In the above image, two rectangles of different widths and uniform colors (gray) are placed on the background with a gradient from dark to light from top to bottom. The two rectangles look lighter at the top and darker at the bottom. Due to lateral suppression, light from the top of each rectangle (relative to the darker background) produces a stronger neuronal response in the brain than the same light from the lower part of the rectangle (relative to the brighter background). Lateral inhibition also occurs in tactile or somatosensory perception. The sense of touch is sensed by activating neural receptors in the skin. There are multiple receptors on the skin that feel pressure. Lateral suppression enhances the contrast between stronger and weaker touch signals. A stronger signal (at the point of contact) has a weaker signal (the periphery of the contact point) that suppresses adjacent signals to a greater extent. This activity allows the brain to determine the exact point of contact. Body regions with greater contact acuity, such as fingertips and tongues, have a smaller receptive field and a higher concentration of sensory receptors.