Resting state signatures of domain and demand-specific working memory performance.

Working memory (WM) is one of the key constructs in understanding higher-level cognition. We examined whether patterns of activity in the resting state of individual subjects are correlated with their off-line working and short-term memory capabilities. Participants completed a resting-state fMRI scan and off-line working and short-term memory (STM) tests with both verbal and visual materials. We calculated fractional amplitude of low frequency fluctuations (fALFF) from the resting state data, and also computed connectivity between seeds placed in frontal and parietal lobes. Correlating fALFF values with behavioral measures showed that the fALFF values in a widespread fronto-parietal network during rest were positively correlated with a combined memory measure. In addition, STM showed a significant correlation with fALFF within the right angular gyrus and left middle occipital gyrus, whereas WM was correlated with fALFF values within the right IPS and left dorsomedial cerebellar cortex. Furthermore, verbal and visuospatial memory capacities were associated with dissociable patterns of low-frequency fluctuations. Seed-based connectivity showed correlations with the verbal WM measure in the left hemisphere, and with the visual WM measure in the right hemisphere. These findings contribute to our understanding of how differences in spontaneous low-frequency fluctuations at rest are correlated with differences in cognitive performance.

A Psychometric Network Analysis of CHC Intelligence Measures: Implications for Research, Theory, and Interpretation of Broad CHC Scores "Beyond g".

For over a century, the structure of intelligence has been dominated by factor analytic methods that presume tests are indicators of latent entities (e.g., general intelligence or g). Recently, psychometric network methods and theories (e.g., process overlap theory; dynamic mutualism) have provided alternatives to g-centric factor models. However, few studies have investigated contemporary cognitive measures using network methods. We apply a Gaussian graphical network model to the age 9-19 standardization sample of the Woodcock-Johnson Tests of Cognitive Ability-Fourth Edition. Results support the primary broad abilities from the Cattell-Horn-Carroll (CHC) theory and suggest that the working memory-attentional control complex may be central to understanding a CHC network model of intelligence. Supplementary multidimensional scaling analyses indicate the existence of possible higher-order dimensions (PPIK; triadic theory; System I-II cognitive processing) as well as separate learning and retrieval aspects of long-term memory. Overall, the network approach offers a viable alternative to factor models with a g-centric bias (i.e., bifactor models) that have led to erroneous conclusions regarding the utility of broad CHC scores in test interpretation beyond the full-scale IQ, g.

QEEG coherence patterns related to mathematics ability in children.

The current study investigates the utility of resting-state EEG coherence values in predicting standardized math scores in children. Quantitative EEG and standardized academic achievement analyses were performed on 60 school-aged children. Analyses assessing intrahemispheric coherence at rest were conducted across the sample of participants and several coherence networks were extracted and compared to standardized math achievement values. Specifically, networks that included Brodmann area 40 (a brain region involved in the cognitive processes responsible for mathematics performance) and whose coherence values were significantly correlated with standardized math scores were examined. Results indicate a total of four coherence networks, two in each hemisphere, that have utility in predicting general math skills in children. In addition to BA 40, these coherence networks include BAs in the right temporal lobe, right frontoparietal lobe, left superior temporal lobe, and the left medial prefrontal cortex. These findings address the current dearth of research on the neurological connectivity patterns that are foundational for mathematics abilities in children. Further, these results lay a foundation for the supplementary use of EEG in the assessment and identification practices surrounding math learning disabilities in children and additionally provide a neurocognitive framework upon which intervention research may be targeted.

Neurocognitive correlates of persisting concussion symptoms in youth.

Many patients that experience a concussion have impairing symptoms that persist beyond typical recovery timeframes. Concussion symptoms often remit within a month, but persisting impairments are difficult to characterize and attribute to concussion given the poorly defined diagnostic criteria of post-concussion syndrome and inadequate understanding of the cognitive symptoms associated with this condition. The current study aims to clarify the cognitive profiles of school-aged concussion patients (n = 21; N = 36; 64% male) that have persisting symptoms to improve the clinical identification methods for this condition. Logistic regression was used to explore the importance of cognitive processing speed and working memory for identifying patients with persisting concussion symptoms (PCS). Additional exploratory analyses were conducted to clarify cognitive domains that may be impacted by having PCS. Findings indicate processing speed and working memory abilities alone are not adequate to identify patients with PCS. Further, measures of processing speed, fluid reasoning, working memory, and long-term retrieval together were found to be necessary to identify those who had a prior concussion with PCS. These findings indicate clinical neuropsychological batteries must include measures of these four cognitive domains when assessing school-aged patients with chronic symptoms that extend beyond three months following injury.

