1 second
Figure 17.4. Human EEG recorded simultaneously from thirty-one electrodes.After his stint in the military, Berger resumed his university studies
but switched to the study of medicine, with the intent to investigate
the human brain and its relation to mind. He hoped to uncover physi-
cal mechanisms related to his sister’s presumed telepathic experience
at the time of his accident (telepathy = feeling at a distance; Greek tele
= distant, pathos = feeling, suffering).
In the 1940s and 1950s, the neurosurgeon Wilder Penfield recorded
electrical activity directly from the cerebral cortex of people who had
their brain exposed during surgeries (as mentioned in Chapter 16).
This allowed for much higher resolution of the locations of neural
activity. Penfield was initially interested in mapping regions in which
seizures originated, in order to carefully excise epileptogenic (seizure-
generating) tissue. He soon appreciated that he could determine, more