The temporal activity is maximal at about 265 ms after word onset and the frontal activity at about 380 ms. By 440 ms, the activity is mainly frontal, and by 560 ms, it has faded away. The generators of potentials evoked by novel and repeated words, summarized from a previous study of about 2500 iEEG recordings , are shown on the right. Such recordings are only performed in epileptics and thus may be affected by pathology and limited sampling. However, they can identify generators without the ambiguities associated with all extracranial electromagnetic measures.
Thick lines show the response to novel words, and thin lines the response to repeated words.
Although the general similarity between the aMEG and iEEG waveforms provide further evidence for the accuracy of the noninvasive estimates, further studies are needed in order to assess the accuracy within-subject, with higher anatomical precision.