The human brain also emits waves, like when a person focuses her attention or remembers something. This activity fires thousands of neurons simultaneously at the same frequency generating a wave — but at a rate closer to 10 to 100 cycles per second.
“the magnetic field of the earth is just strong enough to move the needle of a compass. Signals from the brain are a billionth of that strength.”
Hard to measure, but not impossible. MIT recently installed a new MEG scanner to study the function of the human brain. To capture brain signals, the MEG scanner is in a room shielded with mu metal, a special alloy that blocks external magnetic fields. “Like a rock in the middle of a river, this metal forces all electromagnetic signals to flow around the room and doesn’t let any inside,” says Pantazis.
The MEG scanner consists of a helmet that contains 306 sensors spaced uniformly across its surface. These “superconducting quantum interference detectors” (SQUID) are cooled to near absolute zero, which makes them superconductive and, according to Pantazis, “able to measure even the slightest magnetic signals from the brain.”
The MEG lab, open since March 2011, is used by researchers across MIT. Projects are as diverse as studying visual attention, language processing, or even olfactory responses to pleasant and unpleasant smells. “It is a very exciting field of research, you never know how the brain will respond to different stimuli,” says Pantazis.
https://engineering.mit.edu/engage/ask-an-engineer/can-brain-waves-interfere-with-radio-waves/