Verbal Organization Research Articles

Cognitive Functions in Children at Risk for Congenital Adrenal Hyperplasia Treated Prenatally with Dexamethasone

For more than two decades, the fetuses of pregnant women carrying a fetus at risk of virilizing congenital adrenal hyperplasia (CAH) have received dexamethasone (DEX). While this measure makes traumatizing genital surgery unnecessary by preventing virilization, some have voiced concern about how glucocorticoid therapy may affect fetal programming. This is the first study assessing long-term cognitive development by direct examination of children exposed prenatally to DEX. Twenty-six children at risk (12 boys and 14 girls), along with 35 age- and gender-matched control children, underwent a wide range of neuropsychological tests at 7 to 17 years of age. DEX was administered from postmenstrual week 6 to 7. Women with a previous severely affected child received 20 μg/kg daily up to a maximum daily dose of 1.5 mg. DEX-exposed and control children performed equally well on tests of verbal comprehension and perceptual organization. Mean full-scale IQ scores were comparable in the two groups. No differences were noted on tests of immediate and long-term memory. In evaluating working memory using a freedom-from-distractibility index, scores on the Digit Span, a subtest measuring verbal working memory, were lower in DEX-exposed girls and boys than in control subjects. There were no differences in performance on tests of impulse inhibition or processing speed. On child-completed questionnaires, DEX-exposed children reported having trouble figuring out the answers at school, independently of psychometric intelligence scores. Children without CAH who received short-term treatment had increased self-rated social anxiety. Parental ratings of their child's performance in reading, writing, spelling, and mathematics disclosed no significant differences after adjusting for full-scale IQ. Deficits in some aspects of cognitive function apparently are present in children and adolescents exposed in utero to maternal glucocorticoid therapy, given to prevent virilization when the fetus is at risk of CAH. Larger-scale retrospective studies are needed to confirm or question these findings.

Spontaneous and directed application of verbal learning strategies in bipolar disorder and obsessive‐compulsive disorder

Individuals with bipolar disorder exhibit neuropsychological impairments when they are euthymic (neither depressed nor manic). One of the most consistently reported cognitive problems in euthymic individuals with bipolar disorder is impairment in verbal episodic memory. Recent findings suggest that episodic memory difficulties in these individuals are attributable to difficulties using organizational strategies during encoding. The purpose of the present study was (i) to investigate whether difficulties using organizational strategies in bipolar disorder are due to a failure in spontaneously initiating verbal organization strategies or are due to difficulties implementing such strategies, and (ii) to compare the characteristics of verbal organizational impairment in bipolar disorder with those observed in individuals with obsessive-compulsive disorder (OCD). Study participants were 20 individuals with bipolar I disorder (BP-I), 20 individuals with OCD, and 20 healthy control participants matched for age, gender, and education. Participants completed a verbal encoding paradigm that involved spontaneous and directed use of verbal organization strategies during encoding of word lists. Compared with control subjects, both BP-I and OCD participants showed impaired verbal organization in the spontaneous encoding condition. In the directed encoding condition, OCD patients organized the word lists as well as control participants whereas BP-I participants exhibited lower verbal organization than both control and OCD participants. OCD and BP-I participants' free recall performance did not differ from that of control participants in the spontaneous encoding condition. In the directed encoding condition, BP-I participants recalled fewer words than OCD or control participants. Episodic memory difficulties in OCD are associated with difficulties spontaneously initiating verbal organization strategies during encoding whereas the ability to implement verbal organization when instructed to do so is preserved. BP-I participants, on the other hand, exhibit difficulties in both spontaneously initiating verbal organization strategies and in the ability to implement such strategies when instructed to do so.

NEUROPSYCHOLOGICAL MEASURES AND SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY IN THE DIFFERENTIATION AND CLASSIFICATION OF CEREBRAL PERFUSION DEFICITS IN ALZHEIMER'S DEMENTIA

