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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

Experimental procedure for the emotional face identification task. Example of the trial with male no. 2, and the target stimulus showing the negative facial expression presented on the left side of the screen. In each trial, emotionally neutral and negative/positive facial expression were displayed simultaneously on the computer monitor. To avoid the development of perceptual strategies, subjects were instructed to focus on a dot placed in the middle of the screen during the whole course of the experiment. Subjects were instructed to press the appropriate button on a keyboard as fast as possible once the visual stimuli were displayed.
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Figure 1: Experimental procedure for the emotional face identification task. Example of the trial with male no. 2, and the target stimulus showing the negative facial expression presented on the left side of the screen. In each trial, emotionally neutral and negative/positive facial expression were displayed simultaneously on the computer monitor. To avoid the development of perceptual strategies, subjects were instructed to focus on a dot placed in the middle of the screen during the whole course of the experiment. Subjects were instructed to press the appropriate button on a keyboard as fast as possible once the visual stimuli were displayed.

Mentions: Every trial consisted of the simultaneous presentation of two pictures on the left and right side of the screen for 50 ms. The two pictures showed the same person, on one side with an emotional expression (positive, i.e., joy, or negative, i.e., anger) as the target stimulus, on the other side with a neutral facial expression. The two pictures were followed by two question marks presented in place of the facial affect stimuli. Subjects were instructed to judge on which side of the screen the face with an emotional expression had been shown by pressing the left or right button on the keyboard. A red colored cross was shown for 1000 ms to mark the beginning of a trial and to make the subject fixate the center of the screen. Figure 1 shows an example of the trial structure.


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)

Experimental procedure for the emotional face identification task. Example of the trial with male no. 2, and the target stimulus showing the negative facial expression presented on the left side of the screen. In each trial, emotionally neutral and negative/positive facial expression were displayed simultaneously on the computer monitor. To avoid the development of perceptual strategies, subjects were instructed to focus on a dot placed in the middle of the screen during the whole course of the experiment. Subjects were instructed to press the appropriate button on a keyboard as fast as possible once the visual stimuli were displayed.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: Experimental procedure for the emotional face identification task. Example of the trial with male no. 2, and the target stimulus showing the negative facial expression presented on the left side of the screen. In each trial, emotionally neutral and negative/positive facial expression were displayed simultaneously on the computer monitor. To avoid the development of perceptual strategies, subjects were instructed to focus on a dot placed in the middle of the screen during the whole course of the experiment. Subjects were instructed to press the appropriate button on a keyboard as fast as possible once the visual stimuli were displayed.
Mentions: Every trial consisted of the simultaneous presentation of two pictures on the left and right side of the screen for 50 ms. The two pictures showed the same person, on one side with an emotional expression (positive, i.e., joy, or negative, i.e., anger) as the target stimulus, on the other side with a neutral facial expression. The two pictures were followed by two question marks presented in place of the facial affect stimuli. Subjects were instructed to judge on which side of the screen the face with an emotional expression had been shown by pressing the left or right button on the keyboard. A red colored cross was shown for 1000 ms to mark the beginning of a trial and to make the subject fixate the center of the screen. Figure 1 shows an example of the trial structure.

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