MIT OpenCourseWare http://ocw.mit.edu HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis Fall 2006 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. HST.583: Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006 Harvard-MIT Division of Health Sciences and Technology Course Director: Dr. Randy Gollub. Statistical Signal Processing for fMRI Douglas N. Greve Mark Vangel Anastasia Yendiki Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. Overview • First-Level Univariate Analysis • Signal Modeling • Nuisance Modeling • Noise Modeling • Hypothesis Testing • Correction for Multiple Comparisons • Cross-Subject/Higher Level Analysis • Lab Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. HST583: Statistical Signal Processing for fMRI -- Douglas N. Greve Analysis Goals • Quantify Neural Correlates in fMRI • Amplitude of Hemodynamic Response • Delay/Shape of Hemodynamic Response • Extent/Size of Activation • Localization of function • Quantify Uncertainty • Cross-subject (within group) • Cross-group – eg, Normals, Clinical Populations • Within-subject – EEG/MEG/Optical/Surgical Planning Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. HST583: Statistical Signal Processing for fMRI -- Douglas N. Greve Challenges • • • • • Large Noise – thermal, physiological, motion Small Signal – delay, dispersion Structural/Functional Alignment – within subject Intersubject Alignment Copious amounts of data – eg, 20 subjects, 5 runs per subject, 100 time points per run, 64x64x30 volume = 1.2G data points • More spatial voxels than time points (multiple comparisons problem). • Model Validation Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. HST583: Statistical Signal Processing for fMRI -- Douglas N. Greve Method • Correlational – synchronized stimulus and acquistion • Linear/Gaussian Assumptions • GLM – “General” Linear Model • MSE – Minimum Square Error • LMS – Least Mean Squares • “Massively Univariate” Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. HST583: Statistical Signal Processing for fMRI -- Douglas N. Greve Hemodynamic Response (BOLD) Time-to-Peak (~6sec) Dispersion TR (~2sec) Equilibrium (~16-32sec) Undershoot Delay (~1-2sec) Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. HST583: Statistical Signal Processing for fMRI -- Douglas N. Greve fMRI Noise Synthetic data. HST583: Statistical Signal Processing for fMRI -- Douglas N. Greve Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. Averaging Synthetic data. HST583: Statistical Signal Processing for fMRI -- Douglas N. Greve Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. Typical Analysis Stream • Preprocessing • “Univariate” First-Level GLM Analysis • “Univariate” Higher-Level GLM Analysis • “Multivariate” Analysis • Packages: • SPM – Statistical Parametric Mapping • AFNI – Analysis of Functional NeuroImages • FSL – fMRI Software Library • FS-FAST – FreeSurfer Functional Analysis STream Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. HST583: Statistical Signal Processing for fMRI -- Douglas N. Greve Preprocessing • k-Space reconstruction • Slice-Timing Correction (?) • Motion Correction • Spatial Filtering (Smoothing - FWHM) • Intensity Normalization • Temporal Filtering (or in analysis) • Per-run, within subject Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. HST583: Statistical Signal Processing for fMRI -- Douglas N. Greve Univariate First-Level Analysis • Per-voxel, per-subject • Postulate model of the observable (ie raw time course) • Signal model (eg, hemodynamic response) • Noise model (eg, autocorrelation function) • Drift (eg, mean offset, linear, quadratic) • General Linear Model (GLM) • Parameterized • Linear (superposition) • Least-mean-square estimation of parameters • Hypothesis Test = Contrast of Parameters • Assemble into a map Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. HST583: Statistical Signal Processing for fMRI -- Douglas N. Greve Univariate High-level Analysis • Per-voxel, Cross-subject • Requires intersubject registration • Dave Kennedy • Uses information from First/Lower Levels • GLM to describe relationship • Random Effects • Fixed Effects Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. HST583: Statistical Signal Processing for fMRI -- Douglas N. Greve Multivariate Statistics • Cross-voxel (within map) • Thresholding and multiple comparisons problem • Gaussian Random Fields (GRF) • Principal Component Analysis (PCA/SVD) • Independent Component Analysis • Region-of-Interest Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. HST583: Statistical Signal Processing for fMRI -- Douglas N. Greve Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. HST583: Statistical Signal Processing for fMRI -- Douglas N. Greve Hemodynamic Response Model Time-to-Peak (~6sec) Dispersion TR (~2sec) Equilibrium (~16-32sec) Undershoot Delay (~1-2sec) Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. HST583: Statistical Signal Processing for fMRI -- Douglas N. Greve Visual Activation Paradigm Flickering Checkerboard Visual, Auditory, Motor, Tactile, Pain, Perceptual, Recognition, Memory, Emotion, Reward/Punishment, Olfactory, Taste, Gastral, Gambling, Economic, Acupuncture, Meditation, The Pepsi Challenge, … • Scientific • Clinical • Pharmaceutical Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. HST583: Statistical Signal Processing for fMRI -- Douglas N. Greve Blood Oxygen Level Dependence (BOLD) Oxygenated Hemoglobin (DiaMagnetic) Neurons Deoxygenated Hemoglobin (ParaMagnetic) Lungs Oxygen CO2 Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. HST583: Statistical Signal Processing for fMRI -- Douglas N. Greve Functional MRI (fMRI) Stimulus Localized Neural Firing Localized Increased Blood Flow Localized BOLD Changes Sample BOLD response in 4D Space (3D) – voxels (64x64x35, 3x3x5mm^3) Time (1D) – time points (100, 2 sec) Time 1 Time 2 Time 3 … Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. HST583: Statistical Signal Processing for fMRI -- Douglas N. Greve Analysis Goals Given: • raw fMRI time course and • stimulus presentation times Compute: • Hemodynamic Response (HRF) Amplitude • HRF Confidence Interval Quantify Uncertainty • P-Value • Noise Amplitude } Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. HST583: Statistical Signal Processing for fMRI -- Douglas N. Greve Final Results: Maps • Assign values to each voxel • Display as pseudo-color images • Threshold? Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. HST583: Statistical Signal Processing for fMRI -- Douglas N. Greve Final Results: Tables • List of active regions Cluster TalX TalY TalZ Volume Sig Number (mm) (mm) (mm) (mm^3) (log10) 1 -30.5 13.2 0.2 125.6 5.7 2 4.5 9.7 -20.2 878.1 4.1 3 2.9 -18.0 17.7 400.3 3.2 Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. HST583: Statistical Signal Processing for fMRI -- Douglas N. Greve Final Results: Waveforms • Average raw data over time and space Cite as: Douglas N. Greve, Mark Vangel, and Anastasia Yendiki, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006. (Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed MM DD, YYYY). License: Creative Commons BY-NC-SA. HST583: Statistical Signal Processing for fMRI -- Douglas N. Greve