Biopsychology: localisation and function in the brain

Question 1

What is meant by localisation of function?

Answer 1

The theory that different areas of the brain are responsible for specific behaviours, processes or activities

Question 2

What is the holistic theory?

Answer 2

Where all parts of the brain are responsible for all functions

Question 3

What is lateralisation?

Answer 3

Certain functions are mainly controlled by one hemisphere, either the left or right.

Question 4

Motor area

Answer 4

• located at back of frontal lobe
• controls voluntary movement in the opposite side of the body
• damage= loss of control over fine movements

Question 5

Broca’s area

Answer 5

• located in the left of frontal lobe
• responsible for speech production
• damage= Broca’s aphasia (speech that is slow & lacks fluency)

Question 6

Wernicke’s area

Answer 6

• located in the left of temporal lobe
• responsible for language understanding
• damage= Wernicke’s aphasia (produce nonsense words during their speech)

Question 7

Auditory area

Answer 7

• located in the right temporal lobe
• analyses speech-based information
• damage= partial hearing loss or affect ability to comprehend language (Wernicke’s area)

Question 8

Visual cortex

Answer 8

• located at back of occipital lobe
• each eye sends info from the RVF to RVC & LVF to RVC (right visual cortex)
• damage to LH= blindness in part of RVF of both eyes

Question 9

Somatosensory area

Answer 9

• located at front of both parietal lobes
• separated from motor area by a ‘valley’ called the central sulcus
• sensory info from skin is represented
• receptors from face & hands occupy over half of somatosensory area

Question 10

EVALUATION: Strengths

Answer 10

+ Evidence from neurosurgery
- damage to areas of brain linked to mental disorders
- Dougherty et al reported on 44 people with OCD who had undergone a cingulotomy
- post surgical follow up= after 32 weeks, about 30% met criteria for successful response to surgery
- suggests that behaviours associated with serious mental disorders may be localised

Question 11

EVALUATION: Limitations

Answer 11

Case studies
- unique case studies cannot be generalised
- difficult to make meaningful generalisations from findings of a single individual
- conclusions drawn may depend on the subjective interpretation of researcher

Question 12

EVALUATION STRENGTH: How does the Case of Phineas Gage support localisation?

Answer 12

• was helping to layer a railway track
• iron rod went through his left cheek passing behind his left eye taking away most of his left frontal lobe (responsible for decision making & emotional control)
• however he still survived
• when removed his friends said he had a different personality - quick-tempered, rude and was ‘no longer Gage’

Shows that different parts of the brain are responsible for different functions= frontal lobe may be responsible for regulating mood

Question 13

How does Lashley’s research challenge the localisation theory and support the holistic theory?

Answer 13

• removed areas of the cortex (between 10% and 50%) in rats that were learning the route through a maze
• no area was proven to me more important
  (in terms of rats’ ability to learn the route)
• process of learning seemed to require every part of the cortex rather than being confined to a particular area
• suggests that higher cognitive processes, (e.g. learning) are not localised BUT distributed in a more holistic way in the brain