Individual and age-related differences in children’s working memory

The purpose of this study was to investigate the degree to which age-related and individual differences in children’s working memory (WM) are due to a general or task-specific capacity system. Experiment 1 correlated children’s (N=146; age range 5–19 years) verbal and visual-spatial working memory performance with various intelligence and achievement measures. The results supporting a general system were that (1) visual-spatial and verbal WM measures were significantly intercorrelated with and without age partialed out and (2) both verbal and visual-spatial WM measures were significantly correlated with diverse achievement and intelligence measures. Experiment 2 compared three age groups (N=192; 7-, 10-, and 13-year-olds) on working-memory performance tasks under initial, enhanced (cued), and maintenance conditions. The results supporting a general capacity system were that (1) age-related performance differences in WM were found on all conditions and not isolated to specific processes, (2) the maintenance measures (high-load condition) predicted the variance better in age-related performance than process measures, and (3) although individual differences in WM performance reflected two independent operations, these operations produced similar correlations to achievement within age groups. Overall, the results support a general capacity explanation of age-related and individual differences in children’s WM performance.     

Is Speech Arrest during Wada Testing a Valid Method for Determining Hemispheric Representation of Language?

Background and objective: The intracarotid amobarbital procedure, or Wada test, is the method of choice to determine hemispheric representation of language, and is routinely used in the presurgical evaluation for intractable epilepsy. Some investigators perform comprehensive language assessments, but others base language lateralization solely on speech arrest. This study sought to determine whether speech arrest alone during Wada testing provides valid data regarding language lateralization. Methods: The subjects (previously reported) were 21 patients evaluated for intractable epilepsy, who underwent language lateralization by Wada testing and functional MRI (FMRI). For each patient, language representation was determined by calculating: (1) a Wada laterality index based exclusively on speech arrest; (2) a Wada laterality index based on comprehensive language assessment; and (3) an FMRI laterality quotient. Correlation coefficients and categorical classifications were analyzed. Results: There was no significant correlation between the Wada laterality quotient derived from duration of speech arrest and either the comprehensive Wada language laterality score (r= .35,p= .12) or FMRI language laterality score (r= .32,p= .16). Categorical classification as left, right or bilateral language also showed marked discordance between speech arrest and the other two methods. Conclusion: Duration of speech arrest during Wada testing is not a valid measure of language dominance.     

Conflict resolution and social understanding in six to twelve year old boys

Three different aspects of children's social competency were studied, i.e. social methods, (via their suggested solution to given conflict situations), social understanding (via their explanations of the solution given) and role-taking capacity. 75 boys—ages 6, 8 and 12 years—were interviewed concerning different conflict situations, six of which involved a child/child interaction and six a child/adult interaction. A separate role-taking task was also used. Developmental differences in social methods were found only in situations involving adults, where older children to a greater extent chose altruistic methods for solving the conflict. As regards social understanding, developmental changes were found and correspond to results reported by previous researchers. Role-taking capacity was found to increase with age. Role-taking as measured here was not related to social understanding. Social method and social understanding were significantly related to each other in some of the situations, mainly in those involving only children. The results indicate that different norms prevail for solving conflicts with adults versus with peers, and that the role-taking aspect is but one of several involved in the development of social understanding.     

Memory comparison time for complex digit stimuli: The effect of number length

Woodworth (1938) reported that naming latency increased linearly with the number of digits per number (number length). In the present study, the Sternberg memory scanning paradigm was utilized to investigate this effect. It was found that the slope of the memory scanning function increased linearly with number length: memory scanning time was 40 msec for one-digit numbers, 70 msec for two-digit numbers and 101 msec for 3 digit numbers. The intercepts of the memory scanning functions did not differ for the three types of numbers. Thus the increase in latency may be due to the memory comparison stage of processing. The data suggest that a memory comparison operation occurs for each digit position of the complex memory items composed of more than one digit.     

Naming speed deficits in reading disability: multiple measures of a singular process

Speed of word identification is important in the theories of reading proposed by La Berge and Samuels (1974) and Perfetti (1985), and is substantially correlated with reading skill. However, there is controversy about whether disabled readers have a speed deficit that is restricted to the identification of printed words, or if instead, they have a more general speed deficit in retrieving names of even single digits. To investigate this issue, poor and average readers (N = 43) in grade 2 were assessed on several indices of speed of digit and letter naming, using both continuous-list and discrete-trial methodologies. MANCOVA indicated clear effects of reader group on discrete-trial latencies, as well as an interaction between reader group and the speed with which to-be-named items were presented. A series of hierarchical regression analyses explored the amount of shared variance between various measures of digit naming speed and five indices of reading skill. Latency for word identification shares considerable variance with latency for digit naming, and, in general, accounts for the shared variance of naming speed and several other measures of reading skill. Naming speed contributed variance in reading skill. Naming speed contributed variance in reading skill independently of measures of phonological awareness.     

Learning disabilities, distinctive encoding, and hemispheric resources

The purpose of this study was to isolate possible sources of learning ability differences in distinctive encoding of item-specific and relational information. Two mechanisms postulated as underlying ability group differences were attentional capacity (as inferred from the magnitude and direction of correlations between primary and secondary recall) and resource monitoring strategies (as reflected in measures of selective attention and laterality). In Experiment 1, learning disabled and nondisabled childrens' word recall was compared on dichotic listening recall tasks that included nonorienting instructions, and orienting instructions that directed children's attention toward semantic, phonemic, or structural word features. Disabled children showed lower recall and more diffuse selective attention to word features than nondisabled children. Reciprocity (negative correlations) between targeted and background words within and between ability groups was comparable, except when targeted word features were phonemically organized. Experiment 2 indicated that disabled childrens' cued recall was inferior to that of nondisabled children, even though both ability groups produced comparable symmetrical recall patterns related to ear presentations. Taken together, the results suggest that the locus of disabled childrens' distinctive encoding deficiencies is related to resource monitoring strategies during interhemispheric processing.     

A systemic belief approach to epileptic seizures: A case of being spellbound

A systemic treatment approach, namely systemic belief therapy, has been found to be useful when dealing with families constraining beliefs when experiencing physical health problems. Two interventions which facilitate the altering of constraining beliefs are the externalization of physical symptoms and therapeutic letters. Epileptic seizures are examined in the context of the interaction between families and health care professionals. A case example is presented which highlights the use of this systemic approach to assist a young couple in challenging their beliefs about their ability to control and monitor epileptic seizures.     

Overt repetition as a means of controlling rehearsal

Abstract.— Three different ways of using the concept of rehearsal were discussed. Examples were presented showing confusions in the literature due to a failure to distinguish these three definitions. A free recall experiment was conducted with the purpose of investigating three problems relating to the concept of rehearsal: ( a ) an unclear relationship between overt and covert repetition, ( b ) whether overt repetition excluded other control processes, and (c) whether a shallow repetition produces a permanent memory trace or not. Using a pronounced time pressure it was demonstrated first that overt repetition facilitated recall performance of recency items and that recall of primacy items was facilitated by covert repetition. Secondly, it was shown that overt repetition did not exclude other types of encoding. Finally, a shallow maintaining repetition did not produce a permanent memory trace. The results are interpreted as supporting a level of processing point of view rather than a multistore approach.