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Effects of frontal transcranial direct current stimulation on emotional state and processing in healthy humans.

Nitsche MA, Koschack J, Pohlers H, Hullemann S, Paulus W, Happe S - Front Psychiatry (2012)

Bottom Line: In healthy subjects, however, rTMS of the same areas has no major effect, and the effects of tDCS are mixed.We aimed to evaluate the effects of prefrontal tDCS on emotion and emotion-related cognitive processing in healthy humans.We conclude that tDCS of the prefrontal cortex improves emotion processing in healthy subjects, but does not influence subjective emotional state.

View Article: PubMed Central - PubMed

Affiliation: Department Clinical Neurophysiology, Georg-August-University Goettingen, Germany.

ABSTRACT
The prefrontal cortex is involved in mood and emotional processing. In patients suffering from depression, the left dorsolateral prefrontal cortex (DLPFC) is hypoactive, while activity of the right DLPFC is enhanced. Counterbalancing these pathological excitability alterations by repetitive transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS) improves mood in these patients. In healthy subjects, however, rTMS of the same areas has no major effect, and the effects of tDCS are mixed. We aimed to evaluate the effects of prefrontal tDCS on emotion and emotion-related cognitive processing in healthy humans. In a first study, we administered excitability-enhancing anodal, excitability-diminishing cathodal, and placebo tDCS to the left DLPFC, combined with antagonistic stimulation of the right frontopolar cortex, and tested acute emotional changes by an adjective checklist. Subjective emotions were not influenced by tDCS. Emotional face identification, however, which was explored in a second experiment, was subtly improved by a tDCS-driven excitability modulation of the prefrontal cortex, markedly by anodal tDCS of the left DLPFC for positive emotional content. We conclude that tDCS of the prefrontal cortex improves emotion processing in healthy subjects, but does not influence subjective emotional state.

No MeSH data available.


Related in: MedlinePlus

Emotional face identification: number of correct trials. Baseline-standardized mean number of correct trials are depicted during, and after anodal, cathodal, and placebo tDCS (p1–3; p1 = immediately and 5 min after tDCS, p2 = 10 and 20 min after tDCS, p3 = 30 and 60 min after tDCS). The number of correct trials increases during the course of the experiment, thus indicating learning of the task in all stimulation and emotional conditions. This effect is significant for negative facial expressions under anodal and placebo tDCS conditions for the whole course of the experiment, but not for cathodal tDCS. For positive facial expressions, anodal tDCS caused a significant improvement as compared to baseline in the last two measures, and placebo tDCS in the last measure. Again under cathodal tDCS facial recognition did not improve significantly. Filled symbols indicate significant reaction time differences as compared to baseline values (paired, two-tailed t-tests, p < 0.05). Vertical bars indicate standard error of mean. a, anodal tDCS; c, cathodal tDCS; p, placebo tDCS; pos, positive emotional facial expression; neg, negative emotional facial expression.
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Figure 4: Emotional face identification: number of correct trials. Baseline-standardized mean number of correct trials are depicted during, and after anodal, cathodal, and placebo tDCS (p1–3; p1 = immediately and 5 min after tDCS, p2 = 10 and 20 min after tDCS, p3 = 30 and 60 min after tDCS). The number of correct trials increases during the course of the experiment, thus indicating learning of the task in all stimulation and emotional conditions. This effect is significant for negative facial expressions under anodal and placebo tDCS conditions for the whole course of the experiment, but not for cathodal tDCS. For positive facial expressions, anodal tDCS caused a significant improvement as compared to baseline in the last two measures, and placebo tDCS in the last measure. Again under cathodal tDCS facial recognition did not improve significantly. Filled symbols indicate significant reaction time differences as compared to baseline values (paired, two-tailed t-tests, p < 0.05). Vertical bars indicate standard error of mean. a, anodal tDCS; c, cathodal tDCS; p, placebo tDCS; pos, positive emotional facial expression; neg, negative emotional facial expression.

Mentions: The ANOVA revealed a significant main effect of time (Table 1). As can be seen in Figure 4, this is caused by an increased number of correct answers relative to baseline in the later blocks of the task for all stimulation and facial expression conditions. For the placebo and anodal stimulation condition, but not for cathodal tDCS, this effect is significant during the whole time course of the experiment for the recognition of negative emotional facial expressions. For positive facial expressions, anodal tDCS caused a significant improvement as compared to baseline in the last two measures, and placebo tDCS in the last measure. Baseline values did not differ significantly between the respective stimulation conditions.


