Many cognitive functions, including working memory, are processed within large-scale brain networks. We targeted the right frontoparietal network (FPN) with one session of transcranial direct current stimulation (tDCS) in an attempt to modulate the cognitive speed of a visual working memory task (WMT) in 27 young healthy subjects using a double-blind crossover design. We further explored the neural underpinnings of induced changes by performing resting-state fMRI prior to and immediately after each stimulation session with the main focus on the interaction between a task-positive FPN and a task-negative default mode network (DMN). Twenty minutes of 2 mA anodal tDCS was superior to sham stimulation in terms of cognitive speed manipulation of a subtask with processing of objects and tools in unconventional views (i.e., the higher cognitive load subtask of the offline WMT). This result was linked to the magnitude of resting-state functional connectivity decreases between the stimulated FPN seed and DMN seeds. We provide the first evidence for the action reappraisal mechanism of object and tool processing. Modulation of cognitive speed of the task by tDCS was reflected by FPN-DMN cross-talk changes.

• MeSH
• Frontal Lobe diagnostic imaging   physiopathology   MeSH
• Adult MeSH
• Double-Blind Method MeSH
• Cross-Over Studies MeSH
• Memory, Short-Term physiology   MeSH
• Humans MeSH
• Magnetic Resonance Imaging MeSH
• Adolescent MeSH
• Young Adult MeSH
• Neuropsychological Tests MeSH
• Transcranial Direct Current Stimulation MeSH
• Reaction Time physiology   MeSH
• Parietal Lobe diagnostic imaging   physiopathology   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Enhancing cognitive functions through noninvasive brain stimulation is of enormous public interest, particularly for the aging population in whom processes such as working memory are known to decline. In a randomized double-blind crossover study, we investigated the acute behavioral and neural aftereffects of bifrontal and frontoparietal transcranial direct current stimulation (tDCS) combined with visual working memory (VWM) training on 25 highly educated older adults. Resting-state functional connectivity (rs-FC) analysis was performed prior to and after each stimulation session with a focus on the frontoparietal control network (FPCN). The bifrontal montage with anode over the left dorsolateral prefrontal cortex enhanced VWM accuracy as compared to the sham stimulation. With the rs-FC within the FPCN, we observed significant stimulation × time interaction using bifrontal tDCS. We found no cognitive aftereffects of the frontoparietal tDCS compared to sham stimulation. Our study shows that a single bifrontal tDCS combined with cognitive training may enhance VWM performance and rs-FC within the relevant brain network even in highly educated older adults.

• MeSH
• Frontal Lobe MeSH
• Double-Blind Method MeSH
• Cross-Over Studies MeSH
• Cognition * MeSH
• Cognitive Behavioral Therapy methods   MeSH
• Memory, Short-Term MeSH
• Humans MeSH
• Magnetic Resonance Imaging MeSH
• Neuropsychological Tests MeSH
• Prefrontal Cortex MeSH
• Transcranial Direct Current Stimulation methods   MeSH
• Psychomotor Performance MeSH
• Aged MeSH
• Educational Status MeSH
• Parietal Lobe MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Randomized Controlled Trial MeSH