Effect of Working Memory Updating Training on Retrieving Symptoms of Children With Learning Disabilities

Working memory (WM) deficiency is a primary reason for the poor academic performance of children with learning disabilities (LDs). Studies have shown that the WM of typical children could be improved through training, and WM training contributes to improving their fluid intelligence and academic achievement. However, few studies have investigated WM training for children with LDs, and results have been inconsistent. The present study examined the long-term effects of WM updating training and whether it can mitigate LD symptoms. Fifty-four children with LDs were recruited and divided randomly into a training or control group. The training group underwent adaptive running WM training for 20 days. Before and after training, the 2 groups completed a 2-back task, a digit span task (forward and backward), Raven's Standard Progressive Matrices test, and a scholastic attainment test (Chinese and math). The tests were repeated 6 months later. The results showed that, as compared with the controls, the training group exhibited significant improvements in the digit backward span task, 2-back task, and Raven's Standard Progressive Matrices. The math scores of the training group improved significantly by 6 months after the training. The results of this study suggest that WM updating training could mitigate the cognitive deficits of LDs and improve the WM capacity, fluid intelligence, and math scores of children with LDs. Moreover, the training effects could be maintained for at least 6 months.

Psychosocial Dimensions of Learning Disability Subtypes

Evidence bearing upon the relationships between profiles of neuropsychological assets and deficits, subtypes of learning disabilities, and patterns and degrees of psychosocial functioning is reviewed. The dimensions of incidence and type of psychosocial disturbance and the differential manifestations of these in two subtypes of learning disabilities are examined. Conclusions relating to the neurodevelopmental bases of the pattern of psychosocial functioning most often seen in children and adolescents with the syndrome of nonverbal learning disabilities are emphasized.

Perceptual organization, phonological awareness, and reading comprehension in adults with and without learning disabilities

It is not clear from research whether, or to what extent, reading comprehension is impaired in adults who have learning disabilities (LD). The influence of perceptual organization (PO) and phonological awareness (PA) on reading comprehension was investigated. PO and PA are cognitive functions that have been examined in previous research for their roles in nonverbal LD and phonological dyslexia, respectively. Nonverbal tests of PO and non-reading tests of PA were administered to a sample of adults with postsecondary education. Approximately two thirds of the sample had previously been diagnosed as having LD. In a multiple regression analysis, tests of PO and PA were used to predict scores for tests of reading comprehension and mechanics. Despite the nonverbal nature of the perceptual organizational test stimuli, PO strongly predicted reading comprehension. Tests of PA predicted decoding and reading speed. Results were interpreted as supporting the hypothesis that integrative processes usually characterized as nonverbal were nonetheless used by readers with and without disabilities to understand text. The study's findings have implications for understanding the reading of adults with learning disabilities, and the nature of reading comprehension in general.

Is neuropsychology a psychosocial science?

Many early investigators of brain-behavior relationships focused their investigative efforts on the psychiatric implications of brain damage and dysfunction. Descriptions of emotional dyscontrol and other psychosocial difficulties appeared frequently in their writings. Although dimensions of perception, memory, and cognition dominate the current neuropsychological literature, the psychosocial implications of patterns of neuropsychological assets and deficits retain their importance (e.g., in the study of the dementing diseases of adulthood). Our investigations of brain-behavior relationships and their impact on psychosocial functioning have attempted to expand upon and chart a somewhat different (subtypal) course for this area of study. One clearly evident conclusion of these efforts is that neuropsychology is a psychosocial science. Some implications of our findings for research and clinical practice are outlined.

Efficiency of visual information processing in children at-risk for dyslexia: habituation of single-trial ERPs

To investigate underlying learning mechanisms in relation to the development of dyslexia, event-related potentials to visual standards were recorded in five-year-old pre-reading children at-risk for familial dyslexia (n=24) and their controls (n=14). At the end of second grade the children aged 8 years were regrouped into three groups according to literacy level and risk factor. Single-trial analyses revealed N1 habituation in the normal-reading controls, but not in the normal-reading at-risks, and a N1 amplitude increase in the group of poor-reading at-risks and poor-reading controls. No P3 habituation was found in either group. The normal-reading at-risk group exhibited the longest N1 and P3 latencies, possibly compensating for their reduced neuronal activity during initial information extraction. In contrast, the poor-reading group only showed prolonged P3, and their increase in (initial small) N1 amplitude together with normal N1 latencies, suggests inefficient processing in an early time window, which might explain automatisation difficulties in dyslexic readers.

Nonverbal learning disability: a tutorial for speech-language pathologists

Nonverbal learning disability (NLD) is a diagnostic category that is unfamiliar to most speech-language pathologists. This brief tutorial describes NLD's characteristics, a theoretical model proposed to explain its source, and areas of overlap between NLD and similar diagnostic categories. The communicative profile, made up of difficulties in pragmatic and semantic language in the presence of relatively preserved syntactic skill, is also discussed. Empirical evidence relevant to NLD is also evaluated. Many questions remain unresolved, but until systematic research provides definitive answers, speech-language pathologists are encouraged to rely on careful description of the individual child's communicative strengths and weaknesses to identify appropriate targets and to focus intervention on improving the child's ability to communicate effectively in everyday contexts.

Electrophysiological changes in children with learning and attentional abnormalities as a function of age: event-related potentials to an "oddball" paradigm

This study investigated age-related electrophysiological differences between children diagnosed with Learning Disabilities (LD), Attention Deficit Hyperactivity Disorder (ADHD), LD-ADHD and Conduct Disorder, using Event-Related Potentials recorded during a two-tone discrimination test. Although age-related (N1 and N2 amplitude), as well as diagnostic group-related (P3 latency and amplitude) ERP changes were found, there was no significant interaction between the diagnostic groups and age grouping. We conclude that: 1) Electrophysiological abnormalities in LD and ADHD do not significantly change with age during childhood. This study does not, therefore, support a hypothesis of age-related brain abnormalities in LD and ADHD. 2) Significant group differences for P3 latency and amplitude were found between normal children and the LD groups (LD and LD-ADHD), but not between normal children and those with ADHD alone, suggesting that main correlates of P3 abnormalities in these children are "processing" and not attentional problems.

