as this study shows, as well as others, electric fields do "mess up" with individual synaptic transmission. nature has evolved action potentials as a reliable way to propagate signals in the presence of the myriad sources of electromagnetic radiation on earth. They can be disrupted by appropriately high stimulation such as with TMS . Most likely, the radiation sources that we use every day, phones computers etc do have some effect in neurotransmission but those random failures are probably too few (and too random) to matter significantly or systematically.

here is a recent review: http://sci-hub.tw/https://www.sciencedirect.com/science/arti...

Neuroscience PhD student here. The skull acts as a low-pass filter. EEG recordings are typically low pass filtered at 70Hz or lower for example. This is why you can’t decode eg speech from a EEG: the neural encoding is at a higher frequency band than can be recorded. Even though the signal is much stronger, digital comms equipment is orders of magnitude higher in frequency and does not penetrate the skull well.

What about the radio signal used for MRI imaging, is it blocked by the skull as well? Or is it just strong enough to be able to penetrate the skull?

fMRIs use a crazy strong magnetic field—typically >= 3 Tesla. The signal that is measured is not electrical but rather the blood oxygen level. Effectively, this is a correlate of the metabolic expenditure of nearby neurons. Wass it is also like a low-pass filter except here it’s more like 0.5 Hz or slower. On the plus, you get much improved spatial resolution

MRIs use two magnetic fields, a static one and a dynamic one. And they use a radio signal according to the larmor frequency to excite the spin of the atoms. I was wondering about that radio signal component.

I can't say with 100% certainty that it would have no effect, but the following may be of use:

Frequency of Brain Waves

State Frequency range State of mind

Delta 0.5Hz–4Hz Deep sleep

Theta 4Hz–8Hz Drowsiness (also first stage of sleep)

Alpha 8Hz–14Hz Relaxed but alert

Beta 14Hz–30Hz Highly alert and focused

This has very little relevance to the topic at hand as these refer to electroencephalogram measurements taken through a skin (scalp) patch and conductive gel.

Empirically, we'd want data on how corresponding electromagnetic pulses would affect brain activity -- there should be resonance effects, once the amplitude is high enough.