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Repetitive transcranial magnetic stimulation of dorsolateral prefrontal cortex affects performance of the wisconsin card sorting task during provision of feedback.

Ko JH, Monchi O, Ptito A, Petrides M, Strafella AP - Int J Biomed Imaging (2008)

Bottom Line: Repetitive transcranial magnetic stimulation (rTMS) is a method that allows to disrupt processing within a given cortical region and to affect task performance for which this region is significantly solicited.We applied rTMS to the right DL-PFC and the vertex (control site) in different time points of the WCST.When rTMS was applied to the DL-PFC specifically during the period when subjects were receiving feedback regarding their previous response, WCST performance deteriorated, while rTMS did not affect performance during matching either when maintaining set or during set-shifting.

View Article: PubMed Central - PubMed

Affiliation: Montreal Neurological Institute, McGill University, Montréal, PQ, Canada H3A 2B4.

ABSTRACT
Early functional neuroimaging studies of tasks evaluating executive processes, such as the Wisconsin card sorting task (WCST), only assessed trials in blocks that may contain a large amount of different cognitive processes. More recently, we showed using event-related fMRI that the dorsolateral prefrontal cortex (DL-PFC) significantly increased activity during feedback but not matching periods of the WCST, consistent with its proposed role in the monitoring of information in working memory. Repetitive transcranial magnetic stimulation (rTMS) is a method that allows to disrupt processing within a given cortical region and to affect task performance for which this region is significantly solicited. Here we applied rTMS to test the hypothesis that the DL-PFC stimulation influences monitoring of working memory without interfering with other executive functions. We applied rTMS to the right DL-PFC and the vertex (control site) in different time points of the WCST. When rTMS was applied to the DL-PFC specifically during the period when subjects were receiving feedback regarding their previous response, WCST performance deteriorated, while rTMS did not affect performance during matching either when maintaining set or during set-shifting. This selective impairment of the DL-PFC is consistent with its proposed role in monitoring of events in working memory.

No MeSH data available.


Related in: MedlinePlus

TMS coilwas located over (a) the right DL-PFC (X = 45,  Y = 33,  Z = 25) or (b) the vertex (control) (X = 0,  Y = −35,  Z = 80). The positioning of the TMS coil over theselocations, marked on the native MRI, was performed with the aid of a framelessstereotaxic system.
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Related In: Results  -  Collection


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fig1: TMS coilwas located over (a) the right DL-PFC (X = 45, Y = 33, Z = 25) or (b) the vertex (control) (X = 0, Y = −35, Z = 80). The positioning of the TMS coil over theselocations, marked on the native MRI, was performed with the aid of a framelessstereotaxic system.

Mentions: In order to target the DL-PFC and vertex (control site) in all our subjects(Figure 1), we used a procedure that takes advantage of the standardizedstereotaxic space of Talairach and Tournoux [17] and frameless stereotaxy [18, 19]. A high-resolution MRI of the subjects' brain was acquired and transformed into standardized stereotaxic space using thealgorithm of Collins et al. [20]. The coordinates selected for the right DL-PFC(X = 45, Y = 33, Z = 25) were basedon a previous functional activation study that yielded increased activityduring the feedback period [4]. Of note, in this study, we stimulated the DL-PFClocated in the right hemisphere because this side appeared to be moreconsistently and robustly activated [4]. The control stimulation site (i.e., vertexregion, X = 0, Y = −35, Z = 80) wasalso chosen based on its lack of activation during performance of the WCST inthese previous studies.


Repetitive transcranial magnetic stimulation of dorsolateral prefrontal cortex affects performance of the wisconsin card sorting task during provision of feedback.

Ko JH, Monchi O, Ptito A, Petrides M, Strafella AP - Int J Biomed Imaging (2008)

TMS coilwas located over (a) the right DL-PFC (X = 45,  Y = 33,  Z = 25) or (b) the vertex (control) (X = 0,  Y = −35,  Z = 80). The positioning of the TMS coil over theselocations, marked on the native MRI, was performed with the aid of a framelessstereotaxic system.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2266810&req=5

fig1: TMS coilwas located over (a) the right DL-PFC (X = 45, Y = 33, Z = 25) or (b) the vertex (control) (X = 0, Y = −35, Z = 80). The positioning of the TMS coil over theselocations, marked on the native MRI, was performed with the aid of a framelessstereotaxic system.
Mentions: In order to target the DL-PFC and vertex (control site) in all our subjects(Figure 1), we used a procedure that takes advantage of the standardizedstereotaxic space of Talairach and Tournoux [17] and frameless stereotaxy [18, 19]. A high-resolution MRI of the subjects' brain was acquired and transformed into standardized stereotaxic space using thealgorithm of Collins et al. [20]. The coordinates selected for the right DL-PFC(X = 45, Y = 33, Z = 25) were basedon a previous functional activation study that yielded increased activityduring the feedback period [4]. Of note, in this study, we stimulated the DL-PFClocated in the right hemisphere because this side appeared to be moreconsistently and robustly activated [4]. The control stimulation site (i.e., vertexregion, X = 0, Y = −35, Z = 80) wasalso chosen based on its lack of activation during performance of the WCST inthese previous studies.

Bottom Line: Repetitive transcranial magnetic stimulation (rTMS) is a method that allows to disrupt processing within a given cortical region and to affect task performance for which this region is significantly solicited.We applied rTMS to the right DL-PFC and the vertex (control site) in different time points of the WCST.When rTMS was applied to the DL-PFC specifically during the period when subjects were receiving feedback regarding their previous response, WCST performance deteriorated, while rTMS did not affect performance during matching either when maintaining set or during set-shifting.

View Article: PubMed Central - PubMed

Affiliation: Montreal Neurological Institute, McGill University, Montréal, PQ, Canada H3A 2B4.

ABSTRACT
Early functional neuroimaging studies of tasks evaluating executive processes, such as the Wisconsin card sorting task (WCST), only assessed trials in blocks that may contain a large amount of different cognitive processes. More recently, we showed using event-related fMRI that the dorsolateral prefrontal cortex (DL-PFC) significantly increased activity during feedback but not matching periods of the WCST, consistent with its proposed role in the monitoring of information in working memory. Repetitive transcranial magnetic stimulation (rTMS) is a method that allows to disrupt processing within a given cortical region and to affect task performance for which this region is significantly solicited. Here we applied rTMS to test the hypothesis that the DL-PFC stimulation influences monitoring of working memory without interfering with other executive functions. We applied rTMS to the right DL-PFC and the vertex (control site) in different time points of the WCST. When rTMS was applied to the DL-PFC specifically during the period when subjects were receiving feedback regarding their previous response, WCST performance deteriorated, while rTMS did not affect performance during matching either when maintaining set or during set-shifting. This selective impairment of the DL-PFC is consistent with its proposed role in monitoring of events in working memory.

No MeSH data available.


Related in: MedlinePlus