- Odor is perceived, sorted, and routed, by chemical receptor cells that shape-match to the odor molecules being received, sending signals to the brain to be interpreted.
- The olfactory nerves extend directly into the limbic system of the brain. The path of an odorant leads through the nose to the primary and ancillary olfactory systems, and directly into the brain. The limbic system is known as the old brain and governs our primitive instinctual functions.
- Smell directly accesses the brain through its limbic system and hypothalamus. This is where instincts, emotions, and neurochemical/hormonal regulations of the body are controlled.
- Odors act more directly upon the instinctual and emotional areas and structures of the right brain, and less directly upon the conscious, intellectual mind, or, left brain.
- Imagination and emotion reside in the right brain. The right brain is highly irrational and cannot think. The left brain is the center of conscious cognition and rational thought, and also controls speech.
- Those who suffer from a long term inability to smell (Anosmia) have a higher risk of developing a depressed state of mind. A distorted sense of smell is often a characteristic of someone who is diagnosed with a mental illness.
- 80-90% of taste is actually smell.
- The nostril ‘cycle’ directs air flow alternately through each nostril, to each lung, and to each cerebral hemisphere, helping to distribute air and odors throughout our bodies more or less evenly, and to reduce olfactory receptor fatigue. Just as we possess a dominant hand, we possess a ‘dominant’ nostril.
- Most wiring between our bodies and our brain is done contra- or hetero-laterally. The olfactory bulb-to-brain wiring is a homo-lateral association whereby the right nostril is wired to the right cerebral hemisphere.
- Anti-depressant and sedative effects of essential oils are attributable, in part, to their causing the release of endorphins and enkaphalins – neurochemicals which our bodies create and store, and when released, act as analgesics and tranquilizers.
Reference: Aromatherapy, Scent and Psyche, by Peter & Kate Damian