Chapter 3: The nerve cell

Multiple Choice Questions (1-20)

1.  If the synapse between neurons is inhibitory, the probability of the next neuron firing is

a.  increased

b.  decreased

c.  unchanged

d.  dependent upon the type of neuron

2.  If the synapse between neurons is excitatory, the probability of the next neuron firing is

a.  increased

b.  decreased

c.  unchanged

d.  dependent upon the type of neuron

3.  What is an artificial neural net (ANN)?

a.  the intricate connections between neurons that exist in the brain

b.  a model of a brain function that utilizes idealized neurons

c.  the circuitry that is found in artificial intelligence devices

d.  a tangle of neuronal axons that no longer function properly

4.  The reentrant, or ” two-way”, connections between neuronal arrays are

a.  by far the most common connection type

b.  limited to connections within the cerebral cortex

c.  only about 10% of the connections in the cortex

d.  limited to vision cortex

5.  Hebbian learning refers to notion that “neurons that fire together, wire together.” Its defining feature is that

a.  the threshold for firing an action potential is dependent upon the type of neuron

b.  the formation of a particular type of neuron occurs at the same stage of development

c.  learning involves increased efficiency in synaptic transmission

d.  neural arrays are formed between similar types of neurons

6.  Neural Darwinism can be summarized as

a.  “survival of the organisms with the most complex nervous system”

b.  “survival of the biggest neurons”

c.  “survival of the organisms with the most adaptive nervous system”

d.  “survival of the fittest cells and synapses”

7.  Making predictions about which interpretation of an ambiguous stimulus is likely to be correct involves a kind of processing.

a.  lateral

b.  input-driven

c.  top-down

d.  bottom-up

8.  Which of the following is the best metaphor for neuronal choice points?

a.  sliding on a slide

b.  swinging on a swing set

c.  driving with traffic down a one-way street

d.  choosing a direction at a fork in the road

9.  Hierarchies of neuronal arrays exist for

a.  sensory systems

b.  motor systems

c.  both sensory and motor systems

d.  neither sensory nor motor systems

10.  Learned but non-voluntary processes are called

a.  reflexes

b.  circuits

c.  automatic processes

d.  subconscious processes

11.  Two ways that the brain encodes information are (1) in spatial arrays and maps, and (2) in changing the firing rate of neurons. Which of the following describes these types of coding?

a.  They are both examples of types of spatial coding

b.  The first is an example of temporal spatial coding, and the second is an example of spatial coding

c.  The first is an example of spatial coding, and the second is an example of temporal coding

d.  They are both examples of differing types of temporal coding

12.  How does an “integrate-and-fire” neuron work?

a.  Neurons will fire when they receive any type of information from the neuron before it

b.  The strength of the action potential fired is dependent upon the strength of the signal the neuron receives

c.  Graded voltage inputs are summed, and if a threshold point is crossed, the neuron will fire an all-or-none action potential

d.  The neuron will only fire if it receives information from all of the neurons it receives information from, or not at all

13.  Sensory systems (such as vision, touch, hearing) are

a.  organized in strictly feedforward hierarchies

b.  comprised of roughly 50% one-way and 50% two-way connections

c.  comprised of mostly two-way connections that aid in resolving ambiguous inputs

d.  comprised of mostly one-way connections in order to produce temporal encoding of sensory features

14.  Neuronal arrays that represent spatial patterns are frequently referred to as

a.  spiking codes

b.  semantic networks

c.  maps

d.  hierarchies

19. Some working assumptions in the study of neurons and their connections include

a.  a simplified neuron to build cognitive models from artificial neural nets

b.  connections are either inhibitory or excitatory

c.  most neural connections are two-way

d.  all of the above

20.Finding one’s way home in the dark is an example of

a.  sensori-motor feedforward processing

b.  lateral inhibition

c.  top-down or expectation-driven processing

d.  temporal coding

Short Answer Questions (1-3)

1.  Briefly explain how sensory and motor regions can be viewed as hierarchies.

2.  In your own words, describe the idea behind Hebbian learning. What neural changes are occurring during Hebbian learning?

3.  What role does re-entrant (two-way) connections play in brain function?

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