Very Interesting Junior – July 22, 2019

In the next issue, we

will look at the high-

tech types of scanning

equipment available, and

what they have taught us

about the brain.

Get smart series

PART 2 OF 3

BRAIN 101

Dr Lizzie Harrison is a

medical doctor with a special

interest in neuroscience.

And she really knows how to

use her brain – she’s also

studied veterinary science, is a

social media/screen time

expert and is the editor of

xHQ magazine!

CASE TWO: H.M.

Henry Gustav Molaison (commonly known as H.M. in

medical literature, to protect his identity) died in 2008. He

developed severe amnesia (loss of memory) after undergoing brain

surgery as a type of treatment for epilepsy (a disorder characterised by

frequent seizures). H.M.’s surgery involved the removal of large parts of a

specific part of the brain, called the hippocampus.

Following his surgery, H.M. was unable to create new memories, so failed to remember

anything that had happened to him after his surgery. He would literally wake up each

day with no idea about what had happened to him since he had had the surgery. He

would not remember anything from the previous day, or who people were. However, in

other ways, such as his IQ – his brain function was totally intact.

Scientists and doctors have described the case of H.M. as one of the most useful

cases of all time, as before H.M., scientists generally believed

that memories

were stored throughout the whole brain. However, H.M. called this into

question, as his surgery had only affected one part of the brain (the

hippocampus) and yet had led to a total inability to store or

make any new memories. We now know that the

hippocampus is one of the major centres for

forming memories in the brain.

CASE THREE:

VICTOR LEBORGNE

Before this case, scientists believed that the whole brain was needed

for humans to be able to speak. However, this French patient changed that

thinking. Victor Leborgne could not speak. He was able to produce just one sound

• ‘tan’ – but could not say anything at all that was understandable. Despite this,
  however, he was able to fully understand anything that people said to him. This was
  fascinating to doctors as they had believed that the whole brain would be needed for
  understanding and making speech, yet this case suggested that the two functions of
  understanding and making words were in fact separate in the brain.
  After Victor’s death, a scientist called Broca dissected his brain, and found that a
  specific area was damaged in this patient. It was thus discovered by Broca that this
  specific area in the left frontal lobe (called Broca’s area) was responsible for
  producing speech. It was later discovered that a separate area of the
  brain entirely was needed for understanding of speech. This
  explained why Victor was able to understand what was
  said to him, but was unable to respond.