1. Peter K. Isquith, Robert M. Roth, & Gerard A. Gioia
Tasks of Executive Control™
Peter K. Isquith, Robert M. Roth, & Gerard A. Gioia

2. The TEC is:
a standardized computer-administered measure of two essential executive functions:
Inhibitory Control
Working Memory
Based on established neuroscience methods
For ages 5 through 18 years
With 3 equivalent forms & 2 research forms
Standardized Regression Based Change Scores facilitate interpretation within and between administrations
Stable platform and accurate timing

3. Overview Why the TEC? Basics Psychometrics Interpretation
Stimuli, Administration
Factor, Summary, & Task Scores
Psychometrics
Evidence for Reliability
Evidence for Validity
Interpretation
Cases

4. Why emphasize working memory and inhibitory control?
Rationale for the TEC
Why emphasize working memory and inhibitory control?
Fundamental to enabling other executive functions
Integrity impacts social, emotional, behavioral, and academic functioning
One or both are abnormal in numerous pediatric clinical populations

5. Why develop a new test of working memory and inhibitory control?
Working memory assessment often limited to brief holding of simple information (e.g., digits)
Limited evaluation of temporal or sustained aspects of working memory
Few standardized inhibitory control tasks clinically available
The most sensitive tasks for detecting working memory or inhibitory difficulties are used in neuroscience research, but not available for clinical use

6. Key ingredients
Manipulate working memory and inhibitory control demands in a single paradigm
Assess over a naturalistic, sustained time period
Based on empirical evidence of relationships with, and sensitivity to, brain integrity
Appropriate for use with children and adolescents
Computer assessment for standardized administration and ease of scoring

7. N-Back Paradigm D X Q L G T B X C T R J V N X
0-Back (zero-back)
D X Q L G T B X C T R J V N X
1-Back (one-back)
D Y N N G T B Y C B B J V Q Y
2-Back (two-back)
D Y A L A T B Y C N R N V Q Y

8. N-Back Paradigm Engages working memory over an extended time period
Parametrically increases working memory load
Accuracy and speed improves with age
Poorer performance in children associated with academic, attention, and behavioral problems at school
Poorer performance in children with TBI, ADHD, others
Developed and used extensively in the context of functional neuroimaging

9. N-Back Paradigm fMRI Letter n-back in sample of 24 Adolescents
Hurt et al., 2008, J Pediatrics

10. N-Back Paradigm Meta Analysis of N-Back in 24 Studies
Owen et al., 2005,
Human Brain Mapping

11. Go/No-Go Paradigm

12. Go/No-Go Paradigm
Long history in neuropsychology and behavioral neurology
Accuracy and speed improves with age
Poorer performance in children with ADHD, TBI, others
Used extensively in the context of functional neuroimaging, including many studies of pediatric populations

13. Go/No-Go Paradigm: Imaging Findings
Tamm et al., 2002,
J Am Acad Child Adolesc Psychiatry

14. Administration & Scoring
The Basics
Administration & Scoring

15. Six Tasks 0-Back / No Inhibit 0-Back / Inhibit 1-Back / No Inhibit

16. The Basics
TEC Scores

17. Three Types of Scores:
Factor Scores- multimodal composites across measures provide global view
Summary Scores- unimodal means across tasks provide view of each measure
Task Scores- measures of performance for each measure by task (4 or 6 tasks)

18. Assessing Reliable Change in Neuropsychological Function
Change as statistically significant or clinically significant (meaningful)
Clinical trials/ clinical outcomes research mostly interested in clinically meaningful change

19. Standardized Regression Based (SRB) Change Scores
Take into account measurement error, regression to mean, practice effects
Adjusts for demographic factors
Later scores predicted from earlier scores via regression equations:
1B = b * 0B + a * Age + c * Gender + Constant
Change scores standardized in TEC

20. Measuring Change in Response to increasing TEC Demands
Novel application of SRB change metrics
Compare changes in performance across increasing working memory load (i.e., 0-Back to 1-Back, 1-Back to 2-Back) within inhibitory demand conditions (i.e., no inhibit, inhibit).
How well does individual manage the increasing executive demands across tasks?
May have important clinical implications for limits of their working memory and/or inhibitory control

21. Measuring Change Between TEC Administrations
3 equivalent forms and 2 research forms
No differences between forms in timing, order of stimulus presentation
Equivalent stimuli substituted in each form
SRB Change Scores assist in determining between administration differences

22. The Details:
Psychometrics

23. Influence of Demographics
Age accounts for the largest percentage of variance in scores (0 to 30%)
Gender accounts for <10% of variance in some scores, primarily at younger ages
Boys tend to be faster
Girls tend to be more accurate
Racial/Ethnic background accounts for <3% in any score, and <1% in most scores

24. Reliability Internal consistency >.80 for most scores
Omissions are lower, thus reported but not interpreted
Test-retest >.70 for Factor and Summary scores
Omissions are lower, thus not interpreted

25. Alternate Forms Reliability
Correlations between scores for:
Form 1 to Form 2
Form 1 to Form 3
Factor & Summary scores between-forms consistency range
Task scores lower, from .50 to .95
Response time measures most reliable
Omissions are lowest

26. Evidence of Validity Based On:
Expected developmental changes
Expected performance changes
Factor Structure
Relationships with rating scales
Relationships with executive tasks
Differences between clinical vs control groups

27. Evidence Based on Developmental Changes
Children become:
more accurate with age
Faster with age
More consistent with age

28. Factor Structure
Principal factor analysis (PFA) conducted as exploratory method with oblique rotational procedure (Promax).
Performed on 1176 participants (normative sample) in two age groups: age 5-7 (n = 219; 4 subtests, 22 variables), and age 8-18 (n = 957; 6 subtests, 39 variables).
Three factor structure for 5-7 year olds, 4 factors for 8-18.
Ages 5-7 Years
Ages 8-18 Years
Response Control
Sustained Accuracy
Selective Attention
Response Speed
Response Variability

29. TEC Correlates with Scales on:
Behavior Rating Inventory of Executive Function
BRIEF-SR
Conners’ Parent Rating Scales
Child Behavior Checklist
Post-Concussion Symptom Inventory
Everyday Situations Survey
Family Assessment Device

30. Evidence Based on Relationships with Executive Tasks
Digit Span
Symbol Digit Memory Test
Auditory Consonant Trigrams
Reading/Math Fluency
CVLT-C

31. Evidence Based on Differences Between Clinical & Control Groups
ADHD-I / ADHD-C
mTBI LD
Fragile X

32. Psychometric Summary Large age effects, small gender effects, no bias
Appropriate internal consistency and temporal stability with multiple equivalent forms
Multiple lines of evidence support validity:
Expected developmental changes
Expected performance changes
Factor Structure
Relationships with rating scales
Relationships with executive tasks
Differences between clinical & control groups
Performance improvement tracks recovery

33. Interpretation

34. Interpretive Strategy:
Factor Scores reflect overall performance across measures
Summary Scores reflect overall performance within measures
Task Scores show change with increased working memory load with/without inhibit
SRB Change Scores measure degree of change within and between administrations

35. TEC standardization samplea
Gender & Race/Ethnicity Demographics of the U.S. Population and the TEC Standardization Sample
U.S. population
TEC standardization samplea
Sociodemographic variable %
Gender
Male
51.13
51.68
Female
48.87
48.32
Race/Ethnicity
Caucasian
58.46
59.72
African American
14.86
13.72
Hispanic
19.36
20.07
Other
7.32
6.49