Diffusion and induced magnetic anisotropy in nanocrystalline Fe73.5Si13.5B9Nb3Cu1

⁷¹Ge tracer diffusion was studied to gain insight into the atomistic transport processes underlying the formation of magnetic anisotropy in nanocrystalline soft-magnetic Fe_73.5Si_13.5B₉Nb₃Cu₁. The interfacial diffusion characteristic was determined by the residual intergranular amorphous phase, which gives rise to a strongly reduced interface diffusivity compared with grain boundaries in metals. Ge diffusion in the nanocrystallites, which is considered to characterize Si self-diffusion, is much slower than Fe diffusion owing to the D0₃ order of the Fe₃Si nanocrystallites. Slow Si diffusion in the nanocrystallites is identified as the rate-controlling process for the generation of the field-induced magnetic anisotropy.     

Musical groove modulates motor cortex excitability: A TMS investigation

Groove is often described as a musical quality that can induce movement in a listener. This study examines the effects of listening to groove music on corticospinal excitability. Musicians and non-musicians listened to high-groove music, low-groove music, and spectrally matched noise, while receiving single-pulse transcranial magnetic stimulation (TMS) over the primary motor cortex either on-beat or off-beat. We examined changes in the amplitude of the motor-evoked potentials (MEPs), recorded from hand and arm muscles, as an index of activity within the motor system. Musicians and non-musicians rated groove similarly. MEP results showed that high-groove music modulated corticospinal excitability, whereas no difference occurred between low-groove music and noise. More specifically, musicians’ MEPs were larger with high-groove than low-groove music, and this effect was especially pronounced for on-beat compared to off-beat pulses. These results indicate that high-groove music increasingly engages the motor system, and the temporal modulation of corticospinal excitability with the beat could stem from tight auditory–motor links in musicians. Conversely, non-musicians’ MEPs were smaller for high-groove than low-groove music, and there was no effect of on- versus off-beat pulses, potentially stemming from suppression of overt movement. In sum, high-groove music engages the motor system, and previous training modulates how listening to music with a strong groove activates the motor system.     

Brain correlates of subjective freedom of choice

The subjective feeling of free choice is an important feature of human experience. Experimental tasks have typically studied free choice by contrasting free and instructed selection of response alternatives. These tasks have been criticised, and it remains unclear how they relate to the subjective feeling of freely choosing. We replicated previous findings of the fMRI correlates of free choice, defined objectively. We introduced a novel task in which participants could experience and report a graded sense of free choice. BOLD responses for conditions subjectively experienced as free identified a postcentral area distinct from the areas typically considered to be involved in free action. Thus, the brain correlates of subjective feeling of free action were not directly related to any established brain correlates of objectively-defined free action. Our results call into question traditional assumptions about the relation between subjective experience of choosing and activity in the brain’s so-called voluntary motor areas.     

Acquiring Non-Object Terms: The Case for Time Words

We address the issue of children's understanding of abstract words with two studies on preschoolers' knowledge of the time-duration words minutes, hours, days, and years. The first study examines 4- and 5-year-olds' ability to answer questions about durations of common phenomena with duration terms. The second study examines 4- to 6-year-olds' comprehension of duration terms with a forced-choice pointing task. Both show that preschoolers' knowledge of such words is incomplete, but that it adheres to the pattern proposed in previous work with toddlers for abstract words. More specifically, children form lexical domains for such words even before they know their individual meanings, thereby allowing the children to often respond appropriately but not usually correctly to questions about abstract dimensions like time.     

Motor Processes in Children's Mental Rotation

Previous studies with adult human participants revealed that motor activities can influence mental rotation of body parts and abstract shapes. In this study, we investigated the influence of a rotational hand movement on mental rotation performance from a developmental perspective. Children at the age of 5, 8, and 11 years and adults performed a mental rotation task while simultaneously rotating their hand (guided by a handle). The direction of the manual rotation was either compatible or incompatible with the direction of the mental rotation. Response times increased with increasing stimulus orientation angles, indicating that participants of all age groups used mental rotation to perform the task. A differential effect of the compatibility of manual rotation and mental rotation was found for 5-year-olds and 8-year-olds, but not for 11-year-olds and adults. The results of this study suggest that the ability to dissociate motor from visual cognitive processes increases with age.     

