Lecture 3: Methods of Scientific Thinking

What is a hypothesis?

Part of the scientific method. (if/then statement)

Control Condition

Keep as many conditions the same as possible, except the thing you are specifically testiing

What are two often-used control conditions?

* age matched in human studies
* littermates in rodent studies

What are the three parts of methodology?

1. take away brain activity to look for impairments in behavior test for necessity of a brain area for behavior
2. produce or create brain activity to look for increased behavior test for sufficiency of a brain area for behavior
3. simply record brain activity, don’t show necessity or sufficiency, they just show there may or may not be a relationship (correlation)

What is “Testing Necessity” and what are the techniques to do so?

Take away biological process to take away a behavior

* brain lesion techniques
* neurotransmitter antagonists
* gene knockout organisms
* ion channel blockers

What is lesion methodology?

Removing a part of the brain to test for necessity

Genetic Knockouts

Cut out genes which may encode a specific protein → reduce or remove behavior

Cre

recombinase that can excise (take out) or invert (turn to nonsense) a gene sequence

lox

site on DNA that cre recognizes

What are the three ways we test sufficiency?

1. Induce biological process to induce a behavior
2. Electrophysiological stimulation
3. Neurotransmitter agonist

Electrical stimulation

stimulate neuron → produce behavior, that neurons activity must be sufficient to produce that behavior

What was one of the earliest ways to determine sufficiency of a brain area?

Stimulating neurons in various brain areas to look for induction of behaviors

What are three ways we can record brain activity?

* electrophysiological recording
* functional magnetic resonance imaging (fMRI)
* electroencephalography (EEG)

What does an fMRI allow us to do and see?

A tool that allows us to see changes in blood flow (and, presumably, brain activity) in response to sensory stimuli or correlating with thoughts or memories or motor commands

What is the purpose of an event related potential?

There is too much noise in one measurement of EEG so the ERP averages the responses of multiple EEG’s to smooth out the data

* more time sensitive and cheaper than the fMRI

Which has better spatial resolution? The ERP or the fMRI?

The fMRI