Monday, December 17, 2007

Email and the decline of civilization?

Way off task for this blog...but I enjoyed this column (In the Chronical Review of Higher Education) in defense of email. The author captures much of how I feel....although I hope my emails are not as bad as the author has deliberately written this piece.

Enjoy


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Wednesday, December 12, 2007

IQ's Corner Random Tidbits from Mind Blogosphere 12-13-07

  • Check out the ENL blog for an interesting post on "Walking and chewing gum at the same time: Multi-tasking and complex thinking"
  • Thanks to Mind Hacks for the tip re: a great USB brain t-shirt...just in time for XMAS shopping.
  • The Mouse Trap weighs in (by recommending two articles on intelligence..one my Malcom "Blink" Gladwell and the other by James "Flynn Effect" Flynn) on the importance of IQ and matters of race....a very controversial area to tread with many different opinions. These two articles are only the tip of a number of icebergs.


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Tuesday, December 11, 2007

Controlled attention model of working memory

FYI - More information on the controlled executive attention model of working memory has been posted at IQ's Corner sister blog--the IQ Brain Clock.

Tuesday, December 04, 2007

IQ's Corner recent literature of interest 12-1-07

This weeks recent literature of interest can be found by clicking here.

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Processing speed (Gs) developmental growth on two WJ tests

I just skimmed an interesting (an largely theoretical) article by Kail and Ferrer (2007; Child Development-click here to view) that fit different mathematical models of age-related (developmental) growth to the WJ-R (Woodcock-Johnson--Revised) Visual Matching and Cross Out tests. The article does not have immediate practical applications. I'm was interested in the article since it deals with two tests from the WJ III (conflict of interest note - I'm a coauthor of the WJ III). I also read the article because of the first author...Kail. He, IMHO, is one of the top researchers investigating the nature of developmental growth of cognitive processing speed (Gs).

The abstract for the article is below.

The authors concluded that quadratic and exponential models fit the growth patterns of the Visual Matching and Cross Out tests the bests. The quadratic model was the best fitting model. The authors use this finding to illustrate how such analysis might be useful in exploring the mechanisms that underlie growth in cognitive speed (Gs).

For example, the authors note that the "parameters of these quadratics are often qualitatively like those obtained here: nonlinear change is achieved from a linear increase coupled with a nonlinear (power function) decrease." They then point other physiological/cerebral functions that show similar quadratic growth patterns - e.g., total cerebral volume and total body fat all show the same pattern of quadratic change in childhood and adolescence. The authors suggest that such a finding may suggest that all might have a "common (unspecified) biological base."

Interesting stuff...but not all that practical for the field of applied intelligence testing. However, I think the finding that the two tests showed the same pattern of developmental growth might be interpreted to support the interpretation of the two Gs tests as measuring the same underlying cognitive construct.

As I've written elsewhere, John Horn frequently talked about different types of validity evidence of human ability constructs--structural (factor analytic), genetic or heritability, neurocognitive, criterion-outcome, and developmental. We know from EFA/CFA (structural) studies of the WJ-R and WJ III that Visual Matching and Cross Out load on a common broad Gs factor. Logical content analysis has suggested that they are both measures of the narrow Gs ability of P (perceptual speed). The finding that both VM and CO display the same longitudinal developmental growth pattern, when combined with the extant EFA/CFA structural research that finds these two tests always loading on a common factor, in my opinion supports the validity of the logical narrow (stratum I) classifications of both tests as measures of Gs-P.

Just my two cent applied/practical extraction of information from this largely theoretical piece of research.

