Kleine-Levin Syndrome: Sleep 10 days at a time? You might have it.


“I was hallucinating and after that I don’t remember anything. All of a sudden it just went blank and I just slept for 10 days. I woke up and I was fine again.” [...]

“I was hallucinating and after that I don’t remember anything. All of a sudden it just went blank and I just slept for 10 days. I woke up and I was fine again.” [...]

Louisa is unusual as KLS usually affects teenage boys, who can also exhibit hypersexuality and inappropriate behaviour.

As well as excessive sleeping, symptoms include behaviour changes, irritability, feeling in a dream-like state and binge eating, symptoms that can be mistaken for normal teenage behaviour. [...]

The change in behaviour before and during a sleep episode is one of the most upsetting things for Louisa’s parents, who take it in turns to remain with her. Doctors have told the family it’s crucial to wake Louisa once a day to feed her and get her to the bathroom.

But Lottie admits it can take a while to get her to come round. “I’ve tried before to literally force her to wake up but she just starts swearing and gets so agitated and aggressive.” [...]

Many sufferers have abnormalities in their temporal lobe, the area of the brain involved in behaviour and memory. A scan of Louisa’s brain function revealed she does have abnormalities in her frontal lobe but there are no signs that this has affected her behaviour or memory. (via.)


Prosopagnosia & reading: Is reading competing with facial recognition?


Based on previous work, Dehaene has argued that one of these areas, at the junction of the left occipital and temporal lobes of the brain, is especially important for reading. In literate, but not illiterate, people, written words also triggered brain activity in parts of the left temporal lobe that respond to spoken language. That suggests that reading utilizes brain circuits that evolved to support spoken language, a much older innovation in human communication, Dehaene says.

It makes sense that reading would rely on brain regions that originally evolved to process vision and spoken language, says Dehaene. But this repurposing may have involved a tradeoff. The researchers found that in people who learned to read early in life, a smaller region of the left occipital-temporal cortex responded to images of faces than in the illiterate volunteers. Dehaene suggests that reading may compete with other tasks—such as face perception—for access to this part of the brain. If so, could learning to read make people worse at recognizing faces? Experiments to test this are already under way, but Dehaene says he doesn’t expect to see a huge difference. [...]

The suggestion that literacy competes with face perception in this part of the brain is likely to be controversial as well, he says. “The results … will definitely cause discussion in the scientific community.” (via.)