Connecting Brain, Purpose & Language: Understanding Language Behavior as the Control of Perception

1. Connecting Brain, Purpose & Language:Understanding Language Behavioras the Control of Perception Gary A. Cziko University of Illinois at Urbana-Champaign g-cziko@uiuc.edu; garycziko.net

2. (start recording)

3. Apologies (5) • Not a brain or neuroscientist • Will not summarize or synthesize findings from neural science • Theory and computer simulations I will present are not my own (Wm. T. Powers) • Relativity little research has been done to support theory and arguments I will make • Don’t have fancy PowerPoint slides

4. Excuses (3) • Am interested in biological bases of complex human behavior: education & language • Without Miracles (1995): Darwinian • The Things We Do (2000): Bernardian • Will share with you a fundamental building block for understanding how mind might be created from neurons • Will do some research, simulations and data analysis with you to demonstrate some behavioral phenomena and their possible underlying neural basis

5. Goals of presentation (4) • Explain how we can get human language from neurons (in well under an hour!) • Provide a different perspective on behavior • Neither behavioristic (S-R)nor cognitive (S-O-R) (lineal A -> B causality) • Behavior as purposeful (circular causality) • Offer preliminary implications for understanding language and its underlying neural basis • How we might get mind from neurons • From the simplest unit of perception, thought & behavior to the highest form of human perception, thought & behavior

6. “Presence of mentality”(read-along quote) • “The pursuance of future ends and the • choice of means for their attainment are … • the mark and criterion of the presence of • mentality in a phenomenon. We impute no • mentality to sticks and stones, because they • never seem to move for the sake of anything, • but always when pushed, and then indifferently • and with no sign of choice. So we unhesitatingly • call them senseless.” • --Wm. James, 1890 (American psychologist)

7. Behavior demonstrating“presence of mind” • The rubber-band demo • What is the subject doing?

8. Computerized Rubber-Band Demo • Powers’ computer demo of compensatory tracking (Demo 1; Step F) • Correlation between (visible) Cursor and Handle (S-R) • Correlation between (invisible) Disturbance and Handle

9. Towards a model(read-along quote) • “What we have is a circuit, not an arc or • broken segment of a circle. This circuit is more • truly termed organic than reflex, because the • motor response determines the stimulus, just as • truly as sensory stimulus determines movement. • Indeed, the movement is only for the sake of • determining the stimulus, of fixing what kind of • a stimulus it is . . .” • --John Dewey, 1986 (American psychologist & educator)

10. A model of “compensatory tracking” • Demo 2; Step G; “closing the loop” • Explain components • Behavior with open loop • Close loop • Vary reference level (purpose) • Step • Continuously

12. Characteristics ofPerceptual Control • Provides a model of purposeful (intentional) behavior • Internal reference level (goal, purpose, objective, intention) essential • Perception (“stimulus”) affects behavior (“response”) AND behavior affects perception • Circular rather than lineal (one-way) causation • Perceptual control shown by LOW correlation between perception (“input”) and behavior (“output”) • Test of the “controlled variable” • Behavior understood as a means of controlling perception • Not vice versa as in both behaviorism(S -> R) & cognitive psychology (S -> O -> R) • No clear “independent” or “dependent” variable • Circular not straight line (lineal) causality

13. A Hierarchy of Perceptual Control (3) • More complex behavior seen as control of more complex perceptions • Inputs from lower-level perceptions combined to form higher-level perceptions • not new, e.g, complex cells, neural nets • Outputs from higher levels sent to levels as reference levels (goals, purpose) • new

15. Demonstration of Hierarchy • Volunteer maintains arm parallel to ground • Told to drop arm to side when hand pushed from above • Predictions? • Change in reference level from horizontal to vertical • Lower level will perceive push before upper level perceives it and is able to change the reference level for the lower system • Watch what happens!

16. The Whys and Hows of Behavior (2) • Answers to “why” questions about behavior found by going up to higher-level perceptual control systems • Why am I saying these sentences right now? • Answers to “how” questions about behavior found by going down to lower-level perceptual control systems • How am I saying these sentences right now?

17. Applications of PCT to Language (4) • Language behavior is purposeful, intentional, functional, goal-directed • Provides a social means of controlling one’s perception • Language is hierarchical • auditory intensities > phonetic features > phonemes > morphemes > lexemes > phrases > clauses > discourse • Hierarchy of control from articulation to pragmatics • Language behavior is usually successful despite many disturbances (e.g., environmental noise; objects in mouth)

18. PCT provides a particular form of a connectionist model (3) • Circular perceptual control systems arranged hierarchically • Neurons can compute (perceptrons) and transmit information (senory and motor systems) • Neurons can act as a comparators (using inhibitory and excitatory synapses)

19. PCT provides an architecture for research & discovery (4) • Sensory (afferent) systems combining signals from lower levels • Motor (efferent) systems sending reference levels to lower-level comparators (desired perceptions, not motor commands) • Comparators (comparing upper-level outputs with lower-level inputs, with difference sent as reference level to lower level) • Evidence of control: behavioral and neural (controlled variable)

20. Conclusions (3) • Advances in neurosciences are providing details at the micro level • An understanding of behavior as the control of perception provides a macro framework for understanding the micro-level details • Combining the two provides new important insights into the connections among brain, behavior, language and human purposes • i.e., how mind (and mindful behavior) might be constructed from neurons

21. Resources • Powers, W. T. (1973). Behavior: The control of perception. Chicago: Aldine de Gruyter. • Gary Cziko’s books (full text online via garycziko.net) • Without Miracles (1995) • *The Things We Do (2000) • Control Systems Group website: • www.ed.uiuc.edu/csg (these & other computer demos) • Joel Walters (English, Bar-Ilan U) • Application of PCT to understanding bilingualism

22. Connecting Purpose, Brain, and Language:Understanding Language Behavioras the Control of Perception Gary A. Cziko University of Illinois at Urbana-Champaign g-cziko@uiuc.edu; garycziko.net

24. “What we have is a circuit, not an arc or broken segment of a circle. This circuit is more truly termed organic than reflex, because the motor response determines the stimulus, just as truly as sensory stimulus determines movement. Indeed, the movement is only for the sake of determining the stimulus, of fixing what kind of a stimulus it is, of interpreting it.”(J. Dewey 1986, p. 353) • ”It is possible to step back and treat the mind as one big monster response function from the total environment over the total past of the organism to future actions.“--Allen Newell (1998).

25. (Overview) • Introduction • Demonstration & model of purposeful behavior • Hierarchies of perceptual control • Applications to language • Implications for neural science • Resources for further exploration

26. Demonstration & Model of Perceptual Control (overview) • Rubber-band demo • Powers’ computer demo of compensatory tracking (Demo 1; Step F) • Dewey quote • Powers’ computer model of compensatory tracking (Demo 2; Step G; “closing the loop)