Understanding the Locus Coeruleus and Cognitive Aging with t-VNS
This study is looking into how a part of your brain called the locus coeruleus (LC) and a chemical called norepinephrine relate to how our thinking abilities change as we get older, especially in conditions like Alzheimer's disease. Researchers will use a device called a transcutaneous auricular vagus nerve stimulator (t-VNS) clipped to your outer ear. This device sends a gentle electrical current to a nerve to see how it affects your brain. They will measure your pupil size and heart rate to understand the effects. To join, you need to be 18 or older, speak English, and be able to use a touchscreen, keyboard, and mouse. You also need to be willing to have an MRI scan. The study will look at changes in pupil size, heart rate, and how well you perform on certain attention tests within 15-45 minutes of the intervention.
- Study design
- This is an interventional study planning to enroll 150 participants. The phase of the study is not specified.
- What's involved
- You would undergo an MRI scan lasting about 90 minutes. You would also have a t-VNS device applied to your ear, during which your pupil size and heart rate would be monitored.
- Compensation
- Not stated in the trial record.
- Follow-up
- The primary measurements for this study are taken within 15-45 minutes.
AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.
The Locus Coeruleus, Norepinephrine and Cognitive Aging
At a glance
Conditions
Where it's being run
1 sites across 1 statesWho to contact
This trial hasn't published a contact. View it on ClinicalTrials.gov
Do you actually qualify for this trial?
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Inclusion
Exclusion
What this trial measures
- Tonic pupil size in mm15-45 minutes
The investigators will continuously monitor tonic pupillary size to determine whether it is affected by taVNS. To do so, the investigators will use a EyeLink 1000+ eyetracker and measure pupil diameter continuously throughout the completion of computer-based cognitive tasks, such as an Oddball task, Attentional Boost Effect task, Proactive Interference task, or Tone Gap task. Tonic pupil size are measured with custom software, and pupil size is reported in mm.
- Heart rate variability15-45 minutes
The investigators will continuously monitor heart rate using photoplethysmography (BIOPAC Systems) to calculate heart rate variability, to determine whether it is affected by taVNS. Root mean square of successive differences (RMSSD) will be the specific heart rate metric used.
- Discriminability index on tests including the attentional boost effect task15-45 minutes
The investigators will test performance on measures of attention (e.g. Oddball paradigm, Flanker inhibitory control paradigm, attentional boost effect paradigm) to determine whether performance on this task, specifically d' (discriminability index) is affected by taVNS.
- Phasic pupillary responses in mm15-45 minutes
The investigators will monitor phasic pupillary response size to determine whether they are affected by taVNS. To do so, the investigators will use a EyeLink 1000+ eyetracker and measure pupil diameter continuously throughout the completion of computer-based cognitive tasks, such as an Oddball task, Attentional Boost Effect task, Proactive Interference task, or Tone Gap task. Phasic pupil sizes are measured with custom software, and response size is reported in mm.
- Reaction time on tests including the attentional boost effect task15-45 minutes
The investigators will test performance on measures of attention (e.g. Oddball paradigm, Flanker inhibitory control paradigm, attentional boost effect paradigm) to determine whether performance on this task, specifically reaction time, is affected by taVNS.