Inclusion Criteria:  18 years of age or greater. Fluent English speakers. Medically cleared to play ice hockey.  Exclusion Criteria:  An allergy to the ingredients of Synaquell or Synaquell+ (Magnesium, beta hydroxybutyrate, Glutathione, N-acetyl-L-cysteine, Riboflavin, Magnesium, Leucine, Isoleucine, Valine, Resveratrol, Curcumin Phytosome, Nicotinamide riboside, Docosahexanoic Acid). Clinically documented hearing issues. In-ear hearing aid or cochlear implant. Implanted pacemaker or defibrillator. Metal or plastic implants in skull. Lack of verbal fluency in the English language. History of seizures. Allergy to rubbing alcohol or EEG gel. Unhealthy scalp.