Complete the notes below. Write ONE WORD ONLY for each answer.
Photic sneezing
Background
Some people react to sunlight by:
a prickle in the nose
faster 31 ________ relieved by a sneeze
watery eyes
This ‘photic’ sneeze cannot be controlled and is a 32 ________ reflex.
Sneezing in general
A sneeze is caused by some kind of irritation in the nose.
Nerve endings in the 33 ________ are stimulated, leading to an explosion of air.
It is co-ordinated by the same mechanism that controls the production of 34 ________.
Research into photic sneezing
The condition has been known for thousands of years.
Aristotle: Why does the sun cause sneezing while a 35 ________ does not?
Bacon showed the cause was light.
Everett found 80% of photic sneezers shared the habit with 36 ________.
Indicators
Photic sneezers usually produce the same 37 ________ of sneezes.
The reaction is caused by a 38 ________ in brightness.
The sneeze takes 39 ________ to recharge.
Application
The condition was often ignored apart from some research on photic sneezing among 40 ________.
But studying it may result in breakthroughs for more serious conditions.
Keys
breathing
common
face
tears
fire
relatives
number
contrast
time
pilots
Transcripts
Part 4
You will hear a lecture about a special type of sneezing.
Welcome to this lecture in the health sciences, intended to inspire you and get you thinking about your research project. Today, I want to show you how even ordinary human behaviour, like sneezing, which normally happens when you get a cold, may be worth studying.
Have you ever been walking outside when a bright shaft of sunlight hits you between the eyes? The reaction of some people is immediate: an unpleasant prickling in the nose, an increase in their breathing rate, and an uncontrollable watering of the eyes. Then, almost as quickly, they sneeze and gain relief. This may happen every time they go into the sun.
This so-called photic sneeze or light sneeze is a reflex, which means it can’t be controlled, and it’s very common. Anything between one in ten and one in three people might be affected. In fact, a sneeze is triggered by an irritation of some sort in the linings of the nostrils. The result is a cascade of reactions, beginning with the stimulation of the nerve endings all over the face, and generating an explosive expulsion of air at up to 95 miles an hour — like an extremely localised personal hurricane.
The body’s coordination of such reactions is complicated, and belongs to the subconscious control hardware that regulates other things, for example, tears in the eyes.
People have been interested in the phenomenon of photic sneezing for thousands of years. The Greek philosopher Aristotle once asked, “Why does the sun prompt us to sneeze, whereas the heat of a fire does not?” A partial answer came two thousand years later, when the English philosopher Francis Bacon showed that his photic sneeze had nothing to do with heat. If he closed his eyes when going into the sun, he didn’t sneeze, even though the heat was still there.
Henry Everett, a consultant psychiatrist at Johns Hopkins University Hospital in Baltimore, was the first to make a systematic attempt to understand the condition, noting in 1964 that 30% of the staff employed in the medical department were photic sneezers. Everett did some further investigation. He found that while 80% of sneezers reported other sneezers among their relatives, only 20% of non-sneezers did.
Now there are factors that are certain indicators of a photic sneeze. First of all, those with the condition almost always sneeze a set number of times on exposure to light. In addition to this, the sneeze depends on a contrast in visible brightness — such as when the sun moves out from behind a cloud — and the sneezing fit won’t be repeated immediately. The body needs time before it can be recharged. So if you go back into a darkened space and then immediately re-enter bright light, you will not sneeze again.
Now, on to possible applications of research in this area. The photic sneeze had long been overlooked, because its effects are generally less than serious, although the government did once study it as a risk factor for pilots. Yet work on such a simple disorder might lead to important discoveries on more acute conditions, such as migraine or epilepsy, which are also caused by cross-wires in the nervous system. That is why I encourage you to select something similar for your first investigative medical project. It could be the beginning of something even more useful.
