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RESTING STATE NETWORKS
         Beautiful Noise?
Overview of Talk

    Conclusion

    Methodological
    Recipe and Caveats

    Background

    Future directions
Resting-state fMRI: Beautiful Noise?
Resting-state fMRI: Beautiful Noise?
Conclusion
Resting state networks are:

   Highly robust across cultures, laboratories,
   methods

   Localized to gray matter and predicted by
   tractography

   Found in fMRI, EEG, MEG, and intracranial
   recordings

   Implicated in information processing, multi-
   tasking, memory, learning, development and
   emotion

   Easy to obtain, easy to analyze, and damn
   interesting

   Human connectomics - dont get left behind!
A Methodological Disclaimer

WARNING:
shameless analysis
of low-frequency
fluctuations



                     Source: Smith chapter in Functional MRI: An Introduction to Methods
Resting-state fMRI: Beautiful Noise?
simple recipe for rsfMRI
5-7 minutes of rest

Fixation, or no-fixation.

Place at beginning of scan

Duplicate for maximum effect

Extra ROI timeseries/foci

  ICA vs a priori seed-r

Regression with whole brain and/or task
Life at < .1 HZ
Acquisition
99 problems but acquisition
         aint one
Pre-processing
Band-pass filter:
remove constant offsets
and linear trends,
retain <0.08 Hz

Regression of nuisance
variables; motion,
global signal, average
lateral ventricle, deep
cerebral white matter.
just breath
Analysis: ICA vs seed-based
Data-driven vs a priori
Other Analysis
Task-induced de-activation

Rest-Stimulus interaction

Post-scan rest

Correlation of resting connectivity with cognition, personality,
or psychiatric inventories.
Task induced De-activation
Rest-Stimulus Interaction
Post-Rest
Rest-Inventory Correlation
Why Rest?
Theory and Background
+
A little history
     The default mode of brain function originally proposed by
     Raichle and Fox (2001)

     Attracted initial controversy; why we should resist the baseline

     Has since exploded, evolved into the functional and human
     connectome projects.
  Confusion springs from a failure to distinguish between psychological,
physiological and anatomical accounts. The Rt. Hon. Lord Brain (Brain 1969)
            From a brief history of the DMN (Raichle, 2007)
Human Connectome?
Towards a Discovery Science
  Of Human Brain Function


N = 1,093

24 Centers
Resting States are Predicted by
          Structure




                           Predicting human resting-state
                           functional connectivity from structural
                           connectivity
                           1.   C. J. Honeya, O. Spornsa,1, L. Cammounb, X. Gigandetb, J. P.
 Margulies et al. (2009)        Thiranb, R. Meulicand P. Hagmannb,c
What is Anti-Correlation?
Problems with Anti-r
Resting-state fMRI: Beautiful Noise?
Resting-state fMRI: Beautiful Noise?
Resting-state fMRI: Beautiful Noise?
To be safe


If you want to look at anti-r networks:

  Record respiration

  Avoid global signal regression

  Include a task likely to engage CEN and SAL networks.
A Default Mode?

Marianas Trench Argument: Dont conflate structure with
content!

Rumination, introspection, social cognition

Free-energy

Consciousness?
Picking apart DMN
Although exact function remains unclear, DMN connectivity at rest and
during task-processing now implicated in:

  Schizophrenia

  OCD

  Autism

  ADHD

  Levels of consciousness

  Task-irrelevant thoughts
Measuring the Default


The Resting State Questionnaire (RSQ)

Experience Sampling (Schooler et al)

Differential engagement by task

Correlation with individual differences
Resting-state fMRI: Beautiful Noise?
Future Directions
Resting-state fMRI: Beautiful Noise?
Real Conclusion
There is simply too much multi-modal, multi-cultural evidence to
dismiss slow-wave processing as a feature of mammalian brains

Simple stories; DMN as consciousness, pure anti-correlation,
1:1 mapping between structure and function = FAIL

If you are spending the time and energy doing fMRI, you might
as well spend 5-7 minutes at rest.
THANK YOU



$       +

More Related Content

Resting-state fMRI: Beautiful Noise?

  • 1. RESTING STATE NETWORKS Beautiful Noise?
  • 2. Overview of Talk Conclusion Methodological Recipe and Caveats Background Future directions
  • 5. Conclusion Resting state networks are: Highly robust across cultures, laboratories, methods Localized to gray matter and predicted by tractography Found in fMRI, EEG, MEG, and intracranial recordings Implicated in information processing, multi- tasking, memory, learning, development and emotion Easy to obtain, easy to analyze, and damn interesting Human connectomics - dont get left behind!
  • 6. A Methodological Disclaimer WARNING: shameless analysis of low-frequency fluctuations Source: Smith chapter in Functional MRI: An Introduction to Methods
  • 8. simple recipe for rsfMRI 5-7 minutes of rest Fixation, or no-fixation. Place at beginning of scan Duplicate for maximum effect Extra ROI timeseries/foci ICA vs a priori seed-r Regression with whole brain and/or task
  • 9. Life at < .1 HZ
  • 11. 99 problems but acquisition aint one
  • 12. Pre-processing Band-pass filter: remove constant offsets and linear trends, retain <0.08 Hz Regression of nuisance variables; motion, global signal, average lateral ventricle, deep cerebral white matter.
  • 14. Analysis: ICA vs seed-based Data-driven vs a priori
  • 15. Other Analysis Task-induced de-activation Rest-Stimulus interaction Post-scan rest Correlation of resting connectivity with cognition, personality, or psychiatric inventories.
  • 20. Why Rest? Theory and Background
  • 21. +
  • 22. A little history The default mode of brain function originally proposed by Raichle and Fox (2001) Attracted initial controversy; why we should resist the baseline Has since exploded, evolved into the functional and human connectome projects. Confusion springs from a failure to distinguish between psychological, physiological and anatomical accounts. The Rt. Hon. Lord Brain (Brain 1969) From a brief history of the DMN (Raichle, 2007)
  • 24. Towards a Discovery Science Of Human Brain Function N = 1,093 24 Centers
  • 25. Resting States are Predicted by Structure Predicting human resting-state functional connectivity from structural connectivity 1. C. J. Honeya, O. Spornsa,1, L. Cammounb, X. Gigandetb, J. P. Margulies et al. (2009) Thiranb, R. Meulicand P. Hagmannb,c
  • 31. To be safe If you want to look at anti-r networks: Record respiration Avoid global signal regression Include a task likely to engage CEN and SAL networks.
  • 32. A Default Mode? Marianas Trench Argument: Dont conflate structure with content! Rumination, introspection, social cognition Free-energy Consciousness?
  • 33. Picking apart DMN Although exact function remains unclear, DMN connectivity at rest and during task-processing now implicated in: Schizophrenia OCD Autism ADHD Levels of consciousness Task-irrelevant thoughts
  • 34. Measuring the Default The Resting State Questionnaire (RSQ) Experience Sampling (Schooler et al) Differential engagement by task Correlation with individual differences
  • 38. Real Conclusion There is simply too much multi-modal, multi-cultural evidence to dismiss slow-wave processing as a feature of mammalian brains Simple stories; DMN as consciousness, pure anti-correlation, 1:1 mapping between structure and function = FAIL If you are spending the time and energy doing fMRI, you might as well spend 5-7 minutes at rest.