What's next

A roadmap to the future developments of Brainstorm.

Current topics

Functionnal connectivity

• Integration of different metrics to study the brain connectivity:
  Correlation, coherence, Granger causality, phase locking value

• Development of new ways to represent the connectivity between sensors or brain regions

EEG / epilepsy / intra-cranial recordings

• Editing the position of intracranial electrodes in the MRI viewer

Source modeling

• Computation of equivalent current dipoles
• Beamformers

Large scale analysis

• Parallel processing: Reduce the computation times using the parallel processing toolbox
• Distributed processing: Integrate tools for sending Brainstorm processes on computation clusters

Recordings

• RAW file viewer:
  • Pre-load next page of recordings
  • Documentation: Add definition of bad segments

  • 2DLayout: Doesn't work when changing page => need refresh of GlobalData.Preferences.TopoLayoutOptions.TimeWindow

• EEG reference/storage:
  • Intracranial electrodes: Define and display in the MRI viewer + 3D figures
  • Bad locations: indicate with [NaN NaN NaN] instead of [0 0 0]

  • Bad channels that can be specified at the program level (for sites that have permanently bad channels) => AS Dubarry

• RAW processing:
  • Make it work for all the file formats (at least bandpass filter + sin removal)

  • Events: advanced process for recombining. Example: http://www.erpinfo.org/erplab/erplab-documentation/manual/Binlister.html

• Colormaps:
  • Create a colormap similar to MNE, where extrema are bright
• Import data:
  • Save properties "baseline" and "resample" at the level of the protocol (to re-use for all the files)
• NIRS:
  • Add new data type
  • Display of sensors by pairs oxy/deoxy (red/blue), overlaid
• Images of amplitude: [sensor x time], [trial x time], scout: [trial x time]

  • Can be done with Matrix > View as image: extract cluster, concatenate for all trials

• 2D Layout for multiple conditions

Connectivity

• Tutorial coherence [1xN]
• t-tests on connectivity measures
• Graph view:
  • Fixed scales for intensity sliders
  • Fix zoom in one region
  • Text bigger
  • Too much data in appdata
• Other metrics:
  • Coherence by bands: bst_coherence_band_welch.m
  • Granger by bands: bst_granger_band.m
  • Inter-trial coherence
• Work on progress bars

Processes

• Time-frequency:
  • Frequency bands: extended syntax (ex: [2 3 4], 10:5:90, ...)
  • How to combine 3 orientations for unconstrained sources
  • Display logs as negative
  • 2D Layout in spectrum
  • Make much faster and more memory efficient (C functions coded by Matti ?)
  • Smooth display of TF/PAC maps (option)
  • TF scouts: should display average of TF maps
• Bandpass: Show warning when using inappropriate high-pass filter (precision too high)
• Artifact detection:
  • Detection of bad segments in the RAW files
  • Artifact rejection like SPM: if bad in 20%, bad everywhere
  • Test difference between adjacent samples
• Distributed processing: Brainstorm that can run without Java
• SSP:

  • Display warning if changing the ChannelFlag while there is a Projector applied

  • Show where the attenuation is projected:
    (sum(IK,2)-sum(SSP(k,:)*IK,2)./sum(IK,2)

• Average:
  • Remember how many trials were used per channel
  • Save standard deviation
  • Display standard deviation as a halo around the time series
• Co-registration of MEG runs:
  • SSP: Group projectors coming from different files
  • Finish validation of the method
  • Apply to continuous recordings for correcting head movements

• Current Source Density (CSD) => Ghislaine
  http://psychophysiology.cpmc.columbia.edu/software/CSDtoolbox/index.html

• Other processes:
  • Detrending
  • Moving average
  • Max
  • Median
  • Significance test (Dimitrios, Leo)
  • Spatial smoothing: check / document parameters

• Contact sheets & movies: use average of time windows instead of single instants, for each picture.

• Optical flow

Database

• MEG protocols: More flexible organization of the database; sub-conditions to allow different runs X different conditions.

• Group matrix files => allow to process matrix files by trial types

• Add notes in the folders (text files, visible as nodes in the tree)
• Screen captures: save straight to the database

Source modeling

• Stenroos 2014 paper: Include the following methods

  • Inner and outer skull surfaces generator from FieldTrip (needs SPM, probably not so different from BST)

  • Nolte corrected-sphere model (good model re:Alex)
  • Fast BEM models
• Dipole fitting
• Visualize Beamformer results:
  • Read CTF SAM .svl
  • Display as layers in the MRI viewer
• Unconstrained sources:
  • Compute unconstrained and then project on the normal ?
  • Difference and stat should be: norm(A) - norm(B)
  • Stat and connectivity: what to do? (re-send email John+Sylvain)
• Overlapping spheres: improve the estimation of the spheres for the frontal lobes
• Volume grid:
  • Scouts 3D
  • Test volume sources with all the subsequent processes (timefreq, stat...)
  • Optimize: 3D display (better that 9x9 cubes)
  • Optimize: vol_dilate (with 26 neighbors)
• Magnetic extrapolation: Do the same thing with EEG
• Noise covariance matrix:
  • Storage of multiple noise covariance matrices (just like the head models)
  • Always save as full, then at inversion time, we can decide between full, heteroskedastic (diagonal) or homoskedastic (i.i.d, scalar)

  • Problem of having inividual trials + averages in the condition => Display warning or not?

