Freedom From Distractibility Research Articles

Early diet in preterm infants and later cognition: 10-year follow-up of a randomized controlled trial

BackgroundAchieving adequate nutrition in preterm infants is challenging. The post-discharge period may be critical for influencing growth and cognitive outcomes. We studied the effects of post-discharge nutrition on childhood cognition.MethodsPreterm-born children were randomized at ~36 weeks corrected age (CGA) to either preterm formula (PTF) or term formula (TF) until 6 months, or PTF until 40 weeks CGA, then TF until 6 months (crossover group). Childhood cognition was assessed using the short form Wechsler Intelligence Scale for Children III, allowing computation of full-scale intelligence quotient (FSIQ) and four-factor index scores; verbal comprehension, freedom from distractibility (FDI), perceptual organization (POI), and processing speed (PSI).ResultsNinety-two children were recruited (mean 10.1 years). FSIQ did not differ by group. PTF-fed children had 10-point higher PSI (p = 0.03) compared to crossover. Faster weight gain from term to 12 weeks CGA was associated with 5-point higher FSIQ (p = 0.02) and four-point higher POI (p = 0.04). Infant head growth was positively associated with FSIQ (+3.8 points, p = 0.04) and FDI (+6 points, p = 0.003).ConclusionsWhile there is no long-term impact of post-discharge macronutrient enrichment on childhood cognition, greater weight and head growth in specific epochs is associated with better outcomes. Further studies are needed to determine optimal early diet in preterm infants.ImpactAchieving adequate nutrient intakes in preterm infants before and after hospital discharge is challenging.Nutrient intakes prior to discharge affect later cognitive and metabolic outcomes.Follow-up of a randomized controlled trial shows no cognitive benefit in later childhood from a more nutrient-dense formula compared to standard formula after hospital discharge.Growth in the first year of life is strongly correlated with childhood cognition and emphasizes the importance of nutrition in early life.

Intelligence test at preschool-age predicts reading difficulty among school-aged very low birth weight infants in Japan

ObjectiveTo elucidate whether the results of an intelligence test at preschool age are predictive of reading difficulty (RD) at school age among very low birth weight infants (VLBWI). MethodsSubjects were 48 Japanese children whose birth weight was <1500 g and who regularly visited a follow-up clinic. All subjects completed the Wechsler Intelligence Scale for Children-III (WISC-III) during the last grade of kindergarten, and four reading tasks during the second to fourth grade of elementary school. All participants had a full-scale intelligence quotient score of 85 or higher. Subjects with a standard deviation reading time score greater than 2.0 in two or more tasks were considered to have RD. We evaluated the associations between each WISC-III score and RD using logistic regression analyses. Furthermore, we performed receiver operating characteristic (ROC) analysis to determine a cutoff WISC-III score predictive of RD. ResultsIn the mutually-adjusted model, the adjusted odds ratio per 1 score increase of freedom from distractibility (FD) was 0.832 (95% confidence interval: 0.720–0.962). In the ROC analysis, an FD score of <95.5 was chosen as the cutoff value for predicting RD (sensitivity, 0.77; specificity, 0.74). ConclusionThe present study indicated that a lower FD score at preschool age, which was associated with deficits in verbal working memory and attention, is a risk factor for RD at school age among Japanese VLBWI. Further investigation is desired to clarify the cognitive deficits underlying RD in Japanese-speaking preterm children, and to establish appropriate interventions for these children.

Does Working Memory Impact Functional Outcomes in Individuals With ADHD: A Qualitative and Comprehensive Literature Review

Objective: Working Memory (WM) is a domain of executive functioning often impaired in individuals with ADHD. Although assumed to cause difficulties across functioning, the scope of impairments from WM deficits in ADHD has not been investigated. The aim of this study was to examine outcomes associated with WM deficits in ADHD. Method: We conducted a search of the scientific literature on WM deficits, and Freedom From Distractibility (FFD), in ADHD using PubMed and PsycInfo databases. Results: The final sample included 11 controlled studies of WM/FFD deficits in ADHD with operationalized assessment of outcomes in academic, social, and emotional areas. WM assessment was divided into auditory-verbal memory (AVM) and spatial-visual memory (SWM). Seven studies examined WM deficits in academic functioning, eight studies assessed WM deficits in social functioning, and three assessed WM deficits in psychopathology. Conclusion: The majority of the literature suggests that WM deficits affect primarily academic functioning.

