Think about your thoughts

Rats can introspect8212;so much for the belief that was something only humans were capable of

Whether it is an eerily human bot in a virtual-reality game, an animal looking at you with soulful eyes or a patient in a vegetative state, the question nags and nags and won8217;t go away: is there a thinking, self-aware, conscious mind in there? Not one that exhibits intelligence, since silicon chips do calculations that leave the human brain in the dust. And not one merely capable of empathy or grief or cooperation, which chimps, elephants and species in between all manage. No, the capacity that distinguishes humans has come down to something Augustine identified 1,600 years ago when he asked: what 8220;can be the purport of the injunction, know thyself? I suppose it is the mind should reflect upon itself.8221;

It8217;s called metacognition8212;the ability to think about your thoughts, to engage in self-reflection, to introspect. It was long thought to be not just something that we have more of or do better than machines or animals, but that we have and they lack. To know what you know is not only the mark of a skilled game-show contestant who is quick but not too quick on the buzzer, but also of consciousness, the last stand for human exceptionalism. Now, this claim is on the rocks as both animals and machines show signs they can engage in self-reflection.

In the latest study, scientists tested for introspection in rats. Jonathon Crystal and Allison Foote of the University of Georgia trained rats to push one lever when they heard a short burst of static, and a second lever when they heard a long burst. The reward for a right answer was six food pellets. A wrong answer yielded nothing. But refusing to answer earned the rat a consolation prize of three morsels. Clearly, the smart strategy was to respond if sure of the answer, but pass if not.

The rats got almost perfect scores when they had to identify two-second or eight-second bursts. But when they heard static of intermediate duration and had to choose 8220;long8221; or 8220;short,8221; they were twice as likely to decline the test and take the three pellets; they knew what they didn8217;t know.

To make sure the rats were truly introspecting, the scientists then eliminated the opt-out choice and required the rats to choose 8220;long8221; or 8220;short8221; for the medium bursts.The animals got half right, which suggests that when they opted out it was indeed because they had assessed the contents of their mind8212;do I know this?8212;and made the rational choice, the scientists report in Current Biology. 8220;Rats can reflect on their internal mental states,8221; says Crystal. 8220;They know when they don8217;t know.8221; Other scientists have gotten similar results with dolphins and rhesus monkeys, who also decline to take a test when they don8217;t know the answer. They think about thinking.

Next month an AI conference in Hawaii will feature a dozen studies on introspective machines. 8220;I don8217;t think there is an inherent barrier to self-understanding on the part of machines,8221; says Michael Cox of BBN Technologies. 8220;There is nothing magical, mystical, spiritual or uniquely human about introspection and metacognition.8221;

Questions about consciousness have become especially poignant in the case of comatose patients. Last year scientists in England reported on a young woman who, despite being in a vegetative state, showed brain activity identical to that of healthy volunteers in response to spoken requests that she imagine walking around her home or playing tennis. Critics dismissed the brain signals as little more than reflex: maybe the word 8220;tennis8221; automatically triggered the activity, they said. If so, it was nothing special, and certainly not a sign of a self-reflecting mind. Perhaps, but the new research says we need to be careful about expecting too much of consciousness. As self-awareness dawns on machines and as scientists find it in animals, it may be that vegetative patients are not the only ones whose glimmers of consciousness can be dismissed as nothing special.
-SHARON BEGLEY Newsweek