Here the investigator plan to investigate the effect of tFUS on motor behavior. M1 has been chosen for two fundamental reasons for this study: 1) The use of muscle contraction to generate a detectable evoked potential signal allows for targeting of a precise area within M1 with tFUS, and 2) It is known that M1 is involved in fast learning of sequential motor tasks By targeting M1 with tFUS in neurologically healthy volunteers, we can study the effects of tFUS on motor learning measures (e.g., reaction time, accuracy) while a subject is performing a finger tapping motor learning task. If ultrasound is proven efficacious for stimulating the motor cortex, non-surgical ultrasound could potentially replace costly and risky surgery for the treatment of brain disorders as is common with deep brain stimulation for essential tremor or Parkinson's disease. There is currently no way to affect brain tissue deep into the cortex without surgery, genetic alteration or viral vectors (the latter two are not approved for human use). This technology is non-surgical and as invasive as any diagnostic ultrasound exam. With success, transcranial focused ultrasound could become useful world-wide as a cheap, portable and effective tool for human brain mapping efforts as well as for the diagnosis and potential treatment of a broad range of psychiatric and neurological disorders.
