IQ score differences across time may relfect real changes in the brain

Lay people and many professionals often express consternation when an individuals measured IQ scores are different at different times in their life.  This concern is particularly heightened in high stakes settings where differences in IQ scores can result in changes in eligibility for programs (e.g., social security disability income) or life-or-death decisions (e.g., Atkins MR/ID death penalty cases).

Factors contributing to significant IQ score differences are many (McGrew, in press a) and may include: (a) procedural or test administration errors (e.g., scoring errors; improper nonstandardized test administration; malingering; age vs. grade norms; practice effects), (b) test norm or standardization differences (e.g., norm obsolescence or the Flynn Effect; McGrew, in press b), (c) content differences across different test batteries or between different editions of the same battery, or (d) variations in a person’s performance on different occasions.

 An article "in press" (Neuroimage) by Burgaleta et al. (click here to view copy with annotated comments)  provides the important reminder that differences in IQ scores for an individual (across time) may be due to real changes in general intelligence related to real changes in brain development.  These researchers found that changes in cortical brain thickness were related to changes in IQ scores.  They concluded that "the dynamic nature of intelligence-brain relations...support the idea that changes in IQ across development can reflect meaningful general cognitive ability changes and have a neuroanatomical substrate" (viz., changes in cortical thickness in key brain regions).  The hypothesis was offered that changes in the the cortical areas of  frontoparietal brain network (see P-FIT model of intelligence) may be related to changes in working memory, which in turn has been strongly associated with general reasoning (fluid intelligence; Gf).

The cortical thickness-IQ change relation was deemed consistent with "cellular events that are sensitive to postnatal development and experience."  Possible causal factors suggested included insufficient education or social stimulation during sensitive developmental periods, as well as lifestyle, diet and nutrition, and genetic factors.

• McGrew, K. S. (in press a).  Intellectual functioning:  Conceptual issues.  In E. Polloway (Ed.), Determining intellectual disability in the courts:  Focus on capital cases.  AAIDD, Washington, DC.

•  McGrew, K. S. (in press b).  Norm obsolescence:  The Flynn Effect.  In E. Polloway (Ed.), Determining intellectual disability in the courts:  Focus on capital cases.  AAIDD, Washington, DC.

[Click on images to enlarge]

WJ III Evidence-Based Neurocognitive Assessment: Intervention Planning

Richard Woodcock and Dan Miller are now making the following new approach to neurocognitive assessment available online via School Neuropsychological Training and Resources web page.

Below is a description from the manual.

The purpose of this published set of tables is to provide clinicians with selective sets of WJ III tests that have been shown to be the most informative of cognitive and achievement weaknesses and strengths in known clinical groups. Too often clinicians use a fixed battery approach and administer the majority of the WJ III tests to any child or adult with minimal regard to the underlying clinical diagnosis. The goal of this project is to provide clinicians with a suggested set of tests that could be administered as a starting point for intervention planning, particularly if the clinical diagnosis is already known or highly suspected.

 

Posted with Blogsy

WJ III Evidence-Based Neurocognitive Assessment: Intervention Planning

 

Posted with Blogsy

Brain network research and the P-FIT model of intelligence: The Time Doc's working notebooks

I have been slammed with work this summer an have been unable to blog about exciting research I have been reading in the area of brain networks. I did start a series on the P-FIT model of intelligence, but have yet to get back to it as planned. I will...but it will take some time before I can push more projects off my desk.


I have been dutifully compiling working notebooks on two of the most exciting topics and have decided to make them available to readers now. They include abstracts, images, and select text from various sources. I seem to find new research in these two areas almost daily...so just maintaining these working notebooks is all I have been able to keep up with. I hope readers find them interesting.

Links to the two notebooks are below...and they will also be available at Reports and Publications section (Neurotechnology subsection) of the MindHub





The first is the "Your brain is a network: The Human Connectome and brain network research notebook". It is suggested you view these notes first as the second fits within this context. [Click on images to enlarge]




The second is "Parietal-Frontal Intelligence: The P-FIT research notebook"



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