Cerebral Asymmetry (2)

Question 1

Which behaviours did the evolution of the cerebral hemispheres allow for?

Answer 1

Complex behaviour and higher mental functions

Question 2

What is the posterior cortex largely responsible for?

Answer 2

Somatosensory processing

Question 3

What is the anterior cortex mostly responsible for?

Answer 3

Motor processing

Question 4

What are the four lobes of the brain?

Answer 4

Occipital lobe, temporal lobe, parietal lobe, frontal lobe

Question 5

The differentiation in structure and functioning of the brain between the right and left hemispheres

Answer 5

Cerebral asymmetry

Question 6

The idea that the two hemispheres have separate functions and for some cognitive functions to be specialized to one side of the brain

Answer 6

Laterality

Question 7

What is the left hemisphere broadly responsible for?

Answer 7

1. Producing and understanding language
2. Reading, writing, speech
3. Controlling movement on the right side of the body

Question 8

What is the right hemisphere largely responsible for?

Answer 8

1. Perceiving and processing nonverbal information
2. Spatial tasks
3. Understanding jokes and sarcasm
4. Controlling movement on the left side of the body

Question 9

What are two major environmental and genetic factors that can affect laterality?

Answer 9

1. Handedness (left or right)
2. Sex assigned at birth

Question 10

What are the differences in size between the left and right hemispheres?

Answer 10

Left has more grey matter and is smaller and lighter

Right has less grey matter and is larger and heavier

Question 11

What are the differences in protrusion between the left and right hemispheres?

Answer 11

Left protrudes posteriorly from the parietal/occipital lobes

Right protrudes anteriorly from the frontal lobe

Question 12

What are the differences between the left and right frontal lobes?

Answer 12

Left:
1. Smaller surface Broca’s area, larger cortex under sulci
2. Larger motor cortex area representing the face
3. Longer Wernicke’s area
4. Smaller primary auditory cortex
5. Larger thalamus
6. Larger secondary auditory processing area

Right:
1. Larger surface Broca’s area, smaller cortex under sulci
2. Smaller motor cortex area representing the face
3. Smaller Wernicke’s area
4. Larger primary auditory cortex
5. Smaller thalamus
6. Smaller secondary auditory processing area

Question 13

What are the differences between the left and right temporal lobes?

Answer 13

Smaller on left and larger on right

Question 14

What are the differences between the left and right parietal lobes?

Answer 14

Smaller on left and larger on right

Question 15

What is the difference between the Sylvian fissure on the left and right hemispheres?

Answer 15

Less steep on the left, more steep on the right

Question 16

Generally, what might damage to the left hemisphere produce that is unlikely to occur with damage to the right?

Answer 16

Issues with language comprehension, reading and writing

Question 17

Generally, what might damage to the right hemisphere produce that is unlikely to occur with damage to the left?

Answer 17

Issues with musical ability, musical discrimination, singing

Question 18

Typically begin in a focal region of one hemisphere and spreads through the fibres of the corpus callosum (the commissure) to the same location in the opposite hemisphere.

Answer 18

Seizure

Question 19

The surgical disconnection of the two hemispheres by cutting the fibers of the corpus callosum (split-brain)

Answer 19

Commisurotomy

Question 20

What distinction between left and right brain functioning is important to research on split-brain patients?

Answer 20

Left can access information, initiate speech and communicate information

Right has recognition abilities but cannot initiate speech to communicate information (ex. drawing remains possible)

Question 21

Experimental technique in which two cortical areas are proven to be dissociated by two different behavioural tests

Answer 21

Double dissociation

Question 22

Surgeon electrically stimulates the exposed cortex and records the conscious patient’s responses

Answer 22

Electrical Brain stimulation

Question 23

Uses magnetic fields to either stimulate or inhibit neurons in the brain

Answer 23

Transcranial magnetic stimulation (TMS)

Question 24

Injecting sodium amobarbital into the left or right carotid arteries to anesthetize the hemisphere on the ipsilateral side

Answer 24

Carotid Sodium Amobarbital Injection

Question 25

What are the two main differences left-handed people often present in relation to their functional asymmetry?

Answer 25

1. No asymmetry
2. A reversal of asymmetry

Question 26

What is the genetic theory of handedness?

Answer 26

A dominant gene for right-handedness and a recessive gene for left-handedness

Question 27

What are the two main environmental theories of handedness?

Answer 27

1. Utility/Evolutionary: It is adaptive for a mother to hold an infant in her left hand to be soothed by the rhythm of her heart, thus leaving her right hand to become dominant to attend to other activities.
2. Reinforcement: Our world favours right-handedness in many ways that reinforce it

Question 28

What is the anatomical theory of handedness?

Answer 28

The left hemisphere shows greater maturation/development in most individuals, supporting a better use of the right hand

Question 29

What are some general differences in behaviour between sexes?

Answer 29

1. Motor: Men are better and throwing/catching, women are better at fine motor control
2. Spatial analysis: Men are better at mental rotation and spatial navigation, women are better at identifying movement and landmarks
3. Mathematical aptitude: Men are better at mathematical reasoning, women are better at computation
4. Perception: Men are better at drawing mechanical objects, women are more sensitive to all forms of sensory stimulation (except vision), facial expressions and body language
5. Verbal ability: Women are better at verbal fluency, verbal memory and recalling details of a story