The accurate diagnosis of Dementia of the Alzheimer's Type (DAT) continues to be an area of difficulty for the fields of neuropsychology and neurology. The introduction of new medications that appear to mediate the insidious progression of the disorder increases the need for timely differentiation of DAT from other dementia-related disorders. The present study examined the relationship between hemispheric differences in regional cerebral blood flow with corresponding lateral neuropsychological processing deficits in patients with DAT. Eighty patients with a diagnosis of DAT were administered Single Photon Emission Computerized Tomography (SPECT) scans and a battery of left and right hemisphere neuropsychological-based tasks. The results of ANOVA indicated that patients with DAT who were not suffering from perfusion deficits exhibited significantly fewer neuropsychological deficits than did patients with DAT who had perfusion deficits. The neuropsychological tests that measured verbal ability, logical memory, word-pair learning, reading, arithmetic, and visual-perceptual organization were all significantly lower in the group with perfusion deficits. Further analysis indicated that patients with left hemisphere perfusion deficits tended to have poorer neuropsychological skills than did individuals with right hemisphere perfusion deficits, diffuse perfusion deficits, and no perfusion deficits. A Stepwise Discriminant Analysis was unable to use the neuropsychological variables to classify patients accurately into perfusion deficit groups.

Episodic memory impairment in bipolar disorder and obsessive-compulsive disorder: the role of memory strategies.

There is evidence that individuals with bipolar disorder exhibit neuropsychological impairments not only during mood episodes but also when they are euthymic. One of the most consistently reported cognitive problems in euthymic individuals with bipolar disorder is an impairment in verbal episodic memory. Verbal learning and memory depend on individuals' ability to organize verbal information appropriately during learning. The purpose of the present study was (i) to determine whether episodic memory impairment in euthymic individuals with bipolar disorder is mediated by impairments in organization of verbal information during learning and (ii) to compare the characteristics of memory impairment in bipolar disorder with that previously found in obsessive-compulsive disorder (OCD). Study participants were 30 individuals with DSM-IV bipolar I disorder (BP-I), 30 individuals with DSM-IV OCD and 30 normal control participants matched for age, gender and education. Participants completed the California Verbal Learning Test (CVLT), a well-established measure of verbal learning and memory that enables assessment of verbal organization strategies during learning. Compared with control subjects, both BP-I and OCD participants showed impaired performance in long-delayed free recall and verbal organization strategies during learning. BP-I participants showed greater long-delay free recall difficulties but not greater verbal organization difficulties during learning than OCD participants. For OCD participants, the long-delay recall impairment was mediated by difficulties using verbal organizational strategies during learning. In contrast, the group difference in long-delayed free recall between BP-I and control participants remained significant even when semantic clustering was introduced as a mediator. This indicated that BP-I participants' long-delayed free recall difficulties were mediated to a lesser extent by difficulties using verbal organizational strategies than for OCD participants. Verbal episodic memory problems in individuals with bipolar I disorder and OCD are mediated to different degrees by difficulties using semantic clustering encoding strategies compared with control participants.

Exploratory Factor Analysis of the Wechsler Abbreviated Scale of Intelligence (WASI) in Adult Standardization and Clinical Samples

Exploratory factor analyses were conducted separately on the Wechsler Abbreviated Scale of Intelligence (WASI; The Psychological Corporation, 1999) adult standardization sample (n = 1,145) and a diagnostically heterogeneous adult clinical sample (n = 201). In the latter group, means for age, education, and WASI Full Scale IQ were 59.25 years (SD = 17.52), 12.39 years (SD = 2.88), and 89.91 (SD = 16.00). For each sample, the four WASI subtests were subjected to a principal-axis factor analysis followed by varimax and promax rotations. Two factors were specified to be retained. Verbal Comprehension and Perceptual Organization factors were identified in both analyses. Coefficients of congruence were 0.98 for Factor I and 0.99 for Factor II, suggesting factorial equivalence across the standardization and clinical samples.

Cognitive Development of Lead Exposed Children from Ages 6 to 15 Years: An Application of Growth Curve Analysis

The effect of lead exposure on cognitive growth patterns was assessed in a longitudinal study of 196 children. Performances on tests of verbal comprehension and perceptual organization (Vocabulary & Block Design, Wechsler Intelligence Scales for Children) were measured at ages 6.5, 11 and 15 years. Growth curve analyses revealed that the quadratic model best described the relationship between test scores and age. Children with higher lead levels, as measured at age 15 years, demonstrated lower verbal comprehension scores over time and greater decline in their rate of Vocabulary development at age 15 years, as compared to children with lower lead levels. Lead exposure was not significantly associated with growth in perceptual organization test scores. Socioeconomic status and maternal intelligence were statistically significantly associated with growth patterns for both test scores, independent of the effects of lead. The findings suggest that lead negatively impacts the developmental progression of specific cognitive skills from childhood through adolescence.

