When autistic children get stressed, they often don’t show it. Instead their tension might build until they have a meltdown, which can result in aggression toward others and even self-injury. Because autistic children often don’t understand or express their emotions, teachers and other caregivers can have a hard time anticipating and preventing meltdowns.
A new device developed by Affectiva, based in Waltham, Massachusetts, detects and records physiological signs of stress and excitement by measuring slight electrical changes in the skin. While researchers, doctors, and psychologists have long used this measurement–called skin conductance–in the lab or clinical setting, Affectiva’s Q Sensor is worn on a wristband and lets people keep track of stress during everyday activities. The Q Sensor stores or transmits a wearer’s stress levels throughout the day, giving doctors, caregivers, and patients themselves a new tool for observing reactions. Such data could provide an objective way to see and communicate what might be causing stress for a person, says Rosalind Picard, director of the Affective Computing Research Group at MIT and cofounder of Affectiva. She demonstrated the sensor last month at the Future of Health Technology Summit 2010 in Cambridge, Massachusetts.
“This certainly sounds like interesting technology,” says autism specialist Helen Tager-Flusberg, director of the Lab of Developmental Cognitive Neuroscience at Boston University. She says the sensors will need rigorous data proving their accuracy, but “the promise of new technologies like this may well improve our effectiveness to work with individuals with autism in daily life.”
When a person–autistic or not–experiences stress or enters a “flight or fight” mode, moisture collects under the skin (often leading to sweating) as a sympathetic nervous system response. This rising moisture makes the skin more electrically conductive. Skin conductance sensors send a tiny electrical pulse to one point of the skin and measure the strength of that signal at another point on the skin to detect its conductivity.
“When you see this flight-or-fight response, it doesn’t tell you it’s definitely stress, it just tells you something has changed,” says Picard. “Are they excited, hurting, are they stressed by a sound or person in the room? It doesn’t perfectly correspond to stress as it can also go up with anticipation and excitement, but when you see it change, you know something’s going on and you can look for the cause.” She adds that having clues to a person’s stress levels, which might not otherwise be detectable, could give caregivers and researchers more insight–and possibly a way to anticipate–the harmful behaviors of autism, such as head banging. Caregivers can try to identify and block sources of stress and learn what activities restore calm.
“I’ve been doing this for 25 years, and it’s one of the most exciting things I’ve seen,” says Kathy Roberts, founder and executive director of the Giant Steps School, an institute in Fairfield, Connecticut, for children with autism, many of whom are nonverbal and use assistive technologies, like the iPad’s touch screen, to communicate. The school has been using the Q Sensors for about six months to let therapists see which activities–such as relaxation techniques like breathing exercises–affect the well-being of individual students. Aside from having difficulty communicating, many of the students have trouble understanding their feelings. “Often students can’t really describe their internal state to us at all. What these sensors are allowing us to do is to have direct feedback, which allows us to see this internal state in a very concrete way,” Roberts says. She adds that the Q Sensor is much easier and less obtrusive for autistic students than sitting at a monitor for biofeedback, a traditional method for analyzing emotional states. Roberts believes that the sensors have the potential to reveal more about sleep–which troubles many autistic children–and could even provide early detection for seizures.