Question: How will you know if the electricity produced from the rat brains is the same as that of a human child baring in mind even though rats brains may be similar to humans they may not be the same in this respect?

Tim Fosker answered on 14 Jun 2011:

Hi @snakeman

I’ve never measured the electricity from a rat’s brain because I’m interested in how humans learn language so I only measured brain activity from children’s brains, but this is an excellent question.

You have come across a big problem that we would have comparing the electricity from a rat’s brain and a human’s brain. When we measure electricity from human brains we normally measure it using a cap worn on the head – If we put a small version on a rat we would get very different results, mainly because of the shape of the brain. The voltage over the head is positive and negative but it moves around depending on how the brain is packed into the skull. Rat brains are a very different shape from human brains with a much smaller ‘cortex’ part than humans. So the electricity measured from rat brains and human brains would be very different measured over the head. However, if we took a long needle-like probe we could measure the electricity from single cells this would be very similar in the rats and humans. We can’t go around putting probes in people’s brains so we can’t really compare the electricity from rat and human brains.

I hope this answered your question.