Лако-красочные материалы — производство

Olfaction is a powerfully emotive sense. An odour has the ability to remind us of the past; for instance, to bring back memories of situations from our youth, or to remind us of friends or family. It also has the ability to promote feelings of relaxation or comfort, a property which is made much of by aromatherapists, who also use it to aid the therapeu­tic properties of massage.

The process by which olfactory messages are interpreted is not yet fully understood, but it is known that olfactory messages are trans­mitted from the olfactory bulb along the olfactory nerve directly to the brain, where the path of the message divides into two. One route passes into the olfactory cortex at the front of the brain where identification and differentiation between odours occurs; the other passes into the limbic system at the centre of the brain. The limbic system is believed to be the emotional centre of the brain and it is here that many sensory messages are received and interpreted.

It is believed that this close link between the olfactive sense and the limbic region is the reason for such a close association between smell and emotion. To try to understand this link, researchers have studied the workings of the brain itself. Until recently, few data were available that characterized the nature of odour processing in the brain centres higher than the olfactory bulb. The problem lay in the complexity of the higher brain structures, the lack of understanding of brain mechan­isms and the difficulty of detecting and locating brain activity. There is now a variety of imaging techniques that have been developed to investigate the structure and functionality of the brain.

Brain imaging methods were primarily developed for two purposes: firstly, to visualize structural information about the brain, and secondly to measure its functioning. The methods have developed to facilitate clinical knowledge, diagnosis and treatment and each has its limitations when applied to functional research studies such as olfaction. The chief methods used for visualizing the living brain include standard radio­graphic methods, contrast radiography, computerized axial tomogra­phy, magnetic resonance imaging, positron emission tomography and electroencephalography (EEG).

At Quest, we use spontaneous EEG to measure electrical activity of the brain from the surface of the scalp. A widely available technique, this is also extremely resource-intensive; a typical clinical session may take several hours to complete, including the preparation of the subject, the EEG experiment and collation of the resultant data. The vast amounts of data recorded take time to digitize, summarize and analyse.

In our work we have found significant differences in the quantitative and topographic changes in brain activity recorded from the scalp following presentation of a range of odour types, and relationships have been found between specific features of the recorded signals and measurable effects of the same stimuli on moods or feelings.