fMRI Setup

slice orientations sagittal coronal axial

SPGR Anatomics (1) resolution in-plane 0.9375 mm2 through-plane 1.5 mm

SPGR Anatomics (2)

SPGR Anatomics (3) My notes for spgr movie

Diffusion-Weighted Imaging (1)

Diffusion-Weighted Imaging (2)

Diffusion-Weighted Imaging (3)

Slice Locations

Auditory versus Visual Sentence Task common print(red) speech(blue) R - L Constable, Pugh et al., (NeuroImage 2004)

An Initial Neurobiological Reading Model (Pugh et al. 2000) TEMPOROPARIETAL (DORSAL) Areas: supramarginal, angular, superior temporal (Wernicke’s) gyri Hypothesized Function: Mapping of orthographic to phonological and semantic representations ANTERIOR Areas: inferior frontal gyrus (including Broca’s area) One Hypothesized Function: Articulatory recoding OCCIPITOTEMPORAL (VENTRAL) Areas: occipitotemporal juncture, middle and inferior temporal gyri Hypothesized Function: Linguistically structured memory- based fast word identification system (posterior aspect = “word-form” area)

Auditory versus Visual Sentence Task common print(red) speech(blue) temporoparietal anterior occipitotemporal R - L Constable, Pugh et al., (NeuroImage 2004)

Vasculature Menon & Kim, Trends in Cognitive Sciences, 3(6), 1999.

Vasculature Menon & Kim, Trends in Cognitive Sciences, 3(6), 1999.

Simulated Hemodynamic Response (1) mean = 5000 sd = 100 effect size 0-1%, 0-50 points Gamma function tau=1.08; n=3; delay=3

Variability of the HRF (1) Meizin et al., 2000

Simulated Hemodynamic Response (2) Noise SD = 0 Noise SD = 10 Noise SD = 100

Estimating the Response (3): Simple Subtraction with Overlap Dale & Buckner, 1997 Add stim figure

Linear Deconvolution Neuronal activity is modeled as a sequence of point events. slide courtesy of Matthew Brown, University of Western Ontario

Functional Connectivity activations in Shaywitz et al. 2002 older good readers 74 good readers 7-18 yrs 70 dyslexic readers 7-18 yrs

Functional Connectivity seed voxel correlations older good readers

Functional Connectivity Younger Non-Impaired Older Non-Impaired univariate correlations Younger Dyslexics Older Dyslexics