Spatial Normalisation, Atlases, & Functional Variability

Transcription

1 Spatial Normalisation, Atlases, & Functional Variability Jörn Diedrichsen Institute of Cognitive Neuroscience, University College London

2 Overview Cerebellar normalisation Anatomical reference High-resolution imaging of cerebellar function

3 Functional specialisation VIIa Crus I? Lobule VI M1/Premotor Lobule I-V Motor Cortex VIIa Crus II Prefrontal (46) Lobule VIIb?/M1 Lobule VIII M1 Lobule IX? Lobule X Vestibular system

4 Correspondence

5 ICBM152 Template (MNI brain)

6 Cerebellar normalization MNI 152 normalisation (Standard in SPM 2/5/8) N=20

7 Isolation algorithm

8 Template generation

9 Template generation

10 Template generation

11 Spatially Unbiased Infra-Tentorial Template(SUIT) Diedrichsen (2006), Neuroimage

12 Cerebellar normalization MNI 152 normalisation (Standard in SPM) N=20 Spatially Unbiased Infratentorial Template (SUIT) N=20

13 SUIT - openly available

14 SUIT procedure Cropping Isolation T1 anatomical suit_isolate Cropped image Isolation mask mybrain.nii c_mybrain.nii c_mybrain_pcereb_corr.nii Normalize suit_normalize Masked image Deformation parameters mc_mybrain.nii mc_mybrain_snc.mat Masking Reslicing suit_reslice functional.nii Normalised images wc_functional.nii

15 Functional imaging pipeline Functional raw data Functional data Motion correction Co-registration First-level GLM Contrast images Group data mask, reslice smooth Second-level GLM SUIT Anatomical data Normalisation parameter MNI / Surface Anatomical data Normalisation parameter Group statistics

16 How good is SUIT? Anatomical data Functional data MNI alignment SUIT Percent overlap of different lobules Roughly 10% increase in t-values

17 Overview Cerebellar normalisation Anatomical reference High-resolution imaging of cerebellar function

18 Anatomical reference MNI-space coordinate After nonlinear alignment Cerebellar Atlas (Schmahmann, 2000) 0 Normalisation (SPM) FLIRT (FSL) Segmentation (SPM) SUIT Schmahmann, et al. (2000)

19 Probabilistic atlas Bangor: Jonanthan Flavell IV Royal Holloway: VI V Narender Ramnani Cr I Joshua Balsters Emma Cussans Cr II VIIb VIIIa VIIIb IX IV IV V V VI VI Cr I IX Cr I IX Cr II VIIb VIIIa VIIIb Cr II VIIb VIIIa VIIIb

20 28 ROIs - Greymatter volumes 1cm 3 I-IV V VI Crus I Crus II 50% VIIb VIIIa Left Vermis Right X VIIIb IX

21 Overlap or certainty maps FLIRT SUIT

22 Probabilistic atlas for FSL view

23 Probabilistic atlas in MRICroN Open SUIT.nii Overlay->Add-> Cerbellum_SUIT.nii.gz Open another MRICroN and Yoke

24 Probabilistic Atlas Produced: SUIT FLIRT FNIRT SPM Segmentation Needed: AFNI Freesurfer

25 Region of interest analysis function D=suit_lobuli_summarize({ image1.nii, image2.nii },... atlas, Cerebellum_SUIT.nii outfilename, myfile.txt,... stats, mean, max,...);

26 Reslicing into individual anatomical space Individual anatomy SUIT Cerebellum_SUIT.nii suit_reslice_inv

27 Overview Cerebellar normalisation Anatomical reference High-resolution imaging of cerebellar function

28 Finger activations in primary motor cortex 1cm Subject 2 Subject 1 Thumb Index Middle Ring Little

29 Variability of finger representations saggittal coronal axial [mm] [mm] [mm] posterior medial medial Wiestler et al. (2011). J Neurophys

30 Pattern analysis Analyse local patterns in individual unsmoothed data detect modulation without any overall BOLD increases measure the size of representations detect relationship of different representations (sensory-motor)

31 Multivariate analysis? Trials Linear Classifier P M I T P M I T P M I T Voxels Wiestler et al. (2011). J Neurophys

32 Cerebellar digit maps Movement Stimulation Accuracy task > rest Wiestler et al. (2011). J Neurophys

33 Informative patterns without mean activity increases run 1{ voxel pattern thumb index middle little run 7{..... thumb index middle little voxel activity low high classification accuracy classification mean evoked activity Performance Accuracy percent correct Stimulation Movement 25 V VIII M1 S1

34 Spatial properties of finger patterns Finger patterns P M I T P M I T Correlation between voxels for different distances Correlation V VIII M1 S Spatial distiance [mm] Wiestler et al. (2011). J Neurophys

35 Integration of sensory and motor information Globally in the same area 151 But corresponding patterns? 151 Wiestler et al. (2011). J Neurophys

36 Integration of sensory motor information Stimulation P M I T Movement P M I T Finger correlation V VIII M1 S1 Diedrichsen et al. (2011)

37 Summary a Cortical digit representation b Cerebellar digit representation In the neocortex, movements are presented together with the matching sensory consequence Activated by sensory stimulation In the cerebellum, they are finely interdigitated Activated by movement This may promote learning of novel movement-outcome associations 5mm Characteristics of representations, but not the representations themselves should correspond across participants Wiestler et al. (2011). J Neurophys

38 Acknowledgements SUIT Tobias Wiestler John Schlerf Reza Shadmehr Niall Lally Dagmar Timmann + All Users Atlas Narender Ramnani Joshua Balsters Emma Cussans Jonathan Flavell Matt Webster (FSL) Simon Eickhoff (Anatomy Toolbox) Nick Oosterhof (AFNI) Pattern Tobias Wiestler Nick Oosterhof Karl Friston Ged Ridgeway Grant support James S. McDonnell Foundation