Chapter 7: Malfunctioning Brains

Question 1

What is adaptive plasticity?

Answer 1

• Where the brain changes and develops as a result of learning and new experiences.
• AP allows adults to continue developing synapses as a result of experience; stimulating experiences and environment shape the construction and remodeling of a persons brain throughout life.

Question 2

What is developmental plasticity?

Answer 2

The ability of synapses to be modified. Refers to the development and consolidation of neural pathways in babies, children, and adolescents.

Question 3

What can happen as a cause of concussion?

Answer 3

A persons loss of consciousness for a period of time may lead to temporary or permanent memory loss or brain damage (amnesia.)

Question 4

What is aphasia?

Answer 4

The impairment of language caused by damage to the brain (usually by stroke.)

Question 5

What is Broca’s aphasia?

Answer 5

• A type of aphasia that occurs when the Broca’s area is damaged.
• People with this have difficulty expressing themselves in words or sentences but their ability to understand written and spoken language is largely unaffected.
• Their speech is non-fluent, slow, deliberate and effortful.
• They also struggle to find and use correct names for words.

Question 6

What is Wernicke’s aphasia?

Answer 6

• A type of aphasia that occurs when the Wernicke’s area responsible for comprehension of speech, is damaged.
• People with this have difficulty understanding and producing written and spoken language that makes sense to others.
• Their speech is very fluent but makes no sense, they use nonsense, meaningless words that don’t add up in a sentence.
• They also have difficulty finding and using correct names for words.

Question 7

What is spatial neglect?

Answer 7

• A disorder in which the person affected systematically ignores stimuli on one side of their body.
• Most frequently, there is damage on the right side of the brain, such patients failing to be aware of objects or people to their left.
• Eg; when searching through a visual scene, patients with left neglect tend to look at elements on the right only.
• Patients with spatial neglect can see all the items in a scene, but they have problems allocating attention correctly over these objects, especially as the scene becomes crowded.

Question 8

What causes spatial neglect?

Answer 8

Acquired brain damage caused by either:

• stroke
• traumatic brain injury
• brain tumors
• aneurysm.

Question 9

Which lobe is affected by spatial neglect?

Answer 9

• Spatial neglect is most commonly caused if there is damage in the rear of the right parietal lobe.
• It is not as common with left parietal lobe damage, as it is thought that the right hemisphere of the brain is generally more specialized for spatial memory, while the left side is better tuned for language.

Question 10

What is anosognosia?

Answer 10

• The common condition where sufferers of spatial neglect are blissfully unaware of their deficit.
• Eg; an individual with anosognosia may get ready to go out and only brush the hair on one side of their head, or apply makeup to only one side of their face, or arrive at school wearing only one shoe, etc, and feel completely normal about it.

Question 11

What is pseudoneglect?

Answer 11

• The leftward attentional bias most neurologically normal individuals display.
• This bias causes us to bisect lines slightly to the left of the true centre, the left side of space being favoured, making leftward errors as well as in the judgment of brightness, numerosity, and size.
• A possible explanation related the fact that the right hemisphere is more involved in visual-spatial tasks, relating in us to be more likely to be attuned to objects in our left visual field.

Question 12

What animal models are currently being researched?

Answer 12

• Alzheimer’s disease
• Parkinson’s disease
• Huntington’s disease
• Lateral sclerosis

Question 13

What are ethics regarding animal research?

Answer 13

-A controversial debate continuing over whether or not the suffering endured by research animals is justifiable.

Question 14

How has animal research and its ethics benefitted us?

Answer 14

• Animal subjects being used in current research adds to our knowledge about disease and disorders.
• This furthers our ability to develop effective treatments, eg. The effective treatment of epilepsy in patients who did not respond to medication.

Question 15

What is Parkinson’s disease?

Answer 15

• A neurodegenerative disorder that affects the way you move.
• It is characterised by the degeneration of dopamine levels in the ‘basal ganglia’ (located in the midbrain), leading to dopamine deficiency in the CNS.

-People who develop this disorder present motor symptoms such as; slowness of movement, rigidity, and involuntary tremors.
Non-motor symptoms include; pain, depression, dementia, trouble sleeping.

Question 16

What causes Parkinson’s disease?

Answer 16

-Low and falling dopamine levels (primarily.)
-Aging
It is common for Parkinson’s to begin around 65 years of age, the degeneration progressing over a 15 year period.
-Genetics
Activated by a combinations of genetic and environmental factors (nature and nurture). Abnormal genes seem to lead to Parkinson’s disease in some people.
-Environmental factors
Poisons in the environment such as MPTP- a common contaminant found in street drugs has been found to cause Parkinson’s disease in users.
-Drugs and diet
Consumption of caffeine has been found to decrease the risk of developing Parkinson’s disease. Also, a deficiency in vitamin B has been linked with the development of the disease.

Question 17

What treatment is there for Parkinson’s disease?

Answer 17

• Medication (L-DOPA) that increases dopamine levels and other dopamine agonists that mimic dopamine.
• Healthy diet and some forms of rehabilitation.
• Deep brain stimulation (DBS) where surgeons implant electrodes into a specific part of the brain, sending electrical pulses to the brain.
• Stem cell treatment.
• Gene therapy.