An fMRI scan:
Active regions in the brain appear coloured
Functional MRI (fMRI) can track the brain in action.
When a region of the brain is working, chemical signals
conduct messages from one part of the brain to another,
a process that requires oxygen. Therefore, more oxygenated
blood flows to active areas. It is possible using
very fast scanning to give someone a task to do in
the scanner and find out which brain regions had more
oxygenated blood during that task and therefore which
regions were involved.
fMRI in psychiatric research
fMRI studies have become increasingly common in psychiatry
in the last few years. By providing a picture of the brain
in real time, they have offered the first chance to see
human reactions to drugs and stimuli as they occur.
FMRI has been used to investigate a number of neuropsychiatric
disorders, including depression, schizophrenia, Alzheimers
disease and epilepsy. It is particulary promising as a diagnostic
technique for disorders like schizophrenia which lack accepted
biological markers and are diagnosed on behavioural signs
or self-reported symptoms.
Using fMRI we looked at the pattern of neural activation
in patients with schizophrenia undertaking a language task
and compared these with people who did not have schizophrenia.
We also exploited the potential of fMRI for reapeated scanning
to monitor drug-induced brain changes in a group of men
with schizophrenia on switching from conventional medication
to the atypical antipsychotic Risperidone. This research
opens up the possibility of developing profiles to assess
the probability of a positive response in a patient before
embaking upon expensive and lengthy courses of treatments.
In the future we expect to see many technical advances
in fMRI. Improvement in the resolution of scanning will
extend the range of disease processes that can be studies,
including momentary phenomena such as hallucinations. Researchers
are already attempting this by investigating the combination
of fMRI with electrophysiological techniques such as electroencephalography.
There is also progress towards real time fMRI where brain
activity is revealed during the scan, rather then waiting
to process the data afterwards.