Basics of Neuroethology

Question 1

What is neuroethology?

Answer 1

The study of the neural bases of behavior

Question 2

Tinbergen’s cornerstones of behavioral studies

Answer 2

Function - how does the behavior impact the animal’s chances of survival & reproduction?
Causation - what stimuli elicits response & neural bases of the behavior
Development - how does behavior change w/ age & what early experiences allow behavior to be shown
Evolution history - how does behavior compare w/ similar behaviors in related species

Question 3

Krogh principle

Answer 3

Studying a particular animal/select group of animals (model system) that allows us to understand different brain functions

Question 4

Top-down approach

Answer 4

1. Study stereotyped behavior quantitatively (must be robust & repeatable)
2. What stimuli are involved?
3. What parameters of stimuli is the animal sensitive to?
4. Predict how the behavior changes w/ changes in stimulus parameters
5. What computations should a neural circuit perform to form the basis of observed behavior?
6. Determine specific neural circuitry
7. Lesion circuit & quantify effects on behavior

Question 5

Bottom-up approach

Answer 5

Study the neural circuitry first and connect it to the behavior

Question 6

Characteristics of innate behavior

Answer 6

1. Must be stereotyped and in constant form
2. Must be characteristic of the species
3. Must appear in animals raised in isolation
4. Must be expressed in full form by animals which have been prevented from practicing it

Question 7

Fixed Action Pattern (FAP)

Answer 7

Stereotyped patterns of movement common to all members of a species, often performed in response to specific sign stimuli

Question 8

Lorenz & Tinbergen rule for FAP

Answer 8

Only a part of the complex input is required to elicit the FAP (i.e. goose will continue the FAP related to rolling an egg even if the egg is moved)

Question 9

Properties of FAP

Answer 9

1. Require fairly specific features of stimulus
2. Highly stereotyped within species, or at least w/ one gender
3. One FAP may include sign stimulus for another FAP
4. Not affected by learning

Question 10

3-spined stickleback example of FAP

Answer 10

Male has red stripe on belly when establishing territory, aggressive attack when another male sees him (no attack when the stripe was on top instead of on the belly)

Question 11

Example of interlocking FAPs

Answer 11

1. During breeding season male sticklebacks produce a zigzag dance if a female w/ a swollen belly is encountered
2. Female follows the male into the nest
3. Male prods the base of her tail
4. Female lays eggs, is driven from the nest and male enters to fertilize the eggs

Question 12

Sign stimulus

Answer 12

Stimulus to which a specific reaction pattern (FAP) is tuned

Question 13

Examples of sign stimuli

Answer 13

1. Red spot on beak of herring gull evokes pecking response from nestlings
2. Chirping calls of turkey hen chicks initiates maternal behavior
3. Blood from minnows causes panic response

Question 14

Hardware that encode a behavior (general)

Answer 14

1. Feature detectors (need sensory system specific to sign stimulus)
2. Innate releasing mechanism (functionally organized neural circuit that only focuses on required features to detect sign stimuli and initiate appropriate behavioral response)
3. Motor circuit (specific to generating the FAP)

Question 15

Forms of learning

Answer 15

1. Habituation
2. Classical conditioning
3. Operant conditioning
4. Imprinting
5. Insight learning

Question 16

Habituation

Answer 16

Repeatedly given stimulus unassociated with consequence, ceases to respond (i.e. gill withdrawal in Aplysia in response to a tactile stimulus)

Question 17

Classical conditioning

Answer 17

Pavlov, unconditioned stimulus (US) paired with conditioned stimulus (CS)

Question 18

Operant conditioning

Answer 18

Trial and error, animals respond to stimuli and the response is reinforced (Skinner box, animal presses lever and learns it produces a reward)

Question 19

Imprinting

Answer 19

A predisposition to learn (2-3 day old chicks will imprint and follow any moving objects as “mothers”), properties: critical period, no reinforcement needed, irreversible

Question 20

Insight learning

Answer 20

General capacity to respond to a novel situation, learning occurs too rapidly (trial and error can be discounted), adaptable in ravens (exhibit insight and an ability to see into a situation - can pull up a string on a branch by holding onto a loop and using its beak to pull more of the string)