1 / 27

Memory systems

Memory systems. Off-line processing, consolidation, and interference. Instructions and motor learning. Green and Flowers (1991) Wulf (1997) Verdolini -Marston & Belota (2003) Boyd & Winstein (2004). Purpose. “Complex” skill learning (i.e. real learning)

mikko
Download Presentation

Memory systems

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Memory systems Off-line processing, consolidation, and interference

  2. Instructions and motor learning • Green and Flowers (1991) • Wulf (1997) • Verdolini-Marston & Belota (2003) • Boyd & Winstein (2004)

  3. Purpose • “Complex” skill learning (i.e. real learning) • Occurs in context of both explicit and implicit processes • Trying to understand the interactivity of the two systems in learning

  4. Two views of interaction • Independent • Explicit memory arises from “witnessing” implicit learning and does not assist it • The different systems emerged from different origins • Integrated • Explicit memory is a necessary part of acquiring implicit memory • Explicit memories are transformed into implicit

  5. Method • Provide explicit instruction, learn implicit task • Integrated – explicit should help • Independent – should have either no effect or hinder learning • Serial interception sequence learning • http://reberlab.psych.northwestern.edu/SISL/v0.2.0/SISL.html • Like a continuous version of the classic sequence learning task • Guitar hero! • 12 item repeating sequence

  6. Task • “catch” the balls using the appropriate keys

  7. Method • 2 groups – • Explicit: • memorize the sequence • Watch the balls drop without hitting keys • Print out of sequence visible as they watch • Self-paced • Implicit – none of the above • All: • 24 random cues for familiarization • 6 X 480 learning trial blocks (384 sequenced, 96 novel) • 540 trial test block • 3 different sequences – I from practice • 5 reps per sequence (60 trials) • Used to show performance diffs due to learning

  8. Method • Following practice: • Explicit recognition test • 5 different sequences have two reps each • Rated confidence that sequence was the one practiced • Explicit recall task • Try to produce sequence using keys without balls being seen

  9. Results • No group differences in performance or learning

  10. Results • Differences in explicit recall… Only statistical difference – explicit group could produce the sequence better than the implicit group

  11. Conclusions • Independent, multiple memory systems ideas are better supported • This provides direct evidence against the integrated, single system argument • Implicit learning here is not aided by explicit knowledge • …but it’s not hurt either (unlike earlier studies) • Task specific issues? • Is this learning coordination?

  12. Historically… • H.M. • Squire & others (e.g. Cohen and Squire 1980) • Declarative and procedural memory systems are independent • Alzheimer’s: declarative impaired, procedural not • Huntington’s: procedural impaired, declarative not • fMRI scanning: procedural & declarative “work” lights up different neural circuitry

  13. New evidence… • Willingham (1997) • Activity within medial temporal lobe and striatum associated • Brown and Robertson (2007a and b) • Learning word list after motor skill impairs motor skill • Learning motor skill after word list impairs word learning

  14. Interference paradigm • Consolidation and reconsolidation… • Susceptibility to interference, and time:

  15. Lines of evidence… • A shared resource? • Medial temporal lobes active during both declarative and procedural processing. • Coupling causing shift from independence? • Damage to frontal lobe prevents interference • Wakefulness vs. sleep – dorsolateral prefrontal cortex invoked when awake but not when asleep • Seems to be that frontal lobe makes MTL and Striatum interfere

  16. Interference possibilities & findings

  17. Role of dorsolateral prefrontal cortex…

  18. Function of interference… • When learning motor skill first… • Interference prevented by stimulating motor cortex • Neither memory impaired or enhanced when interference prevented • Interference independent of memory processing • Stimulated areas (DLPFC, M1) seem to be producing the interference…why?

  19. Function of interference… • Why? • New memories are unstable at time of learning • Retrieved memories are unstable when recalled • Maybe instability of both makes for better reorganization of the paired memories? • DLPFC or M1 may • Exert executive control over memory • Select memories susceptible to interference

  20. Brain state & processes • Areas of brain interfere when awake, but not when asleep • When awake, memories are organized interactively • When asleep they are organized independently • Learning… • Independent acquisition but interactive after learning? • Aging • DLPFC function alters with age. Youth – mature – old.

  21. Manipulating interference • Altered sequence of learning to avoid interference? • Maybe, but what’s the function of the interference? • Maybe it leads to greater memory integration?

  22. Memory stability • New memories become resistant to interference over a few hours. • Circuits effecting this change depend on type of practice… • Single block – M1 • Multiple blocks – DLPFC • “Offline” processes stabilize learning.

  23. Offline learning • Can be enhanced by • Sleep (motor learning 20-30%) • Praise • Cues at encoding • Learning & consolidation (offline learning) rely on similar brain areas and chemical processes • Circuitry in bird song similar when actually singing and when dreaming.

  24. Retrieval and stability • Retrieved memories can be interfered with • But only when new information is to be paired with retrieved information • Possible link with need to integrate new with old memory

More Related