Download - Introductory Psychology: Cerebral Cortex
Cerebral Cortex
Brian J. Piper, Ph.D.
Phineas Gage: http://www.youtube.com/watch?v=WGl5SUB8IXM
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The Brain
•The Cerebral Cortex• Our Divided Brain• Right-Left Differences in the Intact Brain
Neuroanatomy OverviewThe cerebral cortex is the intricate fabric of interconnected neural cells that covers the cerebral hemispheres. It is 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 lobes are the
frontal lobe (forehead), parietal lobe (top to rear head), occipital lobe (back head) and temporal lobe (side of
head).
Cortical Divisions
• Sulcus, Fissure-valley
• Gyrus- swelling
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.
Sensory Homunculus
• This is a representation of the brain space given to each bodily area
Visual Function
The functional MRI scan shows the visual cortex is active as the
subject looks at images. C
ourtesy of V.P. C
lark, K. K
eill, J. Ma.
Maisog, S. C
ourtney, L.G
. U
ngerleider, and J.V. H
axby, N
ational Institute of Mental H
ealth
Auditory Function
The functional MRI scan shows the
auditory cortex is active in patients who
hallucinate.
LanguageAphasia is an impairment of language,
usually caused by left hemisphere damage either to Broca’s area (impaired speaking)
or to Wernicke’s area (impaired understanding).
Specialization & Integration
Brain activity when hearing, seeing, and speaking words
The brain is sculpted by our genes but also by our experiences.
Plasticity refers to the brain’s ability to modify itself after some types of injury or illness.
The Brain’s Plasticity
Phantom Limbs
• V.S. Ramachandran has worked with amputees that have pain from their former limb
• Foot fetish• Limb reattachments
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 BrainA procedure in which the two hemispheres of the brain are isolated by cutting the connecting fibers
(mainly those of the corpus callosum) between them.
Corpus Callosum
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rtin M
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Courtesy of T
erence William
s, University of Iow
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Split Brain Patients of Michael Gazziniga
With the corpus callosum severed, objects (apple) presented in the right visual field can be named.
Objects (pencil) in the left visual field cannot.
Divided Consciousness
Long-Video (11 Min): http://www.youtube.com/watch?v=0lmfxQ-HK7Y
Try This!
Try drawing one shape with your left hand and one with your right hand,
simultaneously.B
BC
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.
“Only left-handers are in their right mind.”
Right Left
Left 95%
Right 5%
Handedness
LanguageCenter
Left-handers are more likely to have their language center in their right
cortex
Right Left
Left 95% 70%
Right 5% 30%
Handedness
LanguageCenter
Phineas Gage (1823-1860)
• An accident resulted in severe damage to his left-frontal lobe.
• He survived but “was no longer Gage”
• Records are sparse but he may have adapted.
Is this appropriate?
• http://www.youtube.com/watch?v=PFJPtVRlI64
• Anterior commissure: the anterior (frontal) part of the corpus collosum
Animal Research
• Reduce #
• Reduce discomfort
• Use alternatives
Review: 1. What type of test?
2. Correlations
3.
• Clinical versus counseling psychologist
4.
• A researcher conducts a study on how viewing sexually explicit material influences attitudes towards women. Participants are assigned to groups and then complete a survey about their attitudes.– Independent variable:– Dependent variable:– Design:
5.
• A researcher gives a survey to all of his friends. – Type of research?– Problem(s)?
6. Brain Structure
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c.d.
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f.g.
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6. Brain Structure