Vol 4 Test 4 Part 4

PART 4

You will hear a lecture about a special type of sneezing.

First, you have some time to look at questions 31 to 40.

Now listen carefully and answer questions 31 to 40.

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 behavior 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 or light sneeze is a reflex, meaning it cannot be controlled, and it is very common.

Anywhere between one in ten and one in three people may be affected.

A sneeze is triggered by irritation in the linings of the nostrils.

This leads to a cascade of reactions — stimulation of nerve endings across the face, followed by an explosive expulsion of air at up to 95 miles per hour.

The speed is so powerful it resembles a localized hurricane reflex.

Interest in photic sneezing dates back thousands of years.

Greek philosopher Aristotle asked why sunlight prompts sneezing, but fire heat does not.

A partial explanation came 2,000 years later, when Francis Bacon proved the sneeze was not caused by heat.

He found that closing his eyes prevented sneezing even though heat exposure remained unchanged.

In 1964, Henry Everett, a psychiatrist consultant at John Hopkins University Hospital, made the first systematic attempt to study the condition.

He observed that 30% of medical staff were photic sneezers.

Everett discovered a genetic link — 80% of photic sneezers reported having relatives who also sneeze in light, compared with 20% among non-sneezers.

There are known indicators of a photic sneeze:

1. It occurs a fixed number of times after light exposure.

2. It requires visible brightness contrast, such as sunlight emerging from behind clouds.

3. It does not repeat immediately — the reflex needs time to recharge.

Returning to darkness then immediately entering bright light will not trigger another sneeze.

The disorder was once ignored because its impact is usually not serious.

The government studied it once as a risk factor for pilots.

However, research on simple nervous reflexes like this may help unlock discoveries in acute conditions such as migraine, epilepsy, or nervous system cross-wiring disorders.

That is why I encourage you to choose a similar topic for your first investigative medical research project.

It could be the beginning of something very useful.

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