biopsychology: localisation of the brain

Question 1

What does holistic theory suggest

Answer 1

all parts of the brain were involved in thought and action processing

Question 2

Who argued for localisation of function in the brain?

Answer 2

Broca and Wernicke

Question 3

What is localisation of function?

Answer 3

the idea that different parts of the brain perform different tasks

Question 4

What happens if a certain area of the brain becomes damaged?

Answer 4

The function associated with that area will also be affected

Question 5

How is the brain divided?

Answer 5

Into two symmetrical halves: left and right hemispheres

Question 6

explain localisation

Answer 6

our physical and psychological functions are controlled or dominated by a particular hemisphere

Question 7

Which hemisphere controls the left-hand side of the body?

Answer 7

Right hemisphere

Question 8

Which hemisphere controls the right-hand side of the body?

Answer 8

Left hemisphere

Question 9

How many lobes is the cortex of both hemispheres subdivided into?

Answer 9

Four lobes

Question 10

List the four lobes of the brain.

Answer 10

• Frontal Lobe
• Parietal Lobe
• Temporal Lobe
• Occipital Lobe

Question 11

outline the motor area

Answer 11

• located at the back of the frontal lobe > in both hemispheres
• Controls voluntary movement in the opposite side of the body
• Damage to this area may result in a loss of control over fine movements

Question 12

If damage occurs to the motor area in the left hemisphere, which side of the body is affected?

Answer 12

Right side

Question 13

outline the auditory area

Answer 13

• in the temporal lobe > in both hemispheres
• Analyses speech-based information
• Damage may produce partial hearing loss >
  the more extensive the damage the more extensive the loss
• Information from the left ear goes primarily to the right hemisphere and information from the right ear goes primarily to the left hemisphere.

Question 14

Which hemisphere receives information from the left ear primarily?

Answer 14

Right hemisphere

Question 15

Which hemisphere receives information from the right ear primarily?

Answer 15

Left hemisphere

Question 16

outline the somatosensory area

Answer 16

• at the front of the parietal lobes > in both hemispheres
• Where sensory information from the skin is
  represented
• The amount of somatosensory area given to a
  particular body part indicates its sensitivity, for
  instance receptors on our face and hands occupy
  over half of the somatosensory area.

Question 17

outline the visual area

Answer 17

• in the Occipital lobe > in both hemispheres
• 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
• Damage to the left hemisphere for example can produce blindness in part of the right visual field of both eyes.

Question 18

How does each eye send information to the visual cortex?

Answer 18

From the right visual field to the left visual cortex and from the left visual field to the right visual cortex

Question 19

what hemisphere is Broca’s area in

Answer 19

left hemisphere

Question 20

outline Broca’s area

Answer 20

• Broca identified a small area in the frontal lobe responsible for speech production.
• Damage to Broca’s area causes Broca aphasia

Question 21

explain Broca’s aphasia

Answer 21

characterised by speech that is slow, laborious and lacking in fluency

Question 22

what hemisphere is Wernivcke’s area in

Answer 22

left hemisphere

Question 23

outline Wernicke’s area

Answer 23

• Wernicke identified an area in the temporal lobe as being responsible for language comprehension.
• Damage to Wernicke’s area produces Wernicke’s aphasia

Question 24

explain Wernicke’s aphasia

Answer 24

patients have no problem producing language but their speech is meaningless, they produce nonsense words

Question 25

AO3: evidence against localisation > Lashley

Answer 25

There is evidence against localisation of function Learning is not controlled by one specific area of our brain. **Lashley has supported this claim by removing different areas of rats brains (10- 50%),** whilst the rats were learning a maze. **No area was proven to be more important,** the process of **learning seemed to require every part of the cortex**, rather than being confined to a particular area. WEAKNESS as this seems to suggest that learning is **too complex to be localised**. Therefore contradicting the localisation of function theory COUNTER: Rats learning a maze **cannot be generalised to the complex learning that we see in humans** on a day to day basis. We are therefore reducing this behaviour down to a simple experiment. As a result we cannot conclude that different parts of the brain have a specific function such as learning.

Question 26

AO3: research to support localisation

Answer 26

There are studies to support localisation theory **Phineas Gage** was a railroad worker, whose job was to pack dynamite into the ground, one day the dynamite exploded forcing a **metal rode through his head** and out the other side, causing permanent **damage to his left frontal lobe**. After the incident his friends believed **his personality had completely changed.** STRENGTH as this supports the idea that functions are localised as is suggests the **personality may be located in the frontal (left) lobe.** COUNTER: **Researchers should not attempt to make generalisations based on case studies.** This **study is too unique**, there is a lack of consistent findings for this claim, questioning the reliability. For instance **Gage’s personality may be due to the overall trauma** of the incident rather than the function of the frontal lobe. As a result we cannot conclude that different parts of the brain have a specific function

Question 27

AO3: research against localisation

Answer 27

There is research against the localisation of function theory **Dronkers et al**. (2007) conducted an **MRI scan on Tan’s brain, (he has problems with speech production)** to try to confirm Broca’s findings, that language production resides in the left frontal lobe. Although there was a lesion found in Broca’s area, they also **found evidence of lesions (damage) in other areas of his brain**. As there is damage to multiple areas of his brain, **it can not be concluded that language production is located to this one area of the brain**, the frontal lobe. WEAKNESS as Broca’s findings have therefore **proven to be unreliable** and we cannot conclude that language is localised to a specific area of the brain. EXPAND: Additionally advances in brain imaging techniques such as fMRI mean that neural processes in the brain can be studied with more clarity than ever before. It seems that **language function is distributed far more holistically in the brain** than first thought. Language streams have been identified across the cortex, including brain regions in the right hemisphere as well as subcortical regions such as the thalamus