BCI various imaging technique
Electro encephalograph (EEG)
This is one of the extensively used non-invasive brain wave imaging technique. Many of the present day BCI devices are based on this technology. EEG recording devices uses electrodes which can be attached to various part of the scalp to record the brain waves. Advantage is that is easily wearable, it can be mounted as a head gear. Disadvantage is low spatial resolution, since the brain signals need to traverse through scalp and bone, brain signals may not be be sharp.
Magneto encephalograph (MEG)
This uses magnetic fields generated due to the electrical activity from the brain. This has much more advantage than the EEG, since magnetic signals will not dissipate when passing through the skull. However, devices which used are bulky and expensive.
Positron emission Tomography (PET)
This uses the radioactivity traces injected in the veins. Devices that uses PET, make use of the gamma ray discharged by the radioactivity trace in the blood flow. Though this one is good for detecting cancer, it is not ideal for sustained use of radioactive substances
Functional Magnetic Resonance Imaging (fMRI)
Uses magnetic property of the blood flow. Advantage it is high on spatial resolution but the disadvantage is low temporal resolution and equipment is bulky and expensive.
Functional near Infrared (fNIR)
Measures absorption of scattering of near infrared light directed into the brain. High on spatial resolution, inexpensive and wearable