ADHD in University Settings: Predictive Validity of Quantitative EEG Coherence.

PURPOSE: Research has demonstrated distinct patterns of electroencephalography (EEG) coherence with attention-deficit/hyperactivity disorder (ADHD) in children; however, few studies have examined coherence measures in adults with ADHD. Further, specific research examining EEG coherence within the subgroup of young adults in post-secondary education is absent from the literature. METHODS: The current study investigated the utility of quantitative EEG in predicting ADHD behavioral symptoms in 35 college students with a documented ADHD diagnosis and 35 control students. RESULTS: Increased interhemispheric frontal beta-wave coherence was found in individuals with ADHD. Logistic regression of principle components of quantitative EEG coherence metrics predicted ADHD group membership. CONCLUSIONS: Suggestions for improving ADHD identification in college populations using quantitative EEG are discussed.

QEEG correlates of cognitive processing speed in children and adolescents with traumatic brain injuries.

Both quantitative electroencephalography (qEEG) and cognitive measures have been used to understand the underlying brain changes that occur in individuals after experiencing a traumatic brain injury, however, research exploring the relationship between qEEG patterns and cognitive test performance is scarcely studied in school-aged populations. The purpose of the present study was to explore first, the neuropsychological and academic deficits in young individuals with TBI; and second, the underlying relationship between qEEG patterns and cognitive test performance. Analyses included 21 school-aged participants whom have experienced a recent TBI and 15 school-aged participants whom have never experienced a TBI. Mean subtest and composite scores were compared and regression analyses were used to determine whether alpha band and beta band qEEG coherence values predicted processing speed measures. Results suggest that young individuals who experienced a recent TBI exhibit general deficits in cognition and academic skills beyond what would be expected in the general population. Further, beta band coherence with the frontal brain regions significantly predicted processing speed scores, providing evidence of a relationship between qEEG patterns and processing speed. This outlines a relatively inexpensive method for utilizing neural connectivity to verify cognitive deficits for school-aged individuals with a recent TBI.

Utility of the Bender Visual-Motor Gestalt Test-Second Edition in the assessment of attention-deficit/hyperactivity disorder.

This study examined the use of the Bender Visual-Motor Gestalt Test-Second Edition (BGT-II) with children diagnosed with Attention-Deficit/Hyperactivity Disorder (ADHD). Previous research has examined the relationship of ADHD and visual-motor functioning based on overall developmental scores or specific emotional indicators. Although several studies have examined the relationship of the previous edition of the BGT-II and ADHD symptoms, psychometric issues associated with the original edition limit the validity of the results. The current study examined the utility of the BGT-II in the assessment of behaviors associated with ADHD. A group of 62 subjects diagnosed with ADHD (M=11 yr., 5 mo.; 45 male, 17 female) was compared to a control group of 62 subjects randomly selected from the BGT-II standardization data (M=11 yr., 6 mo; 33 male, 29 female). Several hypotheses were made regarding how areas of deficit, e.g., self-regulation, planning, working memory, and motor control, were expected to manifest in BGT-II performance. With IQ controlled, subjects with ADHD performed more poorly on the BGT-II than subjects with no known disorders; however, the effect size was small (eta(p)=.07). Emotional indicators intended to assess symptoms of ADHD did not demonstrate diagnostic utility.

The Bender-Gestalt II.

In 2003, the Bender-Gestalt II was published. In the present article, the revision process is described, and major changes to the test are discussed. These changes include additional designs, a memory (recall) phase, Motor and Perception supplementary tests, a detailed observation form, a global scoring system, and a large, nationally representative normative base. Directions for future research are also provided.

Construct validity of the Bender-Gestalt II: comparison with Wechsler Intelligence Scale for Children-III.

