2.2 - Biopsycholgy (set C - The Brain)

Question 1

What is meant by localisation of brain function?

Answer 1

Certain/different areas of the brain are responsible for different behaviours, processes or activities

• phinease gage (case study) - first patient who learned something about relation between personality and function of the front parts of the brain
• social and well-balanced personality changed to disrespectful, impatient and stubborn

Question 2

Outline and explain the role of the motor cortex?

Answer 2

• responsible for generation of voluntary motor movements
• located in frontal lobe on both hemispheres - motor cortex on right hemisphere controls muscles on left side of body and same for left motor cortex (different parts of cortex controls different parts of body - arranged logically)
• damage to area may result in loss of control over fine movements

located at the back of frontal lobe

Question 3

Outline and explain the role of the somatosensory cortex?

Answer 3

• detects sensory events from different regions of the body - involved in processing of sensory info related to touch (different area of body have more receptors and thus more sensitive)
• both hemispheres have a somatosensory cortex - cortex on one side receives sensory info from opposite side of body
• allows us to feel and produce sensations of pain, temperature and pressure

located in the partial love at the back of the motor cortex

Question 4

Outline and explain the role of the visual cortex?

Answer 4

• nerve impulses from retina travels via optic nerve to back of brain
• each eye sends information from the right visual field to the left visual cortex and from the left visual field to the right visual cortex
• visual cortex contains different areas that process different types of visual info (colour, shape and movement)
• located in occipital love

Question 5

Outline and explain the role of the auditory cortex?

Answer 5

• begins in cochlea in inner ear - sound waves converted to nerve impulses which travel to auditory cortex (via auditory nerve) stops briefly at brain stem (undergoes basic decoding) and to the thalamus which acts as a relay station before arriving at auditory cortex
• sound largely decoded by the point it reaches auditory cortex allowing for an appropriate response
• damage to area may produce hearing loss

located in temporal lobe

Question 6

Outline Karl lashleys belief about the brain?

Answer 6

• higher cognitive functions such as processes involving learning are not localised but distributed in a more holistic and interlinked way in the brain
• investigated this with rats which were taught to complete a maze (no matter the part of the cortex removed, the rats kept at least partial memory of the maze - suggesting memory did not lie in specific parts of the brain but within a number of locations within the cortex)

Question 7

What can be concluded from Karl lashleys research with rats and the maze?

Answer 7

• concluded memory did not lie in specific parts of the brain - resides instead throughout a number of locations within the cortex (evidence from the fact the rats maintained memory despite areas of cortex being removed)
• no area proven to be more important than any other

Question 8

Outline and explain the role of Broca’s area?

Answer 8

• area of brain which allows us to produce speech (moves muscle required to speak) - damage to area results in inability to produce speech (broca’s aphasia) - reading and writing not as affected
• broca’s aphasia - characterised by trouble with speech (short and simple sentences)

located at the back of frontal lobe - only in left hemisphere

Question 9

Outline and explain the role of wernickes area?

Answer 9

• involved in interpretating and understanding speech (called language comprehension area)
• vital for locating appropriate words from memory to express meaning
• wernickes and Broca’s areas are connected by a neural loop

located in temporal lobe next to primary auditory cortex - only in left hemisphere

Question 10

Outline and explain the case study involving Broca’s area?

Answer 10

• patient called Tan who was unable to speak any words except Tan (understood language)
• MRI scan on Tans brain found a lesion in Broca’s area and there was evidence to suggest other areas had deficits and may have contributed to failure in speech production
• results suggest Broca’s area may not be the only region responsible for speech production

Question 11

Define hemisphere lateralisation?

Answer 11

Hemispheres of the brain are not the same, they specialise in specific mental processes

• for example language which is only involved with the left side of the brain - both localised (broca’s and wernike’s) and lateralised (left side of temporal and frontal lobe)

Question 12

Define hemispheric lateralisation?

Answer 12

Hemispheres of the brain are not the same but functionally different

• each hemisphere specialises in specific mental processes (eg left dominant for language and right excels at visual motor tasks)

Question 13

Define brain plasticity?

Answer 13

The brains ability to change and adapt at a cellular level because of experience (everything external to you which you might engage with like driving, playing a musical instrument etc)

• structure does not change but the neuron’s, synapses and neural pathways constantly change (die out if no longer used)

Question 14

Outline the case study Turk et al on localisation - what does it suggest?

Answer 14

• patient JW, who suffered damage to the left hemisphere but developed the capacity to speak in the right hemisphere - eventually able to speak about information presented to either side of the brain

** suggests that localisation is not fixed and that the brain can adapt following damage to certain areas**

Question 15

Outline 4 AO3 points regarding localisation?

Answer 15

• brain is complex - no one part acts independently of rest - strict localisation impossible
• some functions more localised than other - eg somatosensory and motor functions highly localised compared to more complex functions like personality and consciousness
• human case study support - eg broca’s aphasia seen in patients
• limitations regarding methods/scanning techniques used to investigate localisation

Question 16

Define split-brain research?

Answer 16

Research on people who’ve had their brains split in half - through severing of the corpus callosum (done to treat severe epilepsy)

• research from sperry and gazzaniga

Question 17

Outline split-brain research conducted by sperry and gazzaniga?

Answer 17

• used the fact information from LVF goes to right hemisphere and RVF goes to left hemisphere
• corpus callosum cut in split brain patients so information presented to one hemisphere can not travel to other

Question 18

Outline the procedure into split-brain research conducted by sperry and gazzaniga?

