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Transcript of D-KEFS
About the D-Kefs
Measures multiple aspects of verbal behavioural productivity and cognitive flexibility.
Evaluates effectiveness of novel and semantic search strategies, and assesses flexibility in the implementation of semantic search strategies.
The process approach enables further evaluation of self-monitoring of information search, as well as difficulties related to initiation and sustaining effort.
Uses 3 different conditions:
say words beginning with a specified letter (either F, A or S) as quickly as possible
say words belonging to a designated semantic category (animals or boys' names)
Alternate between saying words from two different categories (Fruits/Furniture)
Scoring: Raw score is the number of correct responses given by examinee and is converted into a scaled score
Colour-Word Interference Test
Measures inhibitory control and cognitive flexibility
Utilises the “Stroop Effect” to identify deficits in inhibition of over-learned behaviours
Colour names are printed in a different colour - must say the color of the ink, not read the word
Runs the same as inhibition, but some words are in boxes. The examinee must read the word in the boxes, not say the colour of the ink
Raw score is determined by the number of seconds that the examinee takes to complete each condition
• D-KEFS (Delis Kaplan Executive Function System)
• Dean Delis, Edith Kaplan, Joel Kramer, 2001
• Assess executive function components (Dubartey, 2003)
• Executive function: control and regulation of cognitive processes, goal-directed behaviour, future-planning. Regulated by the frontal lobes. (Alvarez & Emory, 2006)
• Neurodevelopmental issues, degenerative disorders, traumatic brain injury, epilepsy with still more populations being tested
• Understand the profile of executive dysfunction. To develop strategies with personal strengths and weaknesses in mind
• The 9 substests were designed to stand alone
• Domains such as cognitive flexibility, cognitive shifting, inhibition, problem solving, creativity, planning, reasoning, abstract thinking, concept formation
• Areas known to be sensitive to executive control dysfunction (Dubartey, 2003)
: Cognitive flexibility, Attention,
: Fluent productivity (verbal
domain), lexical organisation
: Fluent productivity (spatial
: Inhibition of verbal
response, Processing speed, Cognitive flexibility
: Problem solving, Verbal + Spatial
concept formation, Cognitive flexibility
: Abstract thinking.
Visual attention, Object recognition, Naming
reasoning, Abstract thinking
: Spatial planning, Response
inhibition, Maintaining instructions
: Metaphorical thinking,
Verbal abstract interpretation
Normative sample of 1750 non-clinical individuals aged 8-89 who were nationally representative (composition was based on the US Census 2000. (Homack, Lee & Riccio, 2005)
• Examiner’s manual
• Technical manual
• Stimulus Book
• Card sets
• Tower stand with colour disks
• Record Forms
• Design Fluency response booklet
• Trail Making response booklet
• Extras $$$: Scoring assistant
Measures concept-formation skills, modality-specific problem-solving skills (verbal/nonverbal), and the ability to explain sorting concepts abstractly
Examinee needs to sort 6 cards (each with a word and picture) into two groups based on as many rules as possible
Scoring based on the description of and sorting of responses
Examineer sorts the the cards, and examinee must identify the rules by which the examineer sorted them
Scoring based on description of responses
Design Fluency Test
Measures multiple aspects of visual behavioural productivity and cognitive flexibility. It evaluates visual productivity with and without distracting stimuli, and switching between stimuli. The process approach is used to assess for difficulties with self-monitoring of performance for rule-adherence, and redundant responding.
Rules are laid out in the stimulus booklet for the examinee to refer to
There are three conditions where the examinee attempts to produce as many novel designs as possible using:
switching between filled and empty dots
Scoring: Raw score is determined by number of correctly drawn designs
Measures the ability to categorize, formulate abstract, yes/no questions, and incorporate the examiner’s feedback to formulate more efficient yes/no questions
Examinee asks the examiner yes or no questions in order to identify a picture the examiner has chosen. The goal is to figure out which picture the examiner has chosen using the least number of questions
Scoring: Abstraction score determined by number of objects eliminated by first questions. Overall score determined using abstraction score and number of questions used to get correct response
Word Context Test
Measures verbal modality, deductive reasoning, integration of multiple bits of information, hypothesis testing, and flexibility of thinking
Given a made up word (in context) and must determine its meaning
Given 5 sentences as clues for each item
Scoring: Number of correct responses, incorrect responses, number of don't know responses, and repeated incorrect responses, quantified and weighted more according to deductive reasoning than accuracy in expressing words.
