Sensory Perception involves the conscious organization and translation of the data or stimuli into
meaningful information. Sensory perception depends on the sensory receptors, reticular activating system
(RAS), and functioning nervous pathways to the brain. The RAS influences awareness of stimuli, which are
received through the five senses: sight, hearing, touch, smell, and taste. Kinaesthetic and visceral senses are
stimulated internally.
RETICULAR ACTIVATING SYSTEM (RAS)
It is responsible for bringing together information from the cerebellum and other parts of the brain with the
sense organs. The RAS is highly selective. For example, a parent may be awakened in the middle of the night at
the slightest murmur of an infant in a bedroom down the hall but may sleep through the loud traffic noises
outside the bedroom window. Destruction of the RAS produces coma and an electroencephalograph pattern
characteristic of sleep.
INPUT OF SENSES
Sensory function begins with reception of stimuli by the senses.
Externally, the senses receiving stimuli are
Vision, hearing, smell, taste, and touch
Receptor organs are the eyes, ears, olfactory receptors in the nose, taste buds of the tongue, and nerve endings
in the skin. Internally, the kinaesthetic and visceral senses receive stimuli. These receptors are nerve endings in
the skin and body tissues. The kinaesthetic sense influences awareness of the placement and action of body
parts. The visceral sense receives stimuli that affect awareness related to the body's large interior organs.
Vision, hearing, smell, and taste are termed, special senses. Touch, kinesthetic sensation, and visceral sensation
are termed somatic senses.
After stimuli are received, they are perceived with the help of the RAS. Sensory perception is a consociates
process of selecting, organizing, and interpreting sensory stimuli requiring intact and functioning sense organs,
nervous pathways, and the brain.
CHARACTERISTICS OF NORMAL SENSORY PERCEPTION
These are the normal measures in quality and quantity of the special and somatic senses.
§ NORMAL VISION is associated with visual acuity at or near 20/20, full field of vision, and tricolour
vision (red, green, blue).