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NEMO ERP Analysis Toolkit ERP Pattern Segmentation An Overview.

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Presentation on theme: "NEMO ERP Analysis Toolkit ERP Pattern Segmentation An Overview."— Presentation transcript:

1 NEMO ERP Analysis Toolkit ERP Pattern Segmentation An Overview

2 NEMO Information Processing Pipeline

3 NEMO Information Processing Pipeline Pattern Decomposition Component

4 NEMO Information Processing Pipeline ERP Pattern Segmentation, Identification and Labeling  Obtain ERP data sets with compatible functional constraints – NEMO consortium data  Decompose / segment ERP data into discrete spatio-temporal patterns – ERP Pattern Decomposition / ERP Pattern Segmentation  Mark-up patterns with their spatial, temporal & functional characteristics – ERP Metric Extraction  Meta-Analysis  Extracted ERP pattern labeling  Extracted ERP pattern clustering  Protocol incorporates and integrates:  ERP pattern extraction  ERP metric extraction/RDF generation  NEMO Data Base (NEMO Portal / NEMO FTP Server)  NEMO Knowledge Base (NEMO Ontology/Query Engine)

5 ERP Pattern Segmentation Tool MATLAB and Directory Configuration  Get Latest Toolkit Version (NEMO Wiki : Screencasts : Versions ) – Update your local (working) copy of the NEMO Sourceforge Repository  Configure MATLAB (NEMO Wiki : Screencasts : NEMO ERP Analysis Toolkit I) – MATLAB R2010a / R2010b, Optimization and Statistics Toolboxes – Add to the MATLAB path, with subfolders:  NEMO_ERP_Dataset_Import / NEMO_ERP_Dataset_Information  NEMO_ERP_Metric_Extraction / NEMO_ERP_Pattern_Decomposition / NEMO_ERP_Pattern_Segmentation  Configure Experiment Folder (NEMO Wiki : Screencasts : NEMO ERP Analysis Toolkit I & II) – Create an experiment-specific parent folder containing Data, Metric Extraction, Pattern Decomposition and Pattern Segmentation subfolders – Copy the metric extraction, decomposition and segmentation script templates from your NEMO Sourceforge Repository working copy to their respective script subfolders – Add the experiment-specific parent folder, with its subfolders, to the MATLAB path

6  File_Name  Electrode_Montage_ID  Cell_Index  Factor_Index  ERP_Onset_Latency  ERP_Offset_Latency  ERP_Baseline_Latency ERP Pattern Segmentation Tool Metascript Configuration – Step 1 of 6: Data Parameters

7  File_Name – Name of an EGI segmented simple binary file, as a single-quoted string  Example: ‘SimErpData.raw’  At present, Metric Extraction only accepts factor files from the Pattern Decomposition tool  Electrode_Montage_ID – Name of an EGI/Biosemi electrode montage file, as a single-quoted string  Valid montage strings: ‘GSN-128’, ‘GSN-256’, ‘HCGSN-128’, ‘HCGSN-256’, ‘Biosemi-64+5exg’, ‘Biosemi-64-sansNZ_LPA_RPA’  The NEMO ERP Analysis Toolkit will require EEGLAB channel location file (.ced) format for all proprietary, user-specified, montages  Cell_Index – Indices of cells / conditions to import, as a MATLAB vector  Indices correspond to the ordering of cells in the data file  See Metric_obj.Dataset.Metadata.SrcFileInfo.Cellcode for the ordered list of conditions  Factor_Index – Indices of PCA factors to import, as a MATLAB vector  Indices correspond to the ordering of factors in the data file ERP Pattern Segmentation Tool Metascript Configuration – Step 1 of 6: Data Parameters

