Verbal Cognition Research Articles

Anodal transcranial direct current stimulation of the prefrontal cortex enhances complex verbal associative thought.

The remote associates test (RAT) is a complex verbal task with associations to both creative thought and general intelligence. RAT problems require not only lateral associations and the internal production of many words but a convergent focus on a single answer. Complex problem-solving of this sort may thus require both substantial verbal processing and strong executive function capacities. Previous studies have provided evidence that verbal task performance can be enhanced by noninvasive transcranial direct current stimulation (tDCS). tDCS modulates excitability of neural tissue depending on the polarity of the current. The after-effects of this modulation may have effects on task performance if the task examined draws on the modulated region. Studies of verbal cognition have focused largely on the left dorsolateral prefrontal cortex (F3 of the 10-20 EEG system) as a region of interest. We planned to assess whether modulating excitability at F3 could affect complex verbal abilities. In Experiment 1 (anodal, cathodal, or sham stimulation over F3 with the reference electrode over the contralateral supraorbital region), we found a significant overall effect of stimulation condition on RAT performance. Post hoc tests showed an increase in performance after anodal stimulation (1 mA) compared to sham (p = .025) and to cathodal stimulation (p = .038). In Experiment 2 (either anodal stimulation at F3 or separately at its homologue F4), we replicated the anodal effect of the first study, but also showed that anodal stimulation of F4 had no effect on RAT performance. These data provide evidence that anodal stimulation of the left dorsolateral prefrontal cortex can improve performance on a complex verbal problem-solving task believed to require significant executive function capacity.

Outcomes of Child Sleep Problems Over the School-Transition Period: Australian Population Longitudinal Study

Adequate sleep optimizes children's learning and behavior. However, the natural history and impact of sleep problems during school transition is unknown. To determine (1) the natural history of sleep problems over the 2-year period spanning school entry and (2) associations of children's health-related quality of life, language, behavior, learning, and cognition at ages 6.5 to 7.5 years with (a) timing and (b) severity of sleep problems. Data were drawn from the Longitudinal Study of Australian Children. Children were aged 4 to 5 years at wave 1 and 6 to 7 years at wave 2. Parent-reported predictors included (1) timing (none, persistent, resolved, incident) of moderate/severe sleep problems over the 2 waves and (2) severity (none, mild, moderate/severe) of sleep problems at wave 2. Outcomes included parent-reported health-related quality of life and language, parent- and teacher-reported behavior, teacher-reported learning, and directly assessed nonverbal (matrix reasoning) and verbal (receptive vocabulary) cognition. Linear regression, adjusted for child age, gender, and social demographic variables, was used to quantify associations of outcomes with sleep-problem timing and severity. Sleep data were available at both waves for 4460 (89.5%) children, of whom 22.6% (17.0% mild, 5.7% moderate/severe) had sleep problems at wave 2. From wave 1, 2.9% persisted and 2.8% developed a moderate/severe problem, whereas 10.1% resolved. Compared with no sleep problems, persistent and incident sleep problems predicted poorest health-related quality of life, behavior, language, and learning scores, whereas resolving problems showed intermediate outcomes. These outcomes also showed a dose-response relationship with severity at wave 2, with effect sizes for moderate/severe sleep problems ranging from -0.25 to -1.04 SDs. Cognitive outcomes were unaffected. Sleep problems during school transition are common and associated with poorer child outcomes. Randomized, controlled trials could determine if population-based sleep interventions can reduce the prevalence and impact of sleep problems.

Verbal cognition and attention deficits do not explain the verbal memory decline associated with pharmacoresistant partial epilepsy

The aim of this study was to explore whether change in verbal memory with time in patients with epilepsy is influenced by performance on tasks assessing verbal cognition or attention/processing speed. Thirty-six patients and twenty-five healthy controls were tested twice with median retest intervals of 4.8 and 3.1 years, respectively. Aspects of verbal memory, verbal cognition, and attention/processing speed were assessed. Decline in one verbal memory variable (Cronholm–Molander Memory Test Paired Associates—Delayed Recall) was the strongest correlate of epilepsy. The second strongest correlate was a decrease in one attention/processing speed variable (Digit Symbol). The relationship between decline in verbal memory and epilepsy was not influenced by the decline in attention/processing speed, and the results did not support the notion that limited mental reserves as reflected in impaired verbal cognition or attention/processing speed can explain the relationship between verbal memory and epilepsy.

