Model research suggests that the abnormal location in the uterus improves the brain’s ability to interpret specific types of sound.
Inside the uterus, the fetuses may begin to hear some sounds at about 20 weeks of gestation. However, due to the moving effect of amniotic fluid and surrounding tissues, the input of their exposure is limited to low-frequency sound.
A new study led by MIT suggests that this impaired sensory implant is beneficial and perhaps necessary for hearing development. Using simple computer models for human hearing processing, scientists have shown that initially limiting input to low-frequency sounds as models learn to perform specific tasks improves their performance.
Along with previous research conducted by the same research team, which showed that early exposure to a blurred face improves the ability of the following computer models of facial recognition, the findings suggest that low-quality input sensors may be essential to other aspects of brain development.
“Instead of thinking of the low level of inclusion as a barrier to biological science, this work believes that perhaps nature is intelligent and gives us the right kind of impetus to develop seemingly better methods later. It is beneficial when we are asked to tackle challenging recognition tasks,” said Pawan Sinha, a theory and computational neuroscience professor at MIT’s Department of Brain and Psychiatry, who led a team of researchers.
In a new study, researchers showed that exposing the integration model of a human hearing system to a full range of frequencies from the beginning led to worse performance over tasks that required long-term data absorption – for example, identifying emotions from a voice clip. From a practical point of view, the findings suggest that premature babies may benefit from being exposed to lower noise levels than the entire volume of sound currently heard in neonatal care centers, the researchers said.
Marin Vogelsang and Lukas Vogelsang, both EPFL students in Lausanne, are the study’s lead authors, recently published in the Development Science journal. Sidney Diamond, a retired neurologist and now an MIT research organization, is the paper’s author.
A few years ago, Sinha and his colleagues became interested in learning how the lower extremities affect subsequent brain development. The question arose partly after researchers had the opportunity to meet and research a young boy born with cataracts that were not released until he was four.
The boy, born in China, was later discovered by an American family and referred to Sinha’s lab at 10. Research reveals that his perception was almost daily, except for one notable factor: He was terrible at seeing faces. Another study of children born blind also revealed a lack of facial features after restoring their eyesight.
Researchers speculate that this damage may result from losing low-quality visual implants commonly found in infants and young children. When babies are born, their vision is horrible – about 20/800, 1/40 normal vision is 20/20. This is in part due to the low packing capacity of photoreceptors in the developing retina. As the baby ages, the receptors become more concentrated, and his vision improves.
“The impression we made was that this initial period of visual acuity or degeneration was very important. Because everything is blurred, the mind needs to cover large areas of the arena,” said Sinha.