Abstract
  • The primary aim of the present study was to examine longitudinal models to determine the function that best describes developmental change in processing speed during childhood and adolescence. In one sample, children and adolescents (N 5503) were tested twice over an average interval of 2 years on two psychometric measures of processing speed: Visual Matching and Cross Out. In another sample, children and adolescents (N 5 277) were tested four times, every 6 months, on Cross Out. Age-related changes in performance on both tasks were examined using six longitudinal models representing different hypotheses of growth. Linear, hyperbolic, inverse regression, and transition models yielded relatively poor fit to the data; the fit of the exponential and quadratic models was substantially better. The heuristic value of these latter models is discussed.
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Monday, December 03, 2007

James "Flynn Effect" Flynn in the news again

James Flynn has been making the rounds recently, probably due to his new book "What is intelligence: Beyond the Flynn Effect.". Check out the following

  • 10 Questions for James Flynn at Gene Expression
  • "Shattering intelligence: Implications for education and interventions" essay at CATO Unbound [Thanks to J. McMaster for this tip]
Click here to view all recent Flynn Effect postings at IQ's Corner

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Friday, November 30, 2007

Random tidbits from the mind blogosphere 11-30-07

  • Check out the ever great Developing Intelligence blog for a interesting posts re: some somewhat surprising research results concerning working memory and using Google PageRank as a semantic memory model of the human brain.
  • Need a break? Check out the video of dart throwing elephants courtesy of Omni Brain.
  • PsycPort reports on a new study suggesting that children with autism may increased gray matter in the brain in areas that govern social processing and learning by observation.


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Thursday, November 29, 2007

WJ III measures of RAN?, speed of lexical access, executive functions?


When time permits, I've been carefully skimming the approx. 30 CHC/WJ III dissertations that I recently acquired and noted at this blog. When I've discovered something of potential importance, I've made DD (Dissertation Dish) posts (all DD-related posts can be found by clicking on the "dissertation" keyword in this blogs index--scroll down left-side of blog).

I just finished skimming a dissertation by one of Dawn Flanagan's students (Kyvelos, 2003). Kyvelos reanalyzed (via CFA) the speeded tests from the WJ III/CAS validity sample (155 elementary school-age subjecxts) which was the foundation of Keith et al.'s CHC-based WJ III/CAS SPR article (2001). At variance from the SPR publication was the inclusion of the WJ III Retrieval Fluency and Rapid Picture Naming Speed tests in the analysis. These tests were NOT included in the Keith et al. 2001 formal publication.

[Conflict of interest note - I'm a coauthor of the WJ III battery]

Although no support was found for the classification of the WJ III and/or CAS speeded tests at the narrow (stratum I) ability level, the analysis did support the validity of separate broad Gs and Glr factors, factors with a latent factor correlation of .74. What I find particularly interesting was the validity for a rate-based Glr factor, which was defined by the following significant loadings:
  • WJ III Retrieval Fluency = .69
  • WJ III Rapid Picture Naming = .56
  • CAS Expressive Attention = .30
In contrast, all other WJ III (Decision Speed, Cross Out, Visual Matching) and CAS speeded tests (Receptive Attention, Planned Connections, Planned Codes, Number Detection, Matching Numbers) all loaded on the broad Gs factor.

Why is this interesting?

First, the most robust post-WJ III publication structural finding I've discovered (in various unpublished analyses I've conducted with the WJ III data files) is the finding that the WJ III Rapid Picture Naming (measures the ability to rapidly identify and orally name pictures of common objects) and Retrieval Fluency (measures fluency in retrieving the names of objects.. the subject is asked to state as many items as they can of three different types) tests "hang together." These two tests seem to be tapping a rate retrieval (Glr) ability distinct from traditional Gs tests. As reported in the broad+narrow CFA in WJ III technical manual, we did specify these two tests to represent the narrow ability of "Naming Facility" under Glr.
  • NA- Ability to rapidly produce accepted names for concepts or things when presented with the thing itself or a picture of it (or cued in some other appropriate way). The naming responses must be in an individuals long-term memory store (i.e., objects or things to be named have names that are very familiar to the individual). In contemporary reading research is ability is called rapid automatic naming (RAN)
That is...evidence was presented in the WJ III TM that these two tests measure the rate aspect (versus the "level" aspect) of Glr. I've repeatedly found these tests grouping together in various exploratory factor analyses, multidimensional scaling analysis, cluster analysis, etc. The Kyvelos (2003) study supports this finding. I've speculated that the common ability is "speed of lexical access"....which I first ran across in Perfetti's reading research.

