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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

The nTMS speech mapping method. An example of images used in object (A) and action naming (B). (C) Timeline of the events in the nTMS speech mapping. The interpicture interval was 2500 ms.
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Figure 1: The nTMS speech mapping method. An example of images used in object (A) and action naming (B). (C) Timeline of the events in the nTMS speech mapping. The interpicture interval was 2500 ms.

Mentions: We used two sets of color pictures with a white background, one with 131 images depicting objects and another with 98 images depicting actions. Object images illustrated a simple object (e.g., a chair; Figure 1A; see also the video in the Supplementary Material). The action images represented a simple event (e.g., playing an instrument; Figure 1B). The subjects were asked to name objects or actions in Finnish as quickly and precisely as possible. Two subjects performed action naming before object naming. The experiment consisted of two baseline sessions without nTMS (one for object and another for action naming) and two nTMS sessions (one with object naming and another with action naming). All sessions were video-recorded for offline analysis. The baseline sessions were done before the nTMS sessions. Images that were unfamiliar or named incorrectly in the baseline session were removed from the image set used during nTMS (see the Supplementary Table). Thus, only fluently named images were used during the nTMS sessions. The numbers of rejected object and action images did not differ significantly (Mann–Whitney U-test; p = 0.26). The images were displayed in random order within the object naming and action naming sessions (see the Supplementary Video). For each subject, all TMS measurements were performed in a row.


Effects of navigated TMS on object and action naming.

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

The nTMS speech mapping method. An example of images used in object (A) and action naming (B). (C) Timeline of the events in the nTMS speech mapping. The interpicture interval was 2500 ms.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: The nTMS speech mapping method. An example of images used in object (A) and action naming (B). (C) Timeline of the events in the nTMS speech mapping. The interpicture interval was 2500 ms.
Mentions: We used two sets of color pictures with a white background, one with 131 images depicting objects and another with 98 images depicting actions. Object images illustrated a simple object (e.g., a chair; Figure 1A; see also the video in the Supplementary Material). The action images represented a simple event (e.g., playing an instrument; Figure 1B). The subjects were asked to name objects or actions in Finnish as quickly and precisely as possible. Two subjects performed action naming before object naming. The experiment consisted of two baseline sessions without nTMS (one for object and another for action naming) and two nTMS sessions (one with object naming and another with action naming). All sessions were video-recorded for offline analysis. The baseline sessions were done before the nTMS sessions. Images that were unfamiliar or named incorrectly in the baseline session were removed from the image set used during nTMS (see the Supplementary Table). Thus, only fluently named images were used during the nTMS sessions. The numbers of rejected object and action images did not differ significantly (Mann–Whitney U-test; p = 0.26). The images were displayed in random order within the object naming and action naming sessions (see the Supplementary Video). For each subject, all TMS measurements were performed in a row.

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