Answer 18

• patient fixates on a dot in centre of screen (information presented to either left or right visual field)
• asked to make responses with either left hand or right hand (controlled by opposite hemisphere) or verbally (controlled by left hemisphere)

Question 19

Outline findings from split-brain research conducted by sperry and gazzaniga?

Answer 19

• If patient was flashed a picture of a dog to the right visual field and asked what they saw they replied ‘dog’ - when picture of ‘cat’ was flashed to left visual field they would say they see nothing
• information from LVF is processed by right hemisphere but it has no language centre - cannot respond verbally (left hemisphere does not receive information about seeing cat, cant say they’ve seen it)

Question 20

Explain what we have learned from split-brain research?

Answer 20

• discovered a number of differences between the 2 hemispheres (left hemispheres is responsible for speech and language and the right specialises in visual-spatial processing and facial recognition
• suggests connectivity between the different regions is important as the operation of different parts

Question 21

evaluate split-brain research - give 2 points?

Answer 21

• issues with generalisation - unusual sample of people (history of severe epilepsy) - some patients experienced more disconnection of hemispheres due to differences in surgical procedure
• recent research disconfirms findings - case study of patient JW who developed ability to speak out or right hemisphere (challenges idea right hemisphere unable to handle language)

-

Question 22

evaluate research into brain lateralisation - give 2 points?

Answer 22

• main strength of hemispheric lateralisation is increased neural processing capacity - using only 1 hemisphere to engage in tasks leaves the other free to engage in another function - Rogers research found in chickens that brain lateralisation is associated with enhanced ability to perform to tasks simultaneously
• disadvantage - associated with lateralisation - people with superior-right hemispheric skills likely to be left handed and suffer higher rates of allergies and problems with immune system

Question 23

Explain contrasting research into lateralisation by Szaflarki?

Answer 23

• found that language became more lateralised to the left hemisphere with increasing age in children and adolescents, but after the age of 25, lateralisation decreased with each decade of life
• raises questions about lateralisation eg whether everyone has one hemisphere that is dominant over the other and whether this dominance changes with ag

Question 24

Give 4 key points surrounding split-brain research?

Answer 24

• There are differences between the two hemispheres
• LH responsible for speech and language
• RH specialises in visual-spatial processing and facial recognition
• Connectivity is as important as the functions of specific parts

Question 25

Explain how neuroplasticity works within the brain?

Answer 25

• describes the brains tendency to modify the structure and function of the brain based on experience.
• occurs in babies, children and adults
• each time you learn something new, synaptic connections and neural pathways are formed - the less you use a neural pathway the weaker it gets until its eventually deleted (synaptic pruning)

brain is in a continual state of change from growth in early years to change and refinement in adulthood

Question 26

Outline the study conducted by magquire into brain plasticity - how did she conduct it, what was found?

Answer 26

Study conducted by looking at taxi drivers in London (who are tasked with having to remember all the streets and places in London) involved around 16 drivers (all men)

• brain scan conducted - showed a particularly large posterior hippocampus (region responsible for 2D spatial processing) which correlated with years of experience (Larger in drivers of over 40 years)
• suggests brain is mailable and changes with what you put into it
• gives insight into what can happen when learning information - can be used to help stroke victims

Question 27

Outline the study conducted by elbert into brain plasticity - how did she conduct it, what was found?

Answer 27

Looking at professional violinists who have finger dexterity in their left hand (much less dexterity required in right hand)

Brain scans of somatosensory cortex revealed an unusually large region devoted to fingers on the left hand (much larger than region for right hand)

asymmetry suggests brain has responded to demands placed upon it - adapts by recruiting more neurones to help support finger control in left hand

Question 28

Explain how plasticity can be negative?

Answer 28

If what you are doing is a negative it leads to new pathways which support negative behaviour

• for example drug use - can lead to changes in behaviour

Question 29

Explain the link between functional recovery and brain plasticity?

Answer 29

Functional recovery - the transfer of functions from a damaged area of the brain after trauma to other undamaged areas - enabled by the brain having plasticity

neuronal unmasking

Question 30

Explain what neuronal unmasking is?

Answer 30

Activation of ‘dormant’ synapses to compensate for damaged areas of the brain - the synapses receive higher input due to damage elsewhere - opens up new neural pathways

• speech and physical therapy help provide input into the brain -

Question 31

Explain what axonal sprouting is?

Answer 31

New nerve endings grow and connect with undamaged areas - creates new pathways around the damaged area

• reformation of blood vessels which connect around neural pathways
• done through continued therapy

Question 32

Explain what recruitment of homologous areas is in regard to functional recovery?

Answer 32

Recruitment of similar areas on the opposite hemisphere to do specific tasks (eg if Broca’s area was damaged an area on the right may take over)

Question 33

Explain why functional recovery is impacted by gender?

Answer 33

Research has shown women recover faster than men

• this is possibly because women are likely to be more willing to accept therapy - where as men are not
• that recovery slows with age

Question 34

Explain the role of cognitive level/educations impact on functional recovery - use research support?

Answer 34

• 769 patients studied - 214 achieved disability-free recovery (DFR) after 1 year
• 39% of patients with 16 or more years of education had achieved DFR compared to just 9% with less than 12 years of education

concluded that cognitive reserve could be a factor in neural adaption during recovery