One of the most common complaint in the neuropsychologist´s office is the one of dwindling memory. People of all ages complain of their memory. Many worry about developing Alzheimer´s disease, even those who have yet not reached middle age. Alzheimer´s disease can certainly affect younger people but it is quite rare. Others worry about having brain injury as a result of a whiplash injury or a minor concussion.
People often seem to have quite unrealistic expectations about what normal memory should be like. They often seem to expect their memory to be perfect which healthy memory rarely is. Normal memory actually is often unreliable, erratic and quite malleable. People also have trouble disentangling memory problems from other cognitive difficulties such as those related to complex attentional functions. They sometimes also confuse memory and language problems. In other words, there is a general tendency to label all cognitive lapses as memory problems. Have you ever heard anyone complain of problems with judgment or visuospatial difficulties? François de La Rochefoucauld, a French 17. century author, was well aware of this and is quoted as having said: “Everyone complains of his memory, and nobody complains of his judgment.” He was right!
Individuals who complain of deficits in memory or attention often obtain normal scores on neuropsychological tests of memory and attention when tested in the neuropsychologist´s office. When asked to give examples of how memory and concentration impairments affect their daily lives, they frequently report what appear to be minor lapses, such as forgetting to stop at the grocery store on the way home from work or opening the refrigerator and not remembering what they were looking for. Such lapses happen to all of us and when they happen to healthy individuals with no history of concussion or whiplash injury we generally attribute them to absent-mindedness. Fortunately, these lapses are generally only a source of inconvenience, amusement or, at worst, embarrassment. However, “minor” lapses of attention, or action slips as they have also been called, can also have catastrophic consequences when high-risk technology is involved, such as nuclear power plants or passenger jets. I investigated the frequency of those normal lapses of memory and attention by having 189 healthy Icelanders record in a diary their memory and attentional lapses during one week. It turned out that they were quite common, the mean number of lapses was just over six per week. One can assume that this is an underestimation as it is likely that some lapses were forgotten and therefore not written down. The lapses were least frequent during weekends and in the evening when people generally are less busy and therefore less distracted. So, next time you have what now often is called a “senior moment” remember that there are other, and more likely, causes to this than brain injury or Alzheimer´s disease!
An article about this research appeared in the Guardian: http://www.guardian.co.uk/science/2007/jul/29/1