Measures spatial planning, rule learning, inhibition of impulsive and perseverative responding, and the ability to establish and maintain instructional set
Goal is to create the picture in stimulus book in fewest number of moves
Examinee is given certain rules about how the discs can be used
Scoring: Points for each item are scored and converted into a raw score according to number of moves used to create tower
measures the ability to form novel, verbal abstractions
Proverbs are read and examinee is asked to interpret orally
Proverb is given, and examinee must choose from four options that best explains the proverb
Scoring: Based on abstraction and accuracy of response
Trail Making Test
Applies the process approach to the assessment of cognitive flexibility
Differentiates deficits in visual scanning, mental sequencing, and motor speed/control from deficits in cognitive flexibility and control
Scoring: Time to complete each condition converted into scaled score and subjected to contrast measures
Miller, D.C. (2009). Best Practices in School Neuropsychology: Guidelines for Effective Practice, Assessment, and Evidence-Based Intervention. John Wiley & Sons: USA
Ramsden, P (2003). [Review of the Delis-Kaplan Executive Function System]. In the fifteenth Mental Measurements Yearbook. Lincoln, NE: Buros Institute of Mental Measurements.
Schmidt, M. (2003). Hit or miss? Insight into executive functions (Test Review). Journal of the International Neuropsychological Society, 9, 962–964.
Uomoto, J. (2010). The contribution of neuropsychological evaluation to traumatic brain injury. In Ashley, J. (Ed.) Traumatic brain injury: Rehabilitation, treatment and case management, p. 843-882. Florida, US: CRC Press
Wodka, E.L, Mosofsky, S.H, Prahme, C., Gidley-Larson, J.c., Loftis, C., Denckla, M.B & Mahone, E.M. (2008). Process examination of executive function in ADHD: sex and subtype effects. The Clinical Neuropsychologist, 22 (5), p 826-841
Autism Spectrum Disorder
Those with ASD have difficulty with Executive Functioning such as: paying attention to minor details but not seeing how they fit into a bigger picture; complex thinking that involves more than one train of thought; maintaining attention; or organising their thoughts and actions
Lopez, Lincoln, Ozonoff, and Lai (2005)
Examined the relationship between executive functions and restricted, repetitive symptoms of ASD. The aim was to investigate how cognitive abilities with ASD are related to the behavioural symptoms using the Trail Making Test, Design Fluency Test, Colour-Word Interference Test, Tower Test, and Verbal Fluency Test
In support of previous literature, the study found that the ASD group performed similarly to the control group on measures of working memory and response inhibition, and that there were deficits in the ASD group for cognitive flexibility and planning
Found a strong positive correlation between cognitive flexibility and restrictive, repetitive behaviours
this provides some evidence that the tendency to perseverate is related to stereotyped behaviours
Planning and fluency abilities were not significantly correlated with restricted repetitive behaviours
Robust correlations between restrictive, repetitive behaviours and working memory and response inhibition
This suggests that relatively preserved executive processes influence restrictive, repetitive symptoms of ASD and that executive strengths and deficits are related to restrictive, repetitive behaviours
Kleinhans, Akshoomoff, and Delis (2005)
Examined executive functions in ASD (HFA and Aspergers) in flexibility, fluency and inhibition using the Colour- Word Inteference Test, Trail Making Test, Verbal Fluency Test and Design Fluency Test
Found that executive dysfunction in ASD was generally mild, with the most consistent deficit found on the measures of verbal fluency
10/12 participants were impaired on either letter fluency, or category switching fluency
Consistently had difficulty only on complex verbal tasks that required generating and initiating efficient cognitve search strategies and problem-solving techniques
- Normative tables for education
and vocabulary level
(Fine, Delis & Holdnack, 2011)
8-89 years old (except Proverbs Test which is 16-89 years old)
90 minutes for all 9 tests
Roughly 15 minutes for individual test
Who can administer the test?
Practice effects (Ramsden, 2003)
Scoring Based on the "cognitive-process" theoretical approach to neuropsychological assessment.
Equal importance on understanding how the examinee attempts to solve the task rather than a single-score method.
Achievement (or aggregate) and process scores for each subtest.
Availability of several ways of scoring (including response accuracy, error rates, and response latencies) offer a wide range of options in interpreting examinee performance.
Interpretation involves conversion of raw scores to age-corrected scale scores – these have a mean of 10 and standard deviation of 3 and percentiles.
No overall composite score (obviously)
Reliability evidence is divided.
Process scores demonstrate extremely low reliability (Strauss, Sherman and Spreen 2006).
Strong age effects. Children at the youngest ages, i.e. 8-10 years generally exhibit the lowest scores
53 of 316 reliability values published in D-KEFS manual were above .80 value, “little reliability” (Schmidt, 2003)
However, this is comparable to Wisconsin Card-Sort Test and Weschler Memory Scale – III. (Delis et al., 2004).
Attributed to these tests tapping a wider spectrum of complex, effortful cognitive processes, rather than homogenous, fundamental tasks such as Vocabulary or Picture Completion subtests, therefore performance variability or measurement error may be greater for more complex tests.
Difficult to use split-half reliabilities on tests of executive functions and memory.
Validity evidence is divided
Schmidt (2003) argues that validity for D-KEFS is poor, due to:
The authors of the D-KEFS rely on the established validity of previous versions of the tasks to support the validity of the tasks comprising the D-KEFS.
For the current combination of tests, validity of studies were conducted on only one of the 9 subtests (i.e. sorting). No other validity studies were conducted on eight subtests of the D-KEFS.
However Delis et al. (2004) pointed out that much of the test development and validity data for the D-KEFS had appeared in the mainstream neuropsychology literature rather than the test manual itself, where it was available for peer review and open to “scientific critique."
Useful for identifying brain damage and diseases that affect cognitive function
Helps determine how deficits in higher order thinking may impact an individual’s functioning. This then can be used to develop coping strategies and rehabilitation programs tailored towards individual’s profile of strengths and weaknesses in executive functions.
Complements traditional tests of intelligence and other basic achievement skills.
The clinical usefulness of the D-KEFS with children is largely unknown.
Some researchers have criticised the limited clinical data presented in the original publication manual (e.g., Schmidt, 2003), specifically in regards to children.
(Homack et al., 2005)
Traumatic Brain Injury (TBI)
Neuropsychological testing has contributed extensively to the rehabilitation of patients with traumatic brain injury (Uomoto, 2010)
Tests in D-KEFS sensitive to brain damage (Homack et al., 2005)
i.e. cognitive switching, inhibition, processing
e.g. 16 rules in the Sorting test
Repetition of instructions
Comprehension of Indirect Requests
(Evans & Hux, 2011)
A note on how D-KEFS scores might be related to day-to-day functioning.
Adults with severe traumatic brain injury benefited from combination of verbal land gestural information when presented with an indirect request. For example, saying ‘Actually…I’m still pretty hungry’ and the gesture is pointing to someone else’s sandwich.
However, hard to distinguish between whether social cognition deficits, or executive functioning deficits.
Behavioural and personality domains not assessed by D-KEFS (Dugbartey, 2003) – yet this shows how it may still provide some insight
Strong, C., Tiesma, D., & Donders, J. (2011)
More research on verbal fluency tasks, less on nonverbal fluency tasks, and rare to examine both together in TBI.
Compared mild-severe TBI to normal controls
TBI patients performed statistically lower than controls on Verbal Fluency test, particularly on category-switching
While classification rate was 65%, verbal fluency test regarded as a useful tool to include in assessment of mild-severe TBI
However, useful to differentiate between moderate and severe brain damage (Finnanger et al., 2013)
Limited discussion on why there is no discrimination on design fluency tests (length of time after injury?)
Little discussion on low classification rate (warning not to use single test to evaluate)
Other useful D-KEFS tests to consider: Sorting Test (Heled, Hoofien, Margalit, Natovich & Agranov, 2011).
Alvarez, J., & Emory, E. (2006). Executive function and the frontal lobes: A meta-analytic review. Neuropsychology Review, 16(1). doi: 10.1007/d22065-006-9002-x
Delis, D. C., Kaplan, E., Kramer, J., & Ober, B. A. (2000). California Verbal Learning Test-Second Edition (CVLT-II). San Antonio, TX: The Psychological Corporation.
Delis, D.C., Kramer, J.H., Kaplan, E. & Holdnack, J. (2004). Reliability and validity of the Delis-Kaplan Executive Function System: An Update. Journal of the International Neuropsychological Society, 10, 301-303.
Dugbartey, A., (2003). [Review of the Delis-Kaplan Executive Function System]. In the fifteenth Mental Measurements Yearbook. Lincoln, NE: Buros Institute of Mental Measurements.
