One of two separate areas of the brain light up when younger people look at a house or a face, but each image activates both areas of the brain at the same time in older persons, according to a study published by Yale University and the University of Illinois, Urbana-Champaign, this month in NeuroReport.
Although the researchers cannot say for sure, one theory that needs further study is that the extra activity in older adults is probably compensation for age-related changes in brain volume or efficiency, according to Christy Marshuetz, assistant professor in the Department of Psychology and a co-author of the study.
The study included a dozen people 18- to 27-years-old, and an equal number of 61- to 80-year-olds. They were asked to remember three images of houses or three images of faces and then asked to decide if another image was from the original set. Functional magnetic resonance imaging was used to track neural changes during these tasks.
Marshuetz said it has been known for some time that there are different regions in the inferior temporal lobes of the brain that respond to faces and to photographs of houses. It is also well established that as humans age, both neural and cognitive function become less differentiated. But the data is sparse and previous studies have examined neural activity only during passive viewing.