This is the 2007 version. Click here for the 2017 chapter 04 table of contents.

Extra Sensory Perception

Could there be more senses beyond the seven we have considered already in this chapter? Certainly there are. If sensation is defined as sensitivity to specific classes of stimuli, then researchers have documented many "extra" sensory capabilities. However, there is a crucial difference between extra sensory abilities (those in addition to the classic senses we have considered) and extrasensory abilities (those involving "psi energy" or other as-yet unverified powers of the mind). In this part of the chapter we will consider both categories.

Natural but Unusual Forms of Perception

Several forms of sensory detection are outside the normal list of seven senses (visual, auditory, olfactory, gustatory, cutaneous, kinesthetic, equilibratory). These forms of sensory detection are not ESP (extrasensory perception) because they all involve known mechanisms. Normal physical processes can explain them. All can be studied in replicable experiments.

Infrared sensitivity

What is radiant heat?

Radiant heat sensitivity is highly developed in humans. Radiant heat is infrared radiation. It is electromagnetic radiation, like light, but it is outside the visible spectrum. The most efficient non-living surface for absorbing heat is black, which is why dark surfaces get hot in the sun. Black surfaces are about 90% efficient in absorbing radiant heat. Human skin (even untanned white skin) is about 95% efficient in absorbing and radiating infrared radiation (Barnes, 1963).

How could infrared sensitivity lead you to sense that a person has entered the room behind you?

Why should human skin be so efficient in absorbing or radiating infrared? It aids temperature regulation. On hot days, we can radiate heat efficiently; on cold days we can absorb a surprising amount of heat from glowing coals or a small fire. On a cold day in a wintry climate, you can feel a wood stove across the room, or a lightbulb turning on, or a person next to you, just by the heat. This may account for some reports of mysterious intuitions about people entering a room. Even if you cannot see them or hear them, you might feel them.

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