PSYC20006 Lecture Notes - Lecture 1: Phosphene, Visual Cortex, Anterograde Amnesia
10 May 2018
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Lecture 1
- TMS
- Transcranial Magnetic Stimulation: “non-invasive” technique to create virtual cortical
“lesions”
- lesion = brain damage, patch of cortex that doesn’t function anymore
- Learn a lot about cognitive functions (in particular links with with brain activity) from
lesion patients, people had strange behaviour or people knew there was specific lesion
in brain and can study what lesion patients can’t do anymore
- E.g. Phineas Gage (1823 - 1860) - American railroad construction worker who suffered
serious injury by an iron rod piercing his head and frontal cortex → led to severe changes
in his personality (very disinhibited, aggressive, showed many traits he had not shown
before), had very precise lesion in prefrontal cortex → conclusion - region that is related
to those personality functions (simplistic approach, not correct)
- TMS: create something that mimics a lesion, looks like a lesion for a moment and
functionally then disappears, precisely study what you can do to certain brain regions
and what deficits you will get, temporary and reversible, localised lesions (at a far
smaller scale) could allow for better understanding the function of specific brain regions
- Patient H.M.: removal of most parts of his hippocampus, parahippocampal gyrus and
amygdala → led to severe anterograde amnesia
- Lesions in Broca and Wernicke areas → linked to impairments of speech production and
language comprehension respectively
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- First rough map of how is brain function linked to cognition
- Not enough patients with specific lesions to study all cognitive functions
- Patients usually have very big lesions and multiple brain regions are affected → hard to
determine what exactly drops out of function and from where; lesions in single,
specialised areas are rare
- Patients are special → brain can recover, permanent lesion in one area (brain might be
able to compensate for the dropout of cortex, other regions of the brain can take over
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Transcranial magnetic stimulation: non-invasive technique to create virtual cortical. Lesions lesion = brain damage, patch of cortex that doesn"t function anymore. Learn a lot about cognitive functions (in particular links with with brain activity) from lesion patients, people had strange behaviour or people knew there was specific lesion in brain and can study what lesion patients can"t do anymore. Patient h. m. : removal of most parts of his hippocampus, parahippocampal gyrus and amygdala led to severe anterograde amnesia. Lesions in broca and wernicke areas linked to impairments of speech production and language comprehension respectively. First rough map of how is brain function linked to cognition. Not enough patients with specific lesions to study all cognitive functions. Patients usually have very big lesions and multiple brain regions are affected hard to determine what exactly drops out of function and from where; lesions in single, specialised areas are rare. [usually happens when they get input from other neurons]) causes neurons to fire randomly.