Second, the other test that loaded on this rate Glr factor was the CAS Expressive Attention test. This task is based on the classic Stroop task (1935) that is typically interpreted as a valid measure of interference, inhibition/disinhibition, and executive control. In this task a subject must name as fast as possible (when presented with printed words in different colored fonts) the color in which the words red, blue, yellow, and green, are printed instead of reading the words themselves. Clearly such a task requires response inhibition and rapid/fluent accessing of a person's lexicon (speed of lexical access).

Bottom line - I believe, based both on published and unpublished research, that the combination of the WJ III Retrieval Fluency and Rapid Picture Naming tests measure some sort of Glr fluency/rate ability, especially as it relates to speed of semantic processing or speed of accessing one's lexicon. The association of these two WJ III tests with a CAS Stroop-like task (Expressive Attention) also suggests that response inhibition is a potentially important component for successful performance on these two WJ III tests. In other words, these two WJ III tests may measure, aside from speed of lexical access or word retrieval fluency (possibly some shared abilities with RAN tasks?), aspects of executive functioning - namely, ability to deal with interference effects and response inhibition.

RE: possible WJ III measures of executive functioning, check out recent posts re: the WJ III Pair Cancellation test.

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IQ's Corner Mind Blogosphere Headlines 11-29-07

All the news thats fit for IQ's Corner readers:

This is the 43rd installment of IQs Corner Headlines from the Brain and Mind Blogsphere. If you like this little e-newsletter you can sign up to receive it daily (delivered to your email inbox by visiting the sign-up boxes at the bottom of this blog page).

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Wednesday, November 28, 2007

Beyond the CHC theory tipping point: Back to the future

I just posted a copy of the PPT slides that served as the first half of two presentations I recently made in Canada re: the CHC (Cattell-Horn-Carroll) theory of intelligence. The latest version is called "Beyond the CHC theory tipping point: Back to the future."

The slide show can be viewed by scrolling down the left-side of this blog page until you reach the "On-line PPT slide" section header. Click on the presentation title and enjoy.


Below is a brief description of the slide show:
  • An overview of the CHC (Cattell-Horn-Carroll) theory of intelligence within a historical and "waves of interpretation" context. Presents idea that CHC has reached the "tipping point" in school psychology..and...this is allowing assessment practitioners to realize past attempts to engage in individual strength and weakness interpretation of CHC based test profiles
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Tuesday, November 27, 2007

WJ III Pair Cancellation - Part 2

More on the WJ III Pair Cancellation test (click here for prior post). I just finished skimming Carper's (2003) dissertation (comparing relations between select NEPSY and WJ III tests). I thought Carper's task analysis description of abilities measured by the WJ III Pair Cancellation test was informative. Carper included the following under Pair Cancellation: Visual scanning, Response inhibition, Interference control, Sequencing, Speed and Fluency, Sustained Attention, Processing Speed, and Motoric Speed

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WJ III Pair Cancellation test as measure of vigilance (sustained attention)

As a result of my recent "harvesting" of various unpublished CHC/WJ III-related thesis/dissertations, my interest in the WJ III Pair Cancellation (PC) test has been rekindled. Since the WJ III was first published I've maintained that the Pair Cancellation test was a good measure of sustained attention or vigilance, an aspect of executive functioning. Unfortunately, we (the WJ III authors) did not report much in the way of special validity studies to support of this interpretation.