Perceptual load in sport and the heuristic value of the perceptual load paradigm in examining expertise-related perceptual-cognitive adaptations

In two experiments, we transferred perceptual load theory to the dynamic field of team sports and tested the predictions derived from the theory using a novel task and stimuli. We tested a group of college students (N = 33) and a group of expert team sport players (N = 32) on a general perceptual load task and a complex, soccer-specific perceptual load task in order to extend the understanding of the applicability of perceptual load theory and further investigate whether distractor interference may differ between the groups, as the sport-specific processing task may not exhaust the processing capacity of the expert participants. In both, the general and the specific task, the pattern of results supported perceptual load theory and demonstrates that the predictions of the theory also transfer to more complex, unstructured situations. Further, perceptual load was the only determinant of distractor processing, as we neither found expertise effects in the general perceptual load task nor the sport-specific task. We discuss the heuristic utility of using response-competition paradigms for studying both general and domain-specific perceptual-cognitive adaptations.     

Effect of a Defining Feature on Negative Priming Across the Life Span

Negative priming paradigms examine selective attention, and may be explained by inhibitory processes (e.g. Tipper, 1985). Our study examines inhibition in children (6-11 years), younger adults (18-22 years), and older adults (60-82 years). Younger adults show inhibition to the reported feature of a stimulus (location or identity) (Milliken, Tipper, & Weaver, 1994) and to the defining feature of a stimulus (identity or colour) (Simone, Carlisle, & McCormick, 1998). Neither children (Tipper, Bourque, Anderson, & Brehaut, 1989) nor older adults (Connelly & Hasher, 1993) have consistently shown significant inhibition to the reported feature of identity, suggesting developmentally impaired inhibitory processing. Our current study demonstrates that both inhibition of a defining feature of identity and a reported feature of location are stable across the life span.     

Movement-based compatibility in simple response tasks

Previous studies reported that movement observation affected movement execution. Using one and the same set of responses (i.e., lifting or tapping the finger), correspondence effects were observed for simple responses when the go-signals were similar to the responses (i.e., movies of finger movements) but not when they were dissimilar (i.e., moving squares). The difference was attributed to a higher degree of ideomotor compatibility with visible limb movements. We tried to provide further evidence for ideomotor theory by manipulating the degree to which different responses matched one and the same set of stimuli (drifting sine-wave gratings). To this end, we measured simple reaction time of dynamic (hand movements) or static (key presses) movements in response to the onset of object motion. Object motion and dynamic responses showed ideomotor compatibility without looking alike; however, both stimulus and response involved continuous displacements. Correspondence effects were observed for dynamic responses, but not for static responses.     

Prospective Memory and Pediatric Traumatic Brain Injury: Effects of Cognitive Demand

This study investigated the effects of pediatric traumatic brain injury (TBI) on prospective memory. Fourteen children and 14 adolescents with TBI were compared with 25 and 23 noninjured children and adolescents, respectively. Based on a prefrontal model, the cognitive demand on the ongoing component of a prospective-memory task was manipulated. Overall, those with TBI had poorer prospective-memory performance than their noninjured peers. Performance was worse in a high cognitive-demand condition than a low, and younger children performed worse than adolescents. Decreases in performance from the low- to high-demand conditions were not significantly different between the two children's groups but were between the two adolescents' groups. Furthermore, the age and injury effects were reflected in the performances on executive function tests: the Self-ordered Pointing Task (SOPT), and the Stroop Color Word Interference Test. The Tower of London (TOL), which did not produce age or injury effects, was nevertheless found to be an important predictor of performance on the high-demand task in those with TBI. Although previous research has demonstrated impaired prospective memory performance in children with TBI, this study attempted to explain why this might occur, specifically that the prefrontal regions might be implicated.     

Post-traumatic stress symptoms in mothers of children with leukaemia undergoing the first 12 months of therapy: Predictive models

The aim of this study consists in the measurement of psychological health and adaptation in mothers of children during the first 12 months of treatment for leukaemia and in the identification of possible early predictors. Ninety-four mothers were followed longitudinally at one week (T1), one month (T2), six months (T3) and 12 months (T4) post-diagnosis. The instruments used were: PTSD symptom checklist, BSI-18, Problem Scale, Ladder of life and an in-depth interview (EFI-C). Couple connectedness, family routine reorganisation, parental communication around the child's illness and trust in the medical care significantly increased from T1 to T4. Two models are proposed concerning possible predictors of mothers’ PTSS at T2 and at T3. Clinical suggestions are proposed on the basis of our empirical findings in order to plan informative, clinical and practical interventions for mothers of children under treatment for leukaemia.