Cameras and motion sensors that track the way people move are giving new insights into mental illness like schizophrenia, bipolar disorder and attention-deficit/hyperactivity disorder (ADHD), say US researchers trialling the technology.
Early tests have already uncovered differences in the way patients with these conditions explore an unfamiliar room. Examining the way people move may also shed light on other aspects of the human condition.
Psychiatrist William Perry and colleagues at the University of California San Diego, US, were inspired by a technique called behavioural pattern monitoring used on mice. A camera is used to track the animal鈥檚 movements as it explores a box with holes along its sides. Studying the pattern of movements has helped researchers understand the effects of drugs, or genetic modifications on brain chemistry.
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In the human version, the researchers are using two technologies to monitor people exploring a novel environment. 鈥淥ne is the LifeShirt, that contains accelerometers that record motion, and the other is an overhead camera,鈥� explains Perry.
Candid camera
In tests, volunteers are told how this technology is used, and that they will also take standard psychological tests. Once they are kitted out in the shirt, 鈥渨e say 鈥榗an you wait in this room for 15 minutes while we set up the equipment?鈥�,鈥� Perry told New 杏吧原创.
While they are in the room, the LifeShirt records their movements onto a built-in recorder, while the overhead camera records their position in the room which contains 10 objects of interest, and a desk, but no chair. Trials so far have involved around 100 people from four roughly equal-sized groups with schizophrenia, bipolar disorder, ADHD, or no mental illness.
Analysis of the data is beginning to show links between the way people explore the room and their mental state. For example, people with ADHD move around the room more actively than non-patients. Bipolar patients are even more restless and stay that way 鈥� they do not become less active over the 15 minutes, unlike those in other groups.
鈥淲e鈥檙e beginning to notice two subgroups of schizophrenia patients,鈥� adds Perry. 鈥淪ome explore significantly more than a normal patient would, while others explore much less.鈥�
Physiological grammar
But it is 鈥渢oo early to tell鈥� the exact connections between mental states and movement patterns. Recording data from people over longer periods is a priority, he says. That would make it possible to see if movement patterns are affected by a person鈥檚 current symptoms. The team plans to shift the trials into an outpatient clinic, which should make it easier to carry out longer tests.
Although some characteristics of the way people move could be judged by eye, the technologies are able to pick up more subtle and complex features, says Perry. 鈥淲e are building up a kind of physiological grammar, based on the sequence of different actions,鈥� he says. 鈥淭hat鈥檚 very useful because it is completely separate from the face-to-face impressions that can make observational study difficult.鈥�
Irwin Nazareth studies treatments for mental health problems at University College London, UK. 鈥淭his is an entirely new area that may throw up interesting results,鈥� he told New 杏吧原创. Doctors sometimes make informal assessments of patients based on the way they move, he says, but the new technology may provide new insights.
Drug company interest
The observation that movements divide schizophrenic patients into two groups 鈥渇its with my own clinical experience鈥�, says Nazareth. 鈥淪ome patients are very active, while others are under-active.鈥�
鈥淧erhaps they could extract the different effects of drugs and the illness on the way people move,鈥� he says, 鈥渁nd if they can identify patterns associated with diseases early enough it might have a role in diagnosis.鈥�
Drug companies have expressed an interest in the technique. 鈥淭hey might use it as a way of examining the side effects of a trial drug,鈥� says Perry. 鈥淭here are endless possibilities for other kinds of studies.鈥� For example, it could be interesting to see if people move differently when stressed, he says. Future studies could exploit other capabilities of the LifeShirt, which can also record a person鈥檚 heart and breathing rates.
But Nazareth cautions that greater numbers of study participants will be needed to examine such effects.