This study investigated the relationships of visuomotor constructs as measured by the Bender-Gestalt II with the subtests of the WISC-III. A factor analysis included the standardized Copy and Recall scores of the Bender-Gestalt II and subtest scores of the WISC-III. The Copy score was predicted to load on measures of visual and spatial thinking and the Recall score on a short-term memory factor. The results of a principal components analysis suggest a four-factor solution with the Bender-Gestalt II Copy score loading on a visual and spatial thinking factor primarily with WISC-III Perceptual Organization subtests. The Recall score loaded on a visual and spatial thinking factor as well as a short-term memory factor with the WISC-III Digit Span subtest. The results suggest the Bender-Gestalt II Copy subtest shared commonality with the visual and spatial tasks given the similarity in the visuomotor demands of each test and was less influenced by processing speed or cultural knowledge than other tests on the visual and spatial thinking factor. Also, results suggest Bender-Gestalt II Recall measures elements of both visual and spatial thinking as well as aspects of short-term memory and memory retrieval. Clinical guidelines for co-administration and underlying processing demands are discussed.

Higher-order factor structures for the WISC-IV: implications for neuropsychological test interpretation.

Factor-analytic studies support a hierarchical four-factor model for the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) with a prominent general, third-order factor. However, there is substantial disagreement on which type of higher-order model best fits the data and how different models should guide test interpretation in clinical practice, with many studies concluding interpretation should primarily be focused on general indicators of intelligence. We performed a series of confirmatory factor analyses with the WISC-IV standardization sample (N = 2,200, ages 6-16 years) to examine model fit and reexamined models used to support test interpretation at the general level. Consistent with previous research, bifactor models were difficult to identify; however, compared with bifactor and hierarchical models, the correlated factors model with no general higher-order factor provided the best fit to the data. Results from this study support the basic four-factor model specified in the WISC-IV technical manual, with test interpretation primarily focused at the factor level, rather than the general level suggested in previous studies.

Development and evaluation of an online, multicomponent working memory battery.

Research has demonstrated strong connections among working memory (WM), higher-level cognition, and academic achievement. Despite the importance of WM, currently available WM tests have practical limitations and lack comprehensive coverage of multiple WM components. The Working Memory Battery (WOMBAT) includes nine subtests measuring multiple content domains and processing demands, in accordance with contemporary WM theoretical frameworks. The current study evaluated the WOMBAT factor structure and identified misfitting items using confirmatory factor analysis and Rasch modeling with scores from 125 adolescents and 177 adults (N = 302). Overall, results indicated the WOMBAT measures separate Verbal, Static Visual-Spatial, and Dynamic Visual-Spatial dimensions, and that more than 98% of items contribute to measurement of those dimensions. This provides support for the theoretical organization of WM into three distinct content domains in the WOMBAT. Misfitting items were identified using infit and outfit indices for further review to improve reliability and stability. Results also demonstrated adequate person separation and Rasch person reliability and item reliability. Test-retest reliability and internal consistency coefficients suggest adequate reliability for early-stage research, but further refinement is needed before the WOMBAT can be used for individual decision making. Implications for future test development and research on the WM construct are provided.

Estimating base rates of impairment in neuropsychological test batteries: a comparison of quantitative models.

Neuropsychologists frequently rely on a battery of neuropsychological tests which are normally distributed to determine impaired functioning. The statistical likelihood of Type I error in clinical decision-making is in part determined by the base rate of normative individuals obtaining atypical performance on neuropsychological tests. Base rates are most accurately obtained by co-normed measures, but this is rarely accomplished in neuropsychological testing. Several statistical methods have been proposed to estimate base rates for tests that are not co-normed. This study compared two statistical approaches (binomial and Monte Carlo models) used to estimate the base rates for flexible test batteries. The two approaches were compared against empirically derived base rates for a multitest co-normed battery of cognitive measures. Estimates were compared across a variety of conditions including age and different α levels (N =3,356). Monte Carlo R(2) estimates ranged from .980 to .997 across five different age groups, indicating a good fit. In contrast, the binomial model fit estimates ranged from 0.387 to 0.646. Results confirm that the binomial model is insufficient for estimating base rates because it does not take into account correlations among measures in a multitest battery. Although the Monte Carlo model produced more accurate results, minor biases occurred that are likely due to skewess and kurtosis of test variables. Implications for future research and applied practice are discussed.

