Stimulation or sensory excitation is the action of various agents or forms of energy (stimuli) on receptors that generate impulses that travel through nerves to the brain.

There are sensory receptors on or near the surface of the body, such as photoreceptors in the retina of the eye, hair cells in the cochlea of the ear, touch receptors in the skin and chemical receptors in the mouth and nasal cavity. There are also sensory receptors in the muscles, joints, digestive tract, and membranes around organs such as the brain, the abdominal cavity, the bladder and the prostate (providing one source of sexual stimulation). Stimulation to the external or internal senses may evoke involuntary activity or guide intentions in action.

When bodily stimulation is perceived, it is traditionally called a sensation, such as a touch, or taste, or smell, or painful ,or pleasurable sensation. This can be thought of as psychological stimulation, which is a stimulus affecting a person’s thinking or feeling processes.

Sexual (erotic) stimulation can be:

  • indirect through
    • visual
    • taste
    • smell
    • touch
    • internal imagery
  • or direct through physical stimulation of the: