Transcutaneous vagus nerve stimulation boosts accuracy during perceptual decision-making.

Area of Science:

• Neuroscience
• Cognitive Science

Background:

• The locus coeruleus-norepinephrine (LC-NE) system regulates behavior, but its precise function is debated.
• Animal studies suggest LC-NE enhances sensory processing (gain hypothesis).
• Human studies propose LC-NE accelerates responses (urgency hypothesis).

Purpose of the Study:

• To investigate the role of the LC-NE system in perceptual decision-making.
• To differentiate between the 'gain' and 'urgency' hypotheses using human participants.
• To explore the effects of transcutaneous vagus nerve stimulation (tVNS) on cognitive function.

Main Methods:

• Two experiments involving transcutaneous vagus nerve stimulation (tVNS) were conducted.
• Experiment 1 (n=22) used pupil dilation to confirm tVNS increases LC-NE activity.
• Experiment 2 (n=21) assessed tVNS effects on a random dot motion task and decision-making.

Main Results:

• tVNS improved task accuracy without altering reaction times, challenging the urgency hypothesis.
• Drift-diffusion modeling indicated tVNS increased evidence accumulation (drift rate), supporting the gain hypothesis.
• Improvements were most significant after errors and in individuals prone to post-error performance declines.

Conclusions:

• Findings support the 'gain' hypothesis, suggesting LC-NE enhances cognitive processing.
• LC-NE's impact appears to adapt to task demands, particularly aiding attention.
• tVNS shows potential in mitigating attentional lapses and improving performance in error-prone contexts.