These words are comparable but not closely synonymous when used to refer to a response to a stimulus or to the ability to make such a response. In a technical sense, sensation is applicable to an impression originating either from within or from outside the body and conveyed to the nervous system by the organs of seeing, hearing, touching, tasting or smelling. The word does not necessarily imply an identification of the stimulus: to experience a sensation of warmth. In general usage, the meaning of sensation is extended to include not only sensing but also the attendant emotional and mental responses: to have a sensation that everyone in the room is staring at you; a recollection that brought a sensation of sadness.

Sense , as here considered, may refer strictly to the physical agencies (taste, touch, sight, hearing and smell) by or through which a person or animal receives impressions from outside his own organism. In the plural it is applicable to the total awareness of the world about one: After the accident he came to his senses in a hospital bed. Whatever one experiences through the senses is a sensation.

Perception in this context involves interpretation of a stimulus and recognition of the object that produces a sensation . Perception is always based on earlier experience and is the process by which one becomes acquainted with his environment. Whereas a sensation does not suggest the agency of the mind, perception implies that the stimulus creating a sensation has been registered, however unconsciously, on the brain ?checked in, as it were, like a guest in a hotel.

Percept , closely related in meaning to perception , is a term in psychology and is applied to the immediate knowledge and recognition of an external object gained by perceiving it. A dog will have the sensation of seeing or even of smelling a chair; he knows that it is an obstacle to be walked round, but he will gain no percept or perception of what a chair actually is.

Feeling , the most general term in the group; is sometimes used loosely in place of sense , sensation and perception . More precisely, feeling applies to the faculty by which one perceives sensations of pain, pressure, heat and cold, contact, etc. It may refer also to kinaesthesia ?the perception of muscular movement, tension or tone derived from the functioning of nerves connected with muscle tissue, skin, joints and tendons: After his spinal injury, he had no feeling in his legs.