Seeing a friend or family member in a vegetative state, characterized by wakefulness without awareness, can be difficult, as it’s impossible to know how effective a visit to the patient is. Do they even know you are there? Although that’s still unclear, a new study has found that these patients do indeed have some level of consciousness, and that brain regions associated with emotions react when they are shown photos of familar faces.
The key to inducing brain reactions, however, was using photos of people who the patient would recognize, the researchers said. “We showed that patients in a vegetative state can react differently to different stimuli in the environment depending on their emotional value,” Dr. Haggai Sharon, of Tel Aviv University’s Functional Brain Center, said in a press release. “It’s not a generic thing; it’s personal and autobiographical. We engaged the person, the individual, inside the patient.”
The study, which was published in the journal PLoS One, looked at four patients, who were classified as being in a persistent (month-long) or permanent (more than three months) vegetative state, as they were shown photos of people that they knew as well as photos of people that they didn’t know. Through functional magnetic resonance imaging (fMRI), they found that all of the patients’ brains showed limbic — relating to emotions and memories — as well as salience — catching their attention — activations. Essentially, seeing these photos not only caught their attention, but also activated parts of the brain that remember familiar faces, or faces at all, for that matter.
Going further, the researchers then looked into whether the responses these patients had were spontaneous or deliberate. They instructed the patients to imagine what their parents’ faces looked like. Brain scans showed that two of the patients’ brains became active in the limbic areas. What’s more, one of those patients — a 60-year-old kindergarten teacher who had been hit by a car — even exhibited activity in the salience areas. Two months after the fMRIs, both of these patients advanced to a minimally conscious state, which meant that their awareness levels would come and go.
The findings show that a patient in a vegetative state might actually recognize familiar faces. They not only possess emotional awareness of the environment but also experience emotional awareness driven by internal processes, such as images,” Dr. Sharon said in the statement.
Previous research has also produced similar results. In October, a study by Cambridge University researchers, published in the journal Neuroimage: Clinical, found that patients in vegetative or minimally conscious states could not only direct their focus toward relevant words that they were being told to concentrate on but even imagine playing tennis. On the other hand, some of the minimally conscious patients were able to react to familiar words, but not to the ones they should have focused on.
Together, both studies provide insights into the intricacies of the vegetative mind. “In order to try and assess the true level of brain function and awareness that survives in the vegetative and minimally conscious states, we are progressively building up a fuller picture of the sensory, perceptual, and cognitive abilities in patients,” Dr. Srivas Chennu, of the University of Cambridge, said in a press release.
Source: Sharon H, Pasternak Y, Ben Simon E, et al. Emotional Processing of Personally Familiar Faces in the Vegetative State. PLoS One. 2013.