lecture 1 - brain tour

Question 1

how many neurons do we have?

Answer 1

10 - 15 billions

Question 2

how many synapses do we have?

Answer 2

trillions

Question 3

cortex

Answer 3

higher level things supported by cortex - 4 lobes/cortex. the number of cells in cortex is related to how much processing power we need.

Question 4

functional specialisation - rule of thumb

Answer 4

frontal cortex is evolved from action planning, the 3 posterior cortices are evolved from sensory processes.

Question 5

frontal lobe function

Answer 5

motor control including speech, planning, changing task, working memory, motivation and personality.

Question 6

what damage to frontal lobe can cause

Answer 6

aphasia, alien hand syndrome

Question 7

features of alien hand syndrome

Answer 7

top of frontal lobe lose control of automatic things body is primed to do eg can’t control arms

Question 8

brocas aphasia in frontal lobe

Answer 8

knows and recognises words but can’t say them so lacks fluency

Question 9

temporal lobe function

Answer 9

hearing, language, object recognition, memory for things

Question 10

what damage to temporal lobe can cause

Answer 10

amnesia, prosopognasia (inability to recognise faces), aphasia (inability to recognise speech)

Question 11

features of aphasia

Answer 11

inability to recognise speech, has motor control of speech, auditory and fluency. lost representation of speech, can’t recognise words or find words - wernikes aphasia

Question 12

features of visual prosopagnosia

Answer 12

can’t recognise any faces

Question 13

cerebellum

Answer 13

automatic actions eg walking, learning, motor skills. correcting actions (contains nearly half all neutrons).

Question 14

parietal lobe function

Answer 14

perception to action, attention, spatial understanding

Question 15

what damage to parietal lobe can do

Answer 15

hemispatial neglect

Question 16

occipital lobe function

Answer 16

visual perception

Question 17

what damage to occipital lobe can do

Answer 17

partial blindness, specific visual deficits, hemispatial neglect, hemeonopia

Question 18

visual cortex

Answer 18

plasticity is less so leads to hemispatial neglect and hemeonopia

Question 19

hemeonopia features

Answer 19

know can’t see one side and look to that side

Question 20

hemispatial neglect features

Answer 20

can be from a stroke or alchzeimers. only use one side of space eg plate, only put makeup on one side. about representation of space and visual.

Question 21

the brain is not like a computer

Answer 21

they store data like units but brain stores memories in a network of neural activations in the brain - enormous storage possibilities. humans are good at generalising and computers are not.

Question 22

why use rehabilitation

Answer 22

successful early on - bing parts of network back online

Question 23

look at diagrams of brain on notes

Question 24

what are 5 major senses

Answer 24

vision, audition, olfaction (smell), gustation (taste) and the somatosenses (‘body’ senses: touch, pain and temperature).

Question 25

what three areas of the cerebral cortex that receive info from the sensory organs?

Answer 25

• The primary visual cortex - received visual info, located at the back of the brain, on inner surfaces of cerebral hemisphere
  
  • The primary auditory cortex - receives auditiory info, located on inner surface of a deep fissure in side of brain
• The primary somatosensory cortex - a vertical strip near the middle of the cerebral hemispheres, receives info from the body senses. Different regions of the primary somatosensory cortex receive info from different regions of the body. The base of the somatosensory cortex, the insula, receives info concerning taste.

Question 26

primary sensory cortex

Answer 26

• 3 regions of primary sensory cortex in each hemisphere receive info from the opposite side of the body. the primary somatosensory cortex of the left hemisphere learns what the right hand is holding, the left primary visual cortex learns what is happening towards the person’s right and so on. The connections between the sensory organs and the cerebral cortex are said to be contralateral.

Question 27

motor cortex

Answer 27

The region of the cerebral cortex most directly involved in the control of movement is the primary motor cortex located just in front of the primary somatosensory cortex.
- Neurons in different parts of the primary motor cortex are connected to muscles in different parts of the body. The connections like in the sensory regions of the cerebral cortex are contralateral - the left primary motor cortex controls the right side of the body and vice versa
- Damage to the left primary motor cortex will result in paralysis in the contralateral hand and sometimes in the left hand - Haaland and Harrington 1989.
The hand you predominantly use appears to be related to the side of the brain that is involved in speech production

Question 28

primary sensory and motor cortex

Answer 28

There is some evidence that the regions recruited during perception (visual, auditory, olfactory, etc) overlap with the regions recruited when we imagine sensory stimuli (sights, sounds, scents) (McNorgan, 2012).