Effects of frontal transcranial direct current stimulation on emotional state and processing in healthy humans.

Nitsche MA, Koschack J, Pohlers H, Hullemann S, Paulus W, Happe S - Front Psychiatry (2012)

Emotional face identification: number of correct trials. Baseline-standardized mean number of correct trials are depicted during, and after anodal, cathodal, and placebo tDCS (p1–3; p1 = immediately and 5 min after tDCS, p2 = 10 and 20 min after tDCS, p3 = 30 and 60 min after tDCS). The number of correct trials increases during the course of the experiment, thus indicating learning of the task in all stimulation and emotional conditions. This effect is significant for negative facial expressions under anodal and placebo tDCS conditions for the whole course of the experiment, but not for cathodal tDCS. For positive facial expressions, anodal tDCS caused a significant improvement as compared to baseline in the last two measures, and placebo tDCS in the last measure. Again under cathodal tDCS facial recognition did not improve significantly. Filled symbols indicate significant reaction time differences as compared to baseline values (paired, two-tailed t-tests, p < 0.05). Vertical bars indicate standard error of mean. a, anodal tDCS; c, cathodal tDCS; p, placebo tDCS; pos, positive emotional facial expression; neg, negative emotional facial expression.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3377009&req=5

Figure 4: Emotional face identification: number of correct trials. Baseline-standardized mean number of correct trials are depicted during, and after anodal, cathodal, and placebo tDCS (p1–3; p1 = immediately and 5 min after tDCS, p2 = 10 and 20 min after tDCS, p3 = 30 and 60 min after tDCS). The number of correct trials increases during the course of the experiment, thus indicating learning of the task in all stimulation and emotional conditions. This effect is significant for negative facial expressions under anodal and placebo tDCS conditions for the whole course of the experiment, but not for cathodal tDCS. For positive facial expressions, anodal tDCS caused a significant improvement as compared to baseline in the last two measures, and placebo tDCS in the last measure. Again under cathodal tDCS facial recognition did not improve significantly. Filled symbols indicate significant reaction time differences as compared to baseline values (paired, two-tailed t-tests, p < 0.05). Vertical bars indicate standard error of mean. a, anodal tDCS; c, cathodal tDCS; p, placebo tDCS; pos, positive emotional facial expression; neg, negative emotional facial expression.
Mentions: The ANOVA revealed a significant main effect of time (Table 1). As can be seen in Figure 4, this is caused by an increased number of correct answers relative to baseline in the later blocks of the task for all stimulation and facial expression conditions. For the placebo and anodal stimulation condition, but not for cathodal tDCS, this effect is significant during the whole time course of the experiment for the recognition of negative emotional facial expressions. For positive facial expressions, anodal tDCS caused a significant improvement as compared to baseline in the last two measures, and placebo tDCS in the last measure. Baseline values did not differ significantly between the respective stimulation conditions.

Bottom Line: In healthy subjects, however, rTMS of the same areas has no major effect, and the effects of tDCS are mixed.We aimed to evaluate the effects of prefrontal tDCS on emotion and emotion-related cognitive processing in healthy humans.We conclude that tDCS of the prefrontal cortex improves emotion processing in healthy subjects, but does not influence subjective emotional state.

View Article: PubMed Central - PubMed

Affiliation: Department Clinical Neurophysiology, Georg-August-University Goettingen, Germany.

ABSTRACT
The prefrontal cortex is involved in mood and emotional processing. In patients suffering from depression, the left dorsolateral prefrontal cortex (DLPFC) is hypoactive, while activity of the right DLPFC is enhanced. Counterbalancing these pathological excitability alterations by repetitive transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS) improves mood in these patients. In healthy subjects, however, rTMS of the same areas has no major effect, and the effects of tDCS are mixed. We aimed to evaluate the effects of prefrontal tDCS on emotion and emotion-related cognitive processing in healthy humans. In a first study, we administered excitability-enhancing anodal, excitability-diminishing cathodal, and placebo tDCS to the left DLPFC, combined with antagonistic stimulation of the right frontopolar cortex, and tested acute emotional changes by an adjective checklist. Subjective emotions were not influenced by tDCS. Emotional face identification, however, which was explored in a second experiment, was subtly improved by a tDCS-driven excitability modulation of the prefrontal cortex, markedly by anodal tDCS of the left DLPFC for positive emotional content. We conclude that tDCS of the prefrontal cortex improves emotion processing in healthy subjects, but does not influence subjective emotional state.

No MeSH data available.


Related in: MedlinePlus