In a study of 14 aged subjects without neurological or psychiatric problems (average age of 74), researchers reported that the more words subjects spoke while attempting to pantomime performance of a simple activity, the more likely they were to make gestural errors. Clinicians have previously observed that subjects with a gestural disorder ("apraxia") may speak instead of gesturing when their ability to pantomime is tested. The researchers wished to learn if the amount of speech normal elderly subjects generated when asked to pantomime an activity (for example, "Show me how to use a hammer to bang a nail") would predict their success at performing the pantomimes. The study is reported in the Feb. 12 issue of Neurology, the scientific journal of the American Academy of Neurology.
The researchers videotaped the subjects pantomiming 30 simple activities (such as hammering, saluting, or using a screwdriver or ice pick). Although subjects were instructed not to speak, they spoke an average of about 45 words while performing the pantomime. The more subjects spoke, the lower their scores on the pantomime task.
There are at least two possible explanations for this inverse relationship, according to study author Anna M. Barrett, MD, Pennsylvania State University College of Medicine. "Speaking may have interfered with gesture production. Any of us can make more errors when we try to talk and do something else simultaneously, such as cooking a complicated meal. It is also possible that subjects who were having trouble generating the correct response may have used speech either as a substitute response or as a means of activating gestures," said Barrett.
Barrett said because the study was relatively small, the results should not be generalized to older subjects as a whole.
The study was supported by the Alzheimer's Disease and Related Disorders Association, the General Clinical Research Center, Pennsylvania State University College of Medicine, the National Institutes of Health, and the Department of Veteran Affairs.
The American Academy of Neurology, an association of 18,000 neurologists and neuroscience professionals, is dedicated to improving patient care through education and research. For more information about the American Academy of Neurology, visit its web site at www.aan.com.
For more information contact: Kathy Stone, 651-695-2763; kstone@aan.com For a copy of the study, contact Cheryl Alementi, 651-695-2737; calementi@aan.com
Journal
Neurology