There is a compelling amount of evidence that suggests the use of aromas can help to improve a learning environment. By stimulating the learners' sense of smell you can make them feel more alert, more relaxed and even improve their long term memory.

For some time now, development professionals have been using visuals, lighting and music to create the optimum learning environment. Not much attention has been paid to the use of aromas.

The whole process of smelling an odour is not merely a result of chemical detection, but it is also influenced by what we have learned about the odour. Now, researchers have discovered how such "perceptual learning" about an odour influences processing of information and is not just about smelling.

Even by using careful labelling, it's easy to measure how we perceive an odour before we even smell it; think about what you might smell before breathing in a scent, depending on whether something is labelled as "fresh cucumber" or "mildew".

Scientist have identified regions of the cortex involved in coding odours; and MRI scans revealed increases in response in the odour-processing areas of our brains that reflected learning. The part of our brain that handles smell - the piriform cortex - is right next door to that responsible for memory and emotion. This has led to our memories becoming intrinsically and strongly linked with odour.

Smell can evoke the emotions surrounding an experience, and it can prompt and even recreate those emotions.

A growing body of research is showing that because of this, smell can be used to improve recall: students who learn in a room infused with the scent of rosemary or lavender are able to remember far more information when they encounter that smell again.

And a study at Harvard University has shown that volunteers who were exposed to bursts of rose scent as they slept after studying were better able to recall the material, even without being exposed to the scent again. The odour intensified the transfer of information to the hippocampus, the part of the brain responsible for forming longer-term memories.

Other research has shown that it is not just memory that odour can affect. Scientists in Germany found that the smell of roses led to people having pleasant dreams, while a whiff of rotten eggs gave them bad dreams. The presence of jasmine in a room has been found to improve volunteers' problem-solving abilities, while peppermint and cinnamon can boost working memory and the ability to concentrate.

Smell can affect physical performance, too. By administering peppermint odours to weightlifters as they trained, they were able to increase the number of repetitions and demonstrated better endurance in the presence of the odour.

The Japanese have been using aromas to improve performance for some time now. In one large company, different odours are diffused into the entire work environment throughout the day. At the start of the day and after lunch a citrus scent is used to stimulate the workforce. Floral aromas are used in the afternoon to improve concentration and wood scents such as cedar are used in the evening to promote calm. By rotating the aromas and timing in relation to how people are feeling at particular times of the day, significant improvements in performance have been achieved. In a similar way, you can use aromas throughout a learning environment, making broad assumptions about the learners' state at any point during the day.

If you are planning on using odours to aid, for example, learning during a PowerPoint, then there are a number of factors that you need to consider when choosing which aroma to use.

The time of day.
Generally, learners will require more stimulating aromas first thing in the morning and immediately after lunch.

The learners' state
All learners are different. While you may have planned the learning environment in advance, and you should be able to make changes if you need to. For example, if a group seem more lethargic than you had anticipated then using lavender would only make matters worse - you could try using lemon to stimulate learning instead.

Obviously it is not going to be practical or safe to use methods such as candles and oil burners during a presentation, but you could consider other ways of diffusing the aromas before you set up your PowerPoint.

There are a number of methods for diffusing aromas in a learning environment and these are listed below. The aim is to create an atmosphere where the aroma is barely perceptible so it is important to be economical whichever method you decide on.

Electric aromatherapy diffusers can be used to disperse the aromas from aromatherapy oils.

A wide variety of room sprays are available and are a good way of creating a different atmosphere quickly.

Potpourri can be used to disperse floral aromas.

Cotton balls with drops of essential oil on them can be placed throughout the room.

Lavender is sometimes called the student's herb because of its long association with relaxation and ability to aid concentration. It has been shown to have similarly beneficial effects on performance to peppermint, especially when there is a form of pressure put onto the learners such as a time limit. Lavender also has uses during the breaks of a learning event. A recent study showed how the use of lavender during breaks helped to improve performance afterwards.

Research presented to the British Psychology Society showed that when the scent of rosemary was present during a learning activity, the long-term memory of the learners improved by about 15%.

Now, isn't it time you thought about the sweet smell of success you will create with your next PowerPoint presentation?