Question 29

association cortex

Answer 29

The regions of primary sensory and motor cortex occupy only a small part of the cerebral cortex the rest does what is done between sensation and action - perceiving, learning and remembering, planning and acting - these processes take place in the association areas of the cerebral cortex.

Question 30

what is the central fissure

Answer 30

it provides an important dividing line between the anterior (front) part of the cerebral cortex and the posterior (back) regions.

Question 31

the anterior region

Answer 31

involved in movement-related activities, such as planning and executing behaviours.

Question 32

posterior region

Answer 32

is involved in perceiving and learning.

Question 33

cerebral cortex has 4 lobes

Answer 33

frontal lobe, parietal lobe, temporal lobe and occupital lobe.

Question 34

how many lobes does the brain have?

Answer 34

Brain contains two of each lobe, one in each hemisphere.

Question 35

location of frontal lobe

Answer 35

everything in front of the central fissure

Question 36

location of parietal lobe

Answer 36

on side of cerebral hemisphere, just behind central fissure, behind the frontal lobe.

Question 37

location of temporal lobe

Answer 37

just forward from base of brain, beneath frontal and parietal lobes

Question 38

location of occipital lobe

Answer 38

lies at very back of brain, behind the parietal and temporal lobes.

Question 39

Brodmann’s Area (BA)

Answer 39

named after Korbinian Broadmann, a german physicisist who in 1909 piblished a map of the brain which divided in into 52 different areas based on cell type and connections between cells - Annesse 2009, Zilles 2018. - Brains cyoarchitecture
- Brodmann also supported idea brain has 6 layers.

Question 40

sensory association cortex

Answer 40

Each primary sensory area of the cerebral cortex sends information to adjacent regions, called the sensory association cortex. Circuits of neurons in the sensory association cortex analyse the information received from the primary sensory cortex; perception takes place there, and memories are stored there. The regions of the sensory association cortex located closest to the primary sensory areas receive information from only one sensory system. Eg region closest to the primary visual cortex analyses visual info and stores visual memories

Question 41

function of Regions of the sensory association cortex located far from the primary sensory areas

Answer 41

they receive information from more than one sensory system so are involved in several kinds of perception and memory. These regions make it possible to integrate info from more than one sensory system eg we can learn the connection between the sight of a particular face and the sound of a particular voice.

Question 42

frontal association cortex

Answer 42

The frontal association cortex is involved in the planning and execution of movements

Question 43

anterior part of frontal lobe

Answer 43

• The anterior part of the frontal lobe - known as the PFC - contains the motor association cortex.

Question 44

what does the motor association cortex control

Answer 44

the primary motor cortex so it directly controls behaviour.

Question 45

sensory association cortex of the posterior part of the brain function

Answer 45

• We behave in response to events happening in the world around us so the sensory association cortex of the posterior part of the brain sends Info about the environment to the motor association cortex (PFC) which translates the info into plans and actions.

Question 46

what is lateralisation of function?

Answer 46

Two cerebral hemispheres don’t perform identical functions. Some functions show evidence of lateralisation as are located primarily on one side of the brain. This is also called functional hemispheric asymmetry. - Human body provides several examples of lateralisation or laterality eg most have two arms, two legs etc. Even with these superficial lateralities there are subtle asymmetries - we are more proficient with one hand than the other etc. - The brain looks symmetrical but this physical feature belies some functional asymmetries.

Question 47

left hemisphere features

Answer 47

more involved in aspects of language - speech production and comprehension and appreciation of sounds in speech than the right hemisphere. - Left lateralisation of language is seen in 94% of right handers and in 74% of non-right handers - Johnstone et al 2021.
- Left hemisphere also plays a role in understanding metaphor

Question 48

right hemisphere features

Answer 48

• Right hemisphere is better than left at recognising faces, mental rotation and comprehending metaphors and it may undertake the linguistic duties of the left hemisphere when the left is damaged.