HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis Fall 2006

Transcription

1 MIT OpenCourseWare HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis Fall 2006 For information about citing these materials or our Terms of Use, visit:

2 Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts 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. elf Reference HST:583 fmri Acquisition Lab1 Susan Whitfield-Gabrieli Sternberg ensorimotor TASKS: Self Reference Sensorimotor Breath holding Sternberg Courtesy of Randy Gollub. Used with permission. Source: Yendiki, A., R. L. Gollub, et al. "Multi-site Characterization of an fmri Working Memory Paradigm: Reliability of Activation Indices." Annual Meeting of the Organization for Human Brain Mapping, Florence, Italy, June 11-15, Breath holding Courtesy of Gary Glover. Used with permission. Courtesy of Gary Glover. Used with permission.

3 Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts Self Reference Task Stimuli: Trait Adjectives POLITE DARING RUDE DEPENDABLE Cue: Does this word apply to you? (self reference condition) or Is this word positive? (semantic condition)

4 Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts Self reference task design Stimuli: trait adjective words Words were drawn from Anderson s (1968) list of normed trait adjectives. The lists were counterbalanced for word valence, length and number of syllables. Presentation: Words are presented in a blocked design. Each word is presented for 3 sec in blocks of ten and prior to each block onset subjects view a 2 sec cue describing their task for upcoming block. Each block is followed by 10 seconds of a rest condition. Each session has 2 blocks per self reference and 2 blocks per semantic conditions in the ABBA format. Total task time: 3min/session, 4 sessions or 12min

5 Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts Schematic illustration of cortical midline structures (CMS) Courtesy Elsevier, Inc., Used with permission. MOPFC= medial orbital prefrontal cortex (BA11, BA12) VMPFC = ventromedial prefrontal cortex (BA10, 11) PACC = pre and subgenual anterior cingulate cortex (BA24, BA25, BA32) SACC = supragenual anterior cingulate cortex (BA24, BA32) PCC = posterior cingulate cortex (BA23) Northroff, G., et al. Self-referential processing in our brain A metaanalysis of imaging studies on the self. NeuroImage 31 (2006):

6 Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts Activation in CMS observed in imaging studies during self related tasks in different domains. Courtesy Elsevier, Inc., Used with permission. Northroff, G., et al. Self-referential processing in our brain A metaanalysis of imaging studies on the self. NeuroImage 31 (2006):

7 Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts Graphic representation of localizations of clusters 2 1 Courtesy Elsevier, Inc., Used with permission. Northroff, G., et al. Self-referential processing in our brain A metaanalysis of imaging studies on the self. NeuroImage 31 (2006):

8 Self Reference, Single Subject (self-semantic) Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts

9 Single subject (4 sessions) Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts

10 Single subject, one session only Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts

11 Single Subject Data Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts

12 Self reference, Group Analysis Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts

13 Frontal regions are prone to susceptibility artifact Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts

14 Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts Phase maps: The field map is a 2D gradient echo sequence which acquires an image at 2 different echo times. This sequence generates 2 types of images, a magnitude image and a phase map. The phase map represents the phase differences of the spins which ultimately represent the local field inhomogeneities. You can display this map to see which regions are prone to susceptibility artifacts.

15 Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts

16 Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts Sensorimotor Task The task consists of a block design with block durations of 16s on/off. When checkerboard appears, subjects presses button using their right index finger and the off-block is fixation/no tapping. There are 15 total, 16s blocks. (4 min) On block parameters: ISI ranges from ms, average ISI = 762ms, std. dev = 156ms. 21 checkerboard flashes per on block, each checkerboard flash duration = 200ms. The sequence begins with an off block.scanner triggers the paradigm (after the dummy scans). fbirn ( functional biomedical informatics research network)

17 Source: Brodmann, Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts

18 Motor and Visual Cortex Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts Motor cortex - BA4 shown in green Visual cortex - BA 17,18,19 from rear view of brain BA 17 is shown in red. BA 18 is orange BA 19 is yellow You ll see LEFT motor cortex (green), since the subject is responding with the right hand, and you ll see bilateral visual cortex. Brain surface extracted from structural MRI data (Wellcome Dept. Imaging Neuroscience, UCL, UK). Brodmann Area data is based on information from the online Talairach demon (electronic version of Talairach and Tournoux, 1988).

19 Example of Sensorimotor Task activation (with visual, motor & auditory) Courtesy of Gary Glover. Used with permission. Note: This task has an additional auditory component so you see temporal lobe activation as well as motor and visual. In addition, the subject is responding with both hands so you see bilateral motor activation as opposed to only the left hemisphere motor (contralateral to response hand) fbirn ( functional biomedical informatics research network) Gary Glover, Stanford University Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts

20 Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts Breath Holding Task This is a calibration task to measure subjects' global vascular reactivity. The task consists of a block design with alternating on/off blocks of 16-second periods of breath holding and normal breathing. During the off-block, the subject sees a green screen during which they are to breathe normally. During the last 2s of the off-block, the screen becomes yellow, signifying to the subject to take a deep breath in and hold. During the on-block (16s), the subject is shown a red screen, during which time they should hold their breath. The subject resumes breathing when they see a green colored screen. 15 total 16s blocks (4 min) Total task time: 4:06

21 Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts Breath holding calibration The entire gray matter volume is activated in each subject by the breath-holding task. This sample data is from Stanford s 3T MRI shows the global response to holding one s breath for 15 seconds. Courtesy of Gary Glover. Used with permission.

22 Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts Sternberg Item Recognition Paradigm (SIRP) A Working Memory Task Each block is composed of three epochs: learn, encode, and probe: 1.5 sec for the learn prompt followed by.5 sec blank screen 6 sec to encode the target digits ( [1, 3, 5] digit sets providing a range of task difficulty) 38 sec for the probe digits (sequential presentation of digits) This means each working memory set lasts a total of 46 seconds. A block of each set size occurs twice in random order within a single run and each working memory set is sandwiched between fixation blocks. The duration of the fixation blocks within a run is random: Total time for all fixation blocks within a run = 78 seconds, (4,20) (min time = 4 sec, max time = 20 sec) Total scan time is thus 46 seconds* seconds+ 6 sec ddas = 360s Total task time: 6:00min Time frames: 180

23 IPS (intraparietal sulcus) Sternberg Task: Group analysis (n=10) HIGH (5) LOW(1) Working Memory Load: Green regions: ROIs of 3 working memory related areas (DLPFC, DLPMC, IPS) and 1 control region (MTG) DLPMC (dorsal lateral premotor cortex) DLPFC (dorsal lateral prefrontal cortex) MTG (middle temp gyrus) Courtesy of Randy Gollub. Used with permission. Source: Yendiki, A., R. L. Gollub, et al. "Multi-site Characterization of an fmri Working Memory Paradigm: Reliability of Activation Indices." Annual Meeting of the Organization for Human Brain Mapping, Florence, Italy, June 11-15, Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts

24 Courtesy of Randy Gollub. Used with permission. Source: Yendiki, A., R. L. Gollub, et al. "Multi-site Characterization of an fmri Working Memory Paradigm: Reliability of Activation Indices." Annual Meeting of the Organization for Human Brain Mapping, Florence, Italy, June 11-15, Cite as: Susan Whitfield-Gabrieli, HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall (Massachusetts