Clinical correlates of working memory deficits in youth with and without ADHD: A controlled study

ABSTRACTObjective: Both working memory (WM; a brain system that provides temporary storage and manipulation of the information) and attention-deficit/hyperactivity disorder (ADHD) have been associated with educational deficits. Since WM deficits are prevalent in children with ADHD, the main aim of the present study was to examine whether educational deficits are driven by working memory deficits or driven by the effect of ADHD itself. Method: Participants were referred youth with (N = 276) and without (N = 241) ADHD ascertained from pediatric and psychiatric sources. Assessment included measures of psychiatric, psychosocial, educational, and cognitive functioning. Education deficits were defined as grade retention or placement in special classes and were assessed using interviews and written rating scales. Working memory was assessed using the Wechsler Intelligence Scale for Children–Revised (WISC–R) Freedom from Distractibility (FFD) factor based on Digit Span, Arithmetic, and Coding. Results: Significantly more youth with ADHD had WM deficits than controls (31.9% vs. 13.7%, p < .05). In ADHD children, WM deficits were significantly (p < .01) associated with an increased risk for grade retention and placement in special classes as well as lower scores on reading and math achievement tests than for ADHD children without WM deficits. In contrast, no other differences were noted in other areas of functioning. Although WM deficits also had some adverse impact on educational and cognitive correlates in non-ADHD controls, these differences failed to attain statistical significance. Conclusion: WM deficits significantly and selectively increase the risk for academic deficits and cognitive dysfunction in children with ADHD beyond those conferred by ADHD. Screening for WM deficits may help identify children with ADHD at high risk for academic and cognitive dysfunction.

Cognitive Recovery and Development after Traumatic Brain Injury in Childhood: A Person-Oriented, Longitudinal Study

Influence of childhood traumatic brain injury (TBI) on cognitive recovery and subsequent development is poorly understood. In this longitudinal study we used cluster analysis to explore acute stage individual profiles of injury age and cognition in 118 children with traumatic brain injury. Repeated measures of cognitive function were conducted at 30 months, indicating recovery, and 10 years post-injury, indicating development. Nine clusters were identified. Recovery was evident in three clusters, two of them with low functioning profiles. Developmental gains occurred for three clusters and an acute profile of higher freedom from distractibility (FFD) and lower processing speed (PS) was related to positive differences. One cluster, average low functioning and especially low verbal comprehension, demonstrated a slower development than peers. This suggests that developmental change after TBI in childhood takes place on a continuum, with both chance of long-term catching up, and risk of poor development. An acute profile of higher FFD and lower PS seemed to reflect injury consequences and were followed by developmental gains. These results challenge previous findings, and warrant further investigation.

Intellectual functioning of childhood leukemia survivors - relation to Tau protein - a marker of white matter injury

Chemo- and radiotherapy used in acute lymphoblastic leukemia (ALL) can influence on brain functioning in the future. In a prospective study we analysed the cognitive functions of ALL survivors in relation to Tau protein as a marker of white matter injury. Thirty-one survivors of childhood ALL (6.3 years after diagnosis); without the signs of CNS involvement, treated with chemotherapy alone, rested in first remission; underwent Intelligence tests- Wechsler Intelligence Scales (WISC-R, WAIS-R). Their results were analyzed in relation to the levels of Tau in cerebrospinal fluid (CSF) obtained during the treatment. The analysis showed that all survivors attained the average scores in intelligence tests. A negative correlation was found between methotrexate (MTX) doses and Freedom from Distractibility (FFD). Females had higher values of Performance Intelligence Quotient (PIQ) than males. A negative correlation was noted of Tau protein levels obtained from the last CSF with: Total and Verbal Intelligence Quotient, PIQ, Perceptual Organisation Index and FFD but not with Verbal Comprehension Index. Our results suggest the possibility of white matter injury during the treatment for ALL with chemotherapy alone. Elevated Tau protein level in CSF at the end of treatment might indicate future difficulties in neurocognitive functioning.

