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Nonverbal learning disability is a neurodevelopmental disorder with a core deficit in visuospatial processing with possibly associated problems in attention, motor, academic, and social skills, but without associated neurologic or genetic syndromes. The present chapter, after a brief historic overview of this disorder, will present fresh evidence that clearly shows neuropsychologic and neuroanatomical distinctions between children with nonverbal learning disability and those with other neurodevelopmental disorders. It ends with an attempt to find shared and valid diagnostic criteria. Acknowledging this disorder as a distinct diagnostic category will open up new research avenues with important scientific and clinical implications.

The study of 5-year-old children with symptoms of attention-deficit hyperactivity disorder (ADHD) is important because it provides an opportunity to discover early intervention strategies for children who are expected to develop severe problems later in life. This chapter presents a research program intended to develop assessment and interventions tools for kindergarten children. Specifically, we present two rating scales (one for teachers and one for parents), two neuropsychological tests, and an intervention program intended to promote controlled attention and working memory. Finally, we present an investigation, with a small group of 5-year-old children with ADHD symptoms, validating the program.

In this research, we examined the relation between reading comprehension and success in a working memory updating task. We tested the hypotheses that poor comprehenders' deficiencies are associated with a specific difficulty in the working memory updating process, particularly in controlling for information that is no longer relevant. In the first experiment, groups of poor and good comprehenders, ages 8-11 years, were administered a working memory updating task. In the second experiment a year later, a subgroup of participants involved in the first experiment was tested with a different updating task. In both experiments, poor comprehenders had less accurate recall performance and made more intrusion errors than did good comprehenders. Moreover, distinguishing intrusion errors on the basis of their permanence in memory, we found that poor comprehenders were more likely to intrude items that were maintained longer in memory than were good comprehenders. This type of error predicted reading comprehension abilities better than did working memory recall. This suggests that the relation between reading comprehension and working memory is mediated by the ability to control for irrelevant information.

Publisher Summary This chapter summarizes some studies that have carried out on vividness of images. In a first series of experiments, variables that may affect vividness ratings were examined. In a second series, the vividness rating procedure was used to contrast different conditions and groups of subjects. By focusing on vividness qualities of images, the chapter aims to suggest that the study of the structural properties of mental images is no less important than the study of their functional properties. To examine the effects on the vividness ratings of groups of different imagery ability, the IDQ imagery test was administered to 88 University students. The main result concerning vividness found in this series of experiments was that all of the six identified characteristics contributed in some way to the vividness of an image. The second series of experiments illustrates how the consideration of the different vividness properties of the images may help in studying critical problems concerning visual imagery.

This study explored the structure of working memory, and its relationship with intelligence in 176 typically-developing children in the 4th and 5th grades at school. Different measures of working memory (WM), and intelligence (g) were administered. Confirmatory factor analyses showed that WM involves an attentional control system and storage aspects that rely on domain-specific verbal (STM-V) and visuospatial (STM-VS) resources. The structural equation models showed that WM predicts a large portion (66%) of the variance in g, confirming that the two constructs are separable but closely related in young children. Findings also showed that only WM and STM-VS are significantly related to g, while the contribution of STM-V is moderate. Theoretical implications for the relationship between WM and g are discussed.

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 children with SLD vis-a-vis typically-developing children. These results have important implications both theoretical, indicating that the g-factor is weakly 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.

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.