Cortical pt 2

Question 1

What are the 3 motor association areas found in the frontal lobe

Answer 1

Primary
Supplementary
Premotor area
see diagram

Question 2

What is the function of the primary motor area

Answer 2

Control fine, discrete, precise voluntary movements and to provide descending signals to execute movements

Question 3

What is the function of the supplementary area

Answer 3

Involved in planning complex movements eg ( internally cued movements ie speech)

Question 4

What is the function of the premotor area

Answer 4

Planning movements that are externally cued ie lifting a glass

Question 5

What are the 2 association areas found in the parietal lobe

Answer 5

Primary somatosensory

Somatosensory association

Question 6

What is the function of the primary somatosensory cortex

note where is it found

Answer 6

Processes somatic sensations arousing from receptors in the body ( fine touch ,vibration , two point discrimination , proprioception , pain and temperature )

parietal lobe

Question 7

What is the function of the somatosensory association cortex and where is it found

Answer 7

Interpret significance of sensory information ie recognising an object placed in the hand + awareness of self and personal space

Parietal lobe

Question 8

What are the 2 association areas found in the occipital lobe and what are their functions

Answer 8

Primary visual –> process visual stimuli

Visual association –> give meaning and interpretation of visual input

see notes for picture

Question 9

What are the two association areas found in the occipital lobe and what is their function

Answer 9

Primary auditory –> Processes auditory stimuli
Auditory association –> gives meaning and interprets auditory input
see note for picture

Question 10

What is an association area

Answer 10

an area of the cerebral cortex that functions in linking and coordinating the sensory and motor areas

Question 11

Name 3 other association areas of the brain and their functions

Answer 11

Broca’s area –> usually in L side of brain. contains motor cortices associated with the production of language ( legion = loss of speech)

Wernicke’s area –> usually in L side of brain. Important for language processing and understanding language. ( legion = not understanding language)

Prefrontal cortex –> attention , adjusting social behaviour, planning , personality expression , decision making ( degeneration often seen in dementia + causes symptoms ie personality shift + loss of inhibitions+ inappropriate behaviour)

Question 12

what are symptoms of frontal lobe lesions

Answer 12

Changes in personality

Inappropriate behaviour

Question 13

what are some symptoms of parietal lobe lesions

Answer 13

Contralateral neglect –> lack of awareness of self and of extra personal space on side of body opposite side of brain where legion occurred. Ie legion in right hemisphere causes person to be unable to dress properly on left side or unable to draw see objects on their left

Question 14

symptoms of temporal lobe lesions

Answer 14

damage to lateral and medial parts can lead to agnosia ( inability to recognise objects and ppl) . damage to medial part can also lead to anterograde amnesia ( inability to form new memories)

Question 15

What connects the broca’s and wernicke’s areas

Answer 15

Arcuate fasciculus

see white matter tracts

Question 16

symptoms of legion to broca’s area

Answer 16

Expressive aphasia ( poor production of speech but comprehension intact)
( motor defect)  

this is different to legion in wernicke’s area

Question 17

Symptoms of legion to wernicke’s area

Answer 17

Receptive aphasia ( poor comprehension of speech but production is fine)

( sensory defect)

this is different to legion in broca’s area

Question 18

Symptoms of legion to primary visual cortex

Answer 18

Blindness in corresponding part of visual field

Question 19

Symptoms of legion to visual association area

Answer 19

Defects in interpretation of visual info ( ie Prosopagnosia –> inability to recognise familiar faces or learn new faces aka face blindness)

Question 20

What imaging techniques can be used to assess cortical function

( remember there are a few ways we do this

1) Measure brain activity in healthy ppl then compare to lesioned ppl
2) Measure brain activity throughout the day / night
3) Measure brain activity while doing a particular activity

Answer 20

1) PET scans –> measures blood flow directly to a brain regions by measuring uptake of radioactive glucose at different areas
2) functional MRI –> measures2 amount of blood O2 in brain
3) EEG–> measures electrical signals produced by brain ( useful for sleep and epilepsy)
4) MEG –> measures magnetic signals prod by brain ( new)

note both EEG and MEG are measured by event related potentials / evoked potentials

Question 21

How to use encephalography ?

Answer 21

place electrodes on head then look at graph produced by event related potentials evoked potentials

if different electrodes are placed at different parts of the body can get a series of waves that reflect sequential activation of neurons along somatosensory pathways and can tell where a problem occurs in the body

( see docs)

Question 22

How do you stimulate the brain to assess cortical function

Answer 22

Assess function of neural circuits –> used electromagnetic induction to stimulate neurons ( TMS / transcranial magnetic stimulation)

Question 23

What is brain stimulation used for

Answer 23

1) investigate neurons controlling movements after a spinal cord injury
2) investigate whether a specific brain area is responsible for a function ie speech

Question 24

What is Transcranial direct current stimulation (tDCS)

Answer 24

Using low direct current over the scalp to increase or decrease neuronal firing rates . can be used to treat epilepsy

Question 25

describe 2 imaging techniques of the brain

Answer 25

Diffusion tensor imaging (DTI) based on diffusion of water molecules

DTI with tractography ( 3d reconstruction to assess neural tracts)