Reliability and validity of Freedom from Distractibility and Processing Speed Factors in the Norwegian WISC-III-version

Egeland, J., Sundberg, H., Andreassen, T.H. & Stensli, O. Reliability and validity of Freedom from Distractibility and Processing Speed Factors in the Norwegian WISC-III-version. Nordic Psychology, 58, 136–149. The reliability and validity of the Freedom from Distractibility (FFD) and Processing Speed (PS) indexes of the WISC-III are controversial. In this first study of the Norwegian translation of WISC-III, 127 protocols from a mixed psychiatric sample were factor-analyzed. Index-scores for subjects with ADHD, Pervasive disorders/nonverbal learning disability, learning disorders, language impairment or anxiety/affective disorders were compared. Results: Only two factors had eigenvalues above 1. They explained 61% of the total variance, thus showing that the WISC-III is primarily a test of a homogenous construct of intelligence. With a more liberal inclusion criteria, the traditional four-factor solution emerged. Comparisons of the four-factor-indexes within each group, showed that the language impaired- group had a significantly lower FFD score compared to the other indexes. The pervasive disorder group was significantly impaired on the PS index. The ADHD group had a flat profile. There was no increased frequency of subjects significantly impaired on the FFD or PS indexes in the ADHD group compared to the other subjects. Conclusion: The study questions the value of the Norwegian version of the WISC-III with regard to assessment of attention and processing speed.

The Swedish WAIS-R Factor Structure and Cognitive Profiles for Adults with Dyslexia

Factor analysis of the Swedish version of the Wechsler Adult Intelligence Scale-Revised (WAIS-R) on a group of 88 adult individuals with dyslexia showed a three-factor structure with a verbal comprehension (VC) factor, a perceptual organization (PO) factor, and a freedom from distractibility (FD) factor. The results of this factor analysis support earlier findings from factor analyses of adults in the original U.S. normative sample and in different clinical groups. The profile of scores for the sample of individuals with dyslexia showed the expected pattern, with PO highest and FD lowest. The predicted pattern was also observed using Bannatyne's recategorization of WAIS-R subtests. As has been true for other typical and exceptional samples, women scored significantly higher than men on the Digit Symbol subtest. Related to this gender difference, Digit Symbol scores proved to be sensitive to problems associated with dyslexia only for men with dyslexia. Also, education level was shown to be related to verbal (V)-performance (P) IQ discrepancy, with larger P > V differences observed for participants with fewer years of formal schooling. Regardless of these gender and education differences, the characteristic factor score and Bannatyne patterns were identified for both men and women and for three different subsamples categorized by educational level.

Analyzing Digit Span Components for Assessment of Attention Processes

The Digit Span (DS) subtest of the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) is thought to be a measure of attention, concentration, sequencing, number facility, and auditory short-term memory. An optional WISC-III subtest and part of the Freedom from Distractibility (FD) factor, DS assesses several cognitive constructs, yet its utility in differential diagnosis has been questioned because poor DS or FD performance has been inconsistently associated with attention processes. In this study of 195 children referred for comprehensive neuropsychological evaluations, Digits Forward (DF) and Digits Backward (DB) component scores were found to be differentially predictive of attention, executive function, and behavior rating measures. Results suggest that DB is associated with attention and executive function processes, not the short-term rote auditory memory processes tapped by DF.

The Relationship Between Intelligence and Performance on the Test of Variables of Attention (TOVA)

The present study explored the relationship between the intelligence of young adults and their performance on the Test of Variables of Attention (TOVA). The study also examined whether significant differences existed between adults with and without attention-deficit/ hyperactivity disorder (ADHD) on TOVA errors of omission, errors of commission, mean correct response time, and variability, as well as on performance on the freedom from distractibility (FD) factor on the Wechsler Adult Intelligence Scale-Revised (WAIS-R). Seventy-nine adults participated in the study, including 17 with ADHD and 62 college students without ADHD. Pearson product-moment correlations indicated that none of the correlations between Full Scale IQ (FSIQ) and TOVA variables were significant. Analysis of variance results revealed that adults with ADHD made more errors of omission on the TOVA than did controls. Between-group differences were not found on the remaining dependent variables.

Confirmatory factor analysis of the WAIS-R in patients with schizophrenia

Although factor scores are commonly used to interpret the Wechsler Adult Intelligence Scale—Revised (WAIS-R), the WAIS-R factor structure has not been investigated in patients with schizophrenia. We used confirmatory factor analysis (CFA) to examine five latent construct models in 169 males with schizophrenia. The WAIS-R standardization sample (ages 35–44; n=250) was used as a comparison group. For both groups, all model fit indexes used to determine model adequacy supported models composed of Verbal Comprehension (VC), Perceptual Organization (PO) and Freedom from Distractibility (FFD) factors. However, the Digit Symbol subtest loaded on both the PO and FFD factors for patients with schizophrenia but only on the FFD factor for the WAIS-R standardization sample. Patients with schizophrenia performed significantly worse on the FFD and PO factors compared to the VC factor, reflecting the well-characterized attention and problem solving deficits associated with schizophrenia. Also, patients with schizophrenia performed significantly worse than the WAIS-R sample on all factors. These results provide support for the validity of the WAIS-R factors in patients with schizophrenia.

