Why Cognitive Testing May Not Give You All the Answers
Why Testing Doesn't Always Tell the Whole Story
During my tenure at Park Academy, my time at the New Vision Autism Center, and now here at BrainWorks, I have read over a thousand psycho-educational, psych or neuropsych reports. The testing done for these reports is generally extensive and provides information about a child's cognitive abilities and academic performance. Parents seek out testing to help understand, generally, why their child is struggling and how to help them.
Although there can be very helpful information contained in the testing data, it does not tell the whole story and generally, what is provided at the end of the report are ways to accommodate the challenges highlighted in the testing with no path forward to help improve them.
Let's look at a couple of examples to help explain this idea.
Example 1: Sarah, age 10
Sarah is struggling with reading and writing. She is easily overwhelmed at school and is starting to engage in work avoidance. She was in OT and speech as a preschooler and has always been sensitive to clothing textures and sounds.
Her cognitive testing, conducted by the school psychologist, provided the following results:
Verbal comprehension: SS 125
Visual-Spatial: SS 102
Fluid Reasoning: SS 97
Processing Speed: SS 74
Working Memory: SS 85
Sarah's overall IQ is in the average range. Looking at the chart below, she has some really good strengths, including verbal comprehension, which is well above average (85-115).
Comprehensive Test of Phonological Processing provided the following scores:
Elision: SS 90
Blending: SS 87
Phoneme Isolation: 72
The school team meets with you and explains that her overall scores are in the average range, which is great news. However, that is not the whole story. Notice the huge discrepancy between her verbal comprehension and processing speed? That is a 50-point difference. In the land of testing, that is clinically significant. In addition, her working memory is very impacted in relation to her other scores. Working memory is a subset of executive functioning, which the school did not assess (they can't, this can only be done by a neuropsych) and may point to a more global challenge in executive functioning.
Why does that matter?
Executive functioning, as I've written about before, is a broad range of skills including attention, sustained attention, divided attention, auditory and viual attention, task switching, inhibition, organization, planning, impulse control, and more. WOW! Housed in the pre-frontal cortex, the last part of the brain to develop, EF is the CEO of the brain and keeps everything running in a coordinated and efficient matter. Deficit in areas of EF can tremendously impact reading, writing (huge demand on working memory), task completion, auditory processing, and more . In other words, academics will suffer.
Furthermore, looking at Sarah's processing speed, we can see that her overall cognitive processing is quite slow and it takes her a lot longer to process incoming and outgoing information than the average child. But that's not the whole story. Look at her phonological processing. See how impacted her scores are there, particularly phoneme isolation? Phonemic awareness is the basis of all reading. In addition, poor phonological processing means that the speed at which her sensory information (auditory, visual, vestibular, and proprioceptive) information is being processed is very slow. Sensory processing is about survival. If the brain can't accurately and efficiently process incoming sensory information, its human might be in danger, so this is a priority. When this happens, it will slow down overall cognitive processing.
Her history of tactile (proprioception) and auditory sensitivity supports this interpretation. The first sense to develop is proprioception. All other senses are dependent on it. So, if there are deficits in proprioception which develops in utero, all other senses that develop after it will be impacted. The brain develops from the bottom up and in a specific pattern, so each piece of development has to be fully realized for the next stage to develop correctly.
Now we can view Sarah through a different lens. Her underactive sensory system is not delivering information efficiently to the thalamus, temporal lobe, and visual cortex. The PFC is not getting its relevant information from the thalamus to act on it. Disorganization in the lower levels of the brain is impacting functioning the higher orders where learning, speech, and EF occur.
Example 2: Josue, Age 14
Josue is a very bright student. He works very hard. He is quick to engage in classroom discussions, is a proficient writer, and is in the highest level of math. Diagnosed with dyslexia in fourth grade, after a year of Orton-Gillingham instruction, he caught up and by the end sixth grade, he was reading at grade level. Although he was functioning very well at school, he found reading to be laborious and felt like he couldn't remember anything he read, but everything he heard.
His parents pursued a neuropscyh eval and had a full evaluation of his executive function. His cognitive testing produced the following scores
Verbal comprehension: SS 125
Visual-Spatial: SS 130
Fluid Reasoning: SS 110
Processing Speed: SS 114
Working Memory: SS 108
On the DKEFs, nearly all of his scores were in the average range except one-Trailmaking. Trailmaking involves using a pencil and tracing from letter to letter and then alternating letters and numbers. They are spread out all over the page in a random pattern. His SS on this test of 72!
Josue's cognitive scores are outstanding! This student has remarkable cognitive strengths. Looking at his executive functioning, overall he is well within the average range except for this one subtest. Why does this one matter? This is the only test that requires quick visual processing and visual tracking. When I saw this score, I pulled a similar test from the CAS and gave it to him in my presence. It was remarkable to see how hard that was for him. I then asked him to track a pencil in multiple directions and that was also poor. I referred them to a neuro optometrist for a full developmental vision assessment and sure enough, he had a significant visual processing deficit. The time it took for information to get from his eyes to his visual cortex was well below average. This was the heart of his challenges in school. He had thought his whole life that he had ADD and dyslexia and really, he had a very specific visual processing disorder.
I have many other examples but I think these two really help highlight how complicated it can be to get to the heart of a child's challenges in school. If you would like more information about how to help your child, please give me a call at (503) 217-4470 or email me at firstname.lastname@example.org. There are answers for your child!