8  ERP_Onset_Latency – Time, in milliseconds, of the first ERP sample point to import, as a MATLAB scalar  0 ms = stimulus onset  Positive values specify post-stimulus time points, negative values pre-stimulus time points  All latencies must be in integer multiples of the sampling interval (for example, +’ve / -’ve multiples of 4 ms @ 250 Hz)  ERP_Offset_Latency – Time, in milliseconds, of the last ERP sample point to import, as a MATLAB scalar  0 ms = stimulus onset  Positive values specify post-stimulus time points, and must be greater than the ERP_Onset_Latency  ERP_Offset_Latency must not exceed the final data sample point (for example, a 1000 ms ERP with a 200 ms baseline: maximum 800 ms ERP_Offset_Latency)  ERP_Baseline_Latency – Time, in negative milliseconds, of the pre-stimulus ERP sample points to exclude from import, as a MATLAB scalar  ERP_Baseline_Latency = 0  no baseline  To import pre-stimulus sample points, specify ERP_Baseline_Latency < ERP_Onset_Latency < 0  All latencies must be within the data range (for example, a 1000 ms ERP with a 200 ms baseline: ERP_Baseline_Latency = -200 ms, ERP_Onset_Latency = 0 ms and ERP_Offset_Latency = 800 ms imports the 800 ms post-stimulus interval, including stimulus onset) ERP Pattern Segmentation Tool Metascript Configuration – Step 1 of 6: Data Parameters

9 ERP Pattern Segmentation Tool Metascript Configuration – Step 2 of 6: Experiment Parameters (Required)  Lab_ID  Experiment_ID  Session_ID  Subject_Group_ID  Subject_ID  Experiment_Info

10 ERP Pattern Segmentation Tool Metascript Configuration – Step 2 of 6: Experiment Parameters (Required)  Lab_ID – Laboratory identification label, as a single-quoted string  Example: ‘My Simulated Lab’  Experiment_ID – Experiment identification label, as a single-quoted string  Example: ‘My Simulated Experiment’  Session_ID – Session identification label, as a single-quoted string  Example: ‘My Simulated Session’  Subject_Group_ID – Subject group identification label, as a single-quoted string  Example: ‘My Simulated Subject Group’  Subject_ID – Subject identification label, as a single-quoted string  Example: ‘My Simulated Subject # 1’  Experiment_Info – Experiment note, as a single-quoted string  Example: ‘tPCA with Infomax rotation’

11 ERP Pattern Segmentation Tool Metascript Configuration – Step 3 of 6: Experiment Parameters (Optional)  Event_Type_Label  Stimulus_Type_Label  Stimulus_Modality_Label  Cell_Label_Descriptor

12 ERP Pattern Segmentation Tool Metascript Configuration – Step 3 of 6: Experiment Parameters (Optional)  Event_Type_Label – MATLAB cell array of cell/condition event type labels  One label per cell/condition, as a single-quoted string  Example: {‘SimEventType1’, ‘SimEventType2’, ‘SimEventType3’}  Stimulus_Type_Label – MATLAB cell array of cell/condition stimulus type labels  One label per cell/condition, as a single-quoted string  Example: {‘SimStimulusType1’, ‘SimStimulusType2’, ‘SimStimulusType3’}  Stimulus_Modality_Label – MATLAB cell array of cell/condition stimulus modality labels  One label per cell/condition, as a single-quoted string  Example: {‘SimStimulusModality1’, ‘SimStimulusModality2’, ‘SimStimulusModality3’}  Cell_Label_Descriptor – MATLAB cell array of cell/condition description labels  One label per cell/condition, as a single-quoted string  Optional Labels: E-prime assigned cell codes imported from input data file  Example: {‘SimConditionDescription1’, ‘SimConditionDescription2’, ‘SimConditionDescription3’}

13 ERP Pattern Segmentation Tool Metascript Configuration – Step 4 of 6: Pattern Segmentation Parameters  Dimension_Flag  Averaging_Protocol  Microstate_Algorithm  Minimum_Microstate - _Duration  Maximum_Transition - _Duration

14 ERP Pattern Segmentation Tool Metascript Configuration – Step 4 of 6: Pattern Segmentation Parameters  Dimension_Flag – Specifies dimensionality of the coordinate space containing the +’ve / -’ve potential centroids, as a MATLAB scalar  Potential centroids are the locations of the centers of scalp-recorded positvity / negativity  Dimension_Flag = 2: Potential centroids are locations in 2D scalp “flat-map” space  Dimension_Flag = 3: Potential centroids are locations in 3D “head-volume” space  Averaging_Protocol – Specifies averaging precedence w.r.t. microstate boundary probability curve extraction, as a single- quoted string  ‘ExtractThanAverage’: Extract subject-specific microstate boundary probability curves, then average across subjects within each cell  ‘AverageThanExtract’: Average ERPs across subjects within each cell, then extract grand average microstate boundary probability curve  Microstate_Algorithm – Specifies the microstate boundary probability computation algorithm, as a MATLAB function handle  @CentroidDissimilarity1D: Considers changes in a 1-parameter centroid location function  @CentroidDissimilarity2D: Considers changes in a 2-parameter centroid location function  @GlobalMapDissimilarity: Considers changes in successive topographic map correlations  @GlobalFieldPower: Considers locations of minimum global field power

