Underlying cognitive processes of the corsi block-tapping task

Die Blockspanne ist eines der verbreitetsten Testverfahren in der klinischen Neuropsychologie, auch bekannt als Cor-si- / Block-Tapping-Test. Das Verfahren gilt als Goldstandard zur Messung des räumlichen Kurzzeit- und Arbeitsgedächtnisses (Baddeley, 2003). Trotz der häufi gen Anwendung im klinischen Alltag fand die Erforschung zugrunde liegender kognitiver Prozesse erstaunlich wenig Be-achtung. Dieser Übersichtsartikel vermittelt den aktuellen Forschungsstand durch Beschreibung der wichtigsten Studien, die anhand von Be-fragungen, Blickbewegungen oder Parallelaufgaben untersuchten, was die Blockspannenaufgabe tatsächlich misst. Dabei wird deutlich, dass nicht nur nonverbale räumliche Aspekte erfasst werden, sondern, insbesondere unter hohen Anforderungen, zusätzlich verbale und exekutive Ressourcen rekrutiert werden. Es wird diskutiert, inwieweit Zahlen- und Blockspannen als Analoga gelten können und ob die Darbietung der Blockspanne rückwärts im Vergleich zur Vorwärtsvariante einen diagnostischen Mehrwert bietet.The Corsi Block-Tapping Task represents the gold standard of neuropsychological assessment of visuospatial short-term and work-ing memory. Despite its frequent application in clinical practice, very little is known about the underlying cognitive processes involved. The present review describes the historical development of the task, its heterogeneity, and moderators that affect performance. We present existing research based on studies using interviews, eye-tracking, or dual-task paradigms and investigate what the Block-Tapping Task actually meas-ures. The results support the assumption that not only visuo-spatial memory is being assessed, but also verbal and executive components, especially in light of higher demands. We discuss whether the spatial span can be regarded as analogous to the digit span and provide informa-tion on differential processes with respect to forward and backward performance

Benefits of Higher Cardiovascular and Motor Coordinative Fitness on Driving Behavior Are Mediated by Cognitive Functioning: A Path Analysis

Driving is an important skill for older adults to maintain an independent lifestyle, and to preserve the quality of life. However, the ability to drive safely in older adults can be compromised by age-related cognitive decline. Performing an additional task during driving (e.g., adjusting the radio) increases cognitive demands and thus might additionally impair driving performance. Cognitive functioning has been shown to be positively related to physical activity/fitness such as cardiovascular and motor coordinative fitness. As such, a higher fitness level might be associated with higher cognitive resources and may therefore benefit driving performance under dual-task conditions. For the first time, the present study investigated whether this association of physical fitness and cognitive functioning causes an indirect relationship between physical fitness and dual-task driving performance through cognitive functions. Data from 120 healthy older adults (age: 69.56 ± 3.62, 53 female) were analyzed. Participants completed tests on cardiovascular fitness (cardiorespiratory capacity), motor coordinative fitness (composite score: static balance, psychomotor speed, bimanual dexterity), and cognitive functions (updating, inhibition, shifting, cognitive processing speed). Further, they performed a virtual car driving scenario where they additionally engaged in cognitively demanding tasks that were modeled after typical real-life activities during driving (typing or reasoning). Structural equation modeling (path analysis) was used to investigate whether cardiovascular and motor coordinative fitness were indirectly associated with lane keeping (i.e., variability in lateral position) and speed control (i.e., average velocity) while dual-task driving via cognitive functions. Both cardiovascular and motor coordinative fitness demonstrated the hypothesized indirect effects on dual-task driving. Motor coordinative fitness showed a significant indirect effect on lane keeping, while cardiovascular fitness demonstrated a trend-level indirect effect on speed control. Moreover, both fitness domains were positively related to different cognitive functions (processing speed and/or updating), and cognitive functions (updating or inhibition), in turn, were related to dual-task driving. These findings indicate that cognitive benefits associated with higher fitness may facilitate driving performance. Given that driving with lower cognitive capacity can result in serious consequences, this study emphasizes the importance for older adults to engage in a physically active lifestyle as it might serve as a preventive measure for driving safety

The effect of high vs. low intensity neuropsychological treatment on working memory in patients with acquired brain injury

Aim: To evaluate the combined effect of compensation therapy and functional training on working memory (WM) in patients with acquired injury and chronic cognitive deficits by investigating the dose-response relationship and specificity of transfer effects. Research design: Double-blind randomized controlled trial. Methods: All patients underwent 4 weeks of compensation therapy in a day-care setting. In addition, they received either 20 sessions of computer-based WM training (n = 11) or attention training (n = 9). Transfer effects on cognition and their functional relevance in daily life were assessed before treatment, after 2 weeks (10 additional training sessions), and after 4 weeks (20 additional training sessions) of therapy. Results: The combined treatment led to significant improvements in WM performance, verbal memory, and self-reported changes in daily life. The amount of training was identified to modulate efficacy: Significant improvements showed only in the later training phase. We observed no differences between the two training schemes (WM vs. attentional training). Conclusions: Even in the chronic phase after brain lesion WM performance can be enhanced by the combination of compensation therapy and computerized cognitive training when applied intensely; both a more general attention and a specific WM training regimen are effective

Memory effects on the magnetic behavior of assemblies of nanoparticles with ferromagnetic core/antiferromagnetic shell morphology

none9Monte Carlo simulations of the dynamic magnetic behavior of an assembly of ferromagnetic core/antiferromagnetic shell nanoparticles are reported and compared with the experimental results on a system of Co nanoparticles in Mn matrix. Memory effects on low-field zero-field-cooled magnetization curves have been investigated. Our simulations show that the memory effects increase with the concentration and that both the interface exchange coupling and the dipolar interparticle interactions contribute to the observed dynamic behavior. In particular the interface exchange interaction provides an additive source for the frustration of the system resulting in an enhancement of the memory effect. The numerical data reproduce well the experimental results confirming the glassy behavior of the investigated nanoparticle systems. © 2013 American Physical Society.mixedVasilakaki M.; Trohidou K.N.; Peddis D.; Fiorani D.; Mathieu R.; Hudl M.; Nordblad P.; Binns C.; Baker S.Vasilakaki, M.; Trohidou, K. N.; Peddis, D.; Fiorani, D.; Mathieu, R.; Hudl, M.; Nordblad, P.; Binns, C.; Baker, S

Memory and superposition in a superspin glass

The non-equilibrium dynamics of the superspin glass state of a dense assembly of similar to 2 nm MnFe2O4 nanoparticles was investigated by means of magnetization, ac susceptibility and Mossbauer spectroscopy measurements and compared to the results of Monte Carlo simulations for a mesoscopic model that includes particles morphology and interparticle interactions. The zero-field cooled (ZFC), thermoremanent (TRM), and isothermal remanent magnetization (IRM) were recorded after specific cooling protocols and compared to those of archetypal spin glasses and their dimensionality. The system is found to display glassy magnetic features. We illustrate in detail, by a number of experiments, the dynamical properties of the low-temperature superspin glass phase. We observe that these glassy features are quite similar to those of atomic spin glasses. Some differences are observed, and interestingly, the non-atomic nature of the superspin glass is also reflected by an observed superspin dimensionality crossover. Monte Carlo simulations-that explicitly take into account core and surface contributions to the magnetic properties of these ultrasmall nanoparticles in direct contact, as well as interparticle interactions-evidence effects of the interplay between (intraparticle) core/surface exchange coupling and (interparticle) dipolar and exchange interactions