https://scitechdaily.com/a-whiff-of-genius-simple-fragrance-method-boosts-cognitive-capacity-by-226/ [Study of] ..men and women aged 60 to 85 without memory impairment. All were given a diffuser and seven cartridges, each containing a single and different natural oil. [Result}..showed a 226% increase in cognitive performance compared to the control group [no essence oil], as measured by a word list test commonly used to evaluate memory.
This says sleeping with essence oils [or some ‘bouquet garni’ (ห่อดอกไม้สมุนไพรแห้ง)] may help improve or retain memory functioning. Giving (real) flowers to people may have (unintentionally) good side effects. Wearing perfumes has not been tested though ;-)
What kind of essence oils? this study does not say (trade secrets?). But traditionally people have been using Sweet Basil (โหระพา), Cedar wood (oil), Rosemary, … and chicken broth (slowly cooked chicken thin soup ซุบน้ำใส) . People also say eating Berries, Nut and Vegetables (of all colors) are good for memory. Chicken broth without water is called Chicken essence ;-)
A potential for farmers to product their special blends of aromatic bouquets for the markets .
A passage from a once popular song by Simon and Garfunkel “..parsley sage, rosemary, and thyme.. Remember me..” tells us about memory herbs ;-)
In Thailand บัวบก พรมมิ กลีบบัวแดง ขมิ้น (Turmeric) are said to help memory function when regularly eaten.
But good food (of all 5 groups of food) are the basic of good health,good brain and good memory.