WISC-III Third Factor: Critical Measurement Issues

Content validity of the Third Factor of the Wechsler Intelligence Scale for Childre-n-Third Edition (WISC-III) was evaluated by asking undergraduates to label the factor represented by items like those on the Arithmetic and Digit Span subtests. Participants unfamiliar with the content of the two subtests choose labels that corresponded with terminology associated with problem solving, memory, and quantitative skills. The concurrent validity of the Third Factor with behavioral measures of attention, hyperactivity, and learning problems was assessed in a sample comprising consecutive referrals to a university-based psychoeducational clinic. There was a moderate relationship between Freedom From Distractibility (FFD) and teacher ratings of learning problems on the Behavior Assessment System for Children-Teacher Rating Scales. There were no significant correlations to suggest concurrent validity between the Third Factor and behavioral ratings of attention problems and hyperactivity. Theoretical and practical implications of the FFD factor are discussed.

INDOMETHACIN (INDO) PROPHYLAXIS AND OUTCOME AT SCHOOL AGE. † 2222

We determined the outcome at school age of children who received INDO for intraventricular hemorrhage (IVH) prevention. Follow-up data were available in 81 children, through developmental testing (n=46) or through completed questionnaires (n=35). Of 81, 26 received INDO; 55 did not (NO-INDO). Thetable shows demographics and outcomes as to school performance, severe neuro/sensory handicaps, and in those tested using the WISC-III, the means of the IQs; i.e., verbal (VIQ), performance (PIQ), full scale (FSIQ), verbal comprehension (VC), perceptual organization (PO), freedom from distractibility (FD), and processing speed (PS). Multiple linear regression was used to determine the effect of birth weight (BW), socioeconomic status (SES), IVH grade and indomethacin, on full scale, verbal and performance IQs, as well as on the 4 factors. We found no differences in outcomes between the INDO and NO-INDO groups. IQ scores were not related to INDO, BW or SES. However, FSIQ was related to sex (p<0.005) and IVH(p<0.02). Verbal IQ was related to sex but not to IVH. PIQ and POIQ were significantly related to IVH (p<0.02). We conclude that INDO for IVH prevention did not affect long-term outcome, however, IVH significantly influenced perceptual organization.

Thyroid hormone and attention in congenital hypothyroidism.

To determine in school-age children with congenital hypothyroidism: (i) frequency of a high thyroxine/high thyrotropin profile; (ii) relations between different levels of thyroxine and thyrotropin and attentional function, and (iii) persistence of effects. Retrospective analysis of an inception cohort. Clinical psychology laboratory in tertiary pediatric hospital. Eighty-six 7 year olds identified with congenital hypothyroidism by newborn screening, who were participating in a long-term prospective study. Wechsler Intelligence Scale for Children-Revised (WISC-R) and Wide Range Achievement Test-Revised (WRAT-R) were administered. WISC-R Full Scale, Verbal and Performance IQs were obtained as well as scores on individual subtests, and three ability composites. Freedom from Distractibility (FFD) served as the indicator of attention. 9.3% of 7 year olds had elevations of both T4 and TSH. These children scored significantly higher on word knowledge and spelling but had significantly lower Digit Span and FFD scores than those in groups with other hormone combinations. Level of thyroxine was the primary predictor of attention, accounting for 10.5% of the variance. Among 9 year olds, 6.1% had T4 and TSH elevations, and although they also scored lowest on FFD, these were not the same children with T4 and TSH elevations at age 7. These results signify that a high T4/high TSH profile contributes to poorer attention. Because the individual children who showed the effect were not the same at the two ages, this suggests that thyroid hormone appears to play a role in regulating attention but does not indicate resistance.

The WISC-III Freedom from Distractibility factor: Its utility in identifying children with attention deficit hyperactivity disorder.

Factor analytic studies of the Wechsler Intelligence Scale for Children—Revised (WISC–R; Wechsler, 1974) have consistently identified what is commonly known as the Freedom From Distractibility (FFD) factor, consisting of the Arithmetic, Digit Span, and Coding subtests (Kaufman, 1979). Support for the validity of this factor stems in part from studies that found significant correlations between the WISC–R FFD subtests and other established measures of attention, such as Continuous Performance Tests (Klee & Garfinkel, 1983) and teacher ratings (Reschly & Reschly, 1979). Additional support comes from investigations that detected significantly lower FFD scores among groups of children with attention deficit hyperactivity disorder (ADHD; American Psychiatric Association, 1987) in comparison with control children (Lufi, Cohen, & Parish-Plass, 1990).

