Lefties--or at least relatives of lefties--may be better than right-handed people at remembering events, according to a new study.
Since the mid-1980s, scientists have known that the two brain hemispheres of left-handers are more strongly connected than those of right-handers. Stephen Christman and Ruth Propper of the University of Toledo, Ohio, suspect that memory for specific events--known as episodic memory--relies heavily on interaction between the hemispheres. Consequently, they reasoned that lefties and righties might differ in episodic memory, but not factual memory--things people know but don't necessarily remember learning--which they say does not rely on interhemisphere interaction.
To test their theory, they asked 62 subjects to watch a series of 55 words flashed on a computer screen. Several minutes later, subjects were asked to write down the words. When errors were subtracted from correct answers, subjects with left-handedness in their families--who may share brain characteristics with their left-handed relatives--achieved an average score of 4.7 compared to 2.7 for those who only had right-handed relatives. There was no such difference in a second task designed to test factual memory.
Sandra Whitelson of McMaster University in Ontario says that the study is "very interesting" because it takes a "complex cognitive ability [episodic memory] and shows that it is associated with a brain structure."
