People in vegetative states might answer questions by using their imaginations.
Posted Aug 10, 2017
I have the privilege of teaching psychology to university students, a privilege that is magnified when I teach PSYC 1, Introduction to Psychology, at UC Riverside. This past academic quarter, I had the honor of teaching this class to 571 students, one of whom came up with a brilliant idea. (Others may have had brilliant ideas, too, but didn't happen to tell me about them.)
The student was Maximiliano Abundez Toledo. Max’s idea came in response to a lecture, given early in the course, in which I described a study that tugs at students' (and my) heartstrings, much as it inspires scientific curiosity.
The study was published in Science magazine (Owen et al., 2006) and concerned a young woman who had suffered a terrible accident. The accident left her completely paralyzed. She was so profoundly incapacitated that she couldn't move a muscle. She couldn’t nod. She couldn’t shake her head. She couldn't even blink or squeeze her eyelids to signal agreement or disagreement with questions. “Do you want to listen to more music?" she might have been asked. No response. “Are you cold?" she might have been queried. Nothing. Yet her brain was alive, as shown by EEG recordings. The nature of her brain waves made it unclear, however, how clear-headed she was. From her EEGs and other measures, doctors attending to her couldn’t tell if she was conscious.
In the Science paper, the authors described a procedure to probe the patient’s mental state. They put her in a scanner and asked her to imagine herself playing tennis, something she had done before. They also asked her to imagine herself walking through her house, which she had done as well. Different parts of her brain became activated when she engaged in the two kinds of imagery. Additionally and of special importance, the parts of her brain that became activated in the two imagery conditions were the same as the parts of the brain that became active in other individuals (all neurologically normal) when they engaged in the same mental acts. The implication was that the patient could understand spoken language and could carry out mental maneuvers suggested to her, essentially as well as others could. This implication was uplifting but also unsettling. Here was someone who was mentally alive but apparently locked in. Could something be done to help her?
Soon after I described this study, Max came to my office and told me he had an idea about a possible way of helping this patient and others like her. "What if," he said in so many words, "she was told to imagine herself playing tennis when she wanted to say yes and imagine herself walking through her house when she wanted to say no, or vice versa?"
I was stunned by the cleverness of Max’s idea and congratulated him on it. "That's a great idea," I exclaimed. Max blushed.
If someone comes up with an idea for a procedure or device, s/he may not be the first person to do so. The idea may have been tried before. You may independently think of putting a stick through a disk and rolling the disk along while supporting a weight on the stick, but what you've done is re-invent the wheel, not invent it. Max and I agreed that we would try to find out if his idea had been implemented. (My expertise in perception and performance doesn't make me an expert in brain imaging or clinical neuroscience per se.)
A few weeks later, after the academic quarter ended, I sent an email to Professor Martin Monti of the UCLA Psychology Department, who is a true expert in brain imaging and clinical neuroscience. My hunch was that Martin might know the answer, and my hunch was right. Martin indicated that the idea had not only been explored, but he and his colleagues had done so. Via his email back to Max and me, Martin shared some references (given below) from this work. One was from a study he did. The others were from successful replications.
What did these studies show? They showed that the method Max had independently conceived can work to a degree one might expect given the brain damage of the individuals involved. Not all patients can use the method and those who can may do so with only limited reliability. Some of the patients some of the time can, in effect, answer yes/no questions covertly when they can’t do so overtly. This is somewhat encouraging but needs more work.
What does my experience with Max show? It shows that classrooms have students with talent. If Max’s idea wasn't completely original, that's much less important than the fact that he came up with it. If his idea isn’t as novel as one might hope, that doesn’t matter. Max will have more ideas. His creativity should be encouraged, and his inventiveness should be rewarded. The same goes for other students, including others who may have ideas, brilliant or otherwise, which they keep to themselves. Encouraging others to express themselves is an important priority, both in the classroom and in the clinic.
Bardin, J. C., Fins, J. J., Katz, D. I., Hersh, J., Heier, L. A., Tabelow, K., Dyke, J. P., Ballon, D. J., Shiff, D., & Voss, H. U. (2011). Dissociations between behavioural and functional magnetic resonance imaging-based evaluations of cognitive function after brain injury. Brain, 134, 769-782.
Cruse, D., Chennu, S., Chatelle, C., Fernández-Espejo, D., Bekinschtein, T. A., Pickard, J. D., Laureys, S., & Owen, A. M. (2012). Relationship between etiology and covert cognition in the minimally conscious state. Neurology, 78, 816-822.
Monti, M. M., Vanhaudenhuyse, A., Coleman, M. R., Boly, M., Pickard, J. D., Tshibanda, L., Owen, A. M... & Laureys, S. (2010). Willful modulation of brain activity in disorders of consciousness. New England Journal of Medicine, 362, 579-589.
Naci, L., & Owen, A. M. (2013). Making every word count for nonresponsive patients. JAMA Neurology, 70, 1235-1241.
Owen, A. M., Coleman, M. R., Boly, M., Davis, M. H., Laureys, S., & Pickard, J. D. (2006). Detecting awareness in the vegetative state. Science, 313, 1402.