Localisation and Lateralisation

Question 1

What is localisation?

Answer 1

The idea that certain functions are located in different areas of the brain.

Question 2

What is holistic theory?

Answer 2

All parts of the brain are involved in the processing of thought and action

Question 3

What is the motor cortex?

Answer 3

an area at the rear of the frontal lobes that controls voluntary movements

Question 4

What is the somatosensory cortex?

Answer 4

area at the front of the parietal lobes that registers and processes body touch and movement sensations

Question 5

What is the visual cortex?

Answer 5

• Primary visual centre, located in occipital lobe
• Spans both hemispheres
• Processes visual signals.

Question 6

What is the auditory cortex?

Answer 6

• Processes hearing, mainly lies within temporal lobes
• Both hemispheres.

Question 7

What is Broca’s area?

Answer 7

left frontal lobe, speech production.

Question 8

How was Broca’s area identified?

Answer 8

Broca’s patient ‘Tan’ could understand language but could only say one word. This led to the idea that speech had different areas in the brain and he identified the Broca area.

Question 9

What is Wernicke’s area?

Answer 9

left temporal lobe, language comprehension

Question 10

How was Wernicke’s area discovered?

Answer 10

Karl Wernicke worked with people who could produce fluent speech but it was meaningless.

Question 11

How is Peterson 1988 a strength for brain localisation?

Answer 11

Brain scans showed that the Broca area was active during a reading task and the Wernicke was active in a listening task.
-Shows the two areas for language function.

Question 12

How are neurological procedures a strength for brain localisation?

Answer 12

Surgeries to treat OCD and depression show that mental disorders are localised.

Question 13

How are strokes a strength for localisation?

Answer 13

Damage to Broca and Wernickes areas cause aphasia.

Question 14

How is Phineas Gage a strength for localisation?

Answer 14

-Damage to his frontal lobe in an accident where a metal pole was forced through his left cheek into the frontal lobe.
-After the accident, his personality had completely changed, suggesting that personality is localised.

Question 15

Weaknesses of localisation?

Answer 15

-Broca’s area has been show to be active during cognitive tasks.
-MRI scans have identified many language areas, which implies language is more holistic.
-The case studies of phinaes gage and tan are impossible to generalise as one gender.

Question 16

How is Lashley 1930 a weaknesses of localisation?

Answer 16

-Removed the part of rats’ brains that was believed to be localised for learning a route to food.
-However the rats ability to find the food was unaffected.
-This suggest some more complex functions are holistic.

Question 17

What is hemispheric lateralisation?

Answer 17

The idea that the two halves of the brain are functionally different and that certain mental processes and behaviours are mainly controlled by one hemisphere rather than the other.

Question 18

What does contra lateral mean?

Answer 18

Affecting or originating in the opposite side.

Question 19

What is the corpus callosum?

Answer 19

the large band of neural fibres connecting the two brain hemispheres and carrying messages between them

Question 20

Sperry background?

Answer 20

-He worked in a hospital that performed a procedure that involved severing the corpus callosum to treat severe epilepsy.

Question 21

Sperry aims?

Answer 21

To investigate the function of the brain without a corpus callosum.

Question 22

Sperry sampling and experimental method?

Answer 22

-Opportunity.
-Quasi lab conditions.
-Repeated measures.

Question 23

Sperry variables?

Answer 23

IV- whether someone had a corpus callosum or not.
DV- performance in a tactile test.

Question 24

Sperry procedure?

Answer 24

Visual tasks- the participants were asked to focus on a cross on the screen. Words or images were flashed to the right or left on the cross for a 1/10 of a second, so they would only be in one visual field. They were asked to identify the object by drawing and speaking.
Tactile tests- partcipants hold an item in one hand and were asked to identify it.

Question 25

Sperry findings?

Answer 25

VISUAL:
-If presented to right visual field, could be identified with speech (because processed on left, speech is on left).
-If presented to left visual field, could no be identified with speech.
TACTILE.
-When held in right hand, could identify with speech.
FRUIT AND FACES:
-Right visual field= fruit.
-Left visual field= faces (because face recognition is in right side).

Question 26

Sperry conclusion?

Answer 26

Certain functions are lateralised.

Question 27

Strengths of Sperry?

Answer 27

-Highly controlled and standardised- high internal validity.
-Ethical because they already had the procedure.
-Supported by PET scans done by Fink in 1996, shows the dominance of one hemisphere for certain activities.

Question 28

Weaknesses of Sperry?

Answer 28

-Small sample of 11 people- hard to generalise.
-Tasks lack mundane realism- lack external validity.
-11 people had different recovery times.