What is the purpose of a brain?
A brain helps us respond (flexibly, quickly, and with control) to changes in the environment
How do we describe behavior?
Structure (what, when, which) Function (what happens as a result of the behavior)
Tinbergen's Four "Whys"
Proximal Causes (Individual): Mechanism & Ontogeny Ultimate Causes (Species): Adaptive Value and Phylogeny
Mechanism
One of Tinbergen's Four Whys. A proximate/individual cause. What is the physiological explanation of the behavior? What in the body or brain changes to initiate the behavior?
Ontogeny
One of Tinbergen's Four Whys. A proximate/individual cause. How did the behavior develop over an animal's lifespan? Is it innate or learned, or both? Is it influenced more by genetics or the environment?
Adaptive Value
One of Tinbergen's Four Whys. An ultimate/species cause. What is the evolutionary explanation of the behavior? How does a behavior contribute to reproductive fitness?
Phylogeny
One of Tinbergen's Four Whys. An ultimate/species cause. How did the behavior change over the evolutionary history of the species?
Empiricism
Forming conclusions based on objective observation, control, and replication
Somatic intervention
We do something to the body and see what happens to behavior (i.e. stimulate brain region, affects movement)
Behavioral intervention
We do something to behavior and see what happens to the body (i.e. present a visual stimulus, causing changes in electrical activity of the brain)
Correlation
We determine (mathematically) if a somatic variable and behavioral variable covary
Delgado's charging bull experiment
Used radio signal to stimulate caudate nucleus (in the basal ganglia) - framed as a "taming center" but actually just makes you turn left
Morgan's Canon/Occam's razor
A simple explanation is more likely than a complex one
DRD4
Encodes Dopamine Receptor D4. Most people have 2R/4R repeat on the axon, some have a 7R repeat (changes the shape of the dopamine D4 receptor - doesn't bind as well). Therefore, it takes more dopamine to get the same response with the 7R repeat. Less activation in the prefrontal cortex and the reward pathway- need more of a stimulus for a good time. Correlated with migration.
The levels of analysis
Social, organ, neural systems, circut level, celular level, synaptic level, molecular level
Applied behavioral neuroscience
focuses on understanding and treating dysfunction
Natural selection
If a trait increases fitness, it is an adaptation and will be passed along to future generations. This requires genetics - a biological mechanism of trait transmission.
Sexual selection
If a trait attracts a mate, it will be passed on to future generations
Mutations
Gene change. Single-nucleotide polymorphisms (single base) and tandem repeat variations (portions repeat).
Silent mutation
Doesn't affect how the gene is expressed
Nonsense mutation
Doesn't code for anything
Missense Mutation
Change in the expressed gene
Frameshift mutation
An insertion or deletion or both - more serious
Directional selection
Stabalizing selection
Disruptive selection
How can we explain the persistence of apparent genetic disadvantage?
There might be advantages (i.e. being a carrier of the sickle cell gene decreases chance of getting malaria)
Is evolution?
No! Not intentional - doesn't have a goal
Convergent evolution
Different species have different ways of solving the same problem (homoplasy)
Homoplasy
behaviors/characteristics appear similar because they emerged to solve similar problems
