kspencer at iti.org (Kevin Spencer) writes:
> By "deep electroencephalograms", did they mean they were
> recording intracranially? This sounds quite bizarre to me. And
> regardless of whether they were recording from inside the scalp
> or the surface, I think that there would be a lot of muscle and
> movement artifacts in the EEG recordings.
It is not uncommon for patients with intractable epilepsy to have
intracranial electrodes implanted when surgical removal of part of the
brain is being contemplated, in order to localize the source of the
disturbance, or to understand what the disturbed tissue is doing. In
many cases these electrodes are exploited for scientific studies,
which can often be done without harming the patient. The two patients
described in the Heath paper were both epileptic.
As a rule, intracranial EEG recordings are much less disturbed by
noise than scalp recordings. It's something like the difference
between listening to a conversation through a thick wall and listening
to it from inside the room.