Cognitive profile of adolescents with math disabilities: are the profiles different from those with reading disabilities?

Adolescents (ages 14-17) with math disabilities (MD, n=12), reading disabilities (RD, n=19), math+reading disabilities (MD+RD, n=12), and average achievers (n=15) were compared on measures of visual-spatial processing, random generation (inhibition), writing speed, short-term memory (STM), and working memory (WM). Adolescents with MD performed significantly lower than adolescents with RD on measures of visual-spatial processing and visual WM. Adolescents with MD outperformed adolescents with RD +MD on measures of random generation and motor speed. Performance of all three low-achieving groups was inferior to average achievers on measures of random generation, motor speed, and verbal WM. The results were interpreted within a multicomponent model that attributed deficits related to MD in adolescents to deficits related the visual-spatial sketchpad of WM.     

Response Inhibition and ADHD Traits: Correlates and Heritability in a Community Sample

Endophenotypes or intermediate phenotypes are of great interest in neuropsychiatric genetics because of their potential for facilitating gene discovery. We evaluated response inhibition, latency and variability measures derived from the stop task as endophenotypes of ADHD by testing whether they were related to ADHD traits in the general population, heritable and shared genetic risk with ADHD traits. Participants were 16,099 children and adolescents, ages 6 to 18 years who visited a local science center. We measured ADHD traits using the Strengths and Weaknesses of ADHD-symptoms and Normal-Behavior (SWAN) rating scale and performance on the stop signal task (SST)—response inhibition (SSRT), response latency (GoRT), and response variability (GoRTSD). Regression analysis was used to assess the relationship of cognitive measures and ADHD traits while controlling for family, age, sex, ethnicity, socioeconomic status and treatment status. Heritability of ADHD and cognitive traits was estimated using SOLAR in 7,483 siblings from 3,507 families that included multiple siblings. Bivariate relationships between pairs of variables were examined. Individuals with greater ADHD trait scores had worse response inhibition, slower response latency, and greater variability. Younger participants and girls had inferior performance although the gender effects were minimal and evident in youngest participants. Inhibition, latency, variability, total ADHD traits, inattention and hyperactivity-impulsivity scores were significantly heritable. ADHD traits and inhibition, but not latency or variability were coheritable. In the largest study in the general population, we found support for the validity of response inhibition as an endophenotype of ADHD.     

On the calculus ratiocinator

The project, entertained by Leibniz and others, of creating an ideal language to facilitate ratiocination, is investigated in detail. Six possible relations between the ideal language (IL) and the natural language (NL) it replaces are studied. (1) IL says exactly what NL says, but says it much more clearly. (2) IL says exactly what NL says, but does so more economically. (3) IL says exactly what NL says, but does so more succinctly. (4) IL says part of what NL says, and says it more perspicuously. (5) IL says part of what NL says, and says it more perspicuously; moreover, there is an effective procedure for going from NL to IL. (6) IL says everything that NL says, plus some things that NL cannot say.     

Growth in working memory and inhibition predicts literacy in English language learners: A cross-sectional and longitudinal study

The purpose of this study was to determine whether cross-sectional and growth effects in second language (L2) literacy are related to the executive component of working memory (WM) and whether inhibition may underlie the links between WM and reading in children whose first language (L1) is Spanish. Elementary school children (grades 1, 2 and 3) were administered a battery of cognitive [WM, short-term memory (STM), random generation, rapid naming, phonological processing], vocabulary and reading measures in both Spanish (L1) and English (L2) in Year 1 and again one year later. The regression analyses showed that L2 growth in WM significantly predicted growth in L2 reading skills even when inhibition was controlled. Further, the contributions of WM to reading growth in both L1 and L2 reading were independent of cross-language skills in phonological processing, STM, oral language and naming speed. Overall, the results suggest the mental activities that underlie WM and inhibition in predictions of L2 literacy reflect independent executive processes.     

