The study examined the relationship between working memory and ADHD symptoms in children aged 6-12. Correlation analyses found the Digit Span and Arithmetic subtests of the WISC-IV were most related to inattentive ADHD symptoms, while Letter Number Sequencing was not significantly correlated. Digit Span Backward was more strongly correlated with inattention than the combined Digit Span scale. Regression analyses showed Arithmetic predicted inattentive symptoms, working memory index predicted hyperactive symptoms, and Digit Span Backward predicted combined ADHD symptoms. The results suggest individual subtests may be more useful than composite scores for understanding ADHD and its subtypes.

1. IntroductionIntroduction Results:Results:
Correlation AnalysesCorrelation Analyses
Conclusions:Conclusions:
•Digit Span and Arithmetic subtests may be most related to ADHDDigit Span and Arithmetic subtests may be most related to ADHD
symptoms, whereas Letter Number Sequencing is not significantlysymptoms, whereas Letter Number Sequencing is not significantly
correlated with ADHD symptomscorrelated with ADHD symptoms
•Within the Digit Span subscale, Digit Span Backward appears to be moreWithin the Digit Span subscale, Digit Span Backward appears to be more
related to inattention symptoms than the combined subscalerelated to inattention symptoms than the combined subscale
•Consistent with WM measurement literature, which also suggests thatConsistent with WM measurement literature, which also suggests that
Digit Span Forward measures short-term memory, not WMDigit Span Forward measures short-term memory, not WM
•Individual subscales may be more useful than the WMI index as a wholeIndividual subscales may be more useful than the WMI index as a whole
for understanding ADHD symptomsfor understanding ADHD symptoms
•Due to differences in task demands and activation of WMDue to differences in task demands and activation of WM
•No WM measures significantly related to impulsive/hyperactiveNo WM measures significantly related to impulsive/hyperactive
symptoms— Might suggest ADHD Inattentive subtype andsymptoms— Might suggest ADHD Inattentive subtype and
Hyperactive/Impulsive subtype are fundamentally differentHyperactive/Impulsive subtype are fundamentally different
•Future Directions:Future Directions: further analysis of data and future studies examiningfurther analysis of data and future studies examining
other variables that may explain ADHD symptoms, including age, gender,other variables that may explain ADHD symptoms, including age, gender,
environment, comoridity with other diseases, etc.environment, comoridity with other diseases, etc.
The Relationship of the Working Memory Index and Subscales to Dimensional Levels of ADHD Symptoms in a
Community Sample
Khalil Boussi
Graduate Student Mentor: Alison Colbert, M.A.
Faculty Sponsors: Jin Bo, Ph.D.
ADHD
Characterized by high levels of inattention, hyperactivity, and impulsivity
•Valid and impairing disorder, but controversy remains over how best
diagnosed
•Symptoms present in general population (Graham, et al., 2007)
•Must meet a certain standard in order to be considered inpaired
•Considered a neurodevelopmental disorder, thus understanding the
underlying cognitive processes leading to symptoms of ADHD may
increase diagnostic and treatment efficacy.
Working Memory (WM)
Limited capacity system for short-term maintenance and manipulation of
information supporting thought processes (Baddeley, 1998).
•Behavioral response dependent on WM capacity to create, maintain,
and match representations of input stimuli (Rapport et al., 2001).
Baddeley’s Revised WM Model (Baddeley, 2000)
Rapport’s Functional WM Model
WM suggested as core deficit of ADHD
•Deficits in WM occur upstream of phenotypic symptoms of ADHD
(Rapport et al., 2008)
•Understanding this underlying construct may lead to enhanced
diagnosis and treatment of ADHD.
Assessment
•ADHD
•No conclusive genetic or laboratory test for clinical diagnosis
•Best Practice: multimethod approach
•WM
•No gold standard of measurement, as no one method is guaranteed to
engage the neural circuitry of working memory.
•Common experimental methods: span tasks, change-detection tasks,
serial addition tasks, etc.
•Working Memory Index (WMI; WISC-IV): common clinical
assessment
Methods:Methods:
Study ObjectiveStudy Objective
To evaluate the relationship between ADHD symptoms and WMTo evaluate the relationship between ADHD symptoms and WM
functioning as assessed by clinical measures in a community samplefunctioning as assessed by clinical measures in a community sample
Main HypothesisMain Hypothesis: Individual subscales and subscale components of the: Individual subscales and subscale components of the
WMI predicted to be negatively related to dimensional levels of ADHDWMI predicted to be negatively related to dimensional levels of ADHD
symptomssymptoms
•Differential relationship expected between tasks and ADHD symptomsDifferential relationship expected between tasks and ADHD symptoms
due to differences in task demand and structuredue to differences in task demand and structure
Participants
•50 Males
•Age 6-12 (mean = 9.12 years)
•ADHD symptoms rather than diagnosis being
measured, formal ADHD diagnosis not necessary for
inclusion
•20% of sample with previous ADHD diagnosis
•Exclusion: history of learning disorder, closed head
injury with LOC, other neurological disorder, or ASD
Measures
•WMI Subtests from WISC-IV
•Digit Span: Forward and Backward
•Letter Number Sequencing
•Arithmetic Subtest: mental arithmetic problem
solving
•Conners-3, Parent: clinical ADHD rating scale
•Demographic Information
Analytic Strategy
•Variables: scores on all subtests and questionnaires
•Pearson Correlation: utilized to characterize
relationships between measures
•Stepwise Linear Regression: utilized to predict
ADHD symptoms based on WM capacity
C3
Inattention
C3
Hyperactive
C3
Combined
Arithmetic -.44**
-.20 -.26
DS
Forward
-.38*
-.14 -.20
DS Backward -.42**
-.19 -.31*
LNS -.19 -.20 -.23
WMI -.35*
-.24 -.31*
**Correlation is significant at the 0.01 level (2-tailed).
*Correlation is significant at the 0.05 level (2-tailed).
Regression Analyses
Model R Square Sig.
Predictor: Arithmetic
•DV: Conners 3P Inattentive .189 .002
Predictor: WMI
•DV: Conners 3P Hyperactive .120 .01
Predictor: Digit Span Backward
•DV: Conners 3P ADHD-Combined .097 .028
ReferencesReferences
Baddeley, A. (1998). Recent developments in working memory. Current opinion in neurobiology, 8(2), 234-238.
Baddeley, A. (2000). The episodic buffer: a new component of working memory?. Trends in cognitive sciences, 4(11), 417-423.
Graham, J., Seth, S. & Coghill, D. (2007). ADHD. Medicine, 35(3), 181-185
Mariani, M., & Barkley, R. A. (1997). Neuropsychological and academic functioning in preschool boys with attention deficit
hyperactivity disorder. Developmental Neuropsychology, 13, 111–129.
Rapport, M. D., Alderson, R. M., Kofler, M. J., Sarver, D. E., Bolden, J., & Sims, V. (2008). Working memory deficits in boys with
Attention-Deficit/Hyperactivity Disorder (ADHD): The contribution of central executive and subsystem processes. Journal of
Abnormal Child Psychology, 36, 825-837.
Rapport, M. D., Chung, K., Shore, G., & Isaacs, P. (2001). A conceptual model of child psychopathology: Implications for
understanding attention deficit hyperactivity disorder and treatment efficacy. Journal of Clinical Child Psychology, 30, 48-58.
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A. Visuospatial Working Memory Task
B. Verbal Working Memory Task
100ms
100ms
900ms
900ms
“Same” testing array
“Same” testing array
“Different” testing array
“Different” testing array