1. Symbol-processing Minds J. Scott Jordan Department of Psychology Illinois State University

2. Algorithms We have already talked about digital versus analog representations. We also discussed the possibility of LOGIC serving as the algorithm by which our minds manipulate representations.

3. Algorithms An example logical algorithm Modus ponens p  q p Therefore, q

4. Algorithms Example modus ponens symbol- processing systems: Clean-up robot Iris 1 the Pearl Jam Fan Iris 2 the Tic-Tac Toe expert

5. Algorithms All of these systems use strings of 1s 0s to represent things Logical operators are then applied to the 1s and 0s to generate inferences and get things done. When we press keys these are translated into 1s and 0s.

6. Algorithms Do these systems have minds? Do these systems have beliefs? Do these systems have memories? Doesn’t the use of modus ponens constitute rational behavior? Doesn’t our legal system judge us based on whether or not we utilized modus ponens?

7. Algorithms Two outcomes YES (some sort of Functionalism) weak symbol-processing hypothesis human symbol-processing hypothesis strong symbol-processing hypothesis NO How do you know?

8. Algorithms The Turing Test