Psychology 3140F/G Lecture 21: Psych 3140F – Week 12 - lecture 21

• School: Western University
• Department: Psychology
• Course: Psychology 3140F/G
• Professor: Debra Jared

Document Summary

The concentration of hydrogen atoms varies with the type of tissue. Bodies of neurons have a modest concentration (gray) Axons of neurons have higher concentrations (white: fmri: specialized mri scan that was developed in the early 1990s it generates images related to the cerebral blood flow that accompanies neural activity. Specifically, it detects changes in the level of blood oxygen. Bold (blood oxygen level dependent signal): hemoglobin has different magnetic properties when it"s not carrying oxygen than what it is. Blood that is low on oxygen is paramagnetic this deoxygenated blood disturbs the magnetic field in the mri machine, thus reducing the mri signal. Blood that is high in oxygen is non-magnetic and doesn"t disturb the field, Nearly any task produces changes in most of the brain producing a brighter image: to associate changes in brain activation with a particular cognitive process, we need to isolate that process from changes related to other processes.