Perceiving is a common English word with a number of related colloquial meanings: it is the act of understanding, realizing, seeing, noticing, or becoming aware of. In modern neuroscience, our working definition of perception is captured well by the Oxford English Dictionary: “The action of the mind by which it refers its sensations to an external object as their cause.” This definition has roots in the corpus of eighteenth-century philosophy–beginning with George Berkeley and David Hume–was expanded upon by later British associationists, and became a foundation of both experimental psychology and modern neuroscience.
There are two essential features of this definition, the first being the distinction between perception and sensation. Sensation is the immediate neurobiological consequence of stimulating sensory transducers such as photoreceptors, mechanoreceptors, and chemoreceptors.…
