Memory & the Cognitive Cycle

1. Memory & the Cognitive Cycle Cognitive Science Seminar—Spring 2003 Stan Franklin

2. Long-term Memory • Procedural Memory • Includes language generation • Implemented in IDA by behavior streams, behaviors, codelets • Declarative Memory • Autobiographical Memory—long-term memory of events • Semantic Memory—long-term memory of facts • Implemented in IDA by Sparse Distributed Memory

3. Declarative Memory • Content Addressable • Small cue often suffices • Associative • Distinctive items easy to retrieve • Similar items tend to blur and loose details • Time span of decades or indefinite—little or no decay • Capacity seemingly unlimited • Retrieval can be voluntary or involuntary

4. Transient Episodic Memory • Content addressable • Small cues often suffice • Associative • Large capacity • Decay rate in hours or perhaps a day • Needed to deal with periodic similar items • Other names • episodic memory (Conway) • extended working memory (Donald)

5. Working Memory • Small capacity • Decays in seconds • Various modal buffers • Implemented as a workspace in IDA

6. Sensory Memory • Sensory or endogenous • Small capacity • Decays in milleseconds • Implemented in IDAby activity in slipnet nodes

7. Memory Diagram

8. IDA’s Cognitive Cycle • Specifies the role of consciousness in cognition • Clarifies the relationship between consciousness and the various memories • Makes explicit the role of consciousness in recruiting relevant resources • Provides a tool for the fine-grained analysis of various cognitive tasks

9. Cognitive Cycle vs Working Memory

10. CC1—Perceiving • Preconscious perception • External or internal • Processing of portions of the stimuli • Creation of meaning • Recognition • Categorization

11. CC2—Store Percept in WM • Percept stored in preconscious buffers of WM • Visuo-spatial sketchpad • Phonological loop • Buffers may contain earlier contents also • Decay time measured in seconds

12. CC3—Local Associations • Uses contents of preconscious WM buffers as the cue • Retrieves local associations from • Transient episodic memory • Declarative memory • Contents of WM plus these associations correspond to • Baddeley’s episodic buffer • Ericsson and Kintsch’s Long-term Working Memory

13. Attention codelets view LTWM Form coalitions with information codelets Vie to bring various portions of contents to consciousness Attention codelet from a previous cycle can win Factors include Relevancy Importance Urgency Insistence Recency CC4—Competition for Consciousness

14. CC5—Conscious Broadcast • Coalition with highest average activation is chosen • Is said to be in the spotlight, or to occupy the global workspace • The information content of the coalition is broadcast to all codelets • GW theory postulates this broadcast as the moment of phenomenal consciousness • Content of consciousness stored in transient episodic memory

15. CC6—Recruitment of Resources • Relevant behavior codelets respond to broadcast • Typically codelets whose variables can be bound from information in the conscious broadcast. • If the successful attention codelet was an expectation codelet, responding codelets may be those some of whose actions can help to rectify the unexpected situation.

16. CC7—Setting Goal Context Hierarchy • Instantiate goal context hierarchy (behavior stream) • If needed • Possibly more than one • Bind variables using information from conscious broadcast • Send environmental activation to appropriate behaviors

17. CC8—Action Chosen • Behaviors (goal contexts) get activation from • Drives • Environment • Other behaviors • The single behavior is chosen that • Is executable • activation over threshold • higher activation than other such behaviors

18. CC9—Action Taken • Chosen behavior binds variables in its behavior codelets • Then releases its behavior codelets including at least one expectation codelet • These behavior codelets perform the task of the behavior • This action may effect the external or internal environment

19. Cognitive Cycles • In humans each cognitive cycle takes about 200ms • An automatized cycle would take less time • Cognitive cycles can overlap • Cycles must maintain the seriality of consciousness • Unconscious activity on each side of the conscious broadcast can operate in parallel • Humans might have a dozen cognitive cycles active during a single second

20. Rate Comparison • Cognitive Cycles—about five per second • Sacades of the Eye—five to seven per second • Hand Tremors—five to seven per second

21. Consciously Mediated Action vs. Voluntary Action Selection • Voluntary action selection • Go to the fridge for orange juice • Choice between go or wait, orange juice or coke or water • Consciously mediated action • Find and grasp the handle • Unconscious actions • Pull the refrigerator door open

22. Hypotheses from the IDA Model • Human cognition functions by means of a continual iteration of cognitive cycles • The existence of transient episodic memory • Contents of consciousness stored in transient episodic memory • Contents of transient episodic memory consolidated into declarative memory • Significant learning can only occur consciously

23. Web and Email Addresses • Stan Franklin • franklin@memphis.edu • www.cs.memphis.edu/~franklin • “Conscious” Software Research Group • www.cs.memphis.edu/~csrg