Weizmann Institute of Science posted a study on May 21, 2020, on how the unconscious mind's response to a sniff test could speculate to a recovery of consciousness. Their conclusion confirmed that if an unconscious individual responds to smell through a slight change in airflow pattern from the nose, they are likely to regain consciousness.
The study was held at the Loewenstein Rehabilitation Hospital in Israel and included 43 brain-injured patients. The researchers had jars with various odors (pleasant and unpleasant scents) up to the patients' noses. The odors were placed under each patient's nose ten times randomly. All patients in a "vegetative state" responded to the sniff test and regained consciousness within days, weeks, or months even if it was a minimal state of consciousness. It also had 92% accuracy in predicting who would survive for at least three years. During the four-year study period, 100% of unconscious brain-injured patients that responded to the sniff test regained consciousness.