Poststimulation time interval-dependent effects of motor cortex anodal tDCS on reaction-time task performance

Area of Science:

• Neuroscience
• Motor Control
• Brain Stimulation

Background:

• Anodal transcranial direct current stimulation (tDCS) is known to induce neuroplasticity, potentially enhancing cognitive, emotional, and motor functions.
• Previous research suggests tDCS over the motor cortex may improve reaction times in various tasks.
• The temporal relationship between tDCS application and task performance is hypothesized to influence its effectiveness.

Purpose of the Study:

• To investigate the impact of anodal tDCS on simple reaction time performance.
• To compare the effects of tDCS at different time intervals (0, 30, and 60 minutes) post-stimulation.
• To determine how the timing of task performance relative to tDCS influences motor response modulation.

Main Methods:

• A single session of anodal tDCS (1.5 mA, 15 min) was applied to the left primary motor cortex (M1).
• Participants performed a go/no-go simple reaction-time task at 0, 30, and 60 minutes after stimulation.
• Sham stimulation served as a control condition.

Main Results:

• Immediate performance improvement (0 min post-tDCS) was observed throughout the reaction-time task.
• A delayed improvement was noted in the final blocks of the task at 30 min post-tDCS.
• No significant performance differences were found at 60 min post-tDCS compared to sham stimulation.

Conclusions:

• Anodal tDCS can enhance motor response speed by modulating motor cortex excitability.
• The efficacy of tDCS in improving motor performance is time-dependent.
• Optimal timing for tDCS application is crucial for achieving desired motor performance enhancements.