Structure
• Brain Imaging Techniques
• Localization of Function
• Hemispheric Asymmetry
Brain Imaging Techniques
• Can experience effect the way the brain
functions?
• If you learned to no longer fear a situation,
what would be the physiological effect?
“There is no magic, it is just magic when we don’t
know what is going on.”
Brain Imaging Techniques
• Phineas P. Gage (1823-1860)
– Railroad construction foreman who had a large iron rod driven
completely through his head, destroying one or both of his brain’s
frontal lobes.
– The damage resulted in behavioral and personality changes that
were very profound.
– Phineas Gage influenced 19th-century thinking about the brain and
localization of function.
– First case suggesting that damage to specific regions of the brain
might affect personality and behavior.
Brain Imaging Techniques
EEG (electroencephalogram)
• Recording of neural activity detected by electrodes.
• Records brain noise.
PET (positron-emission tomography)
• Injecting radioactive isotopes.
• Increased activity results in different colors.
MRI (magnetic resonance imaging)
• Radio frequencies are used.
• The nuclei in atoms of cells turn differently and vibrate differently when hit
with different waves.
• Thus you can gear your scan towards specific cells in the body.
CAT (computed axial tomography)
• Uses tomography; where digital geometry processing is used to generate
a three-dimensional image of the internals of an object from a large series
of two-dimensional X-ray images taken around a single axis of rotation.
Brain Imaging Techniques
EEG:
MRI:
PET:
CAT:
Localization of Function
Localization of function: Specific regions perform
different (though overlapping) tasks.
 Brain Imaging Techniques
 Franz Joseph Gall
 Developed Phrenology
Localization of Function
Information processing in humans and
animals operate similarly.
Localization of Function
Localization of Function
• Why would a dolphin have such a large brain?
• What part of their brain would you expect to be
more advanced than ours?
– Less advanced?
Localization of Function:
Four Lobes
Frontal:
(Motor Cortex)
Parietal:
(Somatosensory
Cortex)
Occipital:
(Visual Cortex)
Temporal:
(Auditory Cortex)
Motor behavior
Expressive
language
Perception of
touch, pressure,
temperature, and
pain.
Interpretation of
visual
information.
Understanding
language
(comprehension)
Memory,
emotion, and
hearing.
Higher level
cognitive
processes
Orientation to
person, place,
time, and
situation
Localization of Function
 Hindbrain
 Pons
 Cerebellum
 Medulla
 Midbrain






Superior/Inferior Colliculi
Tectum
Aqueduct of Sylvius
Substantia Nigra
Reticular Activating System
Red Nucleus
 Forebrain
 Diencephalon
 Telecencephalon
Localization of Function
Cerebrum:
Largest brain structure.
 Controls: Sensory, Motor, Cognition
 Division: Cerebral cortex, Lobes
 Lateralization: Each half specializes.
Corpus Callosum:
 Connects the left and right hemisphere.
 Allows the hemispheres to communicate.
Commissurotomy:
 Severing the corpus callosum.
 Used with patients that have seizures.
Localization of Function
Prefrontal Cortex Divisions:
• Dorsal
– Imitation
– Planning
– Logic
– Sequencing
• Ventral
– Emotional Modulation
Hemispheric Asymmetry
Hemispheric Asymmetry:
Split Brain Research
Localization of Function
Prefrontal lobes structure our world for us and set the path for our
way of thinking. Basically they regulate how we are going to
appraise and approach any situation which affects everything
from stress reactions to our immune response, to our working
memory.
Localization of Function
• Fusiform Gyrus:
–
–
–
–
–
Processing of color information
Face and body recognition
Word recognition
Number recognition
Within-category identification
• Prosopagnosia: (face blindness)
– Disorder of face perception where the
ability to recognize faces is impaired,
while the ability to recognize other objects
may be relatively intact.
Localization of Function
The ventricular system is a set of structures containing
cerebrospinal fluid in the brain. It is continuous with the
central canal of the spinal cord.
Localization of Function
I. Brain Stem:
 Medulla:
 Bodily functions we
don’t have to control.
 Respiration and
heart beat.
 Pons:
 Sleeping.
 Waking.
 Dreaming.
 Reticular Activating System (RAS):
 Distributes incoming stimulation throughout the brain.
 Controls sleeping and waking.
 Utilizes our Zeitgeber (Time-Giver).
Localization of Function
II. Cerebellum:
– Controls balance, smoothness of movement,
starting movement, cessation of movement
– Kinesthetic sense
III. Thalamus:
– Sends sensory messages to the cerebral cortex
– Determines which higher processing center is
best to interpret a given message.
– Vision – Occipital Lobe.
– Sound – Temporal Lobe.
– Tactile – Postcentral Gyrus, Parietal Lobe.
– Taste – Cerebral Cortex, Hypothalamus, Amygdala.
– Smell – Does not pass through. Processed in the
olfactory bulb, amygdala, and hypothalamus.
Localization of Function
IV. Hypothalamus
Hypothalamus: Involved in emotions and drives vital to survival:
(autonomic nervous system)
–
–
–
–
Fear
Hunger
Thirst
Reproduction
• Pituitary gland: Endocrine gland that
releases hormones and regulates the
other endocrine glands.
– “Master Gland”
Localization of Function
V. Amygdala:
• Evaluates sensory information,
determines importance.
– Approach and withdraw reaction.
– Accesses danger or threat to the body.
– Dysfunction in this area causes: Depression
– Controls genuine smile-Dewshane Smile
• Major regions– Central Nucleus- “Go” or “No-Go”
– Medial Nucleus- Smell
Localization of Function
VI. Hippocampus:
• Storage of new information in memory.
• Short term memory
• If something is not successfully stored
in short term memory then it will never
make it into long term memory
• Dreaming.
»
Rat Hippocampus (stained
»
green-Nissl)
Localization of Function
Localization of Function
VII. Limbic System:
• Hypothalamus, Amygdala,
Hippocampus
• Involved in:
– Emotional reactions.
– Motivated behavior.
• Located between the higher order and
lower order processing centers of the
brain.
Localization of Function
• When behavior has adaptive properties the VTA
releases Dopamine and sends it to the Nucleus
Accumbens which causes LTP both there and in
the Forebrain.
• This increases the likelihood of repeating the
behavior.
Localization of Function
Localization of Function
•
•
Broca’s Area: Responsible for speech production.
– Inferior Frontal Gyrus
Wernicke's Area: Responsible for language comprehension.
– Posterior section of the Superior Temporal Gyrus.
Sex and Neuroscience
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Structures that are larger in the
healthy female brain, relative to
cerebrum size
SA (sexual arousal) evoked in
females produced a non-significant
hypothalmic activation. Women
respond less to erotic viewing films...
Structures that are larger in the
healthy male brain, relative to
cerebrum size
Men experience a greater SA to
visual erotic stimuli than women.
This also produced a more intense
activation of the hypothalmic area