[Conflict of interest note - I am a coauthor of the WJ III]

The purpose of this post is to share my recent thinking re: the WJ III PC test. My bottom line conclusion - I still believe that the WJ III Pair Cancellation test is an under appreciated test in the WJ III battery. Because Pair Cancellation's administration is not required to obtain any of the primary cognitive clusters (General Intellectual Ability; CHC factor clusters) it is a test that is often ignored (not administered). I think practitioners need to pay closer attention to the potential of this test, particularly when issues of vigilance, ADHD and executive functions are prominent in a referral for assessment. On what basis do I make this recommendation?

First, lets start with a description of the task. In the WJ III Pair Cancellation task a subject is presented with rows that contain repeating pictures of a dog and a ball (in no particular sequence) and must circle all instances of when the “ball is followed by the dog”. The test has a three-minute time limit. Thus, a subject must locate and mark a repeated pattern of pictures while simultaneously controlling for interference of potentially distracting information (i.e., demonstate good inhibition).

Second, lets consider the CHC basics for Pair Cancellation. As per my most recent CHC classification of all WJ III tests, Pair Cancellation (based on the published CFA analysis in the WJ III Technical Manual) is clearly a speeded test (Gs). Original logical narrow ability content analysis suggested a classification as a measure of P (perceputal speed) and/or AC (sustained attention/concentration). Using Ackerman and colleagues recent fine-grained analysis of perceptual speed measures (which suggests that perceptual speed may be an intermediate stratum ability between narrow and broad abilities defined by four narrow sub-abilities), the Pair Cancellation test might better be consider a measure of "complex perceptual speed" (Pc), which is the "ability to perform visual pattern recognition tasks that impose additional cognitive demands such as spatial visualization, estimating and interpolating, and heightened memory span loads."

Third, in a study of 39 subjects (21 with ADHD; 18 controls) Poock (2005) reported that the Pair Cancellation test, along with the Concept Formation and Auditory Working Memory tests, reliably differentiated ADHD and non-ADHD subjects.

Fourth, there is a rich base of neuropsychological literature that has demonstrated that various "cancellation tasks" are good measures of sustained attention or vigilance. Borrowing from Brawn's (2007) review of the literature:

  • Cancellation Tasks (CTs) are the immediate antecedents to CPT's [continuous performance tests]. Indeed, some researchers refer to CTs as "paper-and-pencil" CPTs (e.g., Barkley, 1998). They assess "...visual selectivity at a fast speed on a repetitive motor response task" (Lezak, 1995, p. 548), by requiring that a subject rapidly scan printed rows of digits, letters, symbols, or pictures in order to mark pre-specified targets interspersed throughout the symbols, or pictures in order to mark pre-specified targets interspersed throught the array.
  • Cancellation Tasks have been demonstrated to be sensitive to response slowing and inattentiveness as a fundtion of diffuse cerebral damage or acute brain conditions, and, like CPTs, they are classified as basic vigilance tests (Lezak, 1995). However, of the two, CPTs may be the purer measure of vigilance. Cancellation tasks require the subject to use a pencil, as well as to quickly and accurately scan rows of printed stimuli; thus, performance relies substantially on motor processing, visual-motor integration, and subject driven visual scanning (Lezak, 1995; Wechsler, 1997b; Woodcock et al., 2001).

Interested readers may wish to check out the recent "meta-search" I completed (and posted) re: the cancellation task assessment paradigm.

Finally, in a previously reported "Carroll analysis" of the complete WJ III battery, Pair Cancellation was found to the strongest loading test on the broad "cognitive" processing speed (Gsc) factor [this analysis also produced a broad "achievement" processing speed factor-Gsa]. In my opinion, this is consistent with the Ackerman-based classification of Pair Cancellation as a measure of complex perceptual speed (Pc).

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Monday, November 26, 2007

Vigilance tasks/tests meta-search

I've added my 3rd IQ's Corner web meta-search link to the appropriate section of this blog (scroll down left side of blog to the "Meta-web searches" section). The topic is cancellation tasks/tests....a test format used primarily in neuropsychology settings to assess vigilance (a component of executive function).

