Psy 123_Lec 5

Psy 123_Lec 5

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Unformatted text preview: blood in his system.” -- William James, Principles of Psychology (1890) Positron Emission Tomography (PET)! Tracks blood flow in the brain by monitoring the distribution of a radioactive tracer that is injected into the blood stream.! In the 1960s and 1970s we begin to see more advanced tecniques. The basic idea is that the subject is injected w/ a radio-active isotope and the half life is ~90 secs, and the scanner (positron) is able to pick up the e- being emitted from the isotopes, thus they collide and form Gamma rays and are able to triagonize exactly where these Gamma rays came from. Go through the process again but this time they are reading words.. And they can pick up the difference by contrasting the brain states. Thus more active when reading the word. Quite successful technique, but the disadvantage is that it is slightly invasive and fussy anatomy. Functional Magnetic Resonance Imaging (fMRI)! “MRI is based on the detection of electromagnetic signals (radio frequency (RF) waves) which emanate from spinning hydrogen protons when they are excited by an RF pulse applied in the presence of an externally generated static magnetic field.” (DeYoe, 1994).! Functional Magnetic Resonance Imaging (fMRI)! MRI: anatomical fMRI: functional low resolution (~3 mm but can be better) many images high resolution (1 mm) one image MRI different tissues have different magnetic susceptibilities Overcame many of the problems of past techniques; can look at the anatomy and the...
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This note was uploaded on 01/18/2014 for the course PSY 123 taught by Professor Staff during the Fall '11 term at UCSB.

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