Such heightened sensory perception in autism may help explain why some people with the disorder are painfully sensitive to noise and bright lights. It also may be linked to some of the complex social and behavioral deficits associated with autism, says Duje Tadin, one of the lead authors on the study and an assistant professor of brain and cognitive sciences at the University of Rochester.
“We think of autism as a social disorder because children with this condition often struggle with social interactions, but what we sometimes neglect is that almost everything we know about the world comes from our senses. Abnormalities in how a person sees or hears can have a profound effect on social communication,” says Tadin.
Although previous studies have found that people with autism possess enhanced visual abilities with static images, this is the first research to discover a heightened perception of motion, the authors write. The findings were reported in the Journal of Neuroscience on May 8 by Tadin, co-lead author Jennifer Foss-Feig, a postdoctoral fellow at the Child Study Center at Yale University, and colleagues at Vanderbilt University.
In the study, 20 children with autism and 26 typically developing children, ages 8 to 17, looked at brief video clips of moving black and white bars and simply indicated which direction the bars were heading, right or left. Each time a participant made the correct direction choice, the next video clip became slightly shorter and thus a little more difficult. When they made a mistake, the next video became a bit longer and thus easier to see. In this way, the researchers were able to measure how quickly children with autism can perceive motion.
The researchers found that when the bars in the image were just barely visible, both groups of children performed identically. When the contrast or darkness of the bars was increased all participants in the study got better at perceiving the direction of movement. “But kids with autism, got much, much better—performing twice as well as their peers,” says Foss-Feig. In fact, the worst performing participant with autism was roughly equal to the average of the participants without autism.
“This dramatically enhanced ability to perceive motion is a hint that the brains of individuals with autism keep responding more and more as intensity increases. Although this could be considered advantageous, in most circumstances if the neural response doesn’t stop at the right level it could lead to sensory overload,” explains Foss-Feig.
Such hypersensitive perception is the neural signature for a brain that is unable to dampen its response to sensory information, note the authors. This same increase in neural “excitability” is also found in epilepsy, which is strongly linked to autism. In fact, as many as one third of individuals with autism also have epilepsy. Normally, the brain puts the brakes on its responses to sound, taste, touch, and other stimuli when they become too intense.
What’s important about this dampening ability is that it’s a ubiquitous mechanism controlling how humans perceive the world. “If the processing of our vision, hearing, and other sensory systems is abnormal in some way, it will have a cascading effect on other brain functions,” says Carissa Cascio, assistant professor of psychiatry at Vanderbilt University, in whose lab the study was conducted. “You may be able to see better, but at some point the brain really is over responding. A strong response to high intensity stimuli in autism could be one reason for withdrawal.”
The research builds on earlier findings that people with autism process visual stimuli differently. For example, previous studies have shown that individuals with autism are better able to perceive basic patterns, are able to see simple line images more quickly, and are more focused on details than individuals without the condition. By contrast, in more complex tasks, like facial recognition, these enhancements become impairments. Likewise, autism is associated with deficits in perceiving motion patterns more complex than the simple moving bars used in this study, such as detecting walking and other biological movements.
Kimberly Schauder, a research assistant at Vanderbilt University, is also an author on the paper. The research was supported by grants from the National Institutes of Health.
Susan Hagen | Newswise
Multi-year study finds 'hotspots' of ammonia over world's major agricultural areas
17.03.2017 | University of Maryland
Diabetes Drug May Improve Bone Fat-induced Defects of Fracture Healing
17.03.2017 | Deutsches Institut für Ernährungsforschung Potsdam-Rehbrücke
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
27.03.2017 | Earth Sciences
27.03.2017 | Life Sciences
27.03.2017 | Life Sciences