Discuss the use of brain-imaging technologies in investigating the relationship between biological factors and behavior
Brain-imaging techniques are used in neuroscience to investigate the relationship between behavior and brain structures, for example after brain damage or to find out which areas of the brain are involved in which cognitive activities (cognitive neuroscience).
Brain-imaging technology is a promising way to investigate the possible relationship between biological factors and behavior, but so far scanning can merely register structures and activity in the brain. It is not possible to determine cause-effect relationships at this point.
MRI scan: magnetic resonance imaging
MRI scans can give detailed pictures of internal structures in the body. The body consists, to a large extent, of water molecules. In the MRI scanner a radio frequency transmitter is turned on and it produces an electromagnetic field.
Strengths of MRI
- MRI scans are particularly to show how the blood flows in the brain and can be used to identify problems with blood circulation. They can be used for the early detection of Alzheimers’ disease.
- They are safe to use since no radioactive material is used.
Limitations of MRI
- They are very expensive.
- Movement may affect the pictures.
- They cannot say anything about cause-effect relationships.
Study to use: Maguire et al. (2000)
fMRI scan: functional magnetic resonance imaging
The fMRI scanner measures changes in blood flow in the active brain. This is associated with use of oxygen and linked to neural activity during information processing. When participants are asked to perform a task, the scientists can observe the part of the brain that corresponds to that function. fMRI scanning is widely used by cognitive neuroscientists and other researchers and its use has increased enormously over the last 10 years.
Strengths of fMRI
- It does not use radioactive substances.
- It can record activity in all regions of the brain.
Limitations of fMRI
- The focus is mostly on localized functioning in the brain and does not take into account the distributed nature of processing in neural networks.
- The results are correlational so it is not possible to establish cause-effect relationships.
Study to use: Fisher et al. (2003)