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Artikkelini tavoite on tutkia inkerinsuomalaisen muistitietoa omasta ja ryhmänsä pakkosiirrosta Leningradin piirityksestä eri puolille Siperiaa toisen maailmansodan aikana. Kysyn, millaisia olivat muistitiedon kertomukset pakkosiirrosta. Aineistonani käytän kahdenkymmenen vuosina 1941–1942 karkotetun inkerinsuomalaisen henkilöhistoriallista haastattelua. Analysoin kertomuksia vastakertomuksen käsitteen avulla. Esitän ensiksi, että pakkosiirrettyjen inkerinsuomalaisten haastateltujen kertomukset pakkosiirrosta olivat usein vastakertomuksina neuvostovallan toimia vastaan, jotka leimasivat suomalaiset vihollisiksi ja toteuttivat epäinhimillisellä tavalla suomalaisten pakkosiirrot kaukaisiin paikkoihin alkeellisiin oloihin. Karkotetut kärsivät syrjinnästä, nälästä, sairauksista, pakkotyöstä ja surkeista elinoloista kuolleisuuden ollessa korkea. Toiseksi esitän, että inkerinsuomalaisten muistitieto sisälsi myös myönteisiä kertomuksia Siperiassa eletystä ajasta vastoin inkerinsuomalaisten hallitsevaa kärsimyskertomusta tai tutkijoiden luomaa kuvaa siitä. Paikallisten ihmisten apu ja paikoin parempi ruokatilanne pelastivat monen hengen. Muistitieto nosti esille neuvostoarjen kohenemisen monissa karkotuspaikoissa 1940-luvun kuluessa, mutta samalla haastateltavat kuvasivat totalitaristisen neuvostojärjestelmän edelleen ongelmalliseksi.

Sensorimotor adaptation, or the capacity to flexibly adapt movements to changes in the body or the environment, is crucial to our ability to move efficiently in a dynamic world. The field of sensorimotor adaptation is replete with rigorous behavioural and computational methods, which support strong conceptual frameworks. An increasing number of studies have combined these methods with electroencephalography (EEG) to unveil insights into the neural mechanisms of adaptation. We review these studies: discussing EEG markers of adaptation in the frequency and the temporal domain, EEG predictors for successful adaptation and how EEG can be used to unmask latent processes resulting from adaptation, such as the modulation of spatial attention. With its high temporal resolution, EEG can be further exploited to deepen our understanding of sensorimotor adaptation.

Sensorimotor adaptation to wedge prisms can alter the balance of attention between left and right space in healthy adults, and improve symptoms of spatial neglect after stroke. Here we asked whether the orienting of spatial attention to visual stimuli is affected by a different form of sensorimotor adaptation that involves physical perturbations of arm movement, rather than distortion of visual feedback. Healthy participants performed a cued discrimination task before and after they made reaching movements to a central target. A velocity-dependent force field pushed the hand aside during each reach, and required participants to apply compensatory forces toward the opposite side. We used event-related potentials (ERPs) to determine whether electroencephalography (EEG) responses reflecting orienting (cue-locked N1) and disengagement (target-locked P1) of spatial attention are affected by adaptation to force fields. After adaptation, the cue-locked N1 was relatively larger for stimuli presented in the hemispace corresponding to the direction of compensatory hand force. P1 amplitudes evoked by invalidly cued targets presented on the opposite side were reduced. This suggests that force field adaptation boosted attentional orienting responses toward the side of hand forces, and impeded attentional disengagement from that side, mimicking previously reported effects of prism adaptation. Thus, remapping between motor commands and intended movement direction is sufficient to bias ERPs, reflecting changes in the orienting of spatial attention in the absence of visuo-spatial distortion or visuo-proprioceptive mismatch. Findings are relevant to theories of how sensorimotor adaptation can modulate attention, and may open new avenues for treatment of spatial neglect.

Although age-related declines in cognitive, sensory and motor capacities are well documented, current evidence is mixed as to whether or not aging impairs sensorimotor adaptation to a novel dynamic environment. More importantly, the extent to which any deficits in sensorimotor adaptation are due to general impairments in neural plasticity, or impairments in the specific processes that drive adaptation is unclear. Here we investigated whether there are age-related differences in electrophysiological responses to reaching endpoint and trajectory errors caused by a novel force field, and whether markers of error processing relate to the ability of older adults to adapt their movements. Older and young adults (N = 24/group, both sexes) performed 600 reaches to visual targets, and received audio-visual feedback about task success or failure after each trial. A velocity-dependent curl field pushed the hand to one side during each reach. We extracted ERPs time-locked to movement onset [kinematic error-related negativity (kERN)], and the presentation of success/failure feedback [feedback error-related negativity (fERN)]. At a group level, older adults did not differ from young adults in the rate or extent of sensorimotor adaptation, but EEG responses to both trajectory errors and task errors were reduced in the older group. Most interestingly, the amplitude of the kERN correlated with the rate and extent of sensorimotor adaptation in older adults. Thus, older adults with an impaired capacity for encoding kinematic trajectory errors also have compromised abilities to adapt their movements in a novel dynamic environment.

