From Samuel Levy, Somerville, Massachusetts, US
Jim Skeels suggests that neural activity could perhaps be recorded closer to the source through a dental implant, which may also be less obtrusive than a full EEG cap on the skull (Letters, 1 December 2018). This is an interesting idea, but a midline slice of the skull shows that a tooth implant would be further away from the brain than a skullcap and signals would have to go through more bone.