Disabilities of arithmetic and mathematical reasoning: perspectives from neurology and neuropsychology

Current research on brain-behavior relationships in disabilities of arithmetic and mathematical reasoning is reviewed from both a neurological and a neuropsychological perspective. Although no entirely satisfactory statement of the relationship between arithmetic skills and brain functions has yet emerged, investigators in this area have provided evidence regarding the involvement of some brain systems in processes of calculation. Also, the developmental importance of right- versus left-hemisphere integrity for the mediation of arithmetic learning and performance has been suggested. We propose that an account of brain-behavior relationships in children intended to explain and predict developmental disabilities of arithmetic learning needs to address several important content and processing distinctions in order to (a) encompass empirically derived subtypes of children with learning disabilities who exhibit difficulties with arithmetic and (b) provide adequate direction for future subtyping and intervention research.

Visual event related potentials and reaction time in normal adults, normal children, and children with attention deficit hyperactivity disorder: differences in short-term memory processing

Visual Event Related Potentials were recorded during a memory search paradigm in 30 normal adults, 17 normal children, and 14 children with Attention Deficit Hyperactivity Disorder (ADHD). Group differences were found in P3 latency and amplitude, Reaction Time and number of errors. The findings indicate a different information processing pattern for ADHD children who possibly use a "self-terminating" as opposed to "exhaustive" search strategy.

Late cognitive brain potentials, phonological and semantic classification of spoken words, and reading ability in children

Event-related potential (ERP), reaction time, and response accuracy measures were obtained during rhyming and semantic classification of spoken words in 10 average (mean age 11.64 years) and 9 impaired reading (mean age 12.10 years) children. The behavioral measures of classification did not distinguish the groups. In the ERPs, rhyme processing produced more pronounced group differences than did semantic processing at about 480 ms, with a relatively more negative distribution for the impaired readers at centroparietal sites. At about 800 ms in both classification tasks, the impaired readers displayed a late positivity that was delayed in latency and of larger amplitude at frontal sites than that for the average readers. The ERP findings suggest that the categorization of spoken words for meaning and sound result in increasingly more aberrant correlates of these processing demands in reading-impaired children.

Assessing adult receptive vocabulary with event-related potentials: an investigation of cross-modal and cross-form priming

This experiment investigated whether a relationship existed between event-related potentials (ERPs) and performance on a standardized measure of receptive vocabulary; a computer adapted version of the Peabody Picture Vocabulary Test-Revised (PPVT-R); using Preschooler, Child, and Adult levels of difficulty. Pictures (N = 90) were presented twice, once paired with a congruent spoken word and again paired with an incongruent word. Two ERP components (PMN and N400) were clearly and reliably larger in response to incongruent than congruent picture/spoken-word pairs. Importantly, ERP differentiation of congruent and incongruent pairs occurred only at vocabulary levels at or below the subjects' psychometrically determined vocabulary range. ERP differentiation did not occur at the highest level of vocabulary where subjects experienced more uncertainty and made more behavioral errors. These results are discussed in relation to the use of ERP measures in the assessment of receptive vocabulary levels.

An innovative method to assess the receptive vocabulary of children with cerebral palsy using event-related brain potentials

This single-case, multiple-control study illustrates the clinical use of ERPs as part of the linguistic and cognitive assessment of individuals who are unable to provide verbal or motor responses due to their multiple handicaps. The single-word receptive vocabulary of a 17-year-old patient with Cerebral Palsy (CP) and three age-matched controls was measured using an event-related potential (ERP) paradigm. The Peabody Picture Vocabulary Test-Revised (PPVT-R) was adapted for computer presentation, with three levels of difficulty (Preschool, Child, Adult). Individual pictures were presented successively, and correctly (congruent) or incorrectly (incongruent) named auditorially. ERP components were derived for both the congruent and incongruent picture-word pairs. As predicted, the N400 ERP component had a higher peak for the incongruent picture-word pairs at the Preschool and Child levels. At the Adult level, the ERP pattern was reversed (higher peak in congruent condition) for the CP patient and for two of the three controls and, it was substantially attenuated for the third control. These ERP findings indicated that picture-word pairs within the range of acquired receptive vocabulary were identified as correct or incorrect but picture-word pairs above an individual's level could not be differentiated as clearly. The findings demonstrate the clinical application of this paradigm to assessing receptive vocabulary in motor- and communication-impaired patients.

Interhemispheric balance patterns detected by selective phonemic dichotic laterality measures in four clinical subtypes of reading-disabled children

Identifying disabilities in word-attack, word-recognition, or reading comprehension, allowed for four categories of reading disability: (1) reading comprehension only (RC), (2) word-attack plus comprehension (WA+RC), (3) word-attack, word-recognition, and comprehension (WA+WR+RC), and (4) word-attack but not comprehension (WA-RC). Along with age-matched controls (AMC) and developmental-delay controls (DDC), the disabled were tested on a directed-attention dichotic task using consonant-vowel combinations. Laterality results for each place of articulation (i.e., bilabial, alveolar, and velar) selectively attested to greater left hemisphere involvement or engagement for the RC group and greater right hemisphere involvement or engagement for the WA+RC group. Performance of the other two disabled groups was consistent with less efficient right hemisphere involvement or callosal transfer. Implications for theory, research, and remediation are discussed.