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Effects of navigated TMS on object and action naming.

Hernandez-Pavon JC, Mäkelä N, Lehtinen H, Lioumis P, Mäkelä JP - Front Hum Neurosci (2014)

Bottom Line: Naming during nTMS was compared with the baseline performance.Both intrasubject and intersubject analysis showed that object naming was significantly more sensitive to nTMS.When the number of errors was compared according to a given area, nTMS to postcentral gyrus induced more errors during object than action naming.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering and Computational Science, Aalto University School of Science Espoo, Finland ; BioMag Laboratory, HUS Medical Imaging Center, Helsinki University Central Hospital Helsinki, Finland.

ABSTRACT
Transcranial magnetic stimulation (TMS) has been used to induce speech disturbances and to affect speech performance during different naming tasks. Lately, repetitive navigated TMS (nTMS) has been used for non-invasive mapping of cortical speech-related areas. Different naming tasks may give different information that can be useful for presurgical evaluation. We studied the sensitivity of object and action naming tasks to nTMS and compared the distributions of cortical sites where nTMS produced naming errors. Eight healthy subjects named pictures of objects and actions during repetitive nTMS delivered to semi-random left-hemispheric sites. Subject-validated image stacks were obtained in the baseline naming of all pictures before nTMS. Thereafter, nTMS pulse trains were delivered while the subjects were naming the images of objects or actions. The sessions were video-recorded for offline analysis. Naming during nTMS was compared with the baseline performance. The nTMS-induced naming errors were categorized by error type and location. nTMS produced no-response errors, phonological paraphasias, and semantic paraphasias. In seven out of eight subjects, nTMS produced more errors during object than action naming. Both intrasubject and intersubject analysis showed that object naming was significantly more sensitive to nTMS. When the number of errors was compared according to a given area, nTMS to postcentral gyrus induced more errors during object than action naming. Object naming is apparently more easily disrupted by TMS than action naming. Different stimulus types can be useful for locating different aspects of speech functions. This provides new possibilities in both basic and clinical research of cortical speech representations.

No MeSH data available.


Related in: MedlinePlus

Cortical sites for both object and action naming errors visualized on an inflated reconstruction of the cortex. Red spheres: no-response errors; green spheres: semantic paraphasias; yellow spheres: phonological paraphasias. (A,B) All cortical sites that elicited nTMS-induced naming errors in the subjects. (C–F) Individual data from subjects S1 and S7. The number, type, and location of the naming errors vary between subjects. The white asterisks indicate the sites of repeated errors at the same location.
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Figure 2: Cortical sites for both object and action naming errors visualized on an inflated reconstruction of the cortex. Red spheres: no-response errors; green spheres: semantic paraphasias; yellow spheres: phonological paraphasias. (A,B) All cortical sites that elicited nTMS-induced naming errors in the subjects. (C–F) Individual data from subjects S1 and S7. The number, type, and location of the naming errors vary between subjects. The white asterisks indicate the sites of repeated errors at the same location.

Mentions: To visually summarize the speech mapping results, the stimulation sites that were associated with naming errors from all eight subjects were projected on the standardized MNI brain template (Mazziotta et al., 2001), using FSL (Smith et al., 2004; Woolrich et al., 2009; Jenkinson et al., 2012) and FreeSurfer (Fischl et al., 1999) softwares. The brain was segmented from the individual T1-weighted MRIs of each subject and registered with the standard brain template in MNI space. Thereafter, the coordinates of the naming error locations were projected into the MNI space, using the transformation matrix given by the registration and overlaid with the inflated cortical surface of the MNI brain template (Figure 2).


Effects of navigated TMS on object and action naming.

Hernandez-Pavon JC, Mäkelä N, Lehtinen H, Lioumis P, Mäkelä JP - Front Hum Neurosci (2014)

Cortical sites for both object and action naming errors visualized on an inflated reconstruction of the cortex. Red spheres: no-response errors; green spheres: semantic paraphasias; yellow spheres: phonological paraphasias. (A,B) All cortical sites that elicited nTMS-induced naming errors in the subjects. (C–F) Individual data from subjects S1 and S7. The number, type, and location of the naming errors vary between subjects. The white asterisks indicate the sites of repeated errors at the same location.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4151040&req=5

Figure 2: Cortical sites for both object and action naming errors visualized on an inflated reconstruction of the cortex. Red spheres: no-response errors; green spheres: semantic paraphasias; yellow spheres: phonological paraphasias. (A,B) All cortical sites that elicited nTMS-induced naming errors in the subjects. (C–F) Individual data from subjects S1 and S7. The number, type, and location of the naming errors vary between subjects. The white asterisks indicate the sites of repeated errors at the same location.
Mentions: To visually summarize the speech mapping results, the stimulation sites that were associated with naming errors from all eight subjects were projected on the standardized MNI brain template (Mazziotta et al., 2001), using FSL (Smith et al., 2004; Woolrich et al., 2009; Jenkinson et al., 2012) and FreeSurfer (Fischl et al., 1999) softwares. The brain was segmented from the individual T1-weighted MRIs of each subject and registered with the standard brain template in MNI space. Thereafter, the coordinates of the naming error locations were projected into the MNI space, using the transformation matrix given by the registration and overlaid with the inflated cortical surface of the MNI brain template (Figure 2).

Bottom Line: Naming during nTMS was compared with the baseline performance.Both intrasubject and intersubject analysis showed that object naming was significantly more sensitive to nTMS.When the number of errors was compared according to a given area, nTMS to postcentral gyrus induced more errors during object than action naming.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering and Computational Science, Aalto University School of Science Espoo, Finland ; BioMag Laboratory, HUS Medical Imaging Center, Helsinki University Central Hospital Helsinki, Finland.

ABSTRACT
Transcranial magnetic stimulation (TMS) has been used to induce speech disturbances and to affect speech performance during different naming tasks. Lately, repetitive navigated TMS (nTMS) has been used for non-invasive mapping of cortical speech-related areas. Different naming tasks may give different information that can be useful for presurgical evaluation. We studied the sensitivity of object and action naming tasks to nTMS and compared the distributions of cortical sites where nTMS produced naming errors. Eight healthy subjects named pictures of objects and actions during repetitive nTMS delivered to semi-random left-hemispheric sites. Subject-validated image stacks were obtained in the baseline naming of all pictures before nTMS. Thereafter, nTMS pulse trains were delivered while the subjects were naming the images of objects or actions. The sessions were video-recorded for offline analysis. Naming during nTMS was compared with the baseline performance. The nTMS-induced naming errors were categorized by error type and location. nTMS produced no-response errors, phonological paraphasias, and semantic paraphasias. In seven out of eight subjects, nTMS produced more errors during object than action naming. Both intrasubject and intersubject analysis showed that object naming was significantly more sensitive to nTMS. When the number of errors was compared according to a given area, nTMS to postcentral gyrus induced more errors during object than action naming. Object naming is apparently more easily disrupted by TMS than action naming. Different stimulus types can be useful for locating different aspects of speech functions. This provides new possibilities in both basic and clinical research of cortical speech representations.

No MeSH data available.


Related in: MedlinePlus