Theory of Mind “emotion”, developmental characteristics and social understanding in children and adolescents with intellectual disabilities

Patterns of development of ToM-emotion abilities in intellectually disabled (ID) children and typically developing (TD) children matched on their developmental age were investigated. The links between cognition, language, social understanding and ToM-emotion abilities were examined. EDEI-R (Perron-Borelli, M. (1996). Echelles Différentielles d’Efficiences Intellectuelles. Forme Révisée (EDEI-R). Paris: Editions et Applications Psychologiques) was used to match participants and to assess social understanding. ECOSSE (Lecocq, P. (1996). L’E.CO.S.SE. Une épreuve de compréhension syntaxico-sémantique. Paris: Presses Universitaires du Septentrion) assessed the level of syntactic and semantic comprehension of French speaking, to ensure a good comprehension of the questions in ToM-emotion tasks. Adapted tasks of the understanding of causes and consequences of emotions (Quintal, G. (2001). La compréhension des émotions chez les enfants d’âge préscolaire dans le cadre d’une théorie de l’esprit. Un-published master's thesis, University of Montreal, Québec) assessed ToM-emotion abilities (Nader-Grosbois, N., Thirion-Marissiaux, A.-F., & Grosbois, M. (2003). Adapted tests for assessment of the Theory of Mind of causes and consequences of emotions (unpublished documents). Louvain-la-Neuve, Belgium). Similarities in the development of ToM-emotion abilities and social understanding were found, respectively, in both groups (delay hypothesis in ID participants). Some differences between groups were observed in the links between social understanding and ToM-emotion abilities. Significant correlations between developmental characteristics (verbal and non-verbal cognition) and ToM-emotion abilities were obtained for both groups. Verbal cognition explained an important part of the variance of ToM results (understanding of causes and consequences of emotions). The impact of chronological age on ToM-emotion abilities was also examined and is discussed.

Dysregulation of X‐linked gene expression in Klinefelter's syndrome and association with verbal cognition

Klinefelter's Syndrome (KS) is a chromosomal karyotype with one or more extra X chromosomes. KS individuals often show language impairment and the phenotype might be due to overexpression of genes on the extra X chromosome(s). We profiled mRNA derived from lymphoblastoid cell lines from males with documented KS and control males using the Affymetrix U133P microarray platform. There were 129 differentially expressed genes (DEGs) in KS group compared with controls after Benjamini-Hochberg false discovery adjustment. The DEGs included 14 X chromosome genes which were significantly over-represented. The Y chromosome had zero DEGs. In exploratory analysis of gene expression-cognition relationships, 12 DEGs showed significant correlation of expression with measures of verbal cognition in KS. Overexpression of one pseudoautosomal gene, GTPBP6 (GTP binding protein 6, putative) was inversely correlated with verbal IQ (r = -0.86, P < 0.001) and four other measures of verbal ability. Overexpression of XIST was found in KS compared to XY controls suggesting that silencing of many genes on the X chromosome might occur in KS similar to XX females. The microarray findings for eight DEGs were validated by quantitative PCR. The 14 X chromosome DEGs were not differentially expressed in prior studies comparing female and male brains suggesting a dysregulation profile unique to KS. Examination of X-linked DEGs, such as GTPBP6, TAF9L, and CXORF21, that show verbal cognition-gene expression correlations may establish a causal link between these genes, neurodevelopment, and language function. A screen of candidate genes may serve as biomarkers of KS for early diagnosis.

Effect of 30% Oxygen Administration on Verbal Cognitive Performance, Blood Oxygen Saturation and Heart Rate

This study investigated the effect of 30% oxygen administration on verbal cognitive performance, blood oxygen saturation, and heart rate. Five male (24.6(+/-0.9) years) and five female (22.2(+/-1.9) years) college students were selected as the subjects for this study. Two psychological tests were developed to measure the performance level of verbal cognition. The experiment consisted of two runs: one was a verbal cognition task, with normal air (21% oxygen) administered and the other was with hyperoxic air (30% oxygen) administered. The experimental sequence in each run consisted of Rest 1 (1 min), Control (1 min), Task (4 min), and Rest 2 (4 min). Blood oxygen saturation and heart rate were measured throughout the four phases. The results of the verbal behavioural analysis reveal that accuracy rates were enhanced with 30% oxygen administration compared to 21% oxygen. When 30% oxygen was supplied, blood oxygen saturation was increased significantly compared to that with 21% oxygen administration, whereas heart rate showed no significant difference. Significant positive correlations were found between changes in oxygen saturation and cognitive performance. This result supports the hypothesis that 30% oxygen administration would lead to increases in verbal cognitive performance.