Evans, K., & Hux, K. (2011). Comprehension of indirect requests by adults with severe traumatic brain injury: Contributions of gestural and verbal information. Brain Injury, 25, 767-776. doi: 10.3109/02699052/2011/576307
Fine, E., Delis, D., & Holdnack, J. (2011). Normative adjustments to the D-KEFS trail making test: Corrections for education and vocabulary level. The Clinical Neuropsychologist, 25(8), 1331-1344. doi: 10.1080/13854046.2011.609838
Finnanger et al. (2013). Differentiated patterns of cognitive impairment 12 months after severe and moderate traumatic brain injury. Brain Injury, 27, 1606-1616. doi: 10.3109/02699052.2013.831127
Heaton, R. K., Chelune, G. J., Talley, J. L., Kay, G. G., & Curtiss, G. (1993). Wisconsin Card Sorting Test manual – Revised and expanded. Lutz, FL: Psychological Assessment Resource, Inc.
Heled, E., Hoofien, D., Margalit, D., Natovich, R., & Agranov, E. (2012). The Delis-Kaplan Executive Function System sorting test as an evaluative tool for executive functions after severe traumatic brain injury: A comparative study. Journal of Clinical and Experimental Neuropsychology, 34(2), 151-159. doi: 10.1080/13803995.2011.625351
Homack, S., Lee, D., & Ricci, C. (2005). Test review: Delis-Kaplan Executive Function System. Journal of Clinical and Experimental Neuropsychology, 27(5). doi:10.1080/13803390490918444
Kleinhans, N., Akshoomoff, N., & Delis, D. C. (2005). Executive functions in autism and Asperger's disorder: Flexibility, fluency, and inhibition. Developmental Neuropsychology, 27(3), 379-401.
Lopez, B. R., Lincoln, A. J., Ozonoff, S., & Lai, Z. (2005). Examining the relationship between executive functions and restricted, repetitive symptoms of autistic disorder. Journal of autism and developmental disorders, 35(4), 445-460.
Paper exploring effects of verbalization on cognitive performance in schizophrenia using tasks from the DKEFS.
Harvey, Galletly, Field and Proeve (2009)
Previous studies have found cognitive remediation strategies (verbalizing) assists in improving performance on a task such as Wisconsin Card Sorting Task for people with schizophrenia.
This study extends previous research by assessing whether verbalizing ongoing actions improves performance on tasks selected from the DKEFS.
22 subjects with schizophrenia
Within subjects design: verbalization vs silence
Small Sample size
Possible learning – sub-verbalisation.
Amount of verbalization differed – needed to control or measure that
However, this study found a new use for the dkefs
Results demonstrated selective benefits of verbalization on a neuropsychological task.
Improvement with verbalization was found on a task requiring multiple executive functioning (eg number-letter switching task)
Poorer performance was found on tasks requiring single-component cognitive functions (i.e visual scanning and motor speed tasks.
the number-letter switching task utilizes higher-order executive functions, thus verbalizing ongoing actions may have guided the participants to use a cognitive strategy that allowed for better conceptual organization.
It also may have decreased distractibility on tasks where greater concentration and attention is required.
However, on simpler tasks, verbalizing may have been a distraction by disrupting the momentum of motor skills and automatic visual scanning processes.
Performance on the tower task however, requires multiple functions (eg rule learning, the ability to plan ahead and response inhibition. ). However, performance did not appear to be enhanced by verbalization on this task.
The authors suggest this is because of the difficulty of the task – it was neither the most difficult or the most easy so cognitive remediation strategies was not detrimental or helpful to their performance
A study by Wodka et al. (2008) examined the performance of typically developing children with children with ADHD on four subtests of the D-Kefs (Trail Making, Verbal Fluency, Color-Word Interference, and Tower).
found: overall children with ADHD did not differ from TD on most optional measures from the D-KEFS.
When sex and ADHD subtype were considered, children with the subtype of ADHD less common for sex were at greater risk for poorer performance.
This suggests the optional “process” scores have limited sensitivity in identifying behavioral differences between children with ADHD and typically developing children (TD). The results of the present study, along with our recent findings when assessing primary scores (Wodka et al., 2006), suggest that the primary summary scores, rather than primary contrast scores or optional process scores, appear to be most sensitive in identifying executive dysfunction in children with ADHD.
Important to note:
D-KEFS should be used with more moderate to severe cognitive dysfunction, because the D-KEFS task
(a) is often helpful in revealing the neurocognitive mechanisms underlying the problem-solving deficit (e.g., due in part to the fact that the patient is asked
to describe his or her sorting strategy); and
(b) tends not to be as frustrating as the Wisconsin (e.g., due to the absent of right-wrong feedback). (Delis et al., 2004).