Multimodal Brain Imaging and Modeling

The completion of cognition and tasks requires the orchestration of spatiotemporal processes distributed in the brain. In connectivity analysis, we interrogate how activities at different brain areas are synchronized in time (functional connectivity). We also attempt to reveal how information is transmitted and integrated across brain areas underlying a task or a condition (effective connectivity). We use MRI, magnetoencephalography and electroencephalogrqphy to study the structural, functional and effective connectivity at the system level.

Selected publications

Wu PY, Chu YH, Lin JL, Kuo WJ, Lin FH. Feature-dependent intrinsic functional connectivity across cortical depths in the human auditory cortex. Sci Rep. 2018 Sep 5;8(1):13287. doi: 10.1038/s41598-018-31292-x.

Jääskeläinen IP, Pajula J, Tohka J, Lee HJ, Kuo WJ, Lin FH. Brain hemodynamic activity during viewing and re-viewing of comedy movies explained by experienced humor. Sci Rep. 2016 Jun 21;6:27741. doi:10.1038/srep27741

Lin FH, Ahveninen J, Raij T, Witzel T, Chu YH, Jääskeläinen IP, Tsai KW, Kuo WJ, Belliveau JW. Increasing fMRI sampling rate improves Granger causality estimates. PLoS One. 2014 Jun 26;9(6):e100319. doi: 10.1371/journal.pone.0100319.

Chu YH, Lin FH, Chou YJ, Tsai KW, Kuo WJ, Jääskeläinen IP. Effective cerebral connectivity during silent speech reading revealed by functional magnetic resonance imaging. PLoS One. 2013 Nov 21;8(11):e80265. doi:10.1371/journal.pone.0080265

Lin FH, Agnew JA, Belliveau JW, Zeffiro TA. Functional and effective connectivity of visuomotor control systems demonstrated using generalized partial least squares and structural equation modeling. Hum Brain Mapp. 2009 Jul;30(7):2232–51.

Lin FH, Hara K, Solo V, Vangel M, Belliveau J, Stufflebeam S, Hämäläinen M. Dynamic Granger-Geweke causality modeling with application to interictal spike propagation. Hum Brain Mapp. 2009 Jun;30(6):1877–96.

Lin FH, Witzel T, Hämäläinen MS, Dale AM, Belliveau JW, Stufflebeam SM. Spectral spatiotemporal imaging of cortical oscillations and interactions in the human brain. Neuroimage. 2004 Oct;23(2):582–95

Magnetic resonance imaging has millimetre spatial resolution and versatile contrasts. It has been extensively used in clinical medicine and neuroscience studies to provide structural, functional and metabolic information. Specifically, structural or anatomical MRI can show cortical and subcortical structures. Functional MRI using intrinsic hemodynamic response contrast has become a prevailing method of mapping human brain function. Magnetic resonance spectroscopy and spectroscopic imaging can quantify and delineate the spatial distribution of metabolites.

We are advancing MRI technology to improve its spatiotemporal resolution and sensitivity. We aim to develop a tailored combination of receiver coil arrays, spatial encoding magnetic fields, main magnetic field, pulse sequences and image reconstruction algorithms to optimize MRI in different applications.

Selected publications

Spatial encoding using nonlinear gradient coils

Hsu YC, Chern IL, Zhao W, Gagoski B, Witzel T, Lin FH. Mitigate B₁⁺inhomogeneity using spatially selective RF excitation with generalized spatial encoding magnetic fields. Magn Reson Med. 2014 Apr;71(4):1458–69.

Lin FH. Multidimensionally encoded magnetic resonance imaging. Magn Reson Med. 2013 Jul;70(1):86–96.

Lin FH, Witzel T, Schultz G, Gallichan D, Kuo WJ, Wang FN, Hennig J, Zaitsev M, Belliveau JW. Reconstruction of MRI data encoded by multiple nonbijective curvilinear magnetic fields. Magn Reson Med. 2012 Oct;68(4):1145–56.

Fast functional MRI

Hsu YC, Chu YH, Tsai SY, Kuo WJ, Chang CY, Lin FH. Simultaneous multi-slice inverse imaging of the human brain. Sci Rep. 2017 Dec 5;7(1):17019. doi: 10.1038/s41598-017-16976-0.

Lin FH, Nummenmaa A, Witzel T, Polimeni J, Zeffiro TA, Wang FN, Belliveau JW. Physiological noise reduction using volumetric functional magnetic resonance inverse imaging. Hum Brain Mapp. 2012 Dec;33(12):2815–30.

Lin FH, Tsai KW, Chu YH, Witzel T, Nummenmaa A, Raij T, Ahveninen J, Kuo WJ, Belliveau JW. Ultrafast inverse imaging techniques for fMRI. Neuroimage. 2012 Aug 15;62(2):699–705.

Tsai KW, Nummenmaa A, Witzel T, Chang WT, Kuo WJ, Lin FH. Multi-projection magnetic resonance inverse imaging of the human visuomotor system. Neuroimage. 2012 May 15;61(1):304–13.

Lin FH, Witzel T, Chang WT, Tsai KW, Wang YH, Kuo WJ, Belliveau JW. K-space reconstruction of magnetic resonance inverse imaging (K-InI) of human visuomotor systems. Neuroimage. 2010 Feb 15;49 (4):3086–98.

