Use of the CTOPP to Validate Phonological Processing Ability

Question

Answer

According to the information provided in this question, there may be one specific explanation of observed discrepancies in the scores. First and foremost, the differences between verbal and performance IQ immediately allude to the learning disability. Very high scores for the Verbal IQ represent this student's great vocabulary knowledge and the ability to extract the information presented in a format that requires good oral language skills. The Performance IQ, on the other hand, relies on the integration of visual information, speed of processing and ability to quickly and accurately integrate spatial information. It also requires a good deal of executive function skills that allow someone to systematically and logically arrange this information to achieve the goal of the task.

Although the results of the CTOPP (Comprehensive Test of Phonological Processing) are not that low (and for some students may actually represent rather high skills in the area of phonological awareness and abilities to manipulate small sublexical units within the word structure), it does not appear to be the case in this example. Phonological memory score accounts for the actual skill in transforming an incoming string of sounds into a coherent group representing a word (even if it is a nonword, it is still constructed according to the rules of phonotactics in English language). Most disturbing seem to be the scores for the Rapid Automatized Naming and Rapid Alternate Naming.

One of the reasons that RAN/RAS is such an important test and such a good predictor of reading, is the fact that it assesses all the complex skills required for reading, i.e., knowledge of alphabet, numbers, vocabulary, word retrieval, visual recognition of the stimuli and, yes, the ability to quickly and accurately access visually presented information for the oral retrieval. The Rapid naming requires the "names" of the letters, numbers and colors (sometimes objects) to be retrieved as quickly and as accurately as possible. The standard score of 81 for a student with very high Verbal IQ may imply that there are no stable representations of abovementioned items. It would be very interesting to know the actual scores for each task, because that may show where the deficits are. The higher score for Alternate Naming is understandable, because this particular task includes a mixture of letters, numbers and colors (objects) and depending on the strength in one of the areas, it can pull the scores up. I think this is exactly the reason for a higher score in this subtest.

All in all, I would suspect that this student may have very subtle difficulty with decoding/encoding (or phonological dyslexia), but because of the great oral language skills can compensate when presented with the actual reading task. What is important in this particular case is to find out if there are discrepancies between reading and spelling sight words, regular words that follow known patterns of syllabic structure, and nonwords. The idea of a criterion-reference test is warranted, but it has to be in conjunction with the standardized measures. For example, Woodcock Johnson Reading Mastery or Achievement Test will give both, age-related and grade-related scores. Wilson Assessment of Decoding and Encoding (WADE, a criterion-reference measure) will allow the assessor to figure out the exact relationship between reading sight words, regular words and nonwords. In addition, the WADE gives an extensive list of all possible phoneme/grapheme combinations that will show if there are deficits (if any) in the fundamental knowledge of phonemes and the ability to map them into graphemes. Combining the information gathered from WJ and WADE may give a full picture of this student's skills and may answer some questions regarding the possible intervention. As I mentioned, this particular student is very skillful at compensatory strategies already, but the underlying deep deficits in the area of phonological encoding/decoding may be rather handicapping as the student enters High School.

Editor's Note: CTOPP (Comprehensive Test of Phonological Processing) is published by LinguaSystems.

Dr. Elena Zaretsky, Ph.D., CCC-SLP, is an Assistant Professor in the Department of Communication Disorders at UMass, Amherst. She is part of the team of professors in that department who received a four-year DOE grant to better educate and train graduate students to work with children with Autism Spectrum Disorders (ASD). Her other interest include language learning disabilities and reading acquisition, as well as issues in bilingualism.