The Crucial Role of Working Memory in Intellectual Functioning

Cognitive psychology offers an important contribution to the understanding of the mechanisms underlying intelligence. In this paper, we synthesize the research showing that, among the different cognitive mechanisms associated with intelligence, working memory has a particularly high explanatory power, especially when considered in its active component involving not only the maintenance (as in short-term memory) but also the manipulation of information. The paper considers two main implications of this finding for the applied and clinical fields. For a start, we examine how intelligence tests take into consideration working memory. Secondly, we consider the highly debated literature on the effects of working memory training on intellectual performance. Theoretical and applied implications for the relationship between working memory and intelligence are discussed

Pros and Cons of Using Intelligence Batteries for the Study of Clinical Populations: A Response to Beaujean (2017)

In his commentary to our study (Toffalini, Giofr\ue8, & Cornoldi, 2017), Beaujean (2017) raised some important issues. In particular, he suggested that the reliability of the WISC-IV indexes may be inadequate for clinical interpretation, that abnormal differences should be discussed rather than statistical significance, and that evidence of the treatment utility of WISC-IV indexes is limited. We agree with Beaujean that using cognitive strengths and weaknesses in isolation for individual clinical decisions is dangerous. However, investigation of groups is somewhat different; comparing group performances under different subtests or conditions, without definitive conclusions, can enhance clinical psychological research

Imaginative Representations of Two- and Three-Dimensional Matrices in Children with Nonverbal Learning Disabilities

Children with non-verbal learning disabilities (NLD) are characterized by high verbal and poor non-verbal intelligence, poor cognitive abilities, school difficulties, and—sometimes—depressive symptoms. NLD children lack visuospatial working memory, but it is not clear whether they encounter difficulties in mental imagery tasks. In the present study, NLD adolescents without depressive symptoms, depressed adolescents without NLD symptoms, and a control group were administered a mental imagery task requiring them to imagine to move along the cells of a 2-D (5 × 5) or 3-D (3 × 3 × 3) matrix. Results showed that NLD adolescents had difficulty at performing the imagery task when a 3-D pattern was involved. It is suggested that 3-D mental imagery tasks tap visuospatial processes which are weak in NLD individuals. In addition, their poor cognitive performance cannot be attributed to a depressive state, as the depressed group had a performance similar to that of controls

Lumpers vs. splitters: Intelligence in children with specific learning disorders

A multigroup bifactor model was used to compare the explained variance and the reliability of the general vs. specific factors of the Wechsler Intelligence Scale for Children-4th edition (WISC-IV) in 1617 Italian children diagnosed with specific learning disorder (SLD) and an Italian normative sample of typically-developing children (with the exclusion of IQ < 70). Results suggested that more than half of the common variance, 56.1%, was accounted for by the domain-specific factors in SLD, against only 39.5% in typical development. The reliability of both general and specific factors was rather limited in SLD, whereas the reliability of the g-factor was good in typical development. An additional analysis using previous information from American data showed very similar results. Our results suggest that the role of the specific factors, of VCI and PSI in particular and WMI to a lesser extent, should be considered as probably largely distinct from the g-factor in children with SLD. Results also seem to indicate that the PRI is a less distinctive factor, which is, in the SLD group, hardly distinguishable from the g-factor. The use of Bayesian priors from American data indicated that results on Italian and American samples of children with SLD were similar, and different from those on the normative samples of both countries, suggesting remarkable cross-cultural and cross-linguistic similarity of the structure of intelligence in children with SLD

Visual experience is not necessary for efficient survey spatial cognition: Evidence from blindness

This study investigated whether the lack of visual experience affects the ability to create spatial infer-ential representations of the survey type. We compared the performance of persons with congenital blindness and that of blindfolded sighted persons on four survey representation-based tasks (Experiment 1). Results showed that persons with blindness performed better than blindfolded sighted controls. We repeated the same tests introducing a third group of persons with late blindness (Experiment 2). This last group performed better than blindfolded sighted participants, whereas differences between participants with late and congenital blindness were nonsignificant. The present findings are compatible with results of other studies, which found that when visual perception is lacking, skill in gathering environmental spatial information provided by nonvisual modalities may contribute to a proper spatial encoding. It is concluded that, although it cannot be asserted that total lack of visual experience incurs no cost, our findings are further evidence that visual experience is not a necessary condition for the development of spatial inferential complex representations. There is a general consensus on the crucial role of visual perception in guiding many of our daily movements in large- and small-scale environ

