Psyc 417 Food Preference Aversion Learning

Questions:

What is every way that food preference and aversion develops? <details>Conditioned and uncondition stimulu & responses</details> What is PKU (phenylketonuria)?<details>is a genetic disorder that makes it so people cannot metabolize an essential amino acid.</details> How does your body know whether or not food contains an amino acid? (what is it called)

<details>It is not from the taste, but it comes from the anterior piriform cortex which detects essential amino acids (EAA).</details> Why is high-fat food preferred over high carb food? How can you see if a brain region is absolutely vital for a specific behavior? How can you study the roles of taste relays in aversion learning? <details>If you destroy part of the taste pathway and see how it affects an aversion learning experiment.</details> What happens to food aversion if you destroy the entire taste relay? <details>It WONT eliminate taste aversion, at most it will attenuate</details> What is the meaning of histology? <details> The study of the microscopic anatomy of an organism </details> How can you destroy food aversion? <details>By destorying the entire amygdala</details> What is a popular uncondition stimulus that is used in experiments? <details>LiCl (lithium chlorine)</details> When does preference for food start developing? <details>in the womb</details> What does cerebration mean? <details> cutting or taking out a whole cortex </details>

Notes

Preference Learning

Perinatal exposure

You are starting to like and dislike certain foods as a fetus!!!

Habituation

The more you eat food the more you like it

Nutrient deficiency

If you are deficient in a nutrient, you might have a temporary preference for certain foods (i.e. lemons)

This is especially true for when an organism lacks essential amino acids. They will even prefer something that tastes bad if it contains an amino acid they need.

Early life exposure

Characteristic flavor that is imprinted in early life (i.e. the foods you eat early in life when you are baby) makes you have a preference

Cultural/Societal differences

People from different cultures and societies enjoy different foods that are not well accepted by other regions.

Our guts can detect amino acid content in the food.

Current social cues

People eat the most when they eat with friends or family. Food preference is induced by peers. This food preference comes from the limbic system.

Taste Aversion

Taste aversion is unique when it comes to classical conditioning, because it doesn't require close temporal proximity between the conditioned stimulus (CS) and unconditioned stimulus (US). It also can be learned after one single pairing of the CS and US. This is stronger even when the CS is novel. Taste aversion can even make inherently rewarding stimuli become aversive. This can lead to anorexia after chemotherapy because of association.

Aversion and avoidance is determined via a taste reactivity test. The difference is that if the animal avoids the food, they won't gape (they might not like it as much, but they won't gape).

In rats, when the parabrachial nucleus is lesioned, then it will severesly disrupt conditioned taste adversion.

Lesions in other brain taste relays imapir acquisition or extinction of a CTA:

lesions in taste amygdala, lateral hypothalamus, and insular cortex show a retard in CCTA learning
lesions in the insular cortex facilitate extinction of a CTA

When you decerebrate a rat (i.e. cut out or disconnect parts of the cerebrum), it won't approach food, but it still acts normal in the taste reactivity test. But it cannot express taste aversion.

An example of this is with shiitake mushrooms. When they are not fully cooked, some people with a specific gene will develop shiitake dermatitis, and they will develop avoidance, not aversion (they might like it, but they will avoid it).