scholarly journals Structural and functional peculiarities of speech system organization in right-handed subjects revealed using functional magnetic resonance imaging. The co-dominant right hemisphere

2017 ◽  
Vol 1 (3) ◽  
Author(s):  
Karlov VA ◽  
Shklovskiy VM ◽  
Konovalov RN ◽  
Zolovkina VS
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Right Hemisphere ◽  
System Organization ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging

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.

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.

Functional Magnetic Resonance Imaging Measures of Blood Flow Patterns in the Human Auditory Cortex in Response to Sound

1998 ◽  
Vol 41 (3) ◽  
pp. 538-548 ◽  
Author(s):  
Sean C. Huckins ◽  
Christopher W. Turner ◽  
Karen A. Doherty ◽  
Michael M. Fonte ◽  
Nikolaus M. Szeverenyi
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Speech Stimuli ◽  
Complex Stimuli ◽  
Scanning Session ◽  
Auditory Research

Functional Magnetic Resonance Imaging (fMRI) holds exciting potential as a research and clinical tool for exploring the human auditory system. This noninvasive technique allows the measurement of discrete changes in cerebral cortical blood flow in response to sensory stimuli, allowing determination of precise neuroanatomical locations of the underlying brain parenchymal activity. Application of fMRI in auditory research, however, has been limited. One problem is that fMRI utilizing echo-planar imaging technology (EPI) generates intense noise that could potentially affect the results of auditory experiments. Also, issues relating to the reliability of fMRI for listeners with normal hearing need to be resolved before this technique can be used to study listeners with hearing loss. This preliminary study examines the feasibility of using fMRI in auditory research by performing a simple set of experiments to test the reliability of scanning parameters that use a high resolution and high signal-to-noise ratio unlike that presently reported in the literature. We used consonant-vowel (CV) speech stimuli to investigate whether or not we could observe reproducible and consistent changes in cortical blood flow in listeners during a single scanning session, across more than one scanning session, and in more than one listener. In addition, we wanted to determine if there were differences between CV speech and nonspeech complex stimuli across listeners. Our study shows reproducibility within and across listeners for CV speech stimuli. Results were reproducible for CV speech stimuli within fMRI scanning sessions for 5 out of 9 listeners and were reproducible for 6 out of 8 listeners across fMRI scanning sessions. Results of nonspeech complex stimuli across listeners showed activity in 4 out of 9 individuals tested.

Sign in / Sign up

Export Citation Format

Share Document