tour through brain part 2 pages 132-135 a.p. 85-90
TRANSCRIPT
OBJECTIVES: The Student Will=
• Describe the 3 parts of the Limbic System• Analyze the Cerebrum into 4 cortex
categories…focusing on the senses
Limbic system
• Amygdala (uh-Mig-dul-uh)+ Hippocampus+ Cerebrum= Limbic System
• Limbic Latin for border• Forms a border for high and low parts of the
Brain• Structures in region we share with other
animals, rage, fear
Part 1:Amygdala (uh -Mig-dul-uh)
• Greek for Almond• Evaluating sensory information• Determines emotional importance- initial
decision• F.E. assesses danger or threat• Mediates anxiety and depression• Supporting evidence=Because PET Scans
show increased neural activity in Amygdala
Part 2: Hippocampus
• Limbic System component• Latin for sea horse• Compares sensory information from what it
knows about the world• Memory system• Tells RAS to cool it• you don’t freak out at every car drives by,
bird chirps, saliva goes down throat
The hippocampus
Responsible forStorage of new information in memory
Comparing sensory information with what the brain expects about the world
Enabling us to form spatial memories for navigating the environment
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Hippocampus cont
• Gateway to memory • Spatial memories• As a result actively navigate through
environment• Spatial- relating to, occupying, or happening
in space
More Hippo.
• With adjacent parts of brain forms new memories, facts and events
• F.E. identify flower, tell story, recall vacation or trip
• Meet person yesterday remember, tone of voice, appearance, location
• Without Hippo could not get info to destinations
How do we know= Subject H.M. (his story is the evidence)
• Brain damaged patients with memory problems
• Patient H.M. having life threatening epilepsy• Epilepsy- Neurological disorder, many causes
and forms, have seizures• Removed Amygdala and most of Hippo• Surgery successful, milder, seizures, control
with meds….But
Memory effected Profoundly
• Remembered everything Before the surgery, However he could not remember anything past 15 minutes.
• Vanished like water down the drain• Because Hippo removed= lost memory• Could acquire new physical skills, problem
solving skills. F.E. playing tennis, puzzles• But could not remember the training sessions in
which he learned these skills!
H.M. cont…
• Could not remember days of week, year, read same magazine over and over
• Stuck in time warp of the past• Doesn't know scientists that have studied him
for decades• Long-term memory problems• Memories need period of time, consolidation,
to stabilize the memory
3rd part: Cerebrum
• Largest part of brain• Higher thinking takes place• Looks like cauliflower • Creatively controls the environment over
animals• Cerebrum divided into halves called Cerebral
hemispheres
The cerebrum
Largest brain structure
Two cerebral hemispheres connected by the corpus callosum.
In charge of most sensory, motor, and cognitive processes
Surrounded by cerebral cortex, a collection of several thin layers of cells (gray matter)
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Cerebrum Cont…
• Hemispheres connected by bands of fibers called Corpus Callosum (CORE-pus- ca-LOW-suhm)
• Left side controls right side of body and vise versa
• However two hemispheres have different talents and tasks, called Lateralization
Cerebral Cortex
• Thin layer of dense packed cells, cover Cerebellum
• Top of the Brain! • Latin for bark• Produce grey tissue so grey matter• 1/8th of inch thick• But ¾ of cells in human brain
Lobes of the cerebral cortex
Occipital lobes (visual cortex)Parietal lobes (somatosensory cortex)Temporal lobesMemory, perception, emotion, and auditory cortexLeft lobe: Wernicke’s area
Frontal lobesEmotion, planning, creative thinking, and motor cortexLeft lobe: Broca’s area
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Lobes of the Cortex
• 4 distinct regions• Occipital (ahk-SIP-uh-tuhl) lobes• Back of head, visual cortex= vision• Visual signals processed • Damage to visual cortex impair vision,
blindness
Parietal Lobes
• Somatosensory cortex• Receives information about pressure, pain,
touch, temp.• Signals from hands, face• Attention and mental operations
Temporal Lobes
• Latin for temples• Sides of brain, just above the ears• Contain audio cortex- processes sounds• Wernicke’s area- involved in language
comprehension
Frontal lobes
• Front of brains cerebral cortex• Motor cortex, controls 600 muscles in body• Short term memory, higher order thinking,
initiative, social judgment• Broca’s Area- speech production
Cortex cont…
• Stimulate with electrical current to parietal lobes= feel in skin; visual cortex, oct. lobes= flash, light
• But some areas stimulated do nothing association cortex, higher mental process
• Prefrontal cortex- barely exists in mice, 7 % in dogs, but 29% in humans
Your turn
Jenny bumps her head and is suddenly unable to see, although the doctor says there is nothing wrong with her eyes? Which part of her brain did Jenny damage?1. The amygdala
2. The hippocampus
3. The occipital lobe of the cerebral cortex
4. The parietal lobe of the cerebral cortex
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Your turnJenny bumps her head and is suddenly unable to see, although the doctor says there is nothing wrong with her eyes? Which part of her brain did Jenny damage?1. The amygdala
2. The hippocampus
3. The occipital lobe of the cerebral cortex
4. The parietal lobe of the cerebral cortex
chapter 4
Phineas GageGage was a railroad construction foreman
An 1848 explosion forced a steel tamping rod through his head
Others said he was “no longer Gage”
Lost his job, worked as a sideshow exhibit
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