Computers, meaning, and consciousness.

This paper uses simple arguments to derive a negative conclusion: that a computer cannot be conscious. If the brain is only a neural computer, brains cannot be conscious. Consciousness implies that there is something else happening in the brain, besides computation. In a running computer, information about outside events is encoded, to enable physical computation. The information required to decode the information (e.g. to interpret volts as bits, or neuron spike trains as numbers) is not inside the computer. The meaning of any computation is not defined inside the computer; it is only defined by some external entity which decodes the results. Without decoding information, a computer contains no information about outside events. In the same way, the meaning of any book is not defined inside the book; the book requires outside knowledge to read it. Consciousness contains meaningful information about external events. If the brain is only a computer, without decoding (which requires external information) it contains no information about external events. If the brain is only a computer, consciousness cannot be realised by events inside the brain. This conclusion is compared with philosophical positions on computational functionalism, representation, and intentionality. Something more than neural computing must be happening in the brain. One suggestion is that the something could be an analogue model of 3-D space. An analogue model contains information which requires little or no decoding. Hence, an analogue model of reality in the brain might be the source of consciousness. This merits further investigation.