Three of the following describe methods what researchers commonly use to determine how the human brain probably functions. Which one is not a commonly used method to study the brain?
a. Documenting the behaviors of people with various kinds of brain injuries
b. Recording brain activity through PET scans, CAT scans, and similar technologies
c. Measuring the levels of various hormones and other substances in the blood
d. Removing a certain part of an animal's brain and observing the animal's subsequent behaviors
Question 2
Which one of the following statements most accurately describes a neuron's threshold of excitation?
a. A neuron responds when it is stimulated by some of its neighboring neurons, but not when it is stimulated by other neighbors.
b. A neuron fires only when its electrical charge reaches a particular level.
c. A neuron is receptive to stimulation from other neurons only at points where there are gaps in its myelin sheath.
d. A neuron will fire at a maximum rate of no more than once every three seconds.
A vertebrate digestive system, as shown in the human.
Human sex chromosomes
The major human endocrine glands and their central nervous system control centers
Researchers and Research Spending, 2009
A bipedal human
Use of forward and reverse genetics to determine gene function