With a fragrance (芳香) through the bedrooms of older adults for two hours every night for six months, memories skyrocketed. Participants in this study by University of California, Irvine (UCI)neuroscientists gained a 226% increase in cognitive capacity compared to the control group. The researchers say the finding transforms the long-known tie between smell and memory into an easy, non-invasive technique for strengthening memory and potentially preventing dementia (痴呆).

The project was conducted through the UCI Center for the Neurobiology of Learning & Memory. It involved men and women aged 60 to 85 without memory impairment. All were given seven small containers, each containing a single and different natural oil. People in the enriched group received full-strength oils. Control group participants were given the oils in tiny amounts. Participants put a different container into their room each evening prior to going to bed, and it activated for two hours as they slept.

People in the enriched group showed a 226% increase in cognitive performance compared to the control group, as measured by a word list test commonly used to evaluate memory. Participants also reported sleeping more soundly. The researchers say the results from their study bear out what scientists learned about the connection between smell and memory.

Scientists have long known that the loss of ability to smell, can predict development of nearly 70 neurological and psychiatric diseases. These include Alzheimer's and other dementias, Parkinson's and alcoholism. Researchers have previously found that exposing people with moderate dementia to up to 40 different smells twice a day over a period of time improved their memories and language skills, eased depression and improved their sense of smell.

The team would next like to study the technique's impact on people with diagnosed cognitive loss. A product based on their study and designed for people to use at home is expected to come onto the market this fall.