A Confirmatory Factor Analysis of the WAIS—III in Patients with Traumatic Brain Injury

Maximum likelihood confirmatory factor analysis was performed on the WAIS-III data of a sample of 166 patients with traumatic brain injury (TBI). Four competing hypothetical models were tested for model fit and parsimony. A four-factor model composed of Verbal Comprehension, Perceptual Organization, Working Memory, and Processing Speed, identical to that proposed for the standardization sample, provided the best fit to the clinical data. The results support the construct validity of these four factors in patients with TBI.

Factor Structure of the French Adaptation of the WISC-III: Three or Four Factors?

The standardization of the French version of the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) was conducted after a careful French adaptation from the U.S. version and extensive field testing. The standardization sample size was 1,120 participants with an age range from 6 years to 16 years. To check the constructive validity of the WISC-III, the same exploratory and confirmatory factor analysis than those used for the validation of the U.S. version was performed. The 4-factor solution found with the U.S. WISC-III was tested. With the French WISC-III, this solution did not fit the data and was very unstable across the age range. A 3-factor solution seemed a better one. According to the factor loadings, the 2 first factors can be called Verbal Comprehension and Perceptual Organization. Two subtests have their highest loading on the third factor: Coding and Symbol Search. This factor can be seen as a measure of the processing speed. However, further research is still needed to clarify the significance of this factor and to understand the difference we observed between the French and the U.S. factor structures.

Factorial Invariance for Combined Wechsler Adult Intelligence Scale-Revised and Wechsler Memory Scale-Revised Scores in a Sample of Clients With Alcohol Dependency*

This study examined the joint factor structure of the WAIS-R and WMS-R in a sample of 289 participants (mostly males) with alcohol dependency. In a confirmatory phase we contrasted a range of factor models derived from previous analyses of the Wechsler scales. The best fitting model incorporated five factors representing Verbal Comprehension, Perceptual Organization, Attention-Concentration, Verbal Memory, and Visual Memory, with reassignment of factor loadings for two subtests. The invariance of the measurement model was then examined comparing data from a large sample of healthy participants (J. R. Carstairs E. A. Shores, 1999). The results indicated that the number of factors was invariant across samples, and four of the factors satisfied the criterion of partial measurement invariance.

Replication of the factor structure of the Wechsler Adult Intelligence Scale—Third Edition with a Canadian Sample.

Exploratory and confirmatory factor analyses of the subtests of the Wechsler Adult Intelligence Scale--Third Edition (WAIS-III; D. Wechsler, 1997b) were conducted on a stratified sample of Canadian adults (n = 718). As was previously demonstrated for the children's version of this scale, the factor model of the American standardization sample was replicated across this Canadian national sample. Results of the factor analyses confirmed the presence of the 4 WAIS-III factors: Verbal Comprehension, Perceptual Organization, Working Memory, and Processing Speed.

La spirale et le fragment. Auto-similarité et rupture

A poem by Robert Herrick is taken as an exemplar of the neo-classical aesthetics of imitation. Herrick appropriates the established topoi and forms of the ode and the elegy to orchestrate a seamless verbal organization with self-similar features to be found from the phonic level to the overall vision. Galway Kinnell on the other hand is representative of a modem aesthetics of incompletude : instead of redundancy and convergence his poem relies on abrupt changes, fragmentation and rupture. How does the reader deal with these two contrasted strategies ? Are the two poles of redundancy and noise mutually exclusive or cooperative ?

Replication of the Wechsler Intelligence Scale for Children—Third edition four-factor model in the Canadian normative sample.

Confirmatory factor analyses of the Wechsler Intelligence Scale for Children-Third Edition (WISC-III ; D. Wechsler, 1991) subtests, using the Canadian normative sample, were conducted to verify the 4-factor model identified for WISC-III in the U.S. normative sample. Because the items and test materials for WISC-III were identical in both samples, this study focused on replication of the factor model across national samples. The Canadian normative sample (N = 1,100) was a stratified random sample of Canadian children, ages 6 to 16. Results for the Canadian sample paralleled those found in the U.S. sample (N = 2,200) and confirmed the presence of the 4 factors previously identified (Verbal Comprehension, Perceptual Organization, Processing Speed, and Freedom From Distractibility). This article also provides justification for the scoring and clinical use of WISC-III factor indexes.

