Outline Of Today’s Discussion

1. Outline Of Today’s Discussion • Information Processing Theory: Psychology • Biological Information Processing • The Computational Approach: Marr’s 3 Levels of Processing

2. Part 1 Information Processing Theory: Psychology

3. Information Processing Theory: Psychology Alan Turing “invented” the digital computer Artificial intelligence – The branch of computer science in which computer programs simulate intelligent behavior. Examples from everyday life? Potential Pop Quiz Question – Generate your own example of how computer vision could have practical applications in everyday life?

4. Information Processing Theory: Psychology Connectionist Neural Network Model In the computer-network model above, what are the biological counterparts to “units”, “connections”, and “activation levels”? How do connectionist models “learn”?

5. Information Processing Theory: Psychology This is an example of an information-processing psychology diagram…. Simple boxes are used to represent complex physiological phenomena, and ‘mental events’ –all of which are strung together in a flow-chart. Note the serial nature of the flow, which is contrary to parallel distributed processing models. (parallel in time, distributed in space across the brain)

6. Information Processing Theory: Psychology This is an example of an information-processing psychology diagram…. Simple boxes are used to represent complex physiological phenomena, and ‘mental events’ –all of which are strung together in a flow-chart. Why do behaviorists dislike the phrase “mental events”?

7. Information Processing Theory: Psychology This is an example of an information-processing psychology diagram…. This box corresponds to Broadbent’s (1958) notion of attention. How would you define attention?

8. Part 2 Biological Information Processing

9. Biological Information Processing Single-cell recording arrangement: Also known as electro-physiology The neural impulse is also called an action potential. (Often measured as ‘firing rate’ or spikes per second.) Rate Codes vs Time Codes Is this basic research, or applied research?

10. Biological Information Processing Diagram of visual receptive fields Potential Pop Quiz Question: Which major theory of vision would be better supported by this diagram, structuralism or gestaltis,? Explain your answer. (Hermann grid demo online)

11. Biological Information Processing David Hubel Torsten Weisel How are they similar to the simple mathematical functions (e.g., linear functions) that we talked about the other day? Nobel Laureates from 1981… and they are almost psychologists! 

12. Part 3 The Computational Approach: Marr’s 3 Levels of Processing

13. The computational Approach: Marr’s 3 levels The computational level – specifies only which input (information) is to mapped to which output (information). At the computational level, there is no specification about HOW the input is to be mapped to the output. Examples of your own?

14. The computational Approach: Marr’s 3 levels The algorithmic level – specifies how a computation is to be executed. In principle, a given computation could be executed many different ways. Example: Many different computer programs can accomplish a given task.

15. The computational Approach: Marr’s 3 levels The implementation level – specifies how the algorithm is carried out on a physical device (a computer or a brain).