Increased left prefrontal brain perfusion after MRI compatible tDCS attenuates momentary ruminative self-referential...

Area of Science:

• Neuroscience
• Cognitive Psychology
• Psychiatry

Background:

• Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique.
• Its effects on spontaneous cognitive processes, like self-referential thoughts, are not fully understood.
• Investigating neuronal-level changes associated with tDCS is crucial.

Purpose of the Study:

• To investigate how tDCS influences momentary self-referential thoughts.
• To explore the neuronal mechanisms underlying these effects using MRI.
• To assess the impact of tDCS on mood and ruminative self-focus.

Main Methods:

• A single-session, sham-controlled, crossover tDCS study with 40 healthy female volunteers.
• Anodal left dorsolateral prefrontal cortex (DLPFC) and cathodal right supraorbital stimulation (1.5 mA, 20 min).
• Brain perfusion measured using arterial spin labeling MRI before and after stimulation; mood and rumination assessed using visual analogue scales and the Momentary Ruminative Self-focus Inventory (MRSI).

Main Results:

• Active tDCS significantly decreased MRSI scores compared to baseline, indicating reduced momentary ruminative self-focus.
• No significant changes in subjective mood were observed after sham-controlled tDCS.
• Increased left prefrontal cortical perfusion correlated with the reduction in ruminative self-referential thoughts.

Conclusions:

• tDCS applied to the DLPFC can effectively attenuate ruminative self-referential thoughts.
• The findings support the hypothesis that tDCS modulates neural activity in the prefrontal cortex to reduce rumination.
• This study provides insights into the neurobiological underpinnings of tDCS effects on cognitive and emotional processes.