Brain Anatomy - Lone Star College System

Report
EXPLORING
PSYCHOLOGY
EIGHTH EDITION IN MODULES
David Myers
PowerPoint Slides
Aneeq Ahmad
Henderson State University
Worth Publishers, © 2011
The Biology of Mind
The Brain
Module 4
Older Brain Structures
 The Brain Stem
 CLOSE UP: The Tools of Discovery –
Having Our Head Examined
 The Thalamus
 The Reticular Formation
 The Cerebellum
 The Limbic System
The Cerebral Cortex
 Structure of the Cortex
 Functions of the Cortex
 The Brain’s Plasticity
Our Divided Brain
 Splitting the Brain
 Right-Left Differences in the Intact Brain
Older Brain Structures
The brainstem is the oldest part of the brain and
central core of the brain, beginning where the
spinal cord swells and enters the skull. It is
responsible for automatic survival functions.
The Medulla [muh-DUL-uh] is the base of the
brainstem that controls heartbeat and breathing.
CLOSE UP: The Tools of Discovery –
Having Our Head Examined
Lesion [LEE-zhuhn]: tissue destruction. A brain
lesion is a naturally or experimentally caused
destruction of brain tissue.
Electroencephalogram (EEG): an amplified
recording of the waves of electrical activity that
sweep across the brain’s surface, measured by
electrodes on the scalp.
PET Scan
Courtesy of National Brookhaven National Laboratories
PET (positron emission
tomography) Scan is a
visual display of brain
activity that detects a
radioactive form of
glucose while the brain
performs a given task.
MRI Scan
MRI (magnetic resonance
imaging) uses magnetic
fields and radio waves to
produce computer generated images of soft
tissue, showing brain
anatomy.
fMRI (functional MRI):
technique for revealing
bloodflow and, therefore,
brain activity by
comparing successive MRI
scans, showing brain
function.
Both photos from Daniel Weinberger, M.D., CBDB, NIMH
MRI scan of a healthy individual
(left) and a person with
schizophrenia (right)
The Brainstem and the Thalamus
The brainstem, including the pons and medulla, is an
extension of the spinal cord.
The thalamus is attached to the top of the brainstem.
The reticular formation passes through both structures.
Older Brain Structures
Thalamus: brain’s sensory switchboard, located on
top of the brainstem; directs messages to the
sensory receiving areas in the cortex and transmits
replies to the cerebellum and medulla.
Reticular Formation: nerve network in the
brainstem that plays an important role in
controlling arousal.
Cerebellum
The cerebellum [sehr uh - BELL-um] is the
“little brain” attached to
the rear of the
brainstem. It helps
coordinate voluntary
movements and
balance.
The Limbic System
The Limbic System is a
neural system (including
the hippocampus,
amygdala, and
hypothalamus)
located below the
cerebral hemispheres;
associated with emotions
and drives.
Amygdala
The Amygdala [ahMIG-dah-la]
consists of two lima
bean-sized neural
clusters linked to
the emotions of fear
and anger.
Hypothalamus
The Hypothalamus lies
below (hypo) the
thalamus. It directs
several maintenance
activities like eating,
drinking, body
temperature, and
control of emotions. It
helps govern the
endocrine system via
the pituitary gland.
Hypothalamus
Reward Center
Rats cross an electrified
grid, accepting painful
shocks, for self-stimulation
when electrodes are
placed in the reward
(hypothalamus) center.
The Cerebral Cortex
The cerebral [seh - REE-bruhl] cortex is the intricate fabric of
interconnected neural cells that covers the cerebral hemispheres.
The body’s ultimate control and information processing center.
Structure of the Cortex
Each brain hemisphere is divided into four lobes that are
separated by prominent fissures. These are the frontal
lobe (forehead), parietal lobe (top to rear head), occipital
lobe (back head) and temporal lobe (side of head).
Functions of the Cortex
The Motor Cortex is the area at the rear of the
frontal lobes that control voluntary movements.
The Sensory Cortex (parietal cortex) receives
information from skin surface and sense organs.
Visual Function
The functional MRI scan
shows the visual cortex
is active as the subject
looks at a photo.
Courtesy of V.P. Clark, K. Keill, J. Ma.
Maisog, S. Courtney, L.G.
Ungerleider, and J.V. Haxby,
National Institute of Mental Health
Association Areas
More intelligent animals have increased
“uncommitted” or association areas of the cortex.
Neurons in these areas integrate information.
Language: Specialization and
Integration
Brain areas involved in language processing
•
Language: Specialization and
Integration
Aphasia: impairment of language, usually caused by
left-hemisphere damage either to Broca’s area or
Wernicke’s area.
Broca’s area: controls language expression; an area of
the frontal lobe, usually in the left hemisphere,
directs muscle movements involved in speech.
Wernicke’s area: controls language reception; usually
in the left temporal lobe, involved in language
comprehension and expression.
Specialization & Integration
Brain activity when hearing, seeing, and speaking
words
The Brain’s Plasticity
The brain is sculpted by our genes but also by our
experiences.
Plasticity refers to the brain’s ability to change by
reorganizing after damage or by building new
pathways based on experience.
Evidence suggests that, contrary to long - held
belief, adult mice and humans can also generate
new brain cells, through neurogenesis, or the
formation of new neurons.
Our Divided Brain
Our brain is divided into two hemispheres.
The left hemisphere processes reading, writing,
speaking, mathematics, and comprehension
skills. In the 1960s, it was termed as the
dominant brain.
Splitting the Brain
A procedure in which the two hemispheres of the
brain are isolated by cutting the connecting fibers
(mainly those of the corpus callosum) between them.
Split Brain Patients
With the corpus callosum severed, objects (apple)
presented in the right visual field can be named.
Objects (pencil) in the left visual field cannot.
Testing the Divided Brain
Try This!
Try drawing one shape with your left hand and
one with your right hand, simultaneously.
BBC
Right-Left Differences in the Intact
Brain
People with intact brains also show left-right
hemispheric differences in mental abilities.
A number of brain scan studies show normal
individuals engage their right brain when
completing a perceptual task and their left brain
when carrying out a linguistic task.

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