Areas of the brain linked to taste perception

The human body’s senses continue to intrigue researchers, attempting to unravel various aspects of the subject, ranging from the first contact of a stimulus with the sensory organ to its arrival in the brain.

Studies conducted on animals, such as rodents and monkeys, and also on humans, have demonstrated various sensory stimuli related to food, such as taste and smell, and have observed a tendency to perform actions to be rewarded or even to escape from stimuli that cause suffering. This helps reinforce the retention of these actions in the human memory and can be fundamental for survival (Kadoshima, 2013). An example of this is the sensation of taste, as bitterness, often caused by substances present in toxic plants, is avoided by animals that have learned to associate such plants with their taste, which in turn indicates the presence of toxic substances that could cause harm to their bodies.

Food is the primary source of energy sought by humans to survive. During development, humans require rapidly metabolized energy sources, such as carbohydrates. Some carbohydrates can also provide a sweet taste, making them more appealing (de Araújo, 2011).

More recent research, published after 2000, has found that substances such as the amino acid glutamate also provide benefits to the body. They are present in breast milk, provide energy for intestinal cells, and also provide another taste, umami, which also stimulates the brain to seek rewards that are palatable (Schwartz et al., 2013; de Araújo et al., 2003).

Neuroimaging tests and neuronal recordings in humans have shown that the main brain regions responsible for taste sensations are the primary gustatory cortex (which is part of the anterior insular cortex-operculum) and its targets, including the orbitofrontal cortex, also called the secondary gustatory cortex, and the anterior cingulate cortex. The secondary gustatory cortex is responsible for receiving sensations of pleasantness, and the anterior cingulate reflects the intensity of the stimulus. For umami taste, specifically, tests revealed that its representation in the medial orbitofrontal cortex tends to provide pleasant sensations. However, when combined with a pleasant aroma, these regions are more activated, demonstrating that taste and smell must work together to enhance the flavor and pleasure of food (de Araujo et al., 2003; Rolls, 2009).

The same tests also revealed that separate and combined stimuli of taste, temperature, and texture produced different intensities in each individual when food was placed in the mouth. These different intensities could be due to modulation by cognition and attention, which may shed light on why some individuals tend to eat more or less, with greater or lesser pleasure (Rolls, 2012; Rolls, 2019).

Through these studies, it is possible to verify that the different sensations provided by food need to be stimulated from the first years of life, as they help humans diversify their diet and expand their nutritional knowledge.

Food is essential to life and, therefore, it is recommended to present all basic tastes (sweet, salty, sour, bitter, and umami), aromas, and textures in sufficient proportions, separately or combined, to allow for the creation of new food experiences and enhance the pleasure of living.