industrial design engineering, royal college of art david sweeney ...

industrial design engineering, royal college of art david sweeney 2007
subsequently experience these sensorial stimuli, the related emotions, and therefore the
memories of the event, are evoked. Lots of things evoke memories, any of the senses,
emotions, other thoughts or other memories. Of all the senses however, olfaction is the
most evocative, and these memories that are evoked are considered to be of a more emotional
nature. This is due to the fact that the olfactory bulb (receptor) terminates deep
within the Limbic system, which is known to be the seat of emotional processing.
Everybody has a hunch that smells have a special relationship with memory, a momentary
reintroduction with an ex-girlfriend’s perfume alters the train of thought and affects on the
emotions, the smell of Play-doh, etc. Prof. Rachel Herz has presented other substantiation
of the smell-evoked memory phenomenon; she claims that there is clear evidence that improvement
of memory resulted from the presence of an ambient odour occurring in both
the learning and recall stages. She summarises her hypothesis that odour hedonic perception
and odour related behaviour results from a learned association between an odour and
an emotional context in which the odour was first encountered. She imparts evidence for
possible odour associative learning and describes its simple mechanism as follows:
1. The emotion paired with the odour imbues it with meaning.
2. The odour can subsequently recall the emotion.
This recalled emotion could then initiate a stream of connected memories, which were
created at the time of first exposure of the smell.
Why this is important can be understood if we realise that every odour that we have ever
smelt has previously been associated with the emotion that was present during the first
encounter with the smell, maybe not definitively, but it will have ultimately effected future
perception in some way. Herz, in order to carry out her experiments to observe whether a
smell can prompt recall of memory, needed to employ a novel smell as the target odour.
The test required that no emotion had previously been attached to the smell in the past;
this was to ensure that the learning experience during the test would have been the unique
association of the scent, i.e. a smell with only one association, and that association was
controlled to occur within the test environment.
A novel smell is a clean slate for associating emotions to.
While a number of companies have produced aroma generators designed to enhance
computer games or TV shows, they have failed commercially because they have been
very limited in the range of smells they can produce.
Before I explain the direction I am proposing to take, I just want to run over a few points
regarding the sensation of smell:
Firstly, to state the most important, empirical fact in olfaction:
“No two molecules differing in structure have ever been found to smell identical”
Luca Turin, 2006
What does this mean? To create the sensation of yellow (experience the quale that is yellow),
I can shine a yellow lamp OR I can shine both a green and a red lamp. Green and
Red can be considered to be primary colours. This doesn’t apply to smells. Good approximations
are possible, but there are over 350 different types of receptors in the nose (compared
to just four in the retina). The old lock and key theories of smell perception could infer
that this limits the number of possible primary odours to 350. Only recently, the vibration
theory of smell perception has been accepted as the probable mechanism for the
sensation of odour, and this shatters the concept of primary smells. So, unless you want to
create a smell that is a mixture of just the smells in your primary scent collection, you can
5