Sensation is initiated by the physical stimuli that surround and inhabit the body. As stimuli impinge on receptors, neural impulses are initiated and speed along specific pathways toward destinations in the brain. During sensation assorted influences come into play; the intensity of stimulation, its repetitiousness, and the range and mixture of stimuli. Stimulation may be subliminal, may produce sensory adaptation, or may be less than optimal. Below, describe the phenomenon being described in terms of the concept listed after it.