Exam 1 - Chapter 2

Question 1

soma

Answer 1

the cell body of a neuron

Question 2

axon

Answer 2

the long extension from a neuron that sends electrical signals to the axon terminals, with an end goal of communicating with other neurons

Question 3

dendrites

Answer 3

the extensions from the soma of a neuron from which the neuron receives chemical signals from other neurons

Question 4

single cell recording

Answer 4

a method of recording nerve activity in which responses from a single cell are recorded, with one end of the recorder in the cell and the other end in the environment surrounding the cell

Question 5

action potential

Answer 5

the signals that neurons use to communicate with one another

Question 6

what is the threshold of excitation for a neuron?

Answer 6

around -55 mV

Question 7

what is the resting potential of a neuron?

Answer 7

about -70 mV

Question 8

what are the stages of an action potential?

Answer 8

the stimulus occurs, the neuron’s charge reaches the threshold of excitation, depolarization occurs, repolarization occurs, hyperpolarization occurs, then resting potential is restored

Question 9

what happens in the depolarization phase of an action potential?

Answer 9

sodium (Na+) ions rush into the neuron and the charge inside the neuron rises to +40 mV

Question 10

what happens in the repolarization stage of an action potential?

Answer 10

sodium (Na+) channels close, potassium (K+) channels open, and K+ rushes out of the neuron, which lowers the charge inside the neuron

Question 11

what happens in the hyperpolarization stage of an action potential?

Answer 11

the charge inside the neuron decreases to -75 mV, making it more difficult for the neuron to fire until it reaches resting potential

Question 12

all-or-none law

Answer 12

action potentials either happen, or they don’t; there is no such thing as a weaker or stronger action potential

Question 13

how do neurons communicate that a stimulus is more or less intense?

Answer 13

changing the rate of firing (AKA rate of action potentials)

Question 14

absolute refractory period

Answer 14

the period after an action potential where the neuron is still firing, so it is impossible for the neuron to fire again; during depolarization and repolarization

Question 15

relative refractory period

Answer 15

the period after an action potential where the neuron is hyperpolarized; it can fire again, but it is more difficult than normal

Question 16

spontaneous activity

Answer 16

the random firing of a neuron that is considered a baseline when measuring neural activity

Question 17

synapse

Answer 17

a small gap that exists between the axon terminals of one neuron and the dendrites of another neuron

Question 18

neurotransmitters

Answer 18

the chemical messengers that travel across the synapse of neurons; allows neurons to communicate

Question 19

receptor sites

Answer 19

the sites on a neuron where they can receive neurotransmitters from other neurons

Question 20

sensory coding

Answer 20

how neurons represent various characteristics of the environment

Question 21

specificity coding

Answer 21

a type of sensory coding hypothesis where a particular object is represented by the firing of a single neuron that responds only to that object

Question 22

sparse coding

Answer 22

a type of sensory coding hypothesis where a particular object is represented by the pattern of firing of a small group of neurons; evidence exists for this hypothesis

Question 23

population coding

Answer 23

a type of sensory coding hypothesis where a particular object is represented by the firing of a large number of neurons; evidence exists for this hypothesis

Question 24

modularity

Answer 24

the idea that specific brain regions are specialized to respond to specific types of stimuli or take part in specific functions

Question 25

module

Answer 25

a structure that processes information about a specific behavior or perceptual quality

Question 26

distributed representations

Answer 26

when a stimulus causes neural activity in a number of different areas of the brain; ex. face processing, pain matrix

Question 27

Broca's area

Answer 27

an area of the brain that is involved with speech production; damage to this area can cause Broca's aphasia, where the patient has trouble producing speech but can comprehend what others are saying

Question 28

Wernicke's area

Answer 28

an area of the brain involved in speech comprehension; damage to this area can cause Wernicke's aphasia, where the patient can produce speech but not convey meaning

Question 29

fMRI

Answer 29

functional magnetic resonance imaging; a type of brain imaging technique that allows researchers to see which part of the brain is active while performing a specific task; uses a strong magnetic field to measure blood flow and determine which areas are receiving more oxygen and therefore performing more work

Question 30

EEG

Answer 30

electroencephalography; a type of brain imaging technique that allows researchers to see what part of the brain is active during a specific task; uses electrical currents along the surface of the brain to measure this activity

Question 31

structural connectivity

Answer 31

a "road map" of fibers that connects different areas of the brain

Question 32

functional connectivity

Answer 32

the neural activity that flows through neural networks