1.6 Positive indicators for dyslexia
Dyslexia is recognized if the person shows various core behavioural symptoms or other features associated with dyslexia.
As mentioned in the previous section, contemporary approaches also involve identifying positive indicators that signal potential dyslexia by their presence. Dyslexia involves specific weaknesses in areas that relate to written language, but because it is not associated with a general lack of ability it also often involves compensatory strengths. For example, Alexander Faludy was verbally gifted from a young age (see the Case Study in section 1.3). For this reason, in addition to assessing the discrepancy between ability and written language skills, psychologists usually take particular note of the profile of strengths and weaknesses on cognitive tests. Discrepancies between verbal and non-verbal IQ may be significant. People with dyslexia often show lower verbal than non-verbal ability, but the reverse pattern is also found, illustrating the variability within dyslexia. Particular profiles on the sub-tests of IQ assessments have been suggested as characteristic of dyslexia. One such profile emphasises deficits on Arithmetic, Coding, Information (general knowledge) and Digit Span (short-term memory capacity) sub-tests. This is called the ACID profile (Thomson and Grant, 1979). However, not all children diagnosed show deficits in all these areas. Bannatyne (1971) advocated grouping the sub-tests according to the kinds of abilities they tap. Studies using this procedure suggest that dyslexic people typically show a profile of above average spatial and conceptual abilities, and below average sequential abilities and acquired knowledge. However, none of these procedures results in clear diagnosis, again emphasising the variation within any dyslexic population.
Behaviours that are indicative of dyslexia include a mixture of weaknesses and strengths, with some factors related to reading and writing, and others apparently unrelated. For example, among his list of positive indicators, Tim Miles (1983) cites directional confusions, poor auditory sequential memory, problems with word repetition and other members of the family with reading or writing problems. Screening for dyslexia usually includes assessments of a wide range of skills, such as visual and auditory perception, integration of different types of sensory information, and aspects of motor function such as balance. If dyslexia really is a neurodevelopmental syndrome, it is highly implausible that this would only affect written language skills, and the evidence does implicate a broader range of abilities. Kinsbourne et al. (1991) assessed dyslexic and non-dyslexic adults on a wide range of neuropsychological tests. They found many differences on tasks bearing no apparent relation to reading, such as rapid alternating movements of the hands or feet, and judging which came first of two simple auditory or visual stimuli presented in quick succession.
Miles (1983) has argued that dyslexia should not be seen as a form of reading disability but as a syndrome: a set of symptoms with a neurological basis. Although each of these individual ‘signs’ (such as problems telling left from right) may also be found in some people with a ‘normal’ reading ability, the presence of more than a certain number of these indicators would suggest a dyslexic profile. When used together with standardised measures of reading and spelling, these kinds of screening measures can provide useful information to guide both research and educational practice.
Simple examples of assessments that focus on positive indicators rather than discrepancies are the checklists often used for initial screening before a formal dyslexia assessment takes place. Table 1 shows the one used by the British Dyslexia Association.
Table 1 British Dyslexia Association – adult dyslexia checklist (1994)
|1||Do you find difficulty telling left from right?|
|2||Is map reading or finding your way to a strange place confusing?|
|3||Do you dislike reading aloud?|
|4||Do you take longer than you should to read a page of a book?|
|5||Do you find it difficult to remember the sense of what you have read?|
|6||Do you dislike reading long books?|
|7||Is your spelling poor?|
|8||Is your writing difficult to read?|
|9||Do you get confused if you have to speak in public?|
|10||Do you find it difficult to take messages on the telephone and pass them on correctly?|
|11||When you have to say a long word, do you sometimes find it difficult to get all the sounds in the right order?|
|12||Do you find it difficult to do sums in your head without using your fingers or paper?|
|13||When using the telephone, do you tend to get the numbers mixed up when you dial?|
|14||Do you find it difficult to say the months of the year forwards in a fluent manner?|
|15||Do you find it difficult to say the months of the year backwards?|
|16||Do you mix up dates and times and miss appointments?|
|17||When writing cheques do you frequently find yourself making mistakes?|
|18||Do you find forms difficult and confusing?|
|19||Do you mix up bus numbers like 95 and 59?|
|20||Did you find it hard to learn your multiplication tables at school?|
Nine or more ‘yes’ responses on the questionnaire could be indicative of dyslexia-type difficulties.
(Source: Vinegrad, 1994)
You may answer yes to several of these questions, but not have dyslexia. This is why they are termed ‘indicators’ and are only used for screening purposes. They cannot ‘diagnose’ dyslexia on their own, and must be used in conjunction with background information and a psychometric assessment.
The need for a balance between identifying dyslexia by a discrepancy between potential and actual achievement, and by the presence of clear symptoms is reflected in a more recent definition from the Orton Dyslexia Society, now known as the International Dyslexia Association:
It is a specific language-based disorder of constitutional origin characterized by difficulties in single word coding, usually reflecting insufficient phonological processing abilities. These difficulties in single word coding are often unexpected in relation to age and other cognitive and academic abilities; they are not the result of generalized developmental disability or sensory impairment. Dyslexia is manifested by variable difficulty with different forms of language, often including, in addition to problems of reading, a conspicuous problem with acquiring proficiency in writing and spelling.
(Miles and Miles, 1999, p. 169)
ACID profile: Refers to the observed deficit in arithmetic, coding, information (general knowledge) and digit span (short-term memory) that is associated with dyslexia by some researchers.
Syndrome: A combination of symptoms which regularly occur together and may have a shared neurological basis.