PSYA01H3 Chapter Notes - Chapter 9.4: Auditory Cortex, Anterograde Amnesia, Positron Emission Tomography
Brain Mechanisms of Selective Attention
Some components of brain sensory system are temporarily sensitized which enhances ability to
detect particular categories of stimuli, (i.e. watching shapes, focused on color, part of visual
cortex devoted to the analysis of it will be increased in activity)
Corbetta – showed screen with 30 color rectangles that could change in shape, colour or speed,
participants asked to say if change detected. Some trials attention only to be paid to one attribute.
PET scanner on brains showed different areas for different attributes being activated
CONSCIOUSNESS AND THE BRAIN
Brain damage can alter one’s consciousness, ex of anterograde amnesia, cannot form verbal
memories but can learn some tasks, does not prevent all kinds of learning but prevents conscious
awareness of what has been learned
If human consciousness related to speed, probably related to brain mechanisms that controls
comprehension and production of speech
This suggests for us to be aware of a piece of info, it must be transmitted to neural circuits in
brain responsible for neural behaviour, several cases of brain damage supports this
Isolation Aphasia: A Case of Global Unawareness
Geschwind, Quadfasel, Segarra – woman suffered brain damage from carbon monoxide
inhalation, spared primary auditory cortex (speech area of brain) and connections between these
areas BUT damaged destroyed large parts of visual association and isolated speech mechanisms
from other parts of brain
Isolation aphasia: language disturbance that includes inability to comprehend speed or produce
meaningful speech without affect ability to repeat speech and learn new sequences of words;
caused by brain damage that isolates brain’s speech mechanisms from other parts of brain
Woman in hospital for 9 years gave no evidence of recognizing objects or people in
environment, eyes could still move around, not spontaneously say anything, answer, or give any
signs that she understood what people said to her, by all criteria, not conscious of anything going
on
BUT she could repeat what was said to her and if they started a poem she knew, she would finish
it
She could also learn new songs and poems and would sing along with radio
Suggests consciousness is not just brain’s speech mechanisms; it is activity prompted by info
received from other parts of brain concerning memories or events presently occurring
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Document Summary
Some components of brain sensory system are temporarily sensitized which enhances ability to detect particular categories of stimuli, (i. e. watching shapes, focused on color, part of visual cortex devoted to the analysis of it will be increased in activity) Corbetta showed screen with 30 color rectangles that could change in shape, colour or speed, participants asked to say if change detected. Some trials attention only to be paid to one attribute. Pet scanner on brains showed different areas for different attributes being activated. Brain damage can alter one"s consciousness, ex of anterograde amnesia, cannot form verbal memories but can learn some tasks, does not prevent all kinds of learning but prevents conscious awareness of what has been learned. If human consciousness related to speed, probably related to brain mechanisms that controls comprehension and production of speech.
