This study aims to determine how non-invasive ear stimulation affects learning. During this study, participants will be asked to complete surveys and come to a lab for about 2.5 hours. Researchers will measure brain waves and other body responses (heart rate), while the ear is stimulated. Participants also will be asked to complete computer tasks. Because brain activity will be measured, participants will be asked to come to the study with clean, dry hair. The study is at MUSC in Charleston. Participants will be compensated for their time. To be eligible, participants must be 18-65 years old, be able to commit 2.5 hours of time to the study, and be able to wear sensors on their hands, arms, and head and sit quietly at a computer.

There are some risks to completing this study. Some questions in the surveys ask about personal thoughts and feelings. The ear stimulation may cause tingling sensations or irritation around the ear.

There are no direct benefits to participants. This study will help researchers improve this ear stimulation as a treatment method.

Meniere's disease is a common cause of vertigo that becomes more common with age. Unfortunately, Meniere's disease and vestibular migraine have significant overlap and are sometimes difficult to diagnose. This is due to a lack of understanding of the true cause of Meniere's disease. Due to the lack of a biomarker (an objective test), the diagnosis of Meniere's disease has been based on clinical history and hearing loss. We are exploring ways to differentiate Meniere's disease and vestibular migraine, potentially through a lab test. In addition, identifying biomarkers may help early diagnosis and direct more personalized treatment strategies, especially early on before hearing loss occurs.

As of yet, the cause of Meniere's disease is uncertain and there is no cure. Given the lack of high level evidence for treatments, we seek to perform a randomized, placebo-controlled, double-blind, crossover, pilot trial of venlafaxine for treating Meniere's disease. Venlafaxine is a safe and well-tolerated medication. It has never been trialed in Meniere's disease, but there is evidence that it could be effective in helping with vertigo attacks and other aspects of the disorder.

Older adults typically have trouble identifying the speech they hear, especially in noisy environments. Fortunately, compared to younger adults, older adults are better able to compensate for difficulties identifying the speech they hear by recruiting the visual system. However, the extent to which older adults can benefit from visual input, and how this influence relates to age-related changes in brain structure and function, have not been thoroughly investigated. The general purpose of this study is to determine how age-related changes in brain structure and function affect how well people hear and see. This study seeks participants with normal hearing to mild hearing loss, who also have normal or corrected-to-normal vision.