Psychology2016

Sensation and Perception 113

Figure 3.13 The Tongue and Taste Buds.
Taste buds are located inside the papillae of the tongue and are composed of small cells that send signals to
the brain when stimulated by molecules of food.

What happens to the taste buds when I burn my tongue? Do they

repair themselves? I know when I have burned my tongue, I can’t

taste much for a while, but the taste comes back.

In general, the taste receptors get such a workout that they have to be replaced
every 10 to 14 days (McLaughlin & Margolskee, 1994). And when the tongue is burned,
the damaged cells no longer work. As time goes on, those cells get replaced and the taste
sense comes back.

THE FIVE BASIC TASTES In 1916 a German psychologist named Hans Henning proposed
that there are four primary tastes: sweet, sour, salty, and bitter. Lindemann (1996) sup-
ported the idea that there is a fifth kind of taste receptor that detects a pleasant “brothy”
taste associated with foods like chicken soup, tuna, kelp, cheese, and soy products,
among others. Lindemann proposed that this fifth taste be called umami, a Japanese word
first coined in 1908 by Dr. Kikunae Ikeda of Tokyo Imperial University to describe the
taste. Dr. Ikeda had succeeded in isolating the substance in kelp that generated the sen-
sation of umami—glutamate (Beyreuther et al., 2007). to Learning Objective 2.3.
Glutamate exists not only in the foods listed earlier but is also present in human breast
milk and is the reason that the seasoning MSG—monosodium glutamate—adds a pleasant
flavor to foods. Although not yet widely accepted, researchers have recently suggested
there may be yet another basic taste. The proposed name for this potential sixth taste is
oleogustus, the taste of fatty acids in the food we eat (Running et al., 2015).
Although researchers used to believe that certain tastes were located on certain
places on the tongue, it is now known that all of the taste sensations are processed all over
the tongue (Bartoshuk, 1993). The taste information is sent to the gustatory cortex, found
in the front part of the insula and the frontal operculum. (See Figure 3.14.) These areas are
involved in the conscious perception of taste, whereas the texture, or “mouth-feel,” of
foods is processed in the somatosensory cortex of the parietal lobe (Buck & Bargmann,
2013; Pritchard, 2012; Shepherd, 2012). The five taste sensations work together, along with
the sense of smell and the texture, temperature, and “heat” of foods, to produce thousands

Figure 3.14 The Gustatory Cortex

The gustatory cortex is found in the anterior

insula and frontal operculum. The insula is

an area of cortex covered by folds of overly-

ing cortex, and each fold is an operculum. In

the coronal section of a human brain above,

the gustatory cortex is found in the regions

colored a light red.

Receptor cell Taste hair

Outer layer of tongue

Taste pore Supporting cell

Nerve fiber

CC