Increase your brain power with Rosemary November 13, 2018 Maria Jimenez WHY: Shakespeare knew what was up when he wrote, “Rosemary, that’s for remembrance.”The herbal essential oil stimulates the brain and keeps you on the ball. A study conducted by the Egyptian Journal of Basic and Applied Science found that inhaling the scent of rosemary increased productivity and improved visual and numerical memory. HOW: Plugging away at your keyboard? Block out office distractions by popping an aromatherapy diffuser into your computer and add a few drops of essential Rosemary oil.