
the other through the
corpus callosum, a
bundle of nerve
fibers.
 Somato-sensory
cortex is a brain area at
the front of the parietal lobes that
registers and processes body sensations
 Motor cortex – a strip of brain tissue area
at the rear of the frontal lobes that
controls voluntary movements
 Output: Motor Cortex (left-hemisphere
section controls the body’s right side)
 Input: Somatosensory Cortex (lefthemisphere section receives input from
the body’s right side)
 See your textbook on page 71
 Individually
answer the following question:
“Can you explain why professional boxers
frequently develop slurred speech and
coordination problems?”
 Share and discuss your answer with partner
 Be prepared to present your answers to the
class


Although larger animals
have larger brains, this
does not mean that
animals with larger brains
are smarter than animals
with smaller brains
For example, a larger
brain is necessary to
control larger muscles in
larger animals and a larger
brain is necessary to
process more sensory
information from the skin
in larger animals - this has
nothing to do with
intelligence.



The brain areas that show
the most changes, as a result
of evolution, are the cerebral
hemispheres (the red areas in
the drawings).
The more recently evolved
animals have a larger
proportion of the brain taken
up by the cerebral cortex.
In the "higher" animals
(especially the higher
mammals), the surface of the
cerebral cortex becomes
folded. This creates grooves
on the surface of the brain
called sulci (singular =
sulcus). The bumps or ridges
on the surface of the brain
are called gyri (singular =
gyrus).
Mnemonics are devices to help us remember – they
are memory aide. They come in many varieties and
can aid memorisation of many types of information.
For instance, the phrase “King Henry Died Marry
Didn’t Care Much” is used to help people remember
the units of the metric system…
 Your task
Create mnemonic devices for each term learned in this
unit – focus primarily on the parts of the brain and
neuron…
Example: “Seeing Medusa would turn you to stone and
cause your medulla to stop functioning so your vital
signs would cease.”
The Reticular Activating System (RAS) causes us to
‘rise and shine’ so we can be alert and ready for
action.”