Touch is perhaps the most intimate of the senses. When you grasp or brush against an object—anything from an outstretched hand to a leather-bound book—you are physically as close to it as you can possibly be. At that moment, specialized skin cells convey a wealth of information, such as shape, texture, size, and weight. Yet when you stop touching that object, much of that information appears to fade away rather quickly. After a few days, you may only be able to bring a vague impression to mind. It would seem then that the sense of touch is largely useful in the moment, and not much after that.
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