Differential Diagnosis of Children with ADHD and ADHD/with Co-Occurring Conduct Disorder

The WISC-R factors, Verbal Comprehension, Perceptual Organization and Freedom from Distractibility (FFD) were examined for their discriminant validity in diagnosing children with Attention Deficit Hyperactivity Disorder (ADHD), ADHD with co-occurring Conduct Disorder (ADHD + CD) and those comprising a clinic control population. Contrary to expectations and clinical practice, the FFD factor did not significantly discriminate among children comprising the three diagnostic groups. The verbal comprehension and perceptual organizational factors significantly distinguished between children with and without conduct disorder, but not between the clinic control and ADHD children. Therefore, the ADHD + CD group's performance on the WISC-R factors qualitatively differs from children with internalizing disorders or ADHD, and as such is most likely a separate population. Furthermore, the use of the FFD factor did not provide sufficient sensitivity for a discriminative diagnosis (a miss rate of 50 percent for clinic control, 64.3 percent for ADHD and 38.1 percent for ADHD + CD).

The hierarchical factor structure of the WAIS-R for alcoholic adults.

A Wherry (1984) hierarchical factor solution was obtained on the WAIS-R subtest intercorrelations for 108 alcoholic adults. An ability arrangement consistent with Vernon's (1950) structure-of-intellect paradigm was found. This ability hierarchy consisted of a strong general intelligence (g) factor defined by all 11 subtests, which accounted for 49% of the variance. The primary level of the ability hierarchy consisted of spatial-perceptual-mechanical (k:m), Freedom from Distractibility (FD), and Verbal Comprehension (VC) factors. Those respective factors accounted for 86%, 4%, and 3% of the total subtest variance.

Relationships among four methods of assessment of children with attention deficit- hyperactivity disorder

The relationship among the Conners Teacher Rating Scale, the Revised Conners Parent Rating Scale, the Revised Behavior Problem Checklist, and the Freedom-From- Distractibility (FD) factor score of the WISC-R are examined for 135 children who were new patient referrals to a pediatric neurology learning disabilities clinic. The results of correlational analysis appear to add further evidence that FD is not a reliable measure of Attention Deficit–Hyperactivity Disorder (AD-HD), but may reflect a weak relationship with performance anxiety. Analysis of the rating scale data from increasingly more homogeneous clinical samples of AD-HD children indicates that the low level of parent-teacher agreement previously reported in the literature may not be a function of low rating-scale reliability, but rather a function of the heterogeneity of the population and the varying diagnostic criteria used by clinician-researchers. Multiple methods are suggested for the assessment of Attention Deficit–Hyperactivity Disorder by both psychologists and physicians.

WISC-R factor scores and student self-ratings of behavior as predictors of academic achievement

The capability of WISC-R Verbal Comprehension (VC), Perceptual Organization (PO), and Freedom from Distractibility (FD) factor scores and student self-ratings of behavior from the Behavior Rating Profile Student Rating Scales (BRP-SRS) to predict academic achievement was investigated. Previous research found that intellectual ability accounted for about 50% of the variance in achievement. Other noncognitive variables are expected to account for a portion of the remaining variance and add significantly to the prediction of achievement. Subjects were public school students referred for psychological evaluations due to learning and behavior problems in the classroom. The results of a multivariate multiple regression analysis indicated that VC and FD factors significantly predicted Woodcock-Johnson Reading, Mathematics, and Written Language cluster scores. The VC and FD factors accounted for a major portion of the variance in achievement. Behavioral self-ratings did not contribute significantly to the prediction of achievement scores.

Hierarchical analyses of the WISC and WISC-R: synthesis and clinical implications

A review of hierarchical factor solutions obtained on normal and atypical samples in twelve previous studies showed ability arrangements in agreement with Vernon's structural paradigm. A composite hierarchy synthesized from these studies includes a general intelligence (g) factor at the apex and major group factors corresponding to the verbal-educational (wed) and spatial-mechanical-practical (kim) dimensions at the subgeneral level. Verbal Comprehension (VC), Freedom from Distractibility (FD), Spatial (k) and Quasi-Specific (QS) minor group factors comprised the third level of the ability hierarchy. Four principles are suggested as guidelines for the clinical interpretation of the WISC-R.