Surgery – Diagnostic testing – Detecting brain electric signal
Reexamination Certificate
2000-02-14
2001-10-02
Lacyk, John P. (Department: 3736)
Surgery
Diagnostic testing
Detecting brain electric signal
Reexamination Certificate
active
06298263
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to odour evaluation and odour selection.
BACKGROUND OF THE INVENTION
In designing a new fragrance many considerations have to be taken into account. First and foremost is the need to have an aesthetically acceptable and safe blend of odorous ingredients which perform adequately in the product form which will be used by consumers. However, it is increasingly important that a fragrance is also designed as far as possible to support the intended market positioning and emotional values of a product. For example, the odour may be required to be compatible with and appropriate for a “caring/reassuring” positioning or to connote “fresh, clean, invigorating”. Achieving these objectives lies within the skill and experience of skilled perfumers and perfumery experts, supported by consumer research and related fields. Nevertheless, despite the combined best efforts of all involved it is still remarkably difficult to design and select successful fragrances, particularly in new odour areas.
It is particularly difficult to gain an understanding of how consumers will perceive a fragrance in terms of positioning in advance of launching a product. Some associations can be probed by consumer research techniques such as surveys and focus groups. These improve our understanding of product attributes and consumer attributes, preferences and sensitivity. However, it is likely there will be also implicit, non-conscious associations which the consumer will not be able or willing to verbalise spontaneously and which could elude even the most probing questioning. The objective of this invention is to probe these implicit associations as a basis to aid odour selection and fragrance design.
SUMMARY OF THE INVENTION
In one aspect the present invention provides a method of odour evaluation for evaluating an odour in relation to a target, comprising testing a subject by presenting the subject with one or more odours under different conditions, at least some being in the presence of one or more targets; monitoring brain activity of the subject; and evaluating the monitored brain activity in relation to odour/target combinations presented to the subject.
Experiments by the present inventors have shown that if a subject is presented with a related odour and target (eg a rose odour and a visual image of a rose) at the same time, the brain activity of the subject is different from that in other circumstances, namely when presented with a less related odour and target (eg a rose odour and a visual image of a flower that is not a rose), an unrelated odour and target (eg a rose odour and an unrelated, non-floral visual image), a target but no odour, or an odour but no target. Brain activity can thus provide an objective measure of the relatedness (or congruence) of an odour and target.
Evaluation of brain activity for odour/target combinations presented to a subject can thus provide a measure of the degree of association between the odour and target in a particular odour/target combinations. These measures can be compared and used as a basis of odour selection, as will be described below.
It is preferred to monitor electrical activity of the brain, preferably event-related potentials (ERPs) which are conveniently monitored using electroencephalography (EEG). Electrical activity on the subject's scape midline at least is preferably monitored.
EEG provides a gross measure of the electrical activity of the brain recorded from the surface of the scalp. In monopolar recording, one electrode is placed above a particular brain structure and the other to a reference point, for example an earlobe. In biopolar recording, the EEG signal is recorded between electrodes placed at two active sites.
The scalp activity reflects the sum of electrical events throughout the head. These include brain activity but also electrical signals from skin, muscles, blood and eyes. Thus if the EEG is to be free of ‘artefacts’ the subject is required to be still and sensorily isolated. Clinically EEG is useful as a diagnostic tool enabling some recognisable EEG wave forms to be identified which are associated with particular states of consciousness or particular types of cerebral pathology.
Spontaneous EEG has been used to show correlations between psychometric properties of odour and spontaneous brain activity in real time following olfactive events.
Event-related potentials are characteristic wave forms associated with a particular stimulus or event. For example, the sensory evoked potential is the change in the cortical EEG signal elicited by the momentary presentation of a sensory stimulus. The stimulus is presented for a very short period of time, typically 10 msecs, and events are recorded for up to 2 seconds after stimulus presentation. The background EEG is often too noisy to see ERPs, thus the experiment needs to be repeated a large number of times and identical scans averaged to yield a high signal:noise ratio. For odour this could typically be 40-100 scans.
Each peak or wave of the elicited ERPs is characterised by whether it is positive or negative and by its latency. For example, the P300 wave is the positive wave that usually occurs about 300 msec after a momentary stimulus only if it has considerable meaning for the subject. In contrast, the small waves recorded in the first few milliseconds after a stimulus are not easily influenced by changing the meaning of the stimulus. They represent primary sensory processing in the brain. Later signals, from say 100 msec, change their characteristics according to the meaning or context of the stimulus. These later potentials are referred to as “event-related potentials” or “cognitive evoked potentials”.
Good results have been obtained by studying variations in the N400 potential, ie the negative peak occurring between about 350 and 600 msec after presentation of the target stimulus. It has been found that the N400 deflection is significantly greater if there is no match or congruence between a simultaneously presented odour and target, enabling identification of related or congruent odour/target combinations. Readings from electrodes on the scalp midline, eg at the frontal midline position (Fz) and the parietal midline position (Pz), have been found particularly useful.
EEG is a particularly useful method for monitoring brain response. EEG can be used both qualitatively and quantitatively; there are a variety of reliable instruments commercially available to record EEG; the measurements can be obtained from electrodes attached to the surface of a subject's scalp with a minimum of discomfort; the number and location of electrodes and can be adjusted to focus on specific structures; the timecourse of activity can be monitored either in real time (for spontaneous activity with or without a stimulus) or following presentation of a stimulus; and finally the frequency of the brain activity can be measured (eg the “alpha” frequency waveband lies between 8 and 13 Hz).
It is known that brain waves change during the perception of odours. This has been related to familiarity, intensity and pleasantness in the frontal region for spontaneous EEG. Although no systematic patterns were identified, it was hypothesised that activity measured in a frontal region was related to evaluation of odour.
Odour can affect mood and this topic has been discussed (J S Jellinek (1994)), Aromachology: A status review. Perfumer and Flavourist, 19, 25-49) under the title of Aromachology. Aromatherapy involves changing physical and psychological states by massage and essential oils topically applied neat or in a neutral carrier.
Work has been carried out investigating changes in visual evoked potentials in the presence of odour. This work primarily investigated odour labelling, and found that presentation of the odour coupled with the requirement to accurately label it evokes a slow negativity which peaks at about 280 msec post-label and lasts until about 900 msec. The labelling process requires recall and recognition and as such is an “explicit” process requiring consc
Behan John Martin
Grigor Joanne Allison
Richardson Anne
Sarfarazi Mehri
Sedgwick Edward Michael
Lacyk John P.
Natniththadha N
Pillsbury & Winthrop LLP
Quest International B.V.
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