Are the inhibitory and faciliatory effects during retrieval of semantically related items present in amnestic mild cognitive impairment?

Prefrontal functions subserve inhibition control for retrieval of semantically related items inducing forgetting 19 a-MCI patients and 29 controls underwent neuropsychological evaluation and retrieval-practice paradigm (RPP) to estimate baseline remember (BR), retrieval-induced facilitation (FAC) and retrieval-induced forgetting (RIF). A-MCI patients underwent also 3 T-MRI to assess relationship between regional grey matter (rGM) volumes and RPP indexes Behaviourally, RIF and FAC were both observed controls, while RIF only was observed in a-MCI patients. In patients but not in controls, RIF was associated with cognitive efficiency and FAC with memory performance. Patients showed also associations between BR and rGM volumes in the precuneus, no association was found between rGM volumes and RIF and FAC. A-MCI patients did not benefit from repeated practice during retrieval of studied items, which is likely due to their memory disorder. In contrast, patient cognitive efficiency would drive retrieval suppression of interfering stimuli.     

Not quite as grown-up as we like to think: parallels between cognition in childhood and adulthood

Greater continuity in cognition between children and adults may exist than is usually appreciated. It was thought that after 3 to 4 years of age, the problem in switching on the dimensional-change card-sort task disappears. We show here, however, that if speed is used as the dependent measure, the effect of the first dimension is evident even in adults. Adults, like preschoolers, show difficulty in switching from a block of sorting by color or shape to a block of sorting by the other dimension. Notably, performance throughout the session was affected by the first dimension by which stimuli were sorted. We hypothesize that perhaps adults never fully outgrow any of the cognitive and perceptual biases of infancy and early childhood. Other examples of such biases that appear to still be present in adults are discussed. Conversely, the assumption that the optimal dependent measure for adults is the most sensitive measure for children is questioned.     

Th.o.m.a.s.: an exploratory assessment of Theory of Mind in schizophrenic subjects

A large body of literature agrees that persons with schizophrenia suffer from a Theory of Mind (ToM) deficit. However, most empirical studies have focused on third-person, egocentric ToM, underestimating other facets of this complex cognitive skill. Aim of this research is to examine the ToM of schizophrenic persons considering its various aspects (first- vs. second-order, first- vs. third-person, egocentric vs. allocentric, beliefs vs. desires vs. positive emotions vs. negative emotions and how each of these mental state types may be dealt with), to determine whether some components are more impaired than others. We developed a Theory of Mind Assessment Scale (Th.o.m.a.s.) and administered it to 22 persons with a DSM-IV diagnosis of schizophrenia and a matching control group. Th.o.m.a.s. is a semi-structured interview which allows a multi-component measurement of ToM. Both groups were also administered a few existing ToM tasks and the schizophrenic subjects were administered the Positive and Negative Symptoms Scale and the WAIS-R. The schizophrenic persons performed worse than control at all the ToM measurements; however, these deficits appeared to be differently distributed among different components of ToM. Our conclusion is that ToM deficits are not unitary in schizophrenia, which also testifies to the importance of a complete and articulated investigation of ToM.     

On quantifying multisensory interaction effects in reaction time and detection rate

Both mean reaction time (RT) and detection rate (DR) are important measures for assessing the amount of multisensory interaction occurring in crossmodal experiments, but they are often applied separately. Here we demonstrate that measuring multisensory performance using either RT or DR alone misses out on important information. We suggest an integration of RT and DR into a single measure of multisensory performance: the first index (MRE*) is based on an arithmetic combination of RT and DR, the second (MPE) is constructed from parameters derived from fitting a sequential sampling model to RT and DR data simultaneously. Our approach is illustrated by data from two audio–visual experiments. In the first, a redundant targets detection experiment using stimuli of different intensity, both measures yield similar pattern of results supporting the “principle of inverse effectiveness”. The second experiment, introducing stimulus onset asynchrony and differing instructions (focused attention vs. redundant targets task) further supports the usefulness of both indices. Statistical properties of both measures are investigated via bootstrapping procedures.     

Design as dream and self-representation: Philip Johnson and the Glass House of Atreus

Philip Johnson's masterpiece--the Glass House--is compared to a dream and conceptualized as containing encrypted and embedded representations of the self. Freud's masterpiece--The Interpretation of Dreams--is the theoretical and methodological model for this approach to design-as-dream. Drawing on Johnson's words and forms set in biographical, historical, and cultural context, interpretive paths are traced from manifest design elements of the Glass House to overdetermined latent meanings, yielding new and surprising insights into the Glass House, its elusive architect, and the process of its design. A mirror that reflects an image, a lens that focuses it, and a prism that reveals its components, the Glass House turns a lucid eye onto its maker.     

Time estimation in Alzheimer's disease and the role of the central executive

The aim of this study was to evaluate the role of short-term memory and attention in time estimation. For this purpose we studied prospective time verbal estimation in 21 patients with Alzheimer's disease (AD), and compared their performance with that of 21 matched normal controls in two different conditions: during a digit span task and during an attentional task. Results showed that the performance of AD patients was significantly worse than that of the controls; the interaction between group and condition was significant. We suggest a role of attentional-executive functions in prospective time estimation.     

Effect of the violation of normality and sphericity in the linear mixed model in split-plot designs

This study aimed to evaluate the robustness of the linear mixed model, with the Kenward-Roger correction for degrees of freedom, when implemented in SAS PROC MIXED, using split-plot designs with small sample sizes. A Monte Carlo simulation design involving three groups and four repeated measures was used, assuming an unstructured covariance matrix to generate the data. The study variables were: sphericity, with epsilon values of 0.75 and 0.57; group sizes, equal or unequal; and shape of the distribution. As regards the latter, non-normal distributions were introduced, combining different values of kurtosis in each group. In the case of unbalanced designs, the effect of pairing (positive or negative) the degree of kurtosis with group size was also analysed. The results show that the Kenward-Roger procedure is liberal, particularly for the interaction effect, under certain conditions in which normality is violated. The relationship between the values of kurtosis in the groups and the pairing of kurtosis with group size are found to be relevant variables to take into account when applying this procedure.