Minimum brain size for consciousness?

In the limit, how small can a brain get and still host an identifiably human-like consciousness?

Obviously, they can be smaller than an adult human's, since children (with smaller brain volumes) and patients who lost upwards of half their brain exhibit behavior that we would consider conscious and report experiencing an internal representation of the world through qualia. Furthermore, since human brains are large, noisy and lossy environments, this means that many brain structures have redundant features to get around this noise problem. Smaller organisms could and often do have smaller cells and don't need as much error-correcting duplication.

So are we talking chimp-brain-size? Dog-brain-size? Ant-ganglion-size? To simplify, assume that the biology in question retains opposable thumbs or at least vocal chords to ease communication.

Re: What do I mean by conscious: do other entities we recognize as conscious recognize it in turn as conscious? This might miss on some (or even most) forms of consciousness, but saves me endless definitional hassles.

posted over 9 years ago

Serban Tanasa‭

41 reputation 55 4 4 0