Localisation vs Holism

Question 1

What did Karl Lashley do in 1950?

Answer 1

Lashley removed areas of the cortex (between 10% and 50%) in rats brains; the rats were learning to run a maze.

Question 2

What did Lashley conclude?

Answer 2

He did not find a specific area involved in learning but concluded that it appeared to occur all over the brain.​

He concluded that complex cognitive tasks are supported by the holistic theory of brain function.​

Question 3

Outline a limitation for Lashley’s study from 1950.

Answer 3

May be difficult to apply to humans, as human brain structure differs from a rats.

Question 4

Outline lateralisation in the left hemisphere.

Answer 4

In the majority of people, language is processed in the left hemisphere.

We look to stroke patients for evidence.

If someone has a stroke on the left side of their brain (their left hemisphere) their speech is affected. ​

Question 5

On what hemisphere are Broca’s and Wernicke’s areas?

Answer 5

Broca’s area (responsible for speech production) and Wernicke’s area (responsible for language processing) are found on the left hemisphere (for most people).

Question 6

Where is language lateralised to?

Answer 6

Language ​is lateralised to the left hemisphere.

Question 7

Name something lateralised to the right hemisphere.

Answer 7

Emotion recognition.

Voluntary movement of the left.

Processed sensory visual information from the left visual field.

Question 8

What did Heller and Levy do in 1981?

Answer 8

If a photo has a face that has been split so one half is smiling and the other is neutral, the emotion displayed in the left-hand side of the picture is the emotion recognised by the participant more quickly.

Question 9

What did Narumoto et al state in 2001?

Answer 9

The right hemisphere is dominant in recognising emotions in others.

Question 10

Why is the right hemisphere dominant for emotion recognition tasks, if it’s the left side of the face that is seen quicker?

Answer 10

Because the information detected by the left visual field is processed by the right side of the brain (visual centre, right occipital lobe).

Question 11

The left hemisphere focuses on detail, and the right processes…

Answer 11

overall patterns.

Question 12

What case study did Clarke, Assal, and de Tribolet study in 1993?

Answer 12

The case study of the lady who couldn’t find her way

Question 13

What did Fink, Halligan et al find in 1996?

Answer 13

Found that if you ask somebody to look at a picture and to identify a small detail, there will be a greater level of activity in the left hemisphere than if they look at the picture holistically which prompts more activity in the right hemisphere.

Question 14

What did the brain scans by Peterson demonstrate in 1988?

Answer 14

Demonstrated that Wernicke’s area was active during a listening task and Broca’s area was active during a reading task.

This evidence suggests these areas of the brain have different functions.

Question 15

What did Tulving et al state in 1994?

Answer 15

Semantic and episodic memories reside in different parts of the prefrontal cortex.

Question 16

What can people who suffer with drug-resistance epilepsy have done? What could complicate this?

Answer 16

Psychosurgery. The affected area can be removed.

Alternatively in a small number of people with drug resistant epilepsy, there is more than one focus / areas so more parts of the brain may need removing. ​

Question 17

How have surgeons previously prevented epilepsy in patients?

Answer 17

In the past surgeons have cut the corpus callosum so that keeps the epilepsy in one half of the brain or even removed one hemisphere completely.

Question 18

Who is Cameron Mott, what happened to her when she was 3-years-old?

Answer 18

At the age of three, Cameron Mott contracted a rare and lethal brain disorder known as Rasmussen’s Encephalitis.

Question 19

What was Rasmussen’s Encephalitis doing to Cameron Mott?

Answer 19

This disease was gradually destroying Cameron’s right hemisphere, and by the time she was six years of age, she was experiencing epileptic fits within minutes of waking.

Question 20

Did medicine treat Cameron Mott?

Answer 20

Medication could not effectively treat.

Question 21

What did Cameron Mott have to wear? What changes did Cameron Mott display before surgery?

Answer 21

She spent years wearing a protective helmet.

Went from a normal bubbly and responsive toddler to a child who was flat and tired.

Her personality changed and her ability to learn declined.

Question 22

What happened to Cameron Mott after her surgery? Why was this?

Answer 22

Cameron was partially paralysed on the left side of her body, as the contralateral structure of the brain means that the right hemisphere controlled her left.

Question 23

What happened to Cameron Mott in the weeks following her surgery?

Answer 23

Over the following weeks Cameron participated in intensive post-surgery rehabilitation, and 6 weeks later she walked out of the hospital with half her brain.

Question 24

What happened to her brain after the hemispherectomy?

Answer 24

Cameron’s left hemisphere, being so plastic due to her age, was able to compensate for the loss of her right hemisphere.

The cavity in which the right hemisphere originally was filled with cerebral-spinal fluid in order to support her now single-hemisphere brain.

Question 25

What did Dougherty et al report in 2002? What does this support?

Answer 25

Reported on 44 OCD patients who had undergone a cingulotomy.

At a post-surgical follow-up to the surgery at 32 weeks, 33% had met the criteria for successful response to surgery, and 14% for partial response.

The success of procedures like this strongly suggest that symptoms and behaviours associated with serious mental disorders are localised.​

However, for 2/3 of the PPs, it wasn’t successful. Only the minority responded positively. This suggests that there may be other areas involved in OCD.

This supports a holistic explanation of brain behaviour, (challenging localisation).

Question 26

If the cingulate gyrus has a problem, what may this lead to?

Answer 26

Problems in the cingulate gyrus often lead to an inability to let go of a thought.

Question 27

What is a cingulotomy?

Answer 27

A neuro-surgical procedure that involves lesioning the cingulate gyrus.

Question 28

Outline 2 strengths of Holistic Theory?

Answer 28

Plasticity. Rehab can work particularly well in children, following brain injuries; implying that lateralisation and localisation are not fixed.

Dougherty et al, (2002. Challenges localisation as there are multiple areas that are involved in the OCD ‘worry cycle’. 66% didn’t recover.

Karl Lashley, (1950). Removed areas of the cortex (between 10% and 50%) in rats’ brains. He did not find a specific area involved in learning but concluded that it appeared to occur all over the brain.

Question 29

Outline 3 strengths of Lateralisation and Localisation of Functioning?

Answer 29

Broca, (1861). Localised the believed area for speech production. Modern day technology has identified this as the correct area.

Wernicke, (1864). Saw patients with damage near the auditory cortex had specific language impairments. This is now dubbed ‘Wernicke’s area’, it is important for language comprehension.

Phineas Gage supports the idea of localisation. His personality changed due to damage in the frontal lobe.

GR supports the idea of localisation. She was cortically blind due to damage in her visual cortex.

Dougherty et al, (2002). Challenges the holistic theory, as for 1/3 of the patients the surgery was positive.