W7 Hearing and Vestibular Senses

What is Reinforced Learning (RL)?

It is the process by which an agent (human, animal or machine) learns from experience to make good behavioral decisions

What is the goal of Reinforcement Learning (RL)?

to learn the best possible strategy for mapping states onto actions

What is Policy?

Strategy or set of rules for mapping states onto actions

How is Reinforced learning and Policy related to each other?

goal of RL is to optimize policy

What is Optimal Policy?

[in biology] maximizes reward and minimizes punishment over entire lifespan of organism

What is Return?

sum total of all the pleasure and pain that you will experience for the rest of your life

What is the mathematical expression of Return?

the temporally discounted sum of future reward

• r > 0 = positive → reward

• r < 0 = negative → punishment

What is Temporal Discount Factor?

y is a value between 0 - 1 that gets progressively smaller over time.

• in return equation, variable describes the fact that all else being equal, an earlier reward is preferred over a later reward

Amygdala is attaches ____ to ___ and ____

values to cues and states

What are the two roles of amygdala function?

• Appetitive (reward driven) learning

• Aversive (punishment driven) learning

What is G_t in the temporally discounted sum of future reward?

stands for the actual sum of all our future pleasure and pain

• prediction as accurately as possible. Cannot actually know with certainty

What is state value (V)?

expected G_t in the current state

What is Pavlovian Fear Conditioning?

Process where people and animals can be trained to be afraid of cues that predict danger

What pathway does auditory information reach the vPAG so that a fear conditioned CS can trigger a freezing response after it has been paired with an aversive US?

bruin cast

ear → cochlear nucleus → vPAG

What part of the ear gathers sound waves from the environment?

Outer ear (Pinna and canal)

What do air molecules do when there is wind?

Air molecules are moving through space to new locations

What do air molecules do when there is sound?

Air molecules are perturbed, and then return to their original position

How do we perceive sound sensation?

Our tympanic membrane (eardrum) is stimulated by vibrating air molecules

What are pressure waves?

alternate cycles of compressed and rarified air

How do pressure waves propagate?

Air molecules provide as medium so pressure waves can propagate over long distances

What is amplitude?

Loudness

What kind of propagation of displacement of air molecules when there is a quiet sound?

small displacement

What kind of propagation of displacement of air molecules when there is a loud sound?

large displacement