Does this actually prove it's a "sense"? It stands to reason that magnetic fields could subtly affect brainwaves, as brainwaves are electromagnetic in nature, but does that indicate that the body actually does anything useful with this perturbation?

They have well demonstrated that they affect the brain on some level, but I think making the jump to call it a sense requires some actual effect on our physiology or behavior that the body takes advantage of as a means to DO something.

I'm inserting my own definition and understanding of what a sense is here, but I'd wager there there aren't too many ways of defining a sense without somehow including perception as a critical aspect. At least not any that people would buy wholesale or would be easily demonstrated scientifically.

A counterexample to this would be ionizing radiation. Radiation is present in our environment, we generally do not perceive it (at least not on any conscious level, and excluding the sense of heat and visible light, both frequencies along the electromagnetic spectrum), and it certainly has effects on the body that are easily perceivable (tanning/sunburn, cancer, etc). Can we sense it? I don't think many folks would argue that we can.

I also notice that the article uses quite a few weasel words, throwing "suggests" and "hints" in to justify the title. Not fantastic journalism IMO.

Cultures whose language requires absolute direction awareness ought to yield individuals who can consciously identify changes in magnetic fields.

It seems like an obvious course of investigation. One wonders whether there was any attempt to recruit such individuals. Not all of them live in inaccessible places -- just most.

Aren't EEG caps full of wires and other metal components? If so, then this study reads like an onion article.

If people can sense it, does that mean magnetic field changes can effect people ?