The Third and Fourth Factors of the WISC-III: What they Don't Measure

Factor analysis of the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) continues to demonstrate support for the Verbal, Performance, and Full Scale IQs, as well as for the Verbal Comprehension (VC) and Perceptual Organization (PO) factors. With the addition of the Symbol Search subtest, however, the factor analysis reported in the examiner's manual yielded two additional factors rather than just one. There is, however, no early evidence that the third and fourth factors are clinically interpretable. This study examined the relationship between the WISC-III third and four factors and other neuropsychological and behavioral measures. Results indicated that although Freedom From Distractibility (EFD) and Processing Speed (PS) correlated significantly with VC and PO factors, the FD and PS factors did not correlate significantly with any of the other measures of attention. The most robust correlations were between measures of immediate/working memory and FFD and PS. When comparing clinical groups (LD/no ADHD, ADHD Predominantly Inattentive, and ADHD Combined Type), no differences emerged on the FFD or PS factors. The clinical validity of these factors remains questionable. The significant relationship between WISC-III factors and measures of immediate/working memory is promising, but in need of additional research.

WISC-R factor structures among White, Mexican American, and African American children: A research note

The factor structure for the Wechsler Intelligence Scale for Children-Revised (WISC-R) was investigated for White (n = 183), Mexican American (n = 129), and African American (n = 139) nonreferred school-age children (6.8 to 14.6 years) of low-to middle-class socioeconomic background. Exploratory and confirmatory factor analyses were performed. The WISC-R factor structure model tested was Kaufman's (1975) three-factor solution that consisted of Verbal Comprehension (VC, Factor 1), Perceptual Organization (PO, Factor 2), and Freedom from Distractibility (FD, Factor 3). The results of the exploratory analyses showed Kaufman's three-factor solution for the three ethnic groups, but the order of Factor 2 and Factor 3 was reversed for the Mexican American and African American samples—thus raising questions about the comparability of the WISC-R factor structure across groups. The confirmatory analyses, which used the orthogonal nested factors approach by Gustafsson and Balke (1993), resulted in a model (for each of the ethnic groups) in which a G factor explained most of the variance (followed by the nested first-order factors—VC, PO, and FD). The results of the confirmatory analyses provide some support for David Wechsler's (1974) original intentions that the WISC-R structure is best described as having a general, or global, factor. © 1997 John Wiley & Sons, Inc.

Matching verbal organizations heard with voiced and whispered vowel sequences

Research shows that listeners exposed to a repeated sequence of steady-state vowels experience phonemic transformations, and hear words and phrases absent in the original stimulus. Similar observations have been made with whispered stimuli. This study investigated the similarity in the organizations heard with voiced and whispered vowel sequences, each made up of six vowels. Listeners heard each set of stimuli and reported what they heard with each arrangement. Then, additional stimuli were presented identical to the first two sets but with the duration of each vowel longer by 40 ms. These stimuli were presented in a different order, and listeners were asked to match each sequence to the verbal organizations heard initially. Most listeners were able to perform the task when the stimulus conditions corresponded to the organization conditions: ‘‘all voiced’’ or ‘‘all whispered.’’ Listeners also performed the matching task in the ‘‘voiced/whispered’’ condition (when they were asked to match voiced stimuli to organizations heard with whispered stimuli) and in the ‘‘whispered/voiced’’ condition (when whispered stimuli were matched to organizations heard with voiced stimuli). The results suggest similarities between perceptual mechanisms responsible for these effects and mechanisms involved in the processing of speech.

Stability of the WPPSI-R and WISC-III Factor Structure Using Cross-Validation of Covariance Structure Models

The reliability of the Verbal Comprehension and Perceptual Organization factors of the WPPSI-R and WISC-III was examined by use of cross-validation of covariance structure models, a new statistical methodology that employs both unrestricted and restricted factor analyses. Reliability of the factor structure would be indicated if the goodness of fit of restricted factor analytic models generated from unrestricted factor patterns did not degrade when tested on other age groups. If the goodness of fit changed in an inconsistent fashion, that would indicate that the factor structure of one or both of the instruments is unreliable. Finally, if the goodness of fit changed in a systematic fashion, getting worse with greater age differences, then an argument for true intellectual changes could be made. Results revealed general consistency in the goodness of fit across age groups. Therefore, it was concluded that a two-factor model that consists of the Verbal Comprehension and Perceptual Organization factors is reliable across age groups and instruments.

