The Effect of Transcutaneous Vagus Nerve Stimulation on Cognitive Function
Condition: Cognitive Function
Study type: Interventional

Summary: 
      Cognitive health is generally considered a key component of quality of life. Current evidence
      indicates that a large number of individuals are at a high risk for cognitive impairment from
      many causes as they age. In order to preserve and enhance positive out-comes by targeted
      efficient preventive and therapeutic strategies it is important to understand potential
      mechanisms and predictors of cognitive health and impairment. Withdrawal of vagal
      (parasympathetic) activity has been proposed as one of the biological pathways involved in
      cognitive impairment. Transcutaneous vagus nerve stimulation (tVNS) has shown potential as a
      noninvasive and safe therapeutic treatment due to its direct influence on brain systems
      involved in cognition. However, the role of vagal modulation in cognitive functioning and
      impairment and the influence of tVNS, particularly long-term tVNS, on cognition are not yet
      completely understood. Here the investigators aim to investigate the effect of long-term
      (14days) intensive transcutaneous vagus nerve stimulation on cognitive functions in
      relatively healthy young-to-older adults.
    

Detailed description: 
      Cognitive health is generally considered a key component of quality of life. Current evidence
      indicates that a large number of individuals are at high risk for cognitive impairment from
      many causes as they age. In order to preserve and enhance positive cognitive health outcomes
      by targeted efficient preventive and therapeutic strategies, it is important to understand
      potential mechanisms and predictors of cognitive health and impairment. Withdrawal of vagal
      (parasympathetic) activity has been proposed as one of the biological pathways involved in
      cognitive impairment. Transcutaneous vagus nerve stimulation (tVNS) has shown potential as
      noninvasive and safe therapeutic treatment due to its direct influence on brain systems
      involved in cognition. However, the role of vagal modulation in cognitive functioning and
      impairment and the influence of tVNS, particularly long-term tVNS, on cognition are not yet
      completely understood. Here the investigators aim to investigate the effect of long-term
      (14days) intensive transcutaneous vagus nerve stimulation on cognitive functions in
      relatively healthy young-to-older adults.

      Little work has been done investigating the effect of long-term tVNS in healthy men and
      women. In light of preventive medicine, the question is whether increased vagus nerve
      modulation and long-term tVNS improve memory and executive functioning and potentially help
      to prevent healthy person vulnerable to cognitive impairment from manifesting cognitive
      deficits. Or if they can slow down the process of cognitive aging inevitable for every human
      being.
    

Intervention name(s): Transcutaneous vagal nerve stimulation; Sham stimulation
Intervention type(s): Device; Device
Intervention description(s): Non-invasive stimulation provided by transcutaneous electrical nerve stimulation device 4hours a day at 25Hz, 250 μs pulse width placed on tragus.; Sham stimulation will be performed using electrodes 4 hours a day placed on earlobe.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Participants will be randomly assigned to one of 4 groups - receiving either transcutaneous vagal nerve stimulation or sham in first 2 weeks (Early group), or being first 2 weeks on the waiting list and receiving either transcutaneous vagal nerve stimulation or sham in the second 2 weeks of the study participation (Late group). The randomization will have two steps: 1.) Prior to the first laboratory session all participants will be assigned into either Early or Late group; 2.) At the end of the pre-intervention laboratory session participants will be randomized between tVNS or sham stimulation.
Masking: Single (Participant)
Primary purpose: Basic Science
Keywords: Cognitive function; transcutaneous vagal nerve stimulation; autonomic nervous system; cognitive health/impairment