The Effect of Oxygen on Verbal Performance : An fMRI Study

This study aimed to investigate the hypothesis that administration of the air with 30% oxygen compared with normal air (21% oxygen) enhances verbal cognitive functioning through increased activation in the brain. Nine male college students participated in the study. The experiment consisted of two runs, one for verbal cognition task with normal air (21% oxygen) and the other for verbal cognition task with hyperoxic air (30% oxygen). Functional brain images were taken with a 3T MRI using the single-shot EPI method. From the results of the verbal behavioral analysis, the accuracy rate was enhanced with 30% oxygen administration when compared to 21% oxygen. The activities were observed at the occipital, parietal, temporal and frontal lobes during both 21% and 30% oxygen administration. There were more activations observed at the right middle frontal gyrus, right inferior frontal gyrus, right superior frontal gyrus, cingulate gyrus, left middle temporal gyrus, and left fusiform gyrus with 30% oxygen administration. These results suggest that a higher concentration of breathed oxygen increases saturation of blood oxygen in the brain, and facilitates verbal performance.

Is there an influence of X‐chromosomal imprinting on the phenotype in Klinefelter syndrome? A clinical and molecular genetic study of 61 cases

Studies on Turner syndrome suggested the presence of X-chromosomal-imprinted genes involved in social and verbal cognition. Imprinted genes on autosomes were shown to affect growth. Could imprinting of such genes on the X chromosome also influence psychomotor development and growth in men with Klinefelter syndrome (KS), who have a supernumerary X? We recorded anthropometric and psychomotor development parameters for 61 males with KS (age range 2-56 years). In 54 cases, we were able to assess intelligence quotient (IQ) and found that impaired speech - and motor developmental problems were reported significantly more often in the paternal X - than in the maternal X group (P = 0.02). We found some significant (P < 0.05) increased body size parameters in the paternal X group, which concurs with data reporting a growth promoting influence of paternally derived genes. Our results suggest X-chromosomal imprinting occurs in males with KS.

Structural analysis of associative chain rows in teenagers with deviant behavior

The lexical-semantic analysis of the internal lexicon structure has shown that teenagers with deviant behavior prefer calling the words designating objects of the environment; they are characterized by the highest frequency of words and predominance of the relatively narrow circle of themes—“interior” and “food, tableware.” Thus, the lexicon nucleus is very structural and is an object component of the world image. Such lexicon structure seems to be due to predominance of the right hemisphere activity. On the contrary, in children without the deviant behavior the nucleus of the verbal cognition can be presented as bipolar: on the one hand, school, school objects, on the other hand, the world of concepts. In the latter case the space of the potential probability activity is reflected. Such lexicon structure seems to be due to predominance of the left hemisphere activity.

A Memory‐Based Theory of Verbal Cognition

The syntagmatic paradigmatic model is a distributed, memory-based account of verbal processing. Built on a Bayesian interpretation of string edit theory, it characterizes the control of verbal cognition as the retrieval of sets of syntagmatic and paradigmatic constraints from sequential and relational long-term memory and the resolution of these constraints in working memory. Lexical information is extracted directly from text using a version of the expectation maximization algorithm. In this article, the model is described and then illustrated on a number of phenomena, including sentence processing, semantic categorization and rating, short-term serial recall, and analogical and logical inference. Subsequently, the model is used to answer questions about a corpus of tennis news articles taken from the Internet. The model's success demonstrates that it is possible to extract propositional information from naturally occurring text without employing a grammar, defining a set of heuristics, or specifying a priori a set of semantic roles.

What makes counting count? Verbal and visuo-spatial contributions to typical and atypical number development

Williams Syndrome (WS) is marked by a relative strength in verbal cognition coupled with a serious impairment in non-verbal cognition. A strong deficit in numerical cognition has been anecdotally reported in this disorder; however, its nature has not been systematically investigated. Here, we tested 14 children with WS (mean age=7 years 2 months), 14 typically developing controls individually matched on visuo-spatial ability (mean age=3 years 5 months) as well as a larger group of typically developing controls (mean age=3 years 4 months) on two tasks to assess their understanding that counting determines the exact quantity of sets (cardinality principle). The understanding of the cardinality principle in children with WS is extremely delayed and only at the level predicted by their visuo-spatial MA. In this clinical group, only language accounted for a significant amount of the variance in cardinality understanding, whereas in the normal comparison group only visuo-spatial competence predicted the variance. The present findings suggest that visuo-spatial ability plays a greater role than language ability in the actual development of cardinality understanding in typically developing children, whereas the opposite obtains for the clinical group.

