Effects of Transcranial Direct Current Stimulation on effort during a working-memory task

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neuromodulation

Background:

• Transcranial Direct Current Stimulation (tDCS) is known to enhance working memory performance.
• The impact of tDCS on cognitive effort, particularly during demanding tasks, remains largely unexplored.
• Understanding effort modulation is crucial for optimizing cognitive enhancement strategies.

Purpose of the Study:

• To investigate the effects of tDCS on effort expenditure during a working-memory task.
• To determine if different tDCS polarities (anodal, cathodal, sham) differentially influence effort-related physiological responses.

Main Methods:

• Participants underwent three sessions of tDCS (anodal, cathodal, sham) over the Dorsolateral Prefrontal Cortex (DLPFC).
• A 2-back task was administered to assess working memory performance and effort.
• Effort was measured using cardiovascular indices, specifically the Initial Systolic Time Interval (ISTI).

Main Results:

• Anodal tDCS over the DLPFC resulted in a significantly shorter ISTI compared to cathodal and sham conditions.
• A shorter ISTI indicates increased cardiovascular effort, suggesting greater engagement during the task.
• Cathodal and sham stimulation showed lower levels of effort.

Conclusions:

• Anodal tDCS over the DLPFC increases perceived effort and task engagement in demanding working-memory scenarios.
• This neuromodulation technique may help individuals sustain performance by enhancing their willingness to exert effort.
• This study provides novel evidence for tDCS influencing the extent of effort individuals commit to challenging cognitive tasks.