Cognitive and developmental influences in visual-motor integration skills in young children.

Measures of visual-motor integration skills continue to be widely used in psychological assessments with children. However, the construct validity of many visual-motor integration measures remains unclear. In this study, we investigated the relative contributions of maturation and cognitive skills to the development of visual-motor integration skills in young children (N = 856). We used a block regression analysis to determine the contribution of maturation, as indicated by age, followed by broad cognitive factors (Study 1) and subsequently by individual subtests in verbal and nonverbal domains subsumed under each factor (Study 2) in explaining score variance of the Bender Visual-Motor Gestalt Test (2nd ed.; BG-II; Brannigan & Decker, 2003) Copy and Recall scores in children between the ages of 4 and 7 years. Results confirm that maturation accounted for a large proportion of variance in both BG-II Copy and Recall performance, above which Stanford-Binet Intelligence Scale (5th ed.; SB-5; Roid, 2003) Quantitative Reasoning and Fluid Reasoning factors significantly contributed to visual-motor integration performance for the Copy phase, and SB-5 Quantitative Reasoning and Visual-Spatial factors accounted for a significant amount of variance for the Recall phase. Additionally, nonverbal domains were more related to visual-motor performance than verbal domains. Results from this study are interpreted to suggest nonverbal reasoning and visual-spatial attention are important contributing factors to visual-motor integration, as measured by the BG-II. Developmental implications of visual-motor integration skills, nonverbal problem solving, and mathematical competence are discussed.

Tactile measures in the structure of intelligence.

This study investigated the relationship of tactile abilities within the framework of a hierarchical structure of mental abilities. Data were analysed from 229 participants who were administered tactile measures from the Dean-Woodcock Sensory Motor Battery along with a battery of conormed cognitive measures representative of the Cattell-Horn-Carroll (CHC) model of intelligence. Multiple measures of tactile performance were used including Palm Writing and Object Identification, and each measure included a lateralized measure (i.e., right/left). Factor analytic results suggest tactile measures have a significant relationship with measures of cognitive ability. In this study, tactile measures involving object identification were more related to cognitive measures of visual processing-speed and overall processing speed; whereas, tactile measures involving the recognition of numbers written on the palm of the hand produced high loadings on a separate factor. Results from this study suggest different tactile measures may differentially load on cognitive factors depending on the common processing demands of the tactile and cognitive measures. Suggestions for differentiating common processing demands between tactile and cognitive measures are discussed.

Development and validation of an attention-deficit/hyperactivity disorder (ADHD) executive function and behavior rating screening battery.

Attention problems are ubiquitous in clinical practice, commonly found in many childhood learning and behavior disorders. Practitioners need cost- and time-effective methods for determining whether children have attention problems due to attention-deficit/hyperactivity disorder (ADHD) or numerous other conditions. This study examined the utility of a 15-minute ADHD screening battery designed to differentiate ADHD (including inattentive, IT, and combined, CT, subtypes), specific learning disability (SLD), and typical child samples. Results for the 368 children (age 6 to 12 years) revealed that the Trail Making Test-Part B (Time/Errors), Hale-Denckla Cancellation Test (Time/Correct), and Child Attention Profile (Inattention/Overactivity) teacher ratings discriminated between typical and ADHD groups (87% correct classification; sensitivity = .64; specificity = .92) and differentiated between IT, CT, and SLD groups (80% correct classification; IT sensitivity = .82, and specificity = .96; CT sensitivity = .84, and specificity = .82). Discriminant function and Bonferroni post hoc results revealed different neuropsychological and behavioral patterns among groups.

Evidence of construct similarity in Executive Functions and Fluid Reasoning abilities.

Executive Functions and Fluid Reasoning are both considered to be core aspects of intelligence and mediated by frontal lobe functioning. However, both constructs considerably overlap, and the distinction between the two constructs is unclear. For this study, three measures of Executive Functions and three measures of Fluid Reasoning were administered to a group of participants. Significant correlations were found establishing an empirical association between these two constructs. Factor analysis and confirmatory factor analysis also provide evidence for construct similarity. Future research in defining these constructs for measurement purposes and using tests of these constructs in clinical practice is discussed.