Sensory, Cognitive, and Linguistic Factors in the Early Academic Performance of Elementary School Children

Standardized sensory, perceptual, linguistic, intellectual, and cognitive tests were administered to 470 children, approximately 96% of the students entering the first grade in the four elementary schools of Benton County, Indiana, over a 3-year period (1995--1997). The results of 36 tests and subtests administered to entering first graders were well described by a 4-factor solution. These factors and the tests that loaded most heavily on them were reading-related skills (phonological awareness, letter and word identification); visual cognition (visual perceptual abilities, spatial perception, visual memory); verbal cognition (language development, vocabulary, verbal concepts); and speech processing (the ability to understand speech under difficult listening conditions). A cluster analysis identified 9 groups of children, each with a different profile of scores on the 4 factors. Within these groups, the proportion of students with unsatisfactory reading achievement in the first 2 years of elementary school (as reflected in teacher-assigned grades) varied from 3% to 40%. The profiles of factor scores demonstrated the primary influence of the reading-related skills factor on reading achievement and also on other areas of academic performance. The second strongest predictor of reading and mathematics grades was the visual cognition factor, followed by the verbal cognition factor. The speech processing factor was the weakest predictor of academic achievement, accounting for less than 1% of the variance in reading achievement. This project was a collaborative effort of the Benton Community School Corporation and a multidisciplinary group of investigators from Indiana University.

Improvement in learning associated with increase in hippocampal formation volume

Background Patients with spontaneous Cushing’s syndrome are exposed to elevated levels of endogenous cortisol for months to years. We previously reported that hippocampal formation volume (HFV) increased in such patients after treatment lowered cortisol to normal concentrations. In the present study, we examined whether the structural increase was associated with improvement in cognition. Methods Twenty-four patients with Cushing’s disease were studied before treatment and following treatment. Magnetic resonance imaging was used to measure HFV and caudate head volume. Neuropsychologic tests of verbal cognition, learning, and memory were also administered. Results Patients showed variability in improvement on neuropsychologic test performance. After partialing out age, education, duration of illness, and time since surgical treatment, greater improvement in word list learning, as measured by the Selective Reminding Test was associated with greater increase in HFV ( r = .59, p < .02). There were no significant associations between improvement in paragraph or paired-word learning or memory tasks and increase in HFV. Improvement in other verbal tasks not strongly dependent on the hippocampus were not significantly associated with increase in HFV. Conclusions After cortisol levels decline to normal concentrations, structural volumetric increase in HFV is accompanied by functional improvement in learning of unrelated words.

Family environment and cognitive abilities in girls with fragile-X syndrome.

There remains some variance in cognitive ability that is unexplained in children with fragile-X syndrome (FXS). Studies in typically developing children suggest that family environment might be one contributor to this unexplained variance. However, the effect of family environment in relation to cognition in atypical children with FXS has been relatively unexplored to date. The present authors examined the putative genetic and environmental factors associated with cognition in a group of age-matched children consisting of 26 females with FXS and 31 typically developing children. All subjects were administered the Wechsler Intelligence Scale for Children-Revised; and the subjects' parents were administered the Wechsler Adult Intelligence Scale-Revised, and completed the Hollingshead Index of Social Status and the Moos & Moos Family Environment Scale. Using a multiple regression analytic strategy, the present authors found that family environment contributed significantly to cognitive abilities in typically developing girls, but did not have a unique contribution to cognitive abilities in girls with FXS. There was a suggestion that, for girls with FXS, socio-economic status, a measure of sociocultural environment, was correlated with IQ. The present study provides a basis for future research on the environmental contributions to cognitive abilities, particularly work related to verbal cognition.

Backward-masking and syllable–rate thresholds have only minor associations with reading achievement, compared to several cognitive and linguistic measures

Rate thresholds for syllable–sequences [the Indiana Test of Auditory Memory and Processing Rate—ITAMPR, Watson and Eddins, J. Acoust. Soc. Am. 105, 1236 (1999)] and backward-masking thresholds, were obtained from 220 children. These measures were only weakly associated with reading achievement and with speech recognition. Other tests, however, accounted for roughly half of the variance in teacher-assigned reading grades. Results of 36 sensory, perceptual processing, linguistic, and cognitive tests and subtests administered to the population from which these children were obtained (approximately 98% of the 472 entering first-graders in Benton County Indiana from 1995 to 1997), were well-described by four factors. These factors and the systematic variance in reading achievement associated with them were: Factor 1 (31%): reading-related skills (phonological awareness, letter- and word-identification); Factor 2 (12%): visual cognition (visual perceptual abilities, spatial perception, visual memory); Factor 3 (9%): verbal cognition (language development, vocabulary, verbal concepts); and Factor 4 (1%): speech processing (the ability to understand speech, measured under difficult listening conditions). These data are inconsistent with the hypothesis that temporal processing deficits are causally related to reading impairments. [Work supported by NIH/NIDCD, Indiana Univ., and the Benton County (Indiana) School Corporation.]

