Introduction Retronasal Smell and the New Age of Flavor
But to Gordon Shepherd, a Yale University neuroscientist, people vastly underrate their sense of smell. 'We think our lives are dominated by our visual sense,' he said, 'but the closer you get to dinner, the more you realize how much your real pleasure in life is tied to smell#185•
I learned about food scientists, who study how food is chewed in the mouth and how it is swallowed. Physiologists study how the smells are carried to the sensory cells in the nose by our breathing in, as when inhaling the aroma of a cup of coffee, and by breathing out, as when we chew and swallow our food.
Psychologists study how smell is combined with taste and the other senses to produce what is called taste but is really flavor, one of the most complex of human sensations.
Cognitive neuroscientists use brain imaging to show how flavor arises from activity at the highest cognitive levels of our brains.
Neuropharmacologists study how the regions of the brain that are activated by cravings for food involve some of the same regions that are activated by cravings for tobacco, alcohol, and drugs of abuse.
Biochemists identify the hormones that circulate in the blood, connecting our bodies with our brains to signal to start eating when we are hungry and stop when we are full.
Anthropologists speculate that cooked food was a major driving force in human evolution.
Molecular biologists have discovered that the sensory receptors for smell form the largest gene family in the genome, and they are studying how the molecules give rise to our perceptions of different smells.
And we are good smellers: behavioral psychologists find that monkeys as well as humans have much more sensitive senses of smell than previously recognized.#188•
This back door approach is called retronasal smell (retro=backward); we can also call it mouth-smell. It contrasts with orthonasal smell (ortho = forward), which is what we call the common sniffing-smell#172•
Human brains are very good at recognizing faces, which can be thought of as a highly developed form of pattern recognition. From our studies we think that the same ability occurs with the patterns laid down by smells—that is, the ability to recognize many different patterns representing as many different smells.#173•
It is important to realize that flavor does not reside in a flavorful food any more than color resides in colorful object. Color arises as differences in wavelengths of light given off by an object; our brains transform those wavelengths into color to give it meaning for our behavior. Similarly, the smells that dominate the sense of flavor arise as differences between molecules; our brains represent those differences as patterns and combine them with tastes and other senses to create smells and flavors that have meaning for our perceptions of food.#181•
1: The Revolution in Smell and Flavor
This story recognizes the old saying "Patriotism is a longing for the food of our homeland." It expresses a loyalty to our home country based on the flavors of the food we were brought up on#200•