DCM for evoked responses Harriet Brown SPM for M/EEG course, 2013
The DCM analysis pathway
Collect data Build model(s) Fit your model parameters to the data Pick the best model Make an inference (conclusion) The DCM analysis pathway
Collect data Build model(s) Fit your model parameters to the data Pick the best model Make an inference (conclusion) The DCM analysis pathway
Data for DCM for ERPs 1.Downsample 2.Filter (1-40Hz) 3.Epoch 4.Remove artefacts 5.Average
Collect data Build model(s) Fit your model parameters to the data Pick the best model Make an inference (conclusion) The DCM analysis pathway
Collect data Build model(s) Fit your model parameters to the data Pick the best model Make an inference (conclusion) The DCM analysis pathway ‘hardwired’ model features
Models
Standard 3-population model (‘ERP’)
Canonical Microcircuit Model (‘CMC’) Granular Layer Supra- granular Layer Infra- granular Layer Output equation:
Canonical Microcircuit Model (‘CMC’)
Granular Layer Supra- granular Layer Infra- granular Layer
Superficial Pyramidal Cells Superficial Pyramidal Cells Canonical Microcircuit Model (‘CMC’) Granular Layer Supra- granular Layer Infra- granular Layer Spiny Stellate Cells Deep Pyramidal Cells Deep Pyramidal Cells Inhibitory Interneurons
Canonical Microcircuit Model (‘CMC’) Granular Layer Supra- granular Layer Infra- granular Layer Superficial Pyramidal Cells Superficial Pyramidal Cells Spiny Stellate Cells Deep Pyramidal Cells Deep Pyramidal Cells Inhibitory Interneurons
Canonical Microcircuit Model (‘CMC’) Granular Layer Supra- granular Layer Infra- granular Layer Superficial Pyramidal Cells Superficial Pyramidal Cells Spiny Stellate Cells Deep Pyramidal Cells Deep Pyramidal Cells Inhibitory Interneurons
Canonical Microcircuit Model (‘CMC’) Granular Layer Supra- granular Layer Infra- granular Layer Superficial Pyramidal Cells Superficial Pyramidal Cells Spiny Stellate Cells Deep Pyramidal Cells Deep Pyramidal Cells Inhibitory Interneurons
Canonical Microcircuit Model (‘CMC’) Granular Layer Supra- granular Layer Infra- granular Layer Superficial Pyramidal Cells Superficial Pyramidal Cells Spiny Stellate Cells Deep Pyramidal Cells Deep Pyramidal Cells Inhibitory Interneurons
Canonical Microcircuit Model (‘CMC’) Granular Layer Supra- granular Layer Infra- granular Layer Superficial Pyramidal Cells Superficial Pyramidal Cells Spiny Stellate Cells Deep Pyramidal Cells Deep Pyramidal Cells Inhibitory Interneurons
Canonical Microcircuit Model (‘CMC’) Granular Layer Supra- granular Layer Infra- granular Layer Superficial Pyramidal Cells Superficial Pyramidal Cells Spiny Stellate Cells Deep Pyramidal Cells Deep Pyramidal Cells Inhibitory Interneurons
Canonical Microcircuit Model (‘CMC’) Granular Layer Supra- granular Layer Infra- granular Layer Superficial Pyramidal Cells Superficial Pyramidal Cells Spiny Stellate Cells Deep Pyramidal Cells Deep Pyramidal Cells Inhibitory Interneurons
Canonical Microcircuit Model (‘CMC’)
Granular Layer Supra- granular Layer Infra- granular Layer
Canonical Microcircuit Model (‘CMC’) Granular Layer Supra- granular Layer Infra- granular Layer Output equation:
Collect data Build model(s) Fit your model parameters to the data Pick the best model Make an inference (conclusion) The DCM analysis pathway ‘hardwired’ model features
Designing your model Area 1Area 2 Area 3 Area 4
Designing your model time (ms) input input (1) Area 1Area 2 Area 3 Area 4
Designing your model time (ms) input input (1) Area 1Area 2 Area 3 Area 4
Designing your model time (ms) input input (1) Area 1Area 2 Area 3 Area 4
Designing your model time (ms) input input (1) Area 1Area 2 Area 3 Area 4
Designing your model time (ms) input input (1) Area 1Area 2 Area 3 Area 4
Designing your model time (ms) input input (1) Area 1Area 2 Area 3 Area 4
Collect data Build model(s) Fit your model parameters to the data Pick the best model Make an inference (conclusion) The DCM analysis pathway
Collect data Build model(s) Fit your model parameters to the data Pick the best model Make an inference (conclusion) The DCM analysis pathway fixed parameters
Fitting DCMs to data
1.Check your data
Fitting DCMs to data 1.Check your data 2.Check your sources
1.Check your data 2.Check your sources 3.Check your model Model 1 V4 IPL A19 OFC V4 IPL A19 OFC V4 IPL Model 2 V4 IPL Fitting DCMs to data
1.Check your data 2.Check your sources 3.Check your model 4.Re-run model fitting
Collect data Build model(s) Fit your model parameters to the data Pick the best model Make an inference (conclusion) The DCM analysis pathway
What questions can I ask with DCM for ERPs? Questions about functional networks causing ERPs Garrido et al. (2008)
What questions can I ask with DCM for ERPs? Questions about connectivity changes in different conditions or groups Boly et al. (2011)
What questions can I ask with DCM for ERPs? Questions about the neurobiological processes underlying ERPs mode x mode 1 peri-stimulus time (ms) x mode 2 peri-stimulus time (ms) x 10 mode 1 peri-stimulus time (ms) x 10 peri-stimulus time (ms) -3 Deep Pyramidal Cell gain changed Superficial Pyramidal Cell gain changed Parameter value V4IPLArea 18SOG Area
How to use DCM for ERPs well A DCM study is only as good as its hypotheses…