The Cerebral Cortex by ewghwehws

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									The Cerebral Cortex
             The Evolving Brain
• Different animal
  species have many
  structures in common,
  including a cerebellum
  and cortex.
• The cortex is much
  larger in mammals
  than in species that
  evolved earlier, such as
  fish and amphibians.
• The cross section of
  the human brain shows
  how the cerebral cortex
  has developed around
  and above more
  primitive brain
  structures.
       When it comes to Cortex…
          Size DOES Matter
• If flattened, a human
  cortex would cover
  about four pages of
  this book.
• A chimpanzee's
  would cover one
  page
• a monkey's a
  postcard
• a rat's a postage
  stamp.
• From Scientific
  American, October
  1994, p. 102.
          Areas of the Cortex




• More intelligent animals have increased
  "uncommitted" or association areas of the
  cortex.
• These vast areas of the brain are responsible
  for integrating and acting on information
  received and processed by sensory areas.
  Developing
    Brain
•Neural tube—beginning of
nervous system develops at 2
weeks after conception
•Neurogenesis—development
of new neurons




 Click above to view a video
         (5:29 long)
               Forebrain Structures


Largest Brain Region
with the most complex
      structures.
What separates us from
      the beasts.
       Cortical Specialization
• Localization—notion that different
  functions are located in different areas
  of the brain

• Lateralization—notion that different
  functions are processed primarily on
  one side of the brain or the other
         Brain has 2 Hemispheres

• Left & Right sides are                   Corpus Callosum
  separate                    Right
                            Hemisphere
• Corpus Callosum : major
  pathway between
  hemispheres
• Some functions are
  ‘lateralized’
   – language on left
   – math, music on right     Left
                              Hemisphere
• Lateralization is never
  100%
Lateralization of the Hemispheres
   Each hemisphere is
   divided into 4 lobes
Frontal

                            Parietal



                          Occipital

                      Temporal
        Lobes of the Cortex
• Frontal lobe—largest lobe, produces
  voluntary muscle movements, involved in
  thinking, planning, emotional control
• Temporal lobe—primary receiving area for
  auditory information
• Occipital lobe—primary receiving area for
  visual information
• Parietal lobe—processes somatic
  information
                 Frontal Lobe
                              Frontal
                               Lobe     Motor
                                        Motor
                            Broca’s     Cortex
                                        Cortex
 • Contains primary motor   Area
   cortex
• No direct sensory input
• Important planning and
  sequencing areas
Broca’s area for speech
• Prefrontal area for
  working memory
                     Temporal Lobe
 Contains primary
auditory cortex
                                     Auditory
• Inputs are auditory, visual        Cortex
  patterns
   –   speech recognition
   –   face recognition
   –   word recognition
                                     Temporal
   –   memory formation
                                       Lobe
• Outputs to limbic System,
  basal Ganglia, and
  brainstem
                Occipital Lobe
• Input from Optic
                                 Occipital
  nerve                          Lobe


• Contains primary
  visual cortex
                                   Visual
  – most is on surface             Lobe
    inside central fissure
• Outputs to parietal
  and temporal lobes
                 Parietal Lobe

 • Inputs from multiple
   senses
    contains primary
                                 Somatosensory
                                    Parietal
                                    Cortex
   somatosensory cortex              Lobe


    borders visual &
   auditory cortex
 Outputs to Frontal lobe
    hand-eye coordination
    eye movements
    attention
   BOREDOM BUSTER!
Let’s Review with Pinky & The Brain.
Motor         Sensory
Cortex:       Cortex:
Located at
              Located at
the back of
              the front of
the Frontal
              the Parietal
Lobe.
              Lobe.


The more
              The more
precise
              sensitive
movements,
              the area, the
the more
              more
motor
              sensory
cortex the
              cortex it
part uses
              uses up.
up.
              Language and the Brain
• Aphasia—partial or
  complete inability to
  articulate ideas or
  understand language
  because of brain injury or
  damage
• Broca’s area—plays role in
  speech production
• Wernike’s area—plays role
  in understanding and
  meaningful speech
                     Aphasias
• Broca’s Aphasia – Damage to Broca’s Area causes a
  person to struggle formulating words while still being
  able to comprehend speech.
• Wernicke’s Aphasia – Damage to Wernicke’s Area
  would cause a person only to be able to speak in
  meaningless words.
• Example of Wernicke’s Aphasia: Asked to describe a
  picture of two boys stealing cookies from behind a
  woman’s back, a patient responded,
• “Mother is away her working her work to get her better,
  but when she’s looking the two boys looking the other
  part. She’s working another time.”
Language Areas of the Brain
How We Read Out Loud

								
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