Multivariate genetic analysis of Wechsler Intelligence Scale for Children--Revised (WISC-R) factors.

Wechsler Intelligence Scale for Children--Revised (WISC-R) factor scores (Verbal Comprehension, Perceptual Organization, and Freedom from Distractibility) were obtained from 574 twin pairs in the Colorado Reading Project and subjected to multivariate genetic analysis. Variances were partitioned into components common to the three WISC-R factors and to those specific to each factor. Substantial commonality, both genetic and environmental, was found among the three factors. The full model fit the data well, and estimates of heritability and environmentality indicated that about half of the phenotypic variance for each factor is due to additive genetic effects. These results were compared to those obtained in a previous twin study of the three Wechsler Adult Intelligence Scale (WAIS) factors by Tambs et al. (1986).

The effects of pitch changes on the perception of vowel sequences

When listeners hear a repeated sequence of steady-state vowels (of the same duration and pitch) phonemic transformations occur, and they report hearing words and phrases absent in the original stimulus. A previous study [M. H. Chalikia, R. Meyer, and R. Lindemann, 34th Psychon. Society Meet. (1993)] investigated the possible effects of variations in vowel duration, pitch, or both. Listeners successfully matched these vowel sequences to the verbal forms heard with vowels of equal duration and pitch (base-line stimuli). In this study a broader variation in pitch was employed, and the vowel sounds were computer-generated rather than naturally produced. Six base-line sequences of six 60-ms vowels (at 100 Hz), followed by a 300-ms silent gap, were used. Four variations of these were created by randomly changing the pitch of individual vowels. Most listeners were able to match the modified vowel sequences to the verbal forms heard with the base-line stimuli, thus confirming the robust, stable nature of the verbal organizations. It is suggested that these organizations are based upon objective acoustic characteristics, and the present stimulus manipulations were probably perceived as prosodic variations.

The effects of duration changes on the perception of vowel sequences

Previous studies have shown that listeners exposed to a repeated sequence of steady-state vowels (of same duration and pitch) experience phonemic transformations, and report hearing words and phrases absent in the original stimulus. A previous study [M. H. Chalikia, R. Meyer, and R. Lindemann, 34th Psychon. Society Meet. (1993)] investigated the possible effects of variations in vowel duration. Duration variations ranged from 30 to 120 ms per vowel. Listeners successfully matched these stimuli to the verbal forms heard with vowels of equal duration and pitch, confirming the robust, stable nature of the verbal organizations. It was suggested that these organizations are based upon objective acoustic characteristics, and the stimulus manipulations were probably perceived as prosodic variations. In this study a broader variation in duration was employed (10–300 ms), in an attempt to examine listeners’ limitations in performing the matching task. Six base-line sequences of six 80-ms vowels (at 100 Hz), followed by a 300-ms silent gap, were used. Four variations of these were created by randomly changing the duration of individual vowels within a sequence. Most listeners were not able to perform the task. Implications concerning the perceptual organization of speech will be discussed.

Spectral fissioning in phonemic transformations.

Listeners presented with a repeated sequence of brief (30- to 100-msec) steady-state vowels hear phonemic transformations--they cannot identify the vowels, but they perceive two simultaneous utterances that differ in both phonemic content and timbre (Warren, Bashford & Gardner, 1990). These utterances consist of either English words or syllables that occur in English words. In the present study, we attempted to determine whether the two percepts represent alternative interpretations of the same formant structures, or whether different portions of the vowels are used for each verbal organization. It was found that separate spectral regions are employed for each verbal form: Components below 1500 Hz were generally used for one form, and components above 1500 Hz for the other. Hypotheses are offered concerning the processes responsible for the verbal organization of the vowel sequences and for the splitting into two spectrally limited forms. It appears that the tendency to organize spectral regions separately competes with, and can overcome, the tendency to integrate the different spectral components of speech into a single auditory image. A contralateral induction paradigm was used in a procedure designed to quantitatively evaluate these opposing forces of spectral fission and fusion.