Week 5 (Chapter 43-45)

Question 1

What are 3 potential triggers for brain reorganization?

Answer 1

• changed input (due to training)
• input loss (due to amputation)
• substrate loss (due to stroke)

Question 2

What are alternate reasons for cortical map changes, rather than cortical reorganization?

Answer 2

• unmasking of pre-existing cortical map connections

- subcortical reorganization

Question 3

What is reorganization?

Answer 3

When a specific neuron or brain region changes so that it becomes responsive to a new input, or produces entirely new output

Question 4

S1 is typically an _____ structure, and M1 an ____ structure

Answer 4

• input

- output

Question 5

What is the difference between S1 and M1 in terms of spatial resolution?

Answer 5

S1 shows more detailed representations of hand digits, while M1 represents body parts more crudely

Question 6

What is a topographic map in terms of brain representations?

Answer 6

An orderly relationship of activity patterns on the cortical sheet that reflects the relationships of stimuli/movements along a specific physical dimension

Question 7

What is gain modulation?

Answer 7

A brain area that used to weakly respond to a stimulus, becomes more responsive to it

Question 8

What happens to neurons in the hand area of S1 when a hand is amputated?

Answer 8

They become activated by the chin

Question 9

What happens to neurons in the hand area of M1 when a hand is amputated?

Answer 9

The neurons still control hand function

Question 10

By utilizing reported phantom sensations, multiple studies have found that ______

Answer 10

Representations relating to the phantom hand persist in the peripheral and central nervous systems

Question 11

What is functional reorganization?

Answer 11

A neural change that is causally related to changes in behaviour

Question 12

What is the likely cause of changes in cortical maps?

Answer 12

Subcortical reorganization

Question 13

What behaviour impairments are caused by dysfunction of the basal ganglia?

Answer 13

Reduction in speed and extent of movement

Question 14

What is a proposed key computational function of the basal ganglia?

Answer 14

Controlling low-level parameters of movement

Question 15

There is a dramatic ____ in cell number as one progresses through the _____ of the basal ganglia

Answer 15

• decrease

- internal circuitry

Question 16

The basal ganglia have a _____ pathway through the ______

Answer 16

• reentrant

- thalamus

Question 17

In mammals, afferent inputs to the basal ganglia come from the ______

Answer 17

Thalamus
Hippocampus
Amygdala
Neocortex

Question 18

In mammals, the _____ and _____ receive all types of cortical input to the basal ganglia

Answer 18

• caudate

- putamen

Question 19

What is considered the primary input nucleus of the basal ganglia?

Answer 19

The striatum

Question 20

The striatum is composed of ~95% _____

Answer 20

inhibitory projection neurons

Question 21

Direct-projecting principal neurons of striatum express _____, while indirect-projecting neurons express _____

Answer 21

• D1-type dopamine receptors

- D2-type dopamine receptors

Question 22

Studies show that the basal ganglia are not necessary for the execution of movements, but for ______

Answer 22

Their invigoration

Question 23

The basal ganglia have also been proposed to contribute to higher-­ level cognitive functions such as _____

Answer 23

Decision-making

Question 24

The act of preparation is distinct from the act of ______ a movement - it happens ___ we need to move

Answer 24

• generating

- before

Question 25

What is preparation?

Answer 25

A rapid process where specified high-level goals are translated into a policy suitable for movement and ready to be evoked when movement initiation is triggered

Question 26

The delay between timing of movement preparation and initiation suggests _______

Answer 26

They are distinct processes

Question 27

What is a fast error?

Answer 27

When a movement is initiated before the correct movement can be selected and prepared

Question 28

Premovement population activity in PM/M1 reliably _______

Answer 28

Converges to a specific state

Question 29

How long does movement preparation take?

Answer 29

No more than 50-100ms

Question 30

Research suggests an overlap between mechanisms by which a decision was formed and ______

Answer 30

The mechanisms for representing a movement