Do you Eat with your Eyes?

Do you Eat with your Eyes?

How do our senses influence what we eat? We could write a science journal about just visual perception. And of course, this is where we start.

What is sense of sight

The major problem in visual perception is that what people see is not simply a translation of an image on the retina. For one thing, we see the world right side up, even though the image on the retina is upside down (because it has passed through the lens). Therefore, it is difficult to explain what happens to create what we actually see. The key, which took centuries to be appreciated, is that the brain works on the data from the eyes, and marries it with memories and guesses, all at lightning speed. The result is an experience of the world which looks to each person as if it were simple reality. However, although based on reality, it is actually a mental construct, built by the brain.

Have you ever flipped through a magazine, and seen a photo of food and thought: “Wow, I’m hungry?” Does watching the food network cause your stomach to growl? Don’t be surprised. According to a study done by the Max Planck Society – a research organization out of Germany – seeing images of food naturally makes you hungry.

How it works
The hormone ghrelin is released in greater amounts when you take in visual stimuli. Ghrelin is produced in the stomach and is responsible for creating appetite by acting on a region in your brain known for controlling the amount of food you eat. When you see a photo of delicious food, ghrelin is rapidly released into the bloodstream, causing a spike in your appetite.

This hormone is great in the wild. Humans’ early ancestors were hunter-gatherers, meaning they hunted animals and picked food as they roamed the earth. They could go days without finding food. When they did find it, they ate as much as they could, knowing they might not find another food source for a long time. Ghrelin helped increase their appetite when they found something edible, and is the reason humans survived.

The sense of smell, or olfaction, is the special sense through which smells (or odors) are perceived.[1] The sense of smell has many functions, including detecting hazards, and pheromones, and plays a role in taste.

It occurs when an odor binds to a receptor within the nasal cavity, transmitting a signal through the olfactory systemGlomeruli aggregate signals from these receptors and transmit them to the olfactory bulb, where the sensory input will start to interact with parts of the brain responsible for smell identification, memory, and emotion.

There are many different causes for alteration, lack, or disturbance to a normal sense of smell, and can include damage to the nose or smell receptors, or central problems affecting the brain. Some causes include upper respiratory infectionstraumatic brain injury, and neurodegenerative disease.

Flavor perception is an aggregation of auditorytastehaptic, and smell sensory information. Retronasal smell plays the biggest role in the sensation of flavor. During the process of mastication, the tongue manipulates food to release odorants. These odorants enter the nasal cavity during exhalation. The olfaction of food has the sensation of being in the mouth because of co-activation of the motor cortex and olfactory epithelium during mastication.

Olfaction, taste, and trigeminal receptors (also called chemesthesis) together contribute to flavor. The human tongue can distinguish only among five distinct qualities of taste, while the nose can distinguish among hundreds of substances, even in minute quantities. It is during exhalation that the olfaction contribution to flavor occurs, in contrast to that of proper smell, which occurs during the inhalation phase of breathing. The olfactory system is the only human sense that bypasses the thalamus and connects directly to the forebrain.

Touch is an easier sense to think about when we are eating. Texture can be felt with your fingers, tongue, teeth and palate. As a baby, texture of food came to us slowly and many times babies had very soft texture foods to start with. Just imagine if all our food was the texture of baby food!  Texture is a huge part of the dining experience. First you see, then you smell and possibly touch, then of course taste and texture…

Five basic tastes can be identified when we eat something:

  1. Sweet. This includes honey, sugar and many other sweeteners.
  2. Salt. This includes table salt.
  3. Sour. This can come from lemons, limes, grapefruit, etc.
  4. Bitter. This can come from cocoa, coffee beans, etc.
  5. Umani. Umami was discovered in 1908 and means pleasant to the taste or savory. Umami taste comes from things like soy sauce or parmesan cheese.

Taste takes on a complex combination of sensations and leads to a chemical feeling factor that affects different sensors and areas of your brain. These are called chemical irritants and can stimulate the trigeminal nerve ends. These types of chemical irritants include burn, heat, cold, pungency, tingling and others. 


Sounds complicated, right? It is, and it takes a chef years to develop the knowledge base to apply these skills. It all starts with a good culinary foundation, an eagerness to learn more and discipline. Cheers, and happy Tuesday!