Agenda Pomona College ֠ Turing test review LCS 11: Cognitive Science ֠ Searle’s Chinese room argument ֠ GQ 2.3 group discussion Chinese room argument ֠ Selection of responses ֠ What makes brains special? Jesse A. Harris ֠ TED talks for next class ⋆ Cynthia Breazeal: The rise of personal robots February 25, 2013 ⋆ David Hanson: Robots that “show emotion” Jesse A. Harris: LCS 11: Cognitive Science, Chinese room argument 1 Jesse A. Harris: LCS 11: Cognitive Science, Chinese room argument 2 Turing test Behavior and functionalism Functionalist slogan What matters is the software, not the The question Can machines think? to hardware; cognitive systems are be replaced with a less ambiguous multiply realizable. formulation: Could some conceivable digital computer perform well in the Behavior imitation game. All that matters is that the machine emulates the appropriate behavior of a human. Jesse A. Harris: LCS 11: Cognitive Science, Chinese room argument 3 Jesse A. Harris: LCS 11: Cognitive Science, Chinese room argument 4
Varieties of AI Chinese room Searle’s slogan Weak AI Use computer in the study of The mind is not a computer program. mind is merely a useful tool. Strong AI With the right set of programs, a computer Chinese room understands and may have Searle uses a thought experiment genuine cognitive states. designed to show that the thesis of Strong AI results in absurdity if taken More on this next class! seriously. Jesse A. Harris: LCS 11: Cognitive Science, Chinese room argument 5 Jesse A. Harris: LCS 11: Cognitive Science, Chinese room argument 6 Chinese room Chinese room ◮ Searle doesn’t understand a word of Chinese ◮ All he has done is manipulate the formal symbols ◮ Has no real understanding of Chinese or the task. ◮ Problem is inherent to formal computers: no meaning associated with the syntax. Jesse A. Harris: LCS 11: Cognitive Science, Chinese room argument 7 Jesse A. Harris: LCS 11: Cognitive Science, Chinese room argument 8
Chinese room GQ 2.3 – Group discussion First, is Searle a functionalist? A physicalist? Or something in between? Open question Second, what do you think Searle mean when he says that ‘brains What does Searle mean by syntax ? cause meaning’? Do you agree or disagree with this assertion? Defend your answers concretely. How about semantics ? Group leaders: Shalina, Thomas, Paul, Orren, Joel, Cole, Juliana, Mary Margaret, Natasha Jesse A. Harris: LCS 11: Cognitive Science, Chinese room argument 9 Jesse A. Harris: LCS 11: Cognitive Science, Chinese room argument 10 Some objections Objections Systems reply (c) The robot reply (f) It’s not the individual who understands Chinese, but the Insert a computer into an autonomous robot, so that it could entire system. interact with the world. Searle’s response Searle’s response Even if the Chinese room were internalized - so that the Adds a set of causal relations with the world, but still don’t English rule book only formed a subpart of the system, we’ve have any understanding as long as the formal inputs and still provided no way to attach meaning to the symbols the outputs go uninterpreted. subsystem manipulates. Jesse A. Harris: LCS 11: Cognitive Science, Chinese room argument 11 Jesse A. Harris: LCS 11: Cognitive Science, Chinese room argument 12
Objections Objections The brain simulator reply (g) The other minds reply Change the character of the computational system so that it Only know other minds via their behavior - can’t verify that simulates the neuronal fi rings in the brain. machines or people really understand something outside of Searle’s response their behavior. What else is there? 1. Problematic for the basis thesis of functionalism – Searle’s response (= fl at-out rejection) shouldn’t have to know anything about how the brain “It is no answer to this argument to feign anesthesia. In works to understand cognition. ‘cognitive sciences’ one presupposes the reality and 2. Simulates wrong things about the brain: modeling the knowability of the mental in the same way that in physical computational properties of the brain still won’t give us sciences one has to presuppose the reality and knowability of intentionality, because we can’t simulate causal physical objects.” (from original 1980 paper, p.422L) properties. Jesse A. Harris: LCS 11: Cognitive Science, Chinese room argument 13 Jesse A. Harris: LCS 11: Cognitive Science, Chinese room argument 14 Objections Against symbol-pushing Many mansions reply The argument in brief: Eventually, the technology will develop so that we can build in the necessary causal processes for intentionality. 1. Programs are purely formal (syntactic). 2. Human minds have mental contents (semantics). Searle’s response 3. Syntax by itself is neither constitutive of, nor su ffi cient 1. Crucially weakens Strong AI thesis that mind is a formal for, semantic content. symbol manipulating device. 4. Therefore, programs by themselves are not constitutive of 2. No purely formal system could ever give rise to cognitive nor su ffi cient for minds. states, because it necessarily lacks real causal import, except to cause the next set of formal processes. Jesse A. Harris: LCS 11: Cognitive Science, Chinese room argument 15 Jesse A. Harris: LCS 11: Cognitive Science, Chinese room argument 16
Wetware and mental contents Simulation and duplication Dependence on brains ◮ Simulation: all you need for simulation is the right input and output and a program to get from input to output. “ ...mental phenomena might be dependent on actual ◮ No one would mistake a simulation of digestion for the physical-chemical properties of actual human brains.” real thing. Intrinsic connection between the wetware (brain) and the kinds of functions it performs, namely, cognitive states. “ Brains are specific biological organs, and their specific biochemical properties enable them to cause Intentionality consciousness and other sorts of mental phenomena. Computer simulations of brain processes provide models “Whatever else intentionality is, it is a biological phenomenon, of the formal aspects of these processes. But the and it is as likely to be as causally dependent on the speci fi c simulation should not be confused with duplication. “ biochemistry of its origins as lactation, photosynthesis, or any (Searle, 1990:29R) other biological phenomena.” Jesse A. Harris: LCS 11: Cognitive Science, Chinese room argument 17 Jesse A. Harris: LCS 11: Cognitive Science, Chinese room argument 18 Simulation and duplication Open discussion 1. Are you convinced by the Chinese room argument? ◮ What about an arti fi cial organ? 2. Do we have to give up Strong AI? ◮ Arti fi cial hearts can be hearts, 3. What about Searle’s positive views regarding despite being constructed of a intentionality and the brain? Do you fi nd those di ff erent set of materials. convincing? ◮ Does Searle’s point still stand? 4. What other metrics do we have for determining whether What’s di ff erent between the an individual is capable of conscious thought or genuine case of arti fi cial hearts and the mental states? mind? Jesse A. Harris: LCS 11: Cognitive Science, Chinese room argument 19 Jesse A. Harris: LCS 11: Cognitive Science, Chinese room argument 20
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