  • Save nAvg in noisecov file, to make it easier to scale to other recordings

  • When deploying to other conditions: Apply destination SSP (NoiseCov = SSP . NoiseCov . SSP' )

• Sources on surface: Display peak regions over time (time = color) => A.Gramfort

• Simulation: synthesize pseudo data-files from a cortex patch (duration, amplitude, noise)

• Calculate ImagingKernel * Gain for a scout

• EEG Source modeling: Manage references and bipolar montages properly (maybe not necessary)
• MEG source modeling: Do reconstruction only for a subset of sensors for estimating dipoles?

Anatomy

• Scouts:
  • Mix constrained/unconstrained/volume sources, using the "Source model" atlas
  • Display edges in the middle of the faces instead of the vertices
  • Project scouts betweens subjects and between hemispheres
  • Display scouts in a tree: hemisphere, region, subregion
  • Downsample to atlas: allow on timefreq/connect files
  • Sort scouts by region in process options
• Generate mixed density surfaces
• Import / registration:
  • Major bug when importing surfaces for an MRI that was re-oriented manually
• Use mid-gray instead of pial surface?

Statistics

• ANOVA: Use LENA functions
  • Output = 1 file per effect, all grouped in a node "ANOVA"
  • Display several ANOVA maps (from several files) on one single figure, using a "graphic accumulator", towards which one can send any type of graphic object
• Permutation tests:
  • t-test only (wilcoxon? sign-test?): paired, equal var, unequal var

    • http://www.adscience.fr/uploads/ckfiles/files/html_files/StatEL/statel_wilcoxon.htm

    • http://www.mathworks.fr/fr/help/stats/signrank.html

    • Less powerful than t-tests
  • nb permutations ~ 1000
  • maximum statistic over "time" or "time and space"
• Permutations / clustering: cf fieldtrip

  • http://fieldtrip.fcdonders.nl/tutorial/cluster_permutation_timelock

  • http://fieldtrip.fcdonders.nl/tutorial/cluster_permutation_freq

• Threshold in time: keep only the regions that are significative for contiguous blocks of time, or over a certain number of time points
  => Process that creates a static representation of a temporal window

• t-test on volume sources

• Paired t-test on unconstrained sources: (convert to flat + Z-score) => AnneSo

  • Question of Gaussianity of the samples: take a subset of samples + Kolmogorov-Smirnov / Shapiro-Wilk test

  • http://fr.wikipedia.org/wiki/Test_de_Shapiro-Wilk

  • http://stats.stackexchange.com/questions/362/what-is-the-difference-between-the-shapiro-wilk-test-of-normality-and-the-kolmog

  • http://www.mathworks.fr/fr/help/symbolic/mupad_ug/perform-shapiro-wilk-test.html

  • http://www.mathworks.fr/fr/help/symbolic/mupad_ref/stats-swgoft.html

  • http://stackoverflow.com/questions/14383115/shapiro-wilk-test-in-matlab

• Create icons for Stat/PAC, Stat/Sprectrum, etc.
• One sample t-test across subjects

Input / output

• EEG File formats:

  • EEG CeeGraph

  • EGI: Finish support for epoched files (formats 3,5,7)

• FieldTrip structures: In / Out

• BCI2000 Input (via EEGLAB plugin)
• Export TF maps to SPM / volumes
• EEGLAB import: Selection of conditions in script mode

Distribution & documentation

• Add Help buttons and menus (in popups, dialog windows...) => Links to the website.

• Introduction tutorials:
  • Processes: Describe all the processes
  • Clusters
  • First steps: Brainstorm preferences
  • Headmodel: explain the fields + how to get the constrained leadfield
  • Sources: Modelized data
  • Sources: theshold min. size (not documented yet)
  • Import raw recordings: Add "detect bad trials/channels" in the pipeline
  • Temporary folder

Current bugs

• Import anatomy folder menu crashes on MacOSX 10.8.5 / Matlab 2013b
• Record tab: Text of epoch number is too big on MacOS
• Menu "Use default EEG cap" doesn't work for a multiple selection (setting the same EEG cap for several subjects)
• in_bst_data_multi: If trials have different sizes, output is random (the one of the first file)
• tree_dependencies: sources files, reprojected on default anatomy; If based on data files that are bad trials, they should be ignored by tree_dependencies, and they are not
• Image viewer has some bugs on some systems
• Screen capture for reports never works: Find another solution
• Screen capture when there is a fading effect in the window manager: captures the window
• Close figure with coherence results should hide the "frequency" slider
• Problems growing scouts on merged surfaces (Emily)
• Edit scout in MRI: small modifications cause huge increase of the scout size

Geeky programming details

• Use Matlab Coder to optimize some processes: Bandpass filter, sinusoid removal
• Hide Java panels instead of deleting them
• mri2scs: convert arguments to meters
• bst_warp and channel_project: Use tess_parametrize_new instead of tess_parametrize
• Shared kernels: do the "get bad channels" operation in a different way (reading all the files is too slow)
• Optimize bst_get:
  • Now study and subject have necessarily the same folder name
  • Replace big switch with separate functions
• Progress bar:
  • Add different levels (to handle sub-processes)
  • Make work correctly with RAW on resting tutorial
  • Uniformize calls in bst_process/Run
  • Add a "Cancel" button
• Line smoothing / anti-aliasing (time series figures)