Italian adaptation of the MOQ-T as a fast screening instrument based on teachers' ratings for identifying developmental coordination disorder symptoms

The present study was designed to collect data on the Italian adaptation of the Motor Observation Questionnaire for Teachers (MOQ-T, Schoemaker, Flapper, Reinders-Messelink, & De Kloet, 2008). We provide data for 2nd, 3rd, 4th and 5th grades, in some cases distinguishing males from females. On the basis of the present and previous evidence (Giofrè et al., 2014) the MOQ-T appears a valid and a fast screening instrument for detecting developmental coordination disorders (DCD) symptoms (on the basis of teachers' ratings) in children and can be very important as a first step in the process for diagnosing DCD

The structure of intelligence in children with specific learning disabilities is different as compared to typically development children

Children with specific learning disabilities (SLDs) are characterized by a poor academic achievement despite an average intelligence. They are therefore typically assessed not only with achievement tests, but also with intelligence tests, usually the Wechsler Intelligence Scale for Children (WISC). The assumption of a discrepancy between IQ and achievement in children with SLD has been questioned, however, and the implications of using different measures in batteries of intellectual subtests have not been thoroughly investigated. The present study examined these issues, taking advantage of a large database of scores obtained in the ten core subtests of the WISC-IV by a group of 910 Italian children with a clinical diagnosis of SLD, who were compared with the children considered for national standardization purposes. Our results support the doubts raised concerning the IQ-achievement discrepancy model, showing that relevant discrepancies can emerge even within the WISC profile. The four main WISC-IV indexes were found differently related to intelligence (measured by means of the g-factor) and the g content of many subtests differed in childrenwith SLD vis-\ue0-vis typically-developing children. These results have important implications both theoretical, indicating that the g-factor isweakly identified in children with SLD children, and practical, indicating that the QI obtained with the WISC-IV may not be a good measure of intellectual functioning for children with SLD, which are discussed

Forward and backward digit span difficulties in children with specific learning disorder

This study examined performance in the forward and backward digit span task of the Wechsler Intelligence Scale for Children–Fourth Edition (WISC–IV) in a large group of children with specific learning disorder (SLD) as compared with a group of typically developing children matched for age and sex. Our results further support the hypothesis that the intellectual difficulties of children with SLD involve working memory in the forward digit span task to a greater extent than in the backward digit span task. The correlation of the two spans with a General Ability Index (GAI) was similar in SLD, and smaller in magnitude than in typically developing children. Despite a GAI within normal range, children with SLD had difficulty with both digit span tasks, but more so for forward span. This pattern was similar for different SLD profiles with clinical diagnoses of dyslexia and mixed disorder, but the impairments were more severe in the latter. Age differences were also investigated, demonstrating larger span impairment in older children with SLD than in younger

Intelligence and working memory control: Evidence from the WISC-IV administration to Italian children

Working memory (WM) has been associated with general intelligence (GI). However, evidence is contradictory, as the relationship has in some cases resulted to be very high, and in other cases very low. To explain these differences, it has been argued that WM is an articulated system and only its more attentional components are strictly related with GI. In particular, it has been argued that WM tasks can be located – according to the task characteristics and the subject's age – along a continuum, from the most passive tasks, which do not require cognitive control, to the most active tasks, which do require high cognitive control. The present study tested this hypothesis using data collected during the standardization of the Italian version of the WISC-IV. WISC-IV, includes four measures, i.e. the arithmetic test, the letter-number sequencing test, the backward and the forward digit span tests, which represent decreasing levels of cognitive control. The analysis of correlations between the four tasks and a measure of GI – obtained with the six basic tasks (related to verbal comprehension and perceptual reasoning, but not to working memory) – confirmed the hypothesis and showed that the pattern of correlations only slightly changes across ages