Methods in Brain Research 1

Question 1

What does neuroimaging do?

Answer 1

Examined the structure and function of the brain and the involvement of cognitive functions.

Question 2

What is neuropsychology?

Answer 2

Examines the effect of the brain lesions on behaviour and mental functions under the assumption that if the lesion of the brain region X impairs function Y, Y must be dependent on the integrity of X.

Brain lesions occurr after strokes, accidents, tumors, cerebral hypoxia, etc.
The study of the effects of brain lesions on behaviour started in mid-1800
Lesions in specific parts of the brain induce deficits in specific cognitive functions, changes in personality or behaviour

Discovered prosopagnasia.

Question 3

What machine examines brain structure?

Answer 3

Magnetic Resonance Imaging (MRI)
Computerised Tomography (CT)
Diffusion Tensor Imaging (DTI)

Question 4

What machine examines brain function?

Answer 4

Functional Magnetic Resonance Imaging (fMRI)
Position Emission Tomography

Question 5

Explain the electric brain activity.

Answer 5

Records currents in the brain or magnetic fields generated from them.
Uses the brain signals to examine the temporal dynamics of mental processes.
Sometimes provides info on brain sources.

Question 6

What machine examines electrical brain activity?

Answer 6

EEG
ERPs
Single unit recordings
MEG

Question 7

Explain non-invasive stimulation.

Answer 7

Delivers electrical currents or magnetic fields to the brain and examines its effects on mental functions under the assumption that the stimulation of brain region X impairs the function of Y.
Y must be dependent on X.
Neuroenhancement tool.

Question 8

What machine performs non-invasive brain stimulation?

Answer 8

TMS
tDCS, tACS

Question 9

What is the function of magnetic resonance imaging (MRI)?

Answer 9

Uses the properties of the magnetic field created by a scanner to produce virtual slices of the brain. To capture the 3D complexity of the brain, slices are produced in three planes: coronal, axial/ horizontal and sagittal.
Different parts of the brain are visible with different slices.

Question 10

State the three planes fMRI does.

Answer 10

Coronal
Axial/ horizontal
Sagittal

Question 11

What does structural MRI do?

Answer 11

Provides information on the structure of the brain.
When patients are in an MRI scanner, they aren’t required to perform specific tasks.
Used for clinical purposes.
Used to correlate the structure of some brain regions with traits.

Question 12

What is the amygdala?

Answer 12

Is a brain region typically associated with emotional processing.

Question 13

What is the function of functional magnetic resonance imaging (fMRI)?

Answer 13

Subjects are placed into a scanner and perform a task while their brain activity is recorded.
Provides information on the areas that are activated during specific tasks and cognitive processes.

Question 14

Explain the BOLD signal.

Answer 14

Oxygen in the blood is an index of brain activity: the higher the oxygenation in that area. Areas with high levels of oxygenation increase the fMRI signal.

Question 15

What is a pro and con of fMRI?

Answer 15

Pro - excellent spatial resolution.
Con - poor temporal resolution.
indirect measurement of brain
activity and doesn’t provide
causal information.

Question 16

Explain the spatial resolution of fMRI.

Answer 16

Excellent
Measures brain activity at a gross level.
Detects activity from brain regions spaced 2mm apart.
Provides information on the neural correlates of mental functions with great precision.

Question 17

Explain the temporal resolution of fMRI.

Answer 17

Poor.
Hemodynamic response generates a sluggish BOLD signal that takes seconds to emerge.
Takes around 5 - 15 seconds for the BOLD signal to reach its peak.
However, the brain comprehends information in a few hundreds of milliseconds.

Question 18

What is transcranial magnetic stimulation (TMS)?

Answer 18

A procedure that applies a magnetic field on the scalp above a given brain region. The magnetic field induces changes in the electrical potentials of that region, which interferes with behaviour.
Induces action potentials in nerve actions.
Stimulation is very brief.
Noninvasive technique.

Question 19

What is transcranial electrical stimulation (tES)?

Answer 19

A noninvasive brain stimulation technique where electrical currents 1 - 2 mA are delivered through two sponge electrodes attached to a current generator.
Anode electrode - positively charged with excitatory effect on neurons.
Cathode electrode - negatively charged with an inhibitory effect on neurons.
TES is not strong enough to induce neuronal firing directly, but the depolarization makes it more likely that a stimulated neuron will fire.
Stimulation is long (5 - 20 minutes), and effects persist after the stimulation.
FDA-approved treatment for depression.

Question 20

What are the applications of non-invasive brain stimulation?

Answer 20

1) Provide information on the neural correlates of a mental process
If brain region A is involved in cognitive function B, the stimulation of A will determine a change in function B
2) Neuroenhancement tool
TMS is an FDA-approved treatment for depression.
Anodal stimulation with tDCS
has been shown to induce
enhancements of virtually any
cognitive function, in patients
too

Question 21

What are the pros of TMS and TMS stimulation?

Answer 21

It provides causal information non-invasively.
Especially with TMS, partial resolution can be precise.
TES is portable and suitable for home use.

Question 22

What are the cons of TMS and TMS stimulation?

Answer 22

TMS can be painful and not everyone can receive it.
TES doesn’t have enough spatial and temporal resolution.

Question 23

What is the best method to investigate the relationship between brain and cognition?

Answer 23

There is no perfect method. The challenge for the cognitive neuroscience is to integrate different information gained from different research methods.

Question 24

How does a neuroscientist find out which part of the brain is involved in face perception?

Answer 24

Randomly create virtual lesions with TMS to different parts of the brain until a decrease in face perception accuracy occurs.
Ask a group of student to perform a face perception task while their brain activity is being recorded with fMRI.
Ask a group of subjects to perform different types of face perception tasks.
Ask a group of students to perform a face perception task while their brain activity is being recorded with EEG.