New ways of Imaging
Latest Developments in Imaging
All of the brain-mapping technologies require inferential reasoning for their interpretation. Our comprehension of how the brain actually functions ranks at 2 on a scale of 100.
DOT is a technique to simultaneously “see” neural activity and study the functioning of the brain. A near-infrared laser is positioned on the scalp. Detectors composed of optical fiber bundles sense how the path of light is altered, either through absorption or scattering, as it traverses brain tissue. This method can be used to measure the absorption of light, which is related to concentration of chemicals in the brain.
It can also measure the scattering of light, related to physiological characteristics such as the swelling of glia and neurons that are associated with neuronal firing. DOT devices are portable and immune to electrical interference. It can detect chemicals such as hemoglobin and cytochromes.
MEG is more precise, but is very expensive and immobile. PET scans, relying on nuclear isotope imaging, expose subjects to potentially significant amounts of radiation. Functional MRIs, which measure blood oxygen changes in relation to neural activity, are safe, but difficult to interpret.
DECI (Dynamic Electrical Cortical Imaging) takes visual impressions every 0,001 second in real-time, whereas the other technologies snap pictures every 2-3 sec. Using the eLORETA algorithm, the software amplifies EEG signals from 32 electrodes placed on the head, and converts them into colour-coded movies of neuronal activity.
Stunning data has been released by the Human Connectome Project. Neuron axonal labeling visualizes the main connection pathways between brain areas. Data is mainly based on high-angular diffusion and diffusion spectrum imaging: dMRI.
The latest scanning device tracks the diffusion of water molecules through nerve fibers, thus allowing the creation of a coordinates system, by painstakingly building up of 3D maps of neurons that are 10x clearer. They are then reconstructed to computer algorithms that explain it all.
