Follow Your Nose

A Aromatherapy is the most widely used complementary therapy in the National Health Service, and doctors use it most often for treating dementia. Some elderly patients have difficulty in verbal interaction, on which conventional medicine has little efficacy. For them, aromatherapy can help get better sleep, increase motivation and reduce disturbed behaviour. So the thinking goes. But last year, a systematic review of health care databases found almost no evidence that aromatherapy is effective in the treatment of dementia. Other findings suggest that aromatherapy works only if you believe it will. In reality, the only research that has precisely revealed it to have an effect was carried out on animals.

B Behavioural studies have consistently suggested that odours can elicit emotional memories far more easily than other sensory cues. And earlier this year, Rachel Herz, of Brown University in Providence, Rhode Island, and colleagues peered into people’s heads using functional Magnetic Resonance Imaging (fMRI) to validate that. They scanned the brains of five women while they either watched a photo of a bottle of perfume that evoked a pleasant memory for them, or smelled that perfume. One woman, as an example, thought of how as a child living in Paris – she would look excitedly at her mother who dressed up to go out and sprayed herself with that perfume. The women themselves depicted the perfume as far more evocative than the photo, and Herz and co-workers found that the scent did indeed activate the amygdala and other brain regions associated with emotion processing far more strongly than the photo-graph. But what’s interesting was that the memory itself was not much better recalled by the fragrance than by the picture. ‘People don’t remember any more details or with any more clarity when the memory is recalled with an odour,’ she says. ‘However, you have this intense emotional feeling viscerally with the odour.’

C That’s hardly surprising, Herz thinks, given how the brain has evolved. ‘The way I like to think about it is that emotion and olfaction are essentially the same things,’ she says. ‘The part of the brain controlling emotion literally comes out from the part of the brain controlling smell.’ That, she says, probably explains why memories for odours that are associated with intense emotions are so strongly entrenched in us, because the smell was initially a survival skill: a signal to approach or to avoid.

D Eric Vermetten, a psychiatrist at the University of Utrecht in the Netherlands, says that doctors have long known about the potential of smells to act as traumatic reminders, but the evidence has been largely anecdotal. Last year, Vermetten and others began to study it through three cases of post-traumatic stress disorder (PTSD) in which patients said either that a certain smell triggered their flashbacks, or that a smell was a feature of the flashback itself. The researchers concluded that odours could be made use of in exposure therapy, or for reconditioning patients’ fear responses.

E After Vermetten presented his findings at a conference, doctors in the audience told him how they had turned this association around and put it to good use. PTSD patients often undergo group therapy, but the traumatic reminders can be exposed by the therapy itself. ‘Some clinicians put a strip of vanilla or a strong, pleasant, daily odorant such as coffee under their patients’ noses, so that they have this continuous olfactory stimulation,’ says Vermetten. So armed, the patients seem to be better protected against flashbacks. It’s purely anecdotal, and nobody knows what’s happening in the brain, says Vermetten, but it’s possible that the neural pathways by which the odour elicits the pleasant, everyday memory override the fear-conditioned neural pathways that respond to verbal cues.

F According to Herz, the therapeutic potential of scent could lie in their very unreliability. She has presented with her perfume-bottle experiment that even though the memories the scent elicits feel more real, it doesn’t guarantee any better recall. And there’s plenty of research to show that our noses can be tricked, because being predominantly visual and verbal creatures, we put more faith in those other modalities. In 2001, for example, Gil Morrot, of the National Institute for Agronomic Research in Montpellier, tricked 54 oenology students by colouring a glass of white wine with a scentless red dye in secret just before they were asked to describe the scent of some red and white wines. The students used terms typically reserved for red wines to describe the coloured wine. What’s more, just like experts, they thought of terms alluding to the wine’s redness and darkness-visual rather than olfactory qualities. Smell, the researchers concluded, cannot be separated from the other senses.

G Last July, Jay Gottfried and Ray Dolan of the Wellcome Department of Imaging Neuroscience in London took that research a step further. They tested how much time people need to respond when naming an aroma, by presenting with an image that was associated with the odour or one that was not. Participants were asked to sniff vanilla and simultaneously showed either the picture of ice cream or of cheese. At the same time, their brains were being scanned in an fMRI machine. People named the smells faster when the picture presented something semantically related to them, and when that happened, a structure called the hippocampus was strongly activated. The research-ers’ interpretation was that the hippocampus plays a role in integrating information from the senses – information that the brain then uses to decide what it is perceiving.

Questions 14 – 18

Reading Passage 2 has seven paragraphs, A–G.

Choose the correct heading for paragraphs A, C–E and G from the list of headings below.

Write the correct number, i–ⅸ, in boxes 14–18 on your answer sheet.

List of Headings

i Remembering the past more clearly

ii Bringing back painful memories

iii Originally an alarm signal

iv The physical effects of scent versus image

v Checking unreliable evidence

vi Reinforcing one sense with another

vii Escaping from reliving the past

viii The overriding power of sight and sound

ix Conflicting views

• 14.Paragraph A
• 15.Paragraph C
• 16.Paragraph D
• 17.Paragraph E
• 18.Paragraph G

Questions 19 – 24

Look at the following findings (Questions 19–24) and the list of researchers below.

Match each finding with the correct researcher, A, B, C or D.

Write the correct letter, A, B, C or D, in boxes 19–24 on your answer sheet.

NB You may use any letter more than once.

List of Researchers

A Rachel Herz

B Eric Vermetten

C Gil Morrot

D Jay Gottfried and Ray Dolan

• 19.Smell can trigger images of horrible events.
• 20.Memory cannot get sharper by smell.
• 21.When both the smell and the picture are given, the stimulation to the brain is stronger.
• 22.Pleasant smells counteract unpleasant recollections.
• 23.It is impossible to isolate smell from visual cues.
• 24.The part of the brain that governs emotion is more stimulated by a smell than an image.

Questions 25 – 26

Choose the correct letter, A, B, C or D.

Write the correct letter in boxes 25 and 26 on your answer sheet.

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