The Daily Telegraph - Features
Our sense of smell is a hard-wired alarm system
The odours etched into the wiring of our brain
Smells and odours evoke the past most vividly of all the senses, recalling not just memories but the feeling of actually being there. For a former deputy editor of this paper, Colin Welch, “the reek of explosives or burning, of cider or calvados” would transport him back 40 years when, as a young soldier, he participated in the Normandy landings. “Unbidden memories bring back those times and I shudder.”
Psychologists seeking to explain this “Proustian” quality of odours have suggested that they are etched more deeply into the wiring of the brain than the other senses because, paradoxically, they are so difficult to pin down. There are many cues to help us recall a person’s face or the sound of a voice, but it is very difficult to imagine what a smell is like – or even give it a name.
Perhaps, but smell perception certainly fulfils an important biological function, most obviously in alerting us to the hazard of foods no longer fit for consumption. But also: “Parents typically report the odour of their baby as the pleasantest of scents,” notes Dr Thomas Hummel of the University of Dresden in an extended review of how odours foster parental bonding. Within hours of giving birth, studies have shown, mothers can distinguish the smell of their child from that of other babies. And so too, apparently, “infants learn to recognise their mother’s individual odour”.
Most recently, as reported in this paper a fortnight ago, scientists have taken their investigations a step further by identifying the specific chemicals involved – distinguishing between those secreted by babies from that of adolescents. For the former, chemicals with a flowery or vanilla “odour attribute” predominate, to be replaced, following the hormonal surge of puberty, by the sweaty, musky and “goat-like”.
No surprises there, but disagreeable body odours in children, paediatrician Dr Michael
Farnham observes, should always prompt a thorough search for their cause. “For a couple of months, a three-year-old girl had been afflicted by an odour so unpleasant that the teacher at her nursery school had had to ban her from the classroom,” he reports. A thorough examination of her nose disclosed a piece of bathroom sponge with the same foul odour. Within an hour of its removal she was smelling sweetly again.
An unfathomable pain in the jaw
This week’s query comes from Mr JP, of Cheltenham, who was always “healthy and active” until a few months ago when he awoke with a severe pain in his jaw lasting half an hour. Since then he has had further episodes. “These leave me feeling exhausted with very tender gums,” he says. Coincidentally or not, he has also been troubled by pain across the shoulders, usually at mealtimes, which prompted his referral to hospital. But several investigations, including an angiogram, proved negative. “My doctors have been very thorough,” he writes, describing it as “frustrating” that his symptoms remain unaccounted for. Any suggestions would be gratefully received.
Check your ‘cocktail’ of drugs
Finally, further to forgetfulness (or mild cognitive impairment) as a side effect of several different types of medicine – as recently mentioned – a family doctor describes how after a heart attack he was prescribed “the usual cocktail of drugs”. On returning to work, he had difficulty concentrating and colleagues “commented on errors creeping into my work, such as not dealing correctly with blood test results”. He eventually consulted his own GP, who advised he discontinue his cholesterollowering Simvastatin. “Within the week, my powers of concentration and energy levels had returned to normal.”