Focus on: Cognition and Prader-Willi syndrome

Guest post by Karra Harrington, BAppSc(Psych) (Hons), MPsych(Clinical), currently PhD student at Florey Institute of Neuroscience and Mental Health and the Cooperative Research Centre for Mental Health.

Why is cognitive testing for children with Prader-Willi syndrome important?

The majority of children with PWS have learning disabilities and difficulties with specific thinking skills, like language or memory. Many may also score in the mild to borderline ranges on IQ testing, showing low results on tests of intellectual functioning (e.g. solving puzzles or knowing about words).

Importantly, even when performing at expected levels on intellectual testing, specific difficulties with learning and thinking skills often still develop for these children. Limitations with social skills and managing emotions are also part of the syndrome and may make it more difficult for the child to learn and develop their thinking skills, particularly as much of school learning is socially based.

What's the difference between a cognitive assessment and an IQ test?

IQ tests involve a series of tasks that are used to determine an individual's intelligence quotient, which is a number representing that individual's general reasoning ability relative to others their same age. These tasks usually involve tests of verbal and visual reasoning, working memory, and processing speed. An individual's IQ tends to remain relatively stable across their life despite new learning and experiences, and for children can be a useful indicator of their general reasoning abilities relative to peers their same age.

In contrast, a cognitive assessment measures specific areas of brain function or thinking skills. This may include, but is not limited to, tests of motor skills, perception, attention and concentration, planning and problem solving, as well as considering aspects of behaviour. A cognitive assessment may not result in a numeric score but will often identify specific strengths and weaknesses for the individual in terms of their thinking and behaviour. Importantly, cognitive function does change over time, particularly for children as they grow and develop.

What is involved in a cognitive assessment?

Cognitive assessments are typically conducted by a psychologist with specialist training, such as a neuropsychologist or an educational and developmental psychologist. An assessment often takes several hours and may be conducted over multiple sessions to ensure the comfort of the child and accuracy of the testing. Tasks may be in verbal, visual, or written formats depending on the child's age and abilities. Often tasks involve activities such as puzzles, playing with blocks, drawing pictures, reading or writing. Following the assessment, usually the psychologist will meet with parents or guardians to discuss results of the assessment and answer any questions, as well as to provide specific strategies to assist the child at home and school based on the results. A written report detailing this information will also typically be provided.

Why should children with Prader-Willi syndrome undergo cognitive assessments?

Cognitive assessments provide a means to determine the specific difficulties each child has, as well as their specific strengths. Prader-Willi is a syndrome, meaning that each person is affected differently, so knowing this information is vital and will enable the development of an individualised plan to assist the child to help reach their maximum potential.

Although specific difficulties will vary between children, the most common skills affected are:Short-term memory (the ability to keep new information in mind over a short time)

  • Sequential processing (the ability to process pieces of visual or auditory information in a specific order)
  • Receptive and expressive language (the ability to understand and use language to communicate both written and verbally)
  • Self-monitoring (the ability to keep track of what you're doing and recognise mistakes).

Children with difficulties in these areas may have trouble following the meaning of a sentence or story when reading or being read to, following a series of instructions, or understanding the concept of later. Additionally, children may be quick to answer 'I don't know' to questions or use very generic language, and may not notice when they make mistakes or miss a step in a task. However, children with PWS will also have relative strengths that can be used to assist them to overcome these difficulties. For example, children with PWS often do better when information is provided visually rather than verbally, and understand concrete concepts (e.g. the meaning of a word) better than more abstract ones (e.g. synonyms of a word).

Is there anything I can do to help build my child's cognitive ability?

Due to the range of difficulties experienced by children with PWS, strategic to build or support their cognitive ability need to be tailored to the individual in order to be most effective. The strengths of the child should be emphasised and can be used to assist with overcoming some of the difficulties. The following strategies may be generally helpful to assist with the more commonly expressed difficulties:

  • Break information or instructions down in to small chunks and only give them to the child one or two at a time, instead of a whole list.
  • Provide visual aids for information presented e.g. write down a checklist, provide pictures as well as words.
  • Repeat instructions or information as often as necessary, and encourage the child to ask for repetition or help rather than saying 'I don't know' or giving up on a task.
  • Check that they understand and explain further if required.
  • Avoid using idioms or figurative language (e.g. say 'keep quiet' rather than 'put a lid on it').

Children with PWS also often experience a range of social and emotional difficulties which may limit their ability to reach their cognitive and academic potential if not addressed. It is therefore important that children are supported and given opportunities to develop social and emotional skills, as well as academic skill. Support should be provided in a consistent and routine manner across the different settings the child is in (e.g home, school etc). Routine and consistency will help minimise anxiety and stress for the child by allowing them to build an understanding of what is expected both of themselves and those around them.