Researchers recruited adults from the Washington University in St. Louis Alzheimer's Disease Research Center to participate in a study on memory efficiency in early stage Alzheimer's. Participants included 109 healthy older adults (average age of almost 75), 41 people with very early Alzheimer's disease (average age of almost 76), 13 people with mild (early) Alzheimer's (average age of almost 77), and 35 younger adults (all 25 or under). Participants were asked to memorize certain neutral words, each of which was assigned a different point value. They were then asked to remember the items, striving for the greatest point value when the items they recalled were added up. While all participants remembered more high-value than low-value items, the Alzheimer's groups were significantly less able than the healthy participants to remember items according to their value.

According to the researchers, this suggests that even people with early stage Alzheimer's become less efficient at separating important information from less important information. In the study, which was published in the American Psychological Association's May issue of Neuropsychology, the researchers "speculated that Alzheimer's disease makes it harder for people to encode what they learn in a strategic way. Because encoding is the first step in long-term memory, this affects their ability to remember things according to their value." Knowing this may enable clinicians to train people with early-stage Alzheimer's to be more strategic and selective when encoding high-value information.