Chapter 3 - The Brain

Question 1

What is the largest portion of the human brain taken up by?

Answer 1

The cerebrum, mostly devoted to controlling voluntary behaviours.

Question 2

What is the cerebral cortex?

Answer 2

A layered structure and the most superficial portion of the human brain.

Question 3

What is gray matter and where does it make up?

Answer 3

Gray matter is made of neuronal cell bodies which makes up for the outermost layer of the brain.

Question 4

What is white matter?

Answer 4

Consists of the nerve tracts that connect neurons to each other (myelinated axons).

Question 5

What does the hippocampus do?

Answer 5

Memory formation.

Question 6

What is an encephalization quotient (EQ)?

Answer 6

EQ measures actual brain size relative to the size that would be predicted on body size alone.

Question 7

What are the four directions of the brain?

Answer 7

Dorsal (top)
Frontal/Anterior (front)
Ventral (bottom)
Caudal/Posterior (back)

Question 8

What are the other planes of the brain?

Answer 8

Sagittal, based on Y+Z coordinate (front and back)
Coronal, based on X+Y coordinate (side to side)
Transverse, based on flat X+Z coordinate (side and back)

Question 9

What is the difference between gyri and sulci?

Answer 9

Gyri are the hills, sulci are the valleys.

Question 10

What does it mean when sensory information is contralateral?

Answer 10

A spatial relationship between brain and body in which one side of the brain controls or receives input from the opposite side of the body.

Left eye sees, right brain thinks, left hand reacts.

Question 11

What are fissures?

Answer 11

Deep sulci which separate the lobes into their regions.

Question 12

What is the frontal lobe for?

Answer 12

Decision making and executive control.

Question 13

What is the parietal lobe for?

Answer 13

Attention, sensory integration and somatosensory processing.

Question 14

What is the temporal lobe for?

Answer 14

Meaning of sensory information, language, and visual memory.

Question 15

What is the occipital lobe for?

Answer 15

Vision.

Question 16

What is the left hemisphere or right hemisphere responsible for?

Answer 16

Left hemisphere - Language
Right hemisphere - Spatial processing

Question 17

What is aphasia?

Answer 17

The loss of language comprehension or expression due to brain damage.

Broca’s aphasia (expressive aphasia) occurs due to damage to inferior frontal gyrus for slow and deliberate speech.

Wernicke’s aphasia (receptive aphasia) occurs to damage to the superior temporal gyrus by speech that is fluid and grammatically correct but not meaningful.

Question 18

What is EEG and what is it good for?

Answer 18

Measuring electrical activity of the active brain measuring using event-related potential (ERP). Good for temporal measurements but not spatial measurements.

Question 19

What is fMRI and what is it good for?

Answer 19

Functional magnetic resonance imaging (fMRI) indirectly measuring activity by relying on neurons engaged in firing activity which must replenish their resources and nutrients using a hemodynamic response (blood delivery to active neurons).

Question 20

What is MVPA?

Answer 20

Multi variate/voxel pattern analysis. Using fMRI data to analyze pattern of brain activity to determine what a participant is looking at or thinking.

Question 21

What are the main steps of MVPA?

Answer 21

1. Deciding which neurons from parts of the brain are included.
2. The pattern of brain activity when participants are engaged in different tasks.
3. After patterns are gathered, one becomes training set and other is test set. Training set is given to computer to train on.
4. Test the computer to identify brain activity from a never-seen-before set.

Question 22

What is EEG better at? What is fMRI better at?

Answer 22

EEG is better for measuring timing of events.
fMRI is better at imaging the events and recording mental events.

Question 23

What is TMS?

Answer 23

Transcranial magnetic stimulation (TMS) uses brief and strong magnetic pulses to penetrate through the skull and disrupt electrical activity of the brain. Test what effect disrupting parts of the cortex has on behaviour. (Disables region temporarily).

Question 24

What is neuroplasticity?

Answer 24

The ability of the brain to recognize the spatial arrangement of its function is not good at something because of their structure but because the brain sends it information first. Not because it is dedicated to that use specifically.

Question 25

What are the three types of neurons and their uses?

Answer 25

Sensory/receptor neurons receive information from the physical world. Conversion of information to neural code is transduction. Motor neurons are responsible for nervous system output that makes our body react and move using signals from the CNS and terminate on muscle fibers. Association neurons responsible for receiving information from neurons and sending to other neurons. Most abundant.

Question 27

What is specificity encoding?

Answer 27

The theory that specific neurons can be selective for specific things and objects like faces. Grandmother cell hypothesis where one specific neuron responds to only one person. Name, face, or idea.

Question 28

What is distributed/population encoding?

Answer 28

Many neurons active in response to a single stimulus. All neurons will be active to different things based on the pattern the neurons are activated.

Question 29

What is sparse coding?

Answer 29

A small number of neurons are active for any complex given stimulus. The particular combination allows the brain to identify the stimulus. Can share some neurons, but have different neurons.