Of course it can you say?
Well it’s been hard to prove because most tests have introduced inaccuracies into the equation and have therefore been inconclusive.
We know animals can sense magnetic fields.
Dogs can even be trained to find a magnet.
Most tests have relied on subjective experience.., IE: The test subjects would report if they felt any difference from the magnetic field being shifted.
Most tests also have had a person connected to EEG in the presence of a magnetic field, and then they would move relative to that magnetic field.
This gives false results because the brain registers movement of the head or body relative to it’s surroundings even without these conditions. This leads to a change in brain activity in relation to a change in position and not a change in any magnetic field.
A third mistake has been to use a strong magnetic field thinking that people would be more likely to feel it.
Studies on animals and particularly on birds have shown that strong magnetic signals are ignored. Maybe they are ignored because they are likely to be an anomaly rather than a significant aid to navigation.
The Earths magnetic field is actually very weak, about 1/100th that of a fridge magnet.
Recent research has found that cells have the ability to build nanocrystals of magnetite (like iron) including in the human brain. Thus a possible way for us to be able to sense magnetic fields was seen as plausible. But still hard to prove.
This recent study however is conclusive evidence of our brain (and likely whole body) being affected by shifts in magnetic fields even if we are completely still.
They did this by having the people hooked up to EEG and sitting still while the magnetic field itself was moved (see picture in the article). And the magnetic strength they used was much weaker than other experiments also.
People still reported no change in feeling or thought when the field was moved.
They were in fact not aware of the experiment at all and reported nothing but sitting in a dark room.
However, the peoples brainwave patterns changed significantly as the field was moved. Almost like a warning signal to be aware of change because the change was independent of the persons location or movement. In other words, the brain had a strong reaction because the shift in the magnetic field could not be predicted by a decision or action to move or be moved.
So it seems our brains ability to sense and respond to the earths magnetic field is present but perhaps underused and therefore only a subtle influence on most people compared to our ancestors. And who knows what effect all the magnetic energy we pour into our world will be having on our and our animal friends lives.
It would seem likely that with training, a person could become more sensitive (and some people naturally are anyway) to these fields.
So here is evidence of something as simple as an external magnet affecting our brain activity.