Penrose, though he's done respectable work in twistor theory in his younger days, in his old age has committed a common mistake of old scientists with very big egos: he carelessly ventured into a domain, neuroscience, with which he has little understanding and yet somehow felt entitled to spout nonsense about how consciousness is related to brain function (though he has no neuroscience credentials, much less has he tried to learn enough about neuroscience to make his absurd theories sound even remotely plausible), and as a result is ridiculed by anyone in the neuroscience community who even bothers to learn and understand what it is that he's proposing along with Hameroff.

In a word, Penrose is a sophist. He would like you to believe that he knows what he's talking about with regard to neuroscience and consciousness, or at the very least, he would like very much to fool himself into believing that he has some actually worth saying that other people should be paying more attention to. Well, I am one of those who is fortunate enough to actually understand what he is proposing (a bose einstein condensate for consciousness mediated by a microtubule network in the brain) and I can say, without a doubt, that it is sheer nonsense and that no-one should take him seriously even if he likes to put on the facade that he has something actually worth saying that other people should listen to.