The study, published in the Proceedings of the National Academy of Sciences, took an innovative approach by examining two groups of individuals with focal brain lesions resulting from injuries or disorders. One cohort consisted of 106 Vietnam veterans who suffered traumatic brain injuries in combat decades ago. The other included 84 patients from rural Iowa who experienced strokes, surgical complications, or other brain injuries.
They did for the god helmet. The wiki page references it as [17] https://doi.org/10.1558%2Fjcsr.v2i2.24573