Neurodevelopmental disorders

Question 1

What two things characterise intellectual disability (ID)?

Answer 1

Impairment in intellectual functioning (IQ less than 70 typically)
Impairment in everyday adaptive abilities –e.g. independent living skills, communication, social participation

Question 2

What is floor effect and when can it occur?

Answer 2

Floor effects occur when even the least difficult items on a test are too difficult for individuals, so participants score zero, or the lowest possible score

Question 3

Why is floor effect a problem?

Answer 3

Having a floor effect means that the test is not sensitive enough to detect differences between individuals with intellectual disability, who are scoring “floor”.

Question 4

How could you adapt cognitive tests for individuals with intellectual disability?

Answer 4

Make test items simpler
Use fewer test items
Use EasyRead documents - large font, pictures, easy vocab
Allow plenty of time
Give model responses
Use simple test instructions - simple vocab

Question 5

What do many studies of intellectual disability use as a comparison population, instead of chronologically age matched controls? and why?

Answer 5

Mental age (MA) matched controls
This accounts for the global intellectual impairment, but ignored importance of experience

Question 6

Name three genetic causes of intellectual disability

Answer 6

Down syndome
Williams syndrome
Fragile X syndrome

Question 7

What brain areas are atypically develoed in Down Syndrome, and how does this map onto the cognitive profile?

Answer 7

Smaller prefrontal contrex - central exetuive functioning impairments (goal oriented behaviours: planning, inhibition, shifting attention)
Small hippocampal volume - memory impairment (particuarly verbal and visual object memory)

Question 8

Which is usually impaired in individuals with Down syndrome?
Dorsal visual stream
Ventral visual stream

Answer 8

Ventral visual stream is impaired, may explain the difficulties with visual object memory

Question 9

What is the link between Down syndrome and dementia?

Answer 9

DS sufferers have a much lower mean age of dementia onset (M=55) than the typically developed population
95% have dementia at 68
The cognitive profile of DS affects the development and presentation of dementia in sufferers

Question 10

What is commonly comorbid in Williams syndrome?

Answer 10

ADHD

Question 11

Is the cognitive profile of Williams syndrome different to or similar to Down syndrome?

Answer 11

Different - verbal ability spared, but visuospatial is impaired in WS, oppostie to DS

Question 12

Which task would ppts with Williams syndrome perform better on, visual span task or spatial span task?

Answer 12

WS ppts would perform better on the visual task (no differcne to MA matched controls) than the spatial task,, as visuospatial abilities impaired

Question 13

Is Fragile X syndrome more common in boys or girls?

Answer 13

FXS is twice as common in boys, due to the presence of only one X chromosome

Question 14

Which is most common and which is rarest?
Down syndrome
Williams syndrome
Fragile X syndrome

Answer 14

Most to least common-
Down syndrome ~40,000 in UK
Fragile X ~12,500 in UK
Willliams syndrome ~3,500 in UK

Question 15

What is commonly comorbid in Fragile X syndrome?

Answer 15

Autism and ADHD