A new edition of Scientific American Mind has arrived with two freely available articles online: one on the distortion of body image in eating disorders and the other on whether brain scans could be a communication channel for people in coma-like vegetative states.
Perhaps the key feature of eating disorders such as anorexia is not just that the person wants to be thin, but that they have a disturbance in their body image so they think they are fat, even when dangerously undernourished.
The SciAmMind article looks at research which attempts to understand how and why body image becomes disturbed and how this can contribute to disorded eating patterns.
This second article discusses the implications of a study [pdf] published recently by Adrian Owen and colleagues suggesting that some patients in a persistent vegetative state or PVS might actually have conscious awareness which they can’t outwardly express (see previously on Mind Hacks).
The first step is getting a general understanding of the patient’s state of mind. Clinicians divide disorders of consciousness into three categories: coma, in which a patient is neither awake nor responsive; vegetative, in which a patient is awake but unresponsive; and minimally conscious, in which a patient is awake and responds to stimuli but has limited capacity to take willful actions. Typically doctors make these categorizations by observing a patient at the bedside. By this method alone, a patient thought to be vegetative could actually be aware.
“It’s really a conundrum. The way that consciousness is typically measured is by basically asking somebody to tell you that they are conscious,” Owen says. “So if someone wasn’t unconscious but couldn’t respond and tell you that, they would be classed as unconscious.” In Owen’s team’s case study, reported in the September 8, 2006, issue of the journal Science, the researchers asked the vegetative patient to imagine herself doing various tasks, including walking through the rooms of her home, while they scanned her brain using fMRI. The resulting images showed that her response matched that of healthy test subjects – she understood the commands and intentionally decided to comply.
Other articles available in the print edition or to subscribers tackle food addiction, brain development in adolescence, perceptual integration, the psychology of stalkers, lithium in the treatment of neurological disorders, pain disorders and implanted ‘brain chips’.
Link to contents for April 2007 issue.
Link to article on body image and eating disorder.
Link to article on communicating in vegetative state.