Lin FH, Witzel T, Mandeville JB, Polimeni JR, Zeffiro TA, Greve DN, Wiggins G, Wald LL, Belliveau JW. Event-related single-shot volumetric functional magnetic resonance inverse imaging of visual processing. Neuroimage. 2008 Aug 1;42 (1):230–47.

Ultra-low-field MRI

Hsu YC, Vesanen PT, Nieminen JO, Zevenhoven KC, DabekJ , Parkkonen L, Chern IL, Ilmoniemi RJ, Lin FH. Efficient concomitant and remanence field artifact reduction in ultra-low-field MRI using a frequency-space formulation. Magn Reson Med. 2014 Mar;71(3):955–65.

Lin FH, Vesanen PT, Nieminen JO, Hsu YC, Zevenhoven KC, Dabek J, Parkkonen LT, Zhdanov AV, Ilmoniemi RJ. Noise amplification in parallel whole-head ultra-low-field magnetic resonance imaging using 306 detectors. Magn Reson Med. 2013 Aug;70(2):595–600.

Lin FH, Vesanen PT, Hsu YC, Nieminen JO, Zevenhoven KC, Dabek J, Parkkonen LT, Simola J, Ahonen AI, Ilmoniemi RJ. Suppressing multi-channel ultra-low-field MRI measurement noise using data consistency and image sparsity. PLoS One. 2013 Apr 23;8(4):e61652. doi:10.1371/journal.pone.0061652.

Magnetoencephalography (MEG) and electroencephalography (EEG) are methods of studying human brain function noninvasively using extracranial (outside the brain) measurements of magnetic fields and electric potentials, respectively. These methods differ from functional MRI in that MEG and EEG are directly sensitive to neuronal activities and have a millisecond temporal resolution.

Our lab is developing MEG and EEG methods to understand better how the human brain works. Specific projects include MEG and EEG source localization, neuronal oscillations and integrating these imaging modalities with MRI.

Selected publications

Chang WT, Ahlfors SP, Lin FH. Sparse current source estimation using loose orientation constraint. Hum Brain Mapp. 2013 Sep;34(9):2190–2201.

Chang WT, Nummenmaa A, Hsieh JC, Lin FH. Spatially sparse source cluster modeling by compressive neuromagnetic tomography. Neuroimage. 2010 Oct 15;53(1):146–60.

Lin FH, Hara K, Solo V, Vangel M, Belliveau J, Stufflebeam S, Hämäläinen M. Dynamic Granger-Geweke causality modeling with application to interictal spike propagation. Hum Brain Mapp. 2009 Jun;30(6):1877–96.

Ahveninen J, Lin FH, Kivisaari R, Autti T, Hämäläinen M, Stufflebeam S, Belliveau JW, Kahkonen S. MRI-constrained spectral imaging of benzodiazepine modulation of spontaneous neuromagnetic activity in human cortex. Neuroimage. 2007 Apr 1;35(2):577–82.

Lin FH, Witzel T, Ahlfors SP, Stufflebeam SM, Belliveau JW, Hämäläinen MS. Assessing and improving the spatial accuracy in MEG source localization by depth-weighted minimum-norm estimates. Neuroimage. 2006 May 15;31(1):160–71.

Lin FH, Belliveau JW, Dale AM, Hämäläinen MS. Distributed current estimates with cortical orientation constraints. Hum Brain Mapp. 2006 Jan;27(1):1–13.

Investigator: Dr. Fa-Hsuan Lin

Our research aims to better understand how our brains work by studying brain activity during behavioral tests that measure cognitive functions. Brain research relies heavily on human subjects. Your participation can lead to the development of new or more effective healthcare treatments.

We are looking for the following individuals to participate in the study:

• Between 20 and 80 years of age
• With normal or corrected-to-normal vision
• With no contraindication to MRI
• With no claustrophobia
• Belonging to either one of the two groups below:
  • Healthy control group: no history of neurological, neurodevelopmental, neurodegenerative, hearing impairment, or psychiatric disorders.
  • Patient group (meet one of the following criteria):
    • With autism spectrum disorder, anxiety, or depression diagnosed by DSM-5 criteria.
    • With a neurological disorder caused by structural, biochemical, or electrical abnormality in the brain.
    • With a neurodevelopmental disorder that affects cognition, communication, emotion expression, impulse control and/or learning abilities.
    • With a neurodegenerative disease characterized by progressive degeneration or death of nerve cells.
    • With hearing impairment with MR-safe cochlear implants.

Participation in this research study will include:

• One 2- to 3-hour visit to Sunnybrook.
• During your study visit you will be asked to
  • Have an MRI scan.
  • Wear a cap to record the electrical activity of your brain and put electrodes to your scalp using conductive gel, during an EEG test.
  • Mount electrodes on your skin to measure the electrical conductivity, muscle, or heart activity.
  • Record the positions and motions of your eyes with an eye-tracker.
• You will be asked to perform the following tasks during MRI scans:
  • Watch short movies
  • Listen to music
  • Respond to auditory or visual stimuli by pressing buttons

The procedures we use in this research are non-invasive and safe. Small monetary compensation will be offered to participants after completing the study.

For more information, please call Dr. Hsin-Ju Lee at 437-345-2700 or email linlab.recruitment@sunnybrook.ca