Response to commentary on the multimodal treatment study of ADHD (MTA): mining the meaning of the MTA

In the December 2000 issue of the Journal of Abnormal Child Psychology, we published a set of papers presenting secondary analyses of the Multimodal Treatment Study of ADHD (MTA), and R. A. Barkley (2000) provided a commentary. A critique of the design of the study (MTA Cooperative Group, 1999) was presented based on a theoretical perspective of a behavioral inhibition deficit that has been hypothesized as the core deficit of ADHD (R. A. Barkley, 1997). The commentary questioned the design and analysis of the MTA in terms of (1) the empirical criteria for selection of components of behavioral (Beh) intervention, (2) the effectiveness of the Beh intervention, (3) the methods for analyses at the group and individual level, (4) implications of the MTA findings for clinical practice, (5) the role of genetics in response to treatment, and (6) the lack of a nontreatment control group. In this response, we relate the content of the papers to the commentary, (1) by reviewing the selection criteria for the Beh treatment, as outlined by K. C. Wells, W. E. Pelham, et al. (2000), (2) by addressing the myth that the MTA Beh treatment was ineffective (Pelham, 1999), (3) by describing the use of analyses at the level of the individual participant, as presented by J. S. March et al. (2000) and W. E. Pelham et al. (2000) as well as elsewhere by J. M. Swanson et al. (2001) and C. K. Conners et al. (2001), (4) by relating some of the suggestions from the secondary analyses about clinically relevant factors such as comorbidity (as presented by J. S. March et al., 2000) and family and parental characteristics (as presented by B. Hoza et al., 2000, S. P. Hinshaw et al., 2000, and K. C. Wells, J. N. Epstein, et al., 2000), (5) by discussing the statistical concept of heritability and the lack of a significant difference in the presence of ADHD symptoms in parents of the MTA families compared to parents in the classmate-control families (as presented by J. N. Epstein, et al., 2000), and (6) by acknowledging that an ethically necessary weakness of the MTA design is that it did not include a no-treatment control group. We discuss the use of secondary analyses to suggest how, when, and for what subgroups effectiveness of the Beh treatment may have been manifested. Finally, we invite others to use the large and rich data set that will soon be available in the public domain, to perform secondary analyses to mine the meaning of the MTA and to evaluate theories of ADHD and response to treatments.     

Does fear of coercion keep people away from mental health treatment? Evidence from a survey of persons with schizophrenia and mental health professionals

Mental health consumer advocates have long argued that involuntary treatment frightens persons with mental disorder and thus deters them from voluntarily seeking help. We surveyed 85 mental health professionals and 104 individuals with schizophrenia spectrum conditions to assess their experience with and perceptions of involuntary treatment and other treatment mandates. Of the clinicians, 78% reported that overall they thought legal pressures made their patients with schizophrenia more likely to stay in treatment. Regarding involuntary outpatient commitment, 81% of clinicians disagreed with the premise that mandated community treatment deters persons with schizophrenia from seeking voluntary treatment in the future. Of the consumer sample, 63% reported a lifetime history of involuntary hospitalization, while 36% reported fear of coerced treatment as a barrier to seeking help for a mental health problem-termed here "mandated treatment-related barriers to care." In bivariate analyses, reluctance to seek outpatient treatment associated with fear of coerced treatment (mandated treatment-related barriers to care) was significantly more likely in subjects with a lifetime history of involuntary hospitalization, criminal court mandates to seek treatment, and representative payeeship. However, experience with involuntary outpatient commitment was not associated with barriers to seeking treatment. Recent reminders or warnings about potential consequences of treatment nonadherence, recent hospitalization, and high levels of perceived coercion generally were also associated with mandated treatment-related barriers to care. In multivariable analyses, only involuntary hospitalization and recent warnings about treatment nonadherence were found to be significantly associated with these barriers. These results suggest that mandated treatment may serve as a barrier to treatment, but that ongoing informal pressures to adhere to treatment may also be important barriers to treatment.     

Patterns of memory loss in three elderly samples

Three groups of people ranging in age from 64 to 88 years performed tasks of word generation, paired-associate recall, and free and cued recall. The groups differed in socioeconomic status, verbal intelligence, and apparent levels of daily activity. A fourth group, consisting of young undergraduates, was also tested. Results showed that whereas there were age-related differences in some tests, these age differences were strongly modulated by characteristics of the participants and characteristics of the tasks. The findings are discussed in a contextualist framework.