This is another DD (dissertation dish - technically this one is a thesis dish for a specialist degree)

This thesis was completed by Carrie Adkins (2006 - click here to find complete reference citation). The title of this thesis was "The The Correlation between Wechsler Adult Intelligence Scale III and Woodcock-Johnson III Cognitive Abilities and WJ III Achievement for College Students: Which is a better predictor of reading achievement?"

Abstract
  • The present study is intended to examine whether the Wechsler Adult Intelligence Scale III or Woodcock-Johnson III Cognitive Abilities would better predict reading achievement on the WJ III Achievement in the college student population. Participants included 29 college students attending a university in the Midwest, being evaluated for a learning disability or academic accommodations. Data were analyzed using Pearson r correlation, Fisher z, and t-test for each intelligence test in comparison to achievement subtests. Results from this study indicated that both IQ scores obtained from the WAISIII and the WJ-III COG correlated with reading significantly, but not highly enough to be construed as achievement tests due to only moderate correlations. Considering the results of this study an examiner may choose either instrument to use when assessing intelligence. Limitations to this study are presented.
Brief blogmaster comments:
  • The thesis author appropriately points out the significant limitation in terms of small sample size and the need for replication in larger samples.
  • The WAIS-III FS IQ correlated .56, .66, and .24 with the WJ III Ach. tests of Letter-Word Identification, Passage Comprehension, and Reading Fluency. The WJ III GIA correlations with the same reading measures were .62, .65, and .34. Statistical tests revealed no significant differences between the respective WAIS-III and WJ III cognitive-reading correlations.
  • A limitation that should be noted is the significant restriction of range of talent/ability. The WAIS III FS IQ had an SD of 14.7 (almost normal), while the WJ III GIA SD was 10.1. The SD's for the respective WJ III achievement tests ranged from 9.8 to 11.7. Clearly there was significant restriction of range on the WJ III measures (due to the referral nature of the sample), a finding that suggests that the WJ III cognitive/achievement correlations are under-estimates of the population correlations. It would have been nice if the author would have presented "corrected" correlations (for range restriciton). Most likely the WJ III GIA correlations with achievement would have been higher.
  • Finally, I would like to have seen the correlations between the respective WAIS-III composite and WJ III CHC composite/cluster scores and reading achievement. Unfortunately, these are not reported.
Conflict of interest note - I'm a coauthor of the WJ III

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XMAS shopping - Serotonin t-shirts


Thanks to Mind Hacks for the tip re: the YAY Serotonin t-shirts that are now available for purchase. Just in time for my holiday shopping

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Sunday, November 25, 2007

Random tidbits from the mind blogosphere 11-25-07

  • Check out the GNIF Brain Blogger blog for interesting post re: how "false" memories may feel true.
  • Thanks to Positive Technology Journal for link to just released report by British Medical Association re: the ethical implications of using technology to enhance cognitive functioning

Wednesday, November 21, 2007

More on brain training for the eldery

Sharp Brains has a more detailed post regarding the topic I blogged about yesterday....new research demonstrating positive effects for brain training in the elderly. Check out SB's post....I consider SB to be the "Ralph Nader" or "Consumer Reports" regarding the growing brain fitness industry.

Random tidbits from mind blogospher e11-21-07

  • Interesting post at BPS re: research on deliberate attempts to feign mental retardation (e.g., in capital punishment cases).
  • Check out "interesting brain web sites" post at the Brain Injury blog - IMHO, the #1 blog related to brain injury news and views.
  • Need a break? Do you tire of doing Excel spreadsheets. Check out new "game" played with Excel. Thanks to the Download Squad for the tip.
  • Infant statisticians? Check out the Mouse Trap for post re: study suggesting that infants may possess some rudimentary understanding of probability.
  • I'm not sure how accurate this new blog feature is, but it is interesting. Check out Omni Brain's post for a link on calculating the readability level of blogs. IQ's Corner came out at the "college level." I'm not surprised given that the focus is largely for scholarly/academic/theoretical information dissemination.


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