Extreme Senses

Sensation is an amazing and necessary part of normal bodily function. Although we use our senses all the time, do you know the human limits to each one?

The formal definition of sensation is: the body's ability for our sense organs (such as the eyes) to bring information in our surrounding environment to our brain as neural messages. This is so that this information can be processed into order, which then enables us to perceive what we have encountered.

Our ability to 'sense things' have captivated psychologists for many years, during this time they have been able to measure the limits of 'normal' sensory limits. Most people believe there are only 5 senses, this is untrue.

There are actually 9, which include:

Taste

Vision

Hearing

Smell

Temperature

Pain

Kinesthesis (the sensation of movement)

Touch (or pressure)

Vestibular sensation (balance)

Here are some incredible examples of testing some of the human senses to the absolute threshold.

Taste - Taste buds can actually register the taste of salt when 1 gram has been dissolved in 500 litres of water.
The tongue can also register sweetness, when 1 teaspoon of sugar has been dissolved in 9 litres of water (this probably differs with smoker's taste buds, as they are damaged from the chemicals in cigarettes).

Vision - The eye can detect the light from candle situated 48 kilometers away on an unpolluted, dark night (I know this sounds unbelievable, but it is true).

Hearing - When the conditions are quiet enough, the ear can hear the tick of a wristwatch from 6 meters away.
In an empty auditorium a whisper from one end can be heard at the other end.

Temperature - The change of only 1 degree in the skins temperature can be easily detected by the body.

Touch - A bee's wing dropped from only 1cm away from the face can be felt by the individual.

Smell - 1 drop of perfume infused into the volume of a room equivalent to the size of 6 roomed house can be detected by the nose. A smell inhaled and registered for the first time, can be recognized 1 year later (without any exposure to it until then).

Pain - Pain is subjective, which means it is very individual for each person. Pain should never be compared. Some people can bear excruciating pain, and some are very sensitive to it.

- Louise Ganey