scholarly journals What is Involved and What is Necessary for Complex Linguistic and Nonlinguistic Auditory Processing: Evidence from Functional Magnetic Resonance Imaging and Lesion Data

2007 ◽  
Vol 19 (5) ◽  
pp. 799-816 ◽  
Author(s):  
Frederic Dick ◽  
Ayse Pinar Saygin ◽  
Gaspare Galati ◽  
Sabrina Pitzalis ◽  
Simone Bentrovato ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Auditory Processing ◽  
Right Hemisphere ◽  
Blood Oxygenation ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Environmental Sound ◽  
Environmental Sounds

We used functional magnetic resonance imaging (fMRI) in conjunction with a voxel-based approach to lesion symptom mapping to quantitatively evaluate the similarities and differences between brain areas involved in language and environmental sound comprehension. In general, we found that language and environmental sounds recruit highly overlapping cortical regions, with cross-domain differences being graded rather than absolute. Within language-based regions of interest, we found that in the left hemisphere, language and environmental sound stimuli evoked very similar volumes of activation, whereas in the right hemisphere, there was greater activation for environmental sound stimuli. Finally, lesion symptom maps of aphasic patients based on environmental sounds or linguistic deficits [Saygin, A. P., Dick, F., Wilson, S. W., Dronkers, N. F., & Bates, E. Shared neural resources for processing language and environmental sounds: Evidence from aphasia. Brain, 126, 928–945, 2003] were generally predictive of the extent of blood oxygenation level dependent fMRI activation across these regions for sounds and linguistic stimuli in young healthy subjects.

scholarly journals Event-Related Functional Magnetic Resonance Imaging Study of the Extrastriate Cortex Response to a Categorically Ambiguous Stimulus Primed by Letters and Familiar Geometric Figures

2001 ◽  
Vol 21 (11) ◽  
pp. 1330-1341 ◽  
Author(s):  
Hélène Gros ◽  
Kader Boulanouar ◽  
Gérard Viallard ◽  
Emmanuelle Cassol ◽  
Pierre Celsis
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Right Hemisphere ◽  
Extrastriate Cortex ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Ambiguous Stimulus ◽  
Form Processing ◽  
Geometric Figures

Functional neuroimaging studies have suggested a specific role of the extrastriate cortex in letter string and visual word form processing. However, this region has been shown to be involved in object recognition and its specificity for the processing of linguistic stimuli may be questioned. The authors used an event-related functional magnetic resonance imaging design with category priming to record the response elicited by the passive viewing of single letters, geometric figures, and of the categorically ambiguous stimulus “O” that pertains to both sets of familiar symbols. Bilateral activations in the extrastriate cortex were found, with a left predominance particularly pronounced for the ambiguous stimulus. Individual analysis of spatial extent and signal intensity showed a priming × stimulus × hemisphere interaction. When primed by the congruous categoric set, a bilateral decrease in activation was observed for letters and geometric figures. The ambiguous stimulus behaved as a letter for the left hemisphere, with decreased activation when primed by letters, whereas in the right hemisphere, an adaptation effect occurred when primed by geometric figures. These priming effects suggest that, for the ambiguous stimulus, letter processing was systematically involved in the left extrastriate cortex. The current results support the existence of a neural substrate for the abstract category of letters.

A Quantitative Physiologic Model of Blood Oxygenation for Functional Magnetic Resonance Imaging

1995 ◽  
Vol 30 (11) ◽  
pp. 669-682 ◽  
Author(s):  
GASSER M. HATHOUT ◽  
SANJIV S. GAMBHIR ◽  
RAMESH K. GOPI ◽  
KONRAD A.T. KIRLEW ◽  
YONG CHOI ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Blood Oxygenation ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Physiologic Model

scholarly journals A Functional Magnetic Resonance Imaging Technique Based on Nulling Extravascular Gray Matter Signal

