Methods of Recording from the Brain

Question 1

What is the most basic kind of recording?

Answer 1

Intracellular or single-unit recording

Question 2

How does the most basic kind of recording work?

Answer 2

an electrode is implanted in a particular neuron and the electrode records the change in the membrane potential.

Question 3

What are the downsides to the most basic kind of recording?

Answer 3

Neurons are very small.

Question 4

What is an alternative to the most basic kind of recording?

Answer 4

Extracellular recording - an electrode measures the membrane potentials from a population of cells from just outside those cells

Question 5

What was phrenology?

Answer 5

This is when an experienced practitioner feels the bumps of your head and explains your neurological traits.

Question 6

Who developed phrenology?

Answer 6

A german neuroanatomist Franz Joseph Gall who thought abilities and personality were located in certain parts of the brain and you could read it by feeling the bumps and contours of the brain.

Question 7

What was phrenology used for?

Answer 7

As it grew, phrenology was used to justify the “inferiority” of certain races, classes, or sexes of human beings.

Question 8

What is EEG? (think egg to remember this)

Answer 8

EEG stands for electroencephalogram and at first metal wires were inserted into the patient’s skull but modern EEG uses small metal discs called electrodes held together by a fabric cap and attached to the surface of the scalp with a little sticky jelly-like material.

Question 9

What was the purpose of EEG?

Answer 9

the purpose of EEG is to record the electrical impulses created by large populations of neurons right through the skull. This appears on the recording equipment as large brain waves.

Question 10

Who invented EEG?

Answer 10

In the 1920s, Hans Berger invented this to provide insights into mental processes.

Question 11

What was EEG used for?

Answer 11

studying sleep, describing the different types of electrical waves that are present in the typical functioning brain and the differences in people without typical functioning brains.

Question 12

What is a dipole, how is it made in the brain, and how well does EEG monitor these dipoles?

Answer 12

an area of negative charge next to an area of positive charge is a dipole The EEG electrodes on the scalp can capture these changes in charge very precisely and can show the changes in electrical activity in a certain field of neurons that take place over just a few milliseconds.

Question 13

In the 1960s, what new information could scientists get from electrodes?

Answer 13

They could use computers to look at the electrical potential directly resulting from a particular stimulus or event shown to a subject, called ERP (event related potential)

Question 14

What are the problems with EEG?

Answer 14

not really useful for pinpointing where in the brain certain activity is coming from, only useful for detecting or imaging activity from the outermost areas of the brain

Question 15

Because of all the problems with EEG, what was a breakthrough?

Answer 15

magnetic resonance imaging or MRI

Question 16

What is cognitive neuroscience?

Answer 16

neuroscience focused on the
cognitive or active thinking processes of living human beings

Question 17

What is MRI?

Answer 17

medical imaging technique that uses a strong magnetic field to
produce detailed images of the inside of the body or other organism

Question 18

How is MRI different from EEG?

Answer 18

MRI - the patient lies on a table inside a large, cylindrical machine called an MRI scanner, and the magnetic field is set up surrounding them

EEG - using a simple cap of electrodes

Question 19

What is MRI used for?

Answer 19

examining parts of the body and detecting abnormalities and diagnosing injuries.

Question 20

What happens to the patient during an MRI scan?

Answer 20

because the patient is put in a strong magnetic field, some of the hydrogen atoms in the body align.

Question 21

List the 5 parts of an MRI scanner?

Answer 21

magnet, gradient coils, radio frequency coils, the patient table, and the bore

Question 22

What can a basic MRI scan produce?

Answer 22

produce detailed images of the tissues inside the body and brain

Question 23

How does an MRI work?

Answer 23

The strong magnetic field created by the MRI scanner causes the atoms in your body to align in the same direction. Radio waves are then sent from the MRI machine and move these atoms out of the original position. As the radio waves are turned off, the atoms return to their original position and send back radio signals.

Question 24

There’s a specific way that processes the relaxation signals the atoms give off in an MRI that lets scientists see brain changes. What is it, what does it involve, and how does it work?

Answer 24

Specifically, red blood
cells carrying oxygen have different magnetic properties than red blood cells that are not carrying oxygen (deoxygenated). This means that when the magnetic field is applied (and when the RF pulse is applied), these forces act differently on oxygenated and deoxygenated blood,

Question 25

How does fMRI (Functional MRI) show what parts of the brain are active in certain tasks?

Answer 25

Changes in blood flow in the brain in almost real time in order to see where neural activity likely is in that brain. This allows us to create activation maps of which parts of the
brain may be involved in a particular task

Question 26

What other name is there for fMRI that better describes the process?

Answer 26

BOLD (blood oxygen level dependent) imaging

Question 27

When was fMRI discovered?

Answer 27

1990s

Question 28

Since then, what has fMRI allowed scientists to do?

Answer 28

it allows scientists to take noninvasive pics of what the brain of a living person is doing. this allows scientists to chart regions on the brain and their functions.

Question 29

What part of the brain has fMRI helped scientists discover, and what does that part do?

Answer 29

they were able to discover the FFA (fusiform face area) which is disproportionately active when subjects are shown pictures of faces as compared to when they are shown other visual items

Question 30

What are the downsides of MRI?

Answer 30

produce a fuzzy image if the subject is not able to hold still within the scanner

MRI scanners are expensive and are usually only located in hospitals and research labs only

these scanners rely on a strong
magnetic field

Question 31

What are the downsides of fMRI?

Answer 31

each pixel of an fMRI image is 1mm3, it is still not detailed enough to tell us what specific
populations of neurons are doing at a particular time.

brain, fMRI can only produce
a new picture of neural activity every few seconds as it takes a few seconds for the blood flow to change in response to a change in neural activity.

Question 32

What does the study guide say when comparing fMRI to EEG?

Answer 32

fMRI has a much lower temporal resolution than EEG and fMRI doesn’t directly record the neurons as specifically as EEG or direct neuron recording

Question 33

How would you describe a BMI?

Answer 33

a brain-machine interface is a system that allows a person to control a device or machine using only their thoughts.

Question 34

What does a BMI typically consist of?

Answer 34

of a device that records
neural activity from a particular brain region, and a computer system that translates that activity into commands
that can be used to control external devices

Question 35

Although BMI is for experimental purposes, what potential impact might it have in the future?

Answer 35

can help people with disabilities as well as enhance human-computer interactions

Question 36

What kind of BMI device has already been designed thanks to the BRAIN Initiative?

Answer 36

a “neuroprosthetic” technology that records from the brain’s speech centers and translates that brain activity into speech

Question 37

How does the training procedure for BMI work?

Question 38

Who gets trained for BMI?

Answer 38

new BMI users

Question 39

The devices that connect to the brain in BMI can be connected in how many ways?

Answer 39

2 ways

Question 40

Explain each method? (BMI)

Answer 40

through implanted devices - often surgically attached directly to brain tissue and thus are only appropriate for individuals with
severe disorders or damage to their nervous systems

wearable devices - often based on tDCS technology or similar external electrodes and although they have fewer risks and side effects than implanted devices, their ability to record brain activity is very limited.

Question 41

What are some skeptical questions that could rise with the growth of BMI?

Answer 41

If you can use your mind to control a device, how can we work to ensure that the device
is not “hackable”? Will some people in the future be able to give themselves an unfair advantage at school or work with these devices? Will this sort of technology be available to everyone or only those individuals with the money to afford the expensive devices?