15 ERP Pattern Segmentation Tool Metascript Configuration – Step 4 of 6: Pattern Segmentation Parameters  Minimum_Microstate_Duration – Specifies the minimum allowable interval for a stable topography to be designated a microstate – Specify Minimum_Microstate_Duration in milliseconds, as a MATLAB scalar  Maximum_Transition_Duration – Specifies the maximum allowable interval of unstable topography to be excluded from the beginning or end of a microstate region – Specify Maximum_Transition_Duration, in milliseconds, as a MATLAB scalar

16 ERP Pattern Segmentation Tool Metascript Configuration – Step 5 of 6: Class Instantiation I Instantiate EGI reader class object Initialize object parameters Import metadata Import signal (ERP) data

17 ERP Pattern Segmentation Tool Metascript Configuration – Step 5 of 6: Class Instantiation II Instantiate Pattern Segmentation class object Initialize object parameters

18 ERP Pattern Segmentation Tool Metascript Configuration – Step 6 of 6: Class Invocation for Grand Average Data Call ComputeMicrostateBoundaries method: Computes microstate boundaries via specified microstate algorithm Call ComputeMicrostateStatistics method: Exclude invalid microstates and compute microstate statistics Call PlotMicrostateAnalysis method: Plot microstate boundary probability curve, microstate statistics and microstate topographies

19 ERP Pattern Segmentation Tool Metascript Configuration – Step 6 of 6: Class Invocation for Subject Average Data Call ComputeMicrostateBoundaries method: Computes microstate boundaries via specified microstate algorithm Call ComputeMicrostateStatistics method: Exclude invalid microstates and compute microstate statistics Call PlotMicrostateAnalysis method: Plot microstate boundary probability curve, microstate statistics and microstate topographies

20 ERP Pattern Segmentation Tool Metascript Configuration – Step 6 of 6: Class Invocation for Subject-Specific Data Call ComputeMicrostateBoundaries method: Computes microstate boundaries via specified microstate algorithm Call ComputeMicrostateStatistics method: Exclude invalid microstates and compute microstate statistics Call PlotMicrostateAnalysis method: Plot microstate boundary probability curve, microstate statistics and microstate topographies ` `

21 ERP Pattern Segmentation Tool Plot Microstate Analysis GUI – 40 millisecond Minimum_Microstate_Duration

22 ERP Pattern Segmentation Tool Plot Microstate Analysis GUI – 30 millisecond Minimum_Microstate_Duration

23  Pattern Segmentation output folder contents – NemoErpPatternSegmentation workspace object in MATLAB (.mat) format – That’s it for now ERP Pattern Segmentation Tool Folder Output for SimErpData.raw Input data fileTime stamp

24 ERP Pattern Segmentation Tool Viewing Pattern Segmentation Class Properties in MATLAB  MATLAB Workspace view NemoErpPatternSegmentation object EgiRawIO object Double click to open…

25 ERP Pattern Segmentation Tool Viewing Pattern Segmentation Class Properties in MATLAB  EPreadDataInput: MATLAB structure of input parameters to ep_readData  Epdata: MATLAB structure of output data and metadata from ep_readData  EGIreadDataInput: MATLAB structure of (optional) input parameters to EGI_readData and EGI_readMetaData  Metadata: MATLAB structure of output metadata from EGI_readMetadata  Data: MATLAB structure of output data from EGI_readData Keep on double clicking …  MATLAB Workspace view

26 ERP Pattern Segmentation Tool Viewing Pattern Segmentation Class Properties in MATLAB  MATLAB Workspace view Keep on double clicking …


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