Lauren Bussey said: "In this study we focused on prospective memory. This involves the ability to remember events that will occur in the future and to remember to complete tasks at particular times. It's critical for everyday functioning. For example: when someone needs to remember to post a letter or to take medication at a particular time."
Rosemary and lavender essential oil were diffused in a testing room by placing four drops on an aroma stream fan diffuser and switching this on five minutes before the participants entered the room. A total of 150 people aged over 65 took part in the study and were randomly allocated to either the rosemary/lavender-scented room or another room with no scent.
Once in the room they undertook tests designed to assess their prospective memory functions. These included remembering to pass on a message at a given time during the procedure, and switching tasks when a specific event occurred. These tasks represent the two components of prospective memory: time-based (remembering to do something at a specific time such as watch a TV show) and event-based (remembering to do something due to an environmental cue such as posting a letter after seeing a post box).
Participants also completed mood assessment before and after undertaking tests in the scented or non-scented rooms.
Analysis of the results showed that the rosemary aroma significantly enhanced prospective memory compared to the room with no aroma. In terms of mood, rosemary significantly increased alertness and lavender significantly increased calmness and contentedness compared to the no aroma control condition