Converging evidence that visuospatial cognition is more age-sensitive than verbal cognition.

In 3 separate experiments, the same samples of young and older adults were tested on verbal and visuospatial processing speed tasks, verbal and visuospatial working memory tasks, and verbal and visuospatial paired-associates learning tasks. In Experiment 1, older adults were generally slower than young adults on all speeded tasks, but age-related slowing was much more pronounced on visuospatial tasks than on verbal tasks. In Experiment 2, older adults showed smaller memory spans than young adults in general, but memory for locations showed a greater age difference than memory for letters. In Experiment 3, older adults had greater difficulty learning novel information than young adults overall, but older adults showed greater deficits learning visuospatial than verbal information. Taken together, the differential deficits observed on both speeded and unspeeded tasks strongly suggest that visuospatial cognition is generally more affected by aging than verbal cognition.

Converging evidence that visuospatial cognition is more age-sensitive than verbal cognition.

Converging evidence that visuospatial cognition is more age-sensitive than verbal cognition.

Longitudinal study of cognitive function in first-episode and recent-onset schizophrenia.

Whether cognitive function in schizophrenia deteriorates, improves, or remains stable is a crucial question. Few studies have examined the longitudinal stability of cognitive function and the relationship between cognitive performance and clinical symptoms over time in a cohort of well-treated patients with schizophrenia. In the present study, 54 patients with first-episode and recent-onset schizophrenia completed a comprehensive cognitive test battery and were rated on symptom measures at index hospitalization and again after 5 years. Performance IQ and full-scale IQ significantly improved, whereas verbal IQ did not change. Group performance improved on some of the neuropsychological tests, including the Circle A letter-cancellation task, free recall of logical memory test score, and the Wisconsin Card Sorting Test. Mean finger-tapping performance worsened over time, whereas performance on other neuropsychological tests did not change. Negative, psychotic, and disorganized symptoms significantly improved over the time period. Changes in negative symptoms were correlated with performance changes in verbal IQ and full-scale IQ but not performance IQ. Improvement in verbal cognition was observed when negative symptoms improved. Psychotic and disorganized symptom dimensions were not correlated with any IQ measure. These results indicate that in a cohort of young patients receiving neuroleptic treatment early in their illness, cognitive performance does not deteriorate--and may improve. Only one of the three symptom dimensions--negative--was associated with change in cognitive performance. This study supports the view that negative symptoms are associated with a poor long-term cognitive outcome and may be closely related to the primary cognitive deficit in schizophrenia.

Language development in children with congenital strokes

The congenital lesion population provides an excellent forum to investigate the issues of innate specialization and plasticity. Effects of early lesions on left and right hemisphere function reflect both the cognitive process under study and biological/neurological factors of lesion parameters and hemispheric maturation rates. In general, toddlers with both congenital left and right lesions show mild to moderate delays in language acquisition. School-age children with left hemisphere lesions have more problems with language and language-based academic skills than those with right hemisphere lesions, but the problems are subtle and do occur in both groups. This pattern stands in sharp contrast with the adult, who shows striking language deficits with acquired lesions only in the left perisylvian region. Thus, there is evidence in these studies of the immature nervous system for both innate specialization and plasticity, as well as a right hemisphere contribution to language acquisition and verbal cognition.

A prospective study of impairment of cognition and memory and recovery after subarachnoid hemorrhage.

In this prospective study, a series of 89 patients with subarachnoid hemorrhage (SAH), most of whom had a "good" neurological outcome, were assessed with a range of tests of memory and cognition as inpatients and at 10 weeks and 12 months after SAH. On tests of verbal cognition and memory, most patients had scores in the normal range 12 months after SAH. However, a significant number of patients still showed impairment on tests of visuospatial construction and memory, mental flexibility, and psychomotor speed at the 12-month assessment. Statistical analyses were carried out for each test score to see whether aneurysm site, location of blood on the admission computed tomographic scan, vasospasm, ischemia, hydrocephalus, grades at admission to and at discharge from hospital, and Glasgow Outcome Scale score at follow-up were associated with test scores. Aneurysm site was not shown to be associated with performance on any test at any time, and the other complications of SAH had only minimal predictive value. The grade at discharge proved to be the best predictor of impairment of cognition and memory at both follow-up assessments. Older subjects did not recover to the same extent as younger subjects by the 12-month assessment. The authors conclude that the diffuse effects of SAH are more important than focal neuropathology in relation to cognitive impairment in this group of patients.