2008 ◽  
Vol 29 (1) ◽  
pp. 144-156 ◽  
Author(s):  
Yuji Shen ◽  
Risto A Kauppinen ◽  
Rishma Vidyasagar ◽  
Xavier Golay
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Gray Matter ◽  
Visual Stimulation ◽  
Brain Activation ◽  
Blood Oxygenation ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Fmri Signal

A new functional magnetic resonance imaging (fMRI) technique is proposed based on nulling the extravascular gray matter (GM) signal, using a spatially nonselective inversion pulse. The remaining MR signal provides cerebral blood volume (CBV) information from brain activation. A theoretical framework is provided to characterize the sources of GM-nulled (GMN) fMRI signal, effects of partial voluming of cerebrospinal fluid (CSF) and white matter, and behaviors of GMN fMRI signal during brain activation. Visual stimulation paradigm was used to explore the GMN fMRI signal behavior in the human brain at 3T. It is shown that the GMN fMRI signal increases by 7.2% ± 1.5%, which is two to three times more than that obtained with vascular space occupancy (VASO)-dependent fMRI (−3.2% ± 0.2%) or blood oxygenation level-dependent (BOLD) fMRI (2.9% ± 0.7%), using a TR of 3,000 ms and a resolution of 2 × 2 × 5 mm3. Under these conditions the fMRI signal-to-noise ratio (SNRfMRI) for BOLD, GMN, and VASO images was 4.97 ± 0.76, 4.56 ± 0.86, and 2.43 ± 1.06, respectively. Our study shows that both signal intensity and activation volume in GMN fMRI depend on spatial resolution because of partial voluming from CSF. It is shown that GMN fMRI is a convenient tool to assess CBV changes associated with brain activation.

Distinctive Cortical Articulatory Representation in Cleft Lip and Palate: A Preliminary Functional Magnetic Resonance Imaging Study

2006 ◽  
Vol 43 (5) ◽  
pp. 620-624 ◽  
Author(s):  
Hideo Shinagawa ◽  
Takashi Ono ◽  
Ei-ichi Honda ◽  
Tohru Kurabayashi ◽  
Atsushi Iriki ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Sensorimotor Cortex ◽  
Cleft Lip ◽  
Cleft Lip And Palate ◽  
Blood Oxygenation ◽  
Cortical Representation ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging

Objective: To investigate cortical representation of articulation of the bilabial plosive in patients with cleft lip and palate. Design: We examined cortical representation for /pa/-articulation in cleft lip and palate patients using blood oxygenation level–dependent functional magnetic resonance imaging. Subjects: Data from four postsurgical adult cleft lip and palate patients were compared with those from six healthy volunteers. Results: Activation foci were found in the bilateral primary sensorimotor cortex in all cleft lip and palate patients, as in the controls. The sensorimotor cortex ipsilateral to the side of cleft lip and palate showed greater activation in unilateral cleft lip and palate patients, whereas the sensorimotor cortex contralateral to the side on which cheiloplasty had been performed earlier showed greater activation in a bilateral cleft lip and palate patient. Conclusions: The results suggest that there may be an ipsilateral dominance in cortical representation during bilabial articulation to the side of the cleft in the upper lip.

Pediatric Functional Magnetic Resonance Imaging: Clinical Applications

2017 ◽  
Vol 16 (02) ◽  
pp. 078-093
Author(s):  
Kirk Welker ◽  
Mai-Lan Ho
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Study Design ◽  
Pediatric Population ◽  
Clinical Applications ◽  
Blood Oxygenation ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Design Data

AbstractTask-based functional magnetic resonance imaging (fMRI) is an imaging technique based on blood oxygenation level-dependent imaging. Maps of brain activation are generated during the performance of designated tasks involving eloquent functions, such as motor, sensory, visual, auditory, and/or language. Optimal performance of fMRI in children requires consideration of multiple psychological and physiological parameters. Also, a solid technical understanding is needed for appropriate study design, implementation, processing, and interpretation. In this article, the authors review the key principles of fMRI technique, study design, data processing, and interpretation. The important clinical applications in the pediatric population will be highlighted, accompanied by example cases from their institution.

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