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Behavioral and electrophysiological effects of transcranial direct current stimulation of the parietal cortex in a visuo-spatial working memory task.

Heimrath K, Sandmann P, Becke A, Müller NG, Zaehle T - Front Psychiatry (2012)

Bottom Line: The results showed that tDCS modulated WM performance and its underlying electrophysiological brain activity in a polarity-specific way.This result can be considered an important step toward a better understanding of the mechanisms involved in tDCS-induced modulations of cognitive processing.This is of particular importance for the application of electrical brain stimulation as a therapeutic treatment of neuropsychiatric deficits in clinical populations.

View Article: PubMed Central - PubMed

Affiliation: Section of Neuropsychology, Department of Neurology, Otto-von-Guericke University Magdeburg Magdeburg, Germany.

ABSTRACT
Impairments of working memory (WM) performance are frequent concomitant symptoms in several psychiatric and neurologic diseases. Despite the great advance in treating the reduced WM abilities in patients suffering from, e.g., Parkinson's and Alzheimer's disease by means of transcranial direct current stimulation (tDCS), the exact neurophysiological underpinning subserving these therapeutic tDCS-effects are still unknown. In the present study we investigated the impact of tDCS on performance in a visuo-spatial WM task and its underlying neural activity. In three experimental sessions, participants performed a delayed matching-to-sample WM task after sham, anodal, and cathodal tDCS over the right parietal cortex. The results showed that tDCS modulated WM performance and its underlying electrophysiological brain activity in a polarity-specific way. Parietal tDCS altered event-related potentials and oscillatory power in the alpha band at posterior electrode sites. The present study demonstrates that posterior tDCS can alter visuo-spatial WM performance by modulating the underlying neural activity. This result can be considered an important step toward a better understanding of the mechanisms involved in tDCS-induced modulations of cognitive processing. This is of particular importance for the application of electrical brain stimulation as a therapeutic treatment of neuropsychiatric deficits in clinical populations.

No MeSH data available.


Related in: MedlinePlus

Transcranial direct current stimulation effect on oscillatory brain activity: Event-related spectral perturbation (ERSP) time-frequency plots are given for the sham, anodal, and cathodal conditions. The figure shows the results separately for the attend left (above) and the attend right (below) conditions. Differences between the conditions were computed by subtracting the active ERSPs (anodal, cathodal) from the sham ERSP (left and middle row) or by subtracting the cathodal ERSP from the anodal ERSP (right row). The white contour indicates significant differences between the conditions (P < 0.05, corrected for multiple comparisons). Note the different scaling for the ERSP plots (sham, anodal, and cathodal condition; upper rows) and the difference plots (lower rows).
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Figure 5: Transcranial direct current stimulation effect on oscillatory brain activity: Event-related spectral perturbation (ERSP) time-frequency plots are given for the sham, anodal, and cathodal conditions. The figure shows the results separately for the attend left (above) and the attend right (below) conditions. Differences between the conditions were computed by subtracting the active ERSPs (anodal, cathodal) from the sham ERSP (left and middle row) or by subtracting the cathodal ERSP from the anodal ERSP (right row). The white contour indicates significant differences between the conditions (P < 0.05, corrected for multiple comparisons). Note the different scaling for the ERSP plots (sham, anodal, and cathodal condition; upper rows) and the difference plots (lower rows).

Mentions: Non-parametric cluster permutation statistics were computed on ERSPs to compare the different tDCS conditions. This analysis was conducted separately for the attend left and attend right condition and revealed a significant decrease in the alpha band (6–16 Hz), at the latency range of 96–432 ms (t11 ≥ 2.2, P < 0.05) after cathodal as compared to anodal tDCS at electrode Pz for the attend right condition only. Figure 5 shows the ERSP time frequency plots for the sham condition and the active stimulation conditions (anodal, cathodal) plus the corresponding differences at electrode Pz.


Behavioral and electrophysiological effects of transcranial direct current stimulation of the parietal cortex in a visuo-spatial working memory task.

Heimrath K, Sandmann P, Becke A, Müller NG, Zaehle T - Front Psychiatry (2012)

Transcranial direct current stimulation effect on oscillatory brain activity: Event-related spectral perturbation (ERSP) time-frequency plots are given for the sham, anodal, and cathodal conditions. The figure shows the results separately for the attend left (above) and the attend right (below) conditions. Differences between the conditions were computed by subtracting the active ERSPs (anodal, cathodal) from the sham ERSP (left and middle row) or by subtracting the cathodal ERSP from the anodal ERSP (right row). The white contour indicates significant differences between the conditions (P < 0.05, corrected for multiple comparisons). Note the different scaling for the ERSP plots (sham, anodal, and cathodal condition; upper rows) and the difference plots (lower rows).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3378949&req=5

Figure 5: Transcranial direct current stimulation effect on oscillatory brain activity: Event-related spectral perturbation (ERSP) time-frequency plots are given for the sham, anodal, and cathodal conditions. The figure shows the results separately for the attend left (above) and the attend right (below) conditions. Differences between the conditions were computed by subtracting the active ERSPs (anodal, cathodal) from the sham ERSP (left and middle row) or by subtracting the cathodal ERSP from the anodal ERSP (right row). The white contour indicates significant differences between the conditions (P < 0.05, corrected for multiple comparisons). Note the different scaling for the ERSP plots (sham, anodal, and cathodal condition; upper rows) and the difference plots (lower rows).
Mentions: Non-parametric cluster permutation statistics were computed on ERSPs to compare the different tDCS conditions. This analysis was conducted separately for the attend left and attend right condition and revealed a significant decrease in the alpha band (6–16 Hz), at the latency range of 96–432 ms (t11 ≥ 2.2, P < 0.05) after cathodal as compared to anodal tDCS at electrode Pz for the attend right condition only. Figure 5 shows the ERSP time frequency plots for the sham condition and the active stimulation conditions (anodal, cathodal) plus the corresponding differences at electrode Pz.

Bottom Line: The results showed that tDCS modulated WM performance and its underlying electrophysiological brain activity in a polarity-specific way.This result can be considered an important step toward a better understanding of the mechanisms involved in tDCS-induced modulations of cognitive processing.This is of particular importance for the application of electrical brain stimulation as a therapeutic treatment of neuropsychiatric deficits in clinical populations.

View Article: PubMed Central - PubMed

Affiliation: Section of Neuropsychology, Department of Neurology, Otto-von-Guericke University Magdeburg Magdeburg, Germany.

ABSTRACT
Impairments of working memory (WM) performance are frequent concomitant symptoms in several psychiatric and neurologic diseases. Despite the great advance in treating the reduced WM abilities in patients suffering from, e.g., Parkinson's and Alzheimer's disease by means of transcranial direct current stimulation (tDCS), the exact neurophysiological underpinning subserving these therapeutic tDCS-effects are still unknown. In the present study we investigated the impact of tDCS on performance in a visuo-spatial WM task and its underlying neural activity. In three experimental sessions, participants performed a delayed matching-to-sample WM task after sham, anodal, and cathodal tDCS over the right parietal cortex. The results showed that tDCS modulated WM performance and its underlying electrophysiological brain activity in a polarity-specific way. Parietal tDCS altered event-related potentials and oscillatory power in the alpha band at posterior electrode sites. The present study demonstrates that posterior tDCS can alter visuo-spatial WM performance by modulating the underlying neural activity. This result can be considered an important step toward a better understanding of the mechanisms involved in tDCS-induced modulations of cognitive processing. This is of particular importance for the application of electrical brain stimulation as a therapeutic treatment of neuropsychiatric deficits in clinical populations.

No MeSH data available.


Related in: MedlinePlus