Thomas Dierks,
University Hospital for Psychiatry, Bern, Switzerland
The efforts to understand the organization and function of the brain on a systems level have been to a large degree facilitated by the development of novel and powerful methods of noninvasive neuroimaging. These techniques have not only been used for understanding normal brain function but also provided new insights into the physiological basis of neuropsychiatric disorders.
On the other hand these techniques have also been used for less scientific purposes like crime detection and mapping of consumer preferences. For a critical evaluation of study results gained by these techniques, knowledge about their possibilities and limitations are helpful. Most of these techniques are more or less complementary to each other in different domains.
Whereas electrophysiological [EEG, MEG] techniques are characterized by an excellent time resolution, some Magnetic Resonance Imaging [fMRI] techniques, and to some extent also Nuclear Medicine [PET] techniques, are characterized by a high spatial resolution. Additionally, the functional techniques also differ in the measured epiphenomena of neuronal activity, like cerebral blood flow, glucose metabolism, density of neurotransmitters and others. But also the possibility to assess the cerebral structure and structural connectivity has changed the way we look upon the brains functional architecture. By combining these techniques, both functional and structural, we can now gain unprecedented insights into the relation between cognition, emotion, behaviour, and psychopathology on one side, and brain physiology and anatomy on the other side, The limitations of these techniques should, however, be taken into consideration when forming interpretations of data. |