Publisher´s version (útgefin grein)., Whereas aerobic training has found to be beneficial for inhibitory control, less is known on the efficiency of other exercise types in children. The present study compared the effects of aerobic and coordinative training on behavioral and neurophysiological measures of inhibitory control. Forty-five children were randomly assigned (1:1:1 ratio) to groups performing aerobic training, coordinative training or assisted homework sessions over 10 weeks. Before and after intervention, all participants completed a Flanker task. The P300 component of event-related potentials elicited from the task was recorded via electroencephalography. Additionally, aerobic fitness and gross-motor skills were assessed using 20 m Shuttle Run and Heidelberg Gross-Motor Test, respectively. Statistical analyses revealed no time by group interactions for the P300 component (amplitude, latency), p = 0.976, eta(2) = 0.007, and behavioral performance (reaction time, accuracy), p = 0.570, eta(2) = 0.045. In contrast, there was a significant group-difference in pre- to post-test changes in aerobic fitness, p = 0.008, eta(2) = 0.246, with greater improvements following aerobic and coordinative training compared to assisted homework sessions. In conclusion, no differences regarding the efficiency of aerobic and coordinative training for the enhancement of inhibitory control were found as both exercise programs failed to elicit changes in speed and accuracy of stimulus evaluation and the allocation of attentional resources., The German Research Foundation (BU 1837/5-2). Additionally, E.R. was supported by a UQ Postdoctoral Research Fellowship., "Peer Reviewed"

It is well-established that expertise developed through continuous and deliberate practice has the potential to delay age-related decline in fine motor skills. However, less is known about the underlying mechanisms, that is, whether expertise leads to a higher performance level changing the initial status from which age-related decline starts or if expertise-related changes result in qualitatively different motor output and neural processing providing a resource of compensation for age-related changes. Thus, as a first step, this study aims at a better understanding of expertise-related changes in fine motor control with respect to force output and respective electrophysiological correlates. Here, using a multidimensional approach, we investigated fine motor control of experts and novices in precision mechanics during the execution of a dynamic force control task. On the level of force output, we analyzed precision, variability, and complexity. We further used dynamic mode decomposition (DMD) to analyze the electrophysiological correlates of force control to deduce brain network dynamics. Experts' force output was more precise, less variable, and more complex. Task-related DMD mean mode magnitudes within the α-band at electrodes over sensorimotor relevant areas were reduced in experts, and lower DMD mean mode magnitudes related to the force output in novices. Our results provide evidence for expertise dependent central adaptions with distinct and more complex organization and decentralization of sensorimotor subsystems. Results from our multidimensional approach can be seen as a step forward in understanding expertise-related changes and exploiting their potential as resources for healthy aging.

Visuomotor adaptation involves the learning of a new mapping between a spatial goal and well-learned movements. In order to learn a new visuomotor transformation, visual attention is needed to monitor movements and their visual consequences. Once a transformation is learnt, it can be executed automatically without attentional control. Using steady-state visual evoked potentials (SSVEPs) measured from EEG activity, we examined how visual attention changes during the early phase of visuomotor adaptation. SSVEPs were elicited by a green disc flickering at 15 Hz which was either the movement target or the cursor that participants controlled. Participants performed an adapted continuous visuomotor adaptation task with either 60° or 120° screen cursor rotation, and changes in 15-Hz SSVEP power were examined. Participants' performance improved over time in all conditions, with the rate of learning significantly influenced by the degree of rotation. SSVEPs at 15 Hz showed a significant change over time with adaptation for 60° rotations, but not for 120° rotations, such that SSVEPs elicited by the stimuli were significantly lower for 60° compared with 120° rotation conditions over the last adaptation blocks. This suggests that visual attention to the movement target and feedback reduces over time as performance improves during visuomotor adaptation for easier rotations, but must be maintained throughout the task for more difficult 120° rotations that might require more strategic control.

The pure exposure to extensive tactile stimulation, without the requirement of attention or active training, has been revealed to enhance sensorimotor functioning presumably due to an induction of plasticity in the somatosensory cortex. The induced effects, including increased tactile acuity and manual dexterity have repeatedly been observed in basic as well as clinical research. However, results vary greatly in respect to the strength and direction of the effects on the behavioral and on the brain level. Multiple evidences show that differences in the stimulation protocols (e.g., two vs. multiple stimulation sites) and parameters (e.g., duration, frequency, and amplitude) might contribute to this variability of effects. Nevertheless, stimulation protocols have not been comprehensively compared yet. Identifying favorable parameters for tactile stimulation interventions is especially important because of its possible application as a treatment option for patients suffering from sensory loss, maladaptive plasticity, or certain forms of motor impairment. This review aims to compare the effects of different tactile stimulation protocols and to assess possible implications for tactile interventions. Our goal is to identify ways of optimizing stimulation protocols to improve sensorimotor performance. To this end, we reviewed research on tactile stimulation in the healthy population, with a focus on the effectiveness of the applied parameters regarding psychophysiological measures. We discuss the association of stimulation-induced changes on the behavioral level with alterations in neural representations and response characteristics.

From the conceptual and methodological framework of the dynamical systems approach, force control results from complex interactions of various subsystems yielding observable behavioral fluctuations, which comprise both deterministic (predictable) and stochastic (noise-like) dynamical components. Here, we investigated these components contributing to the observed variability in force control in groups of participants differing in age and expertise level. To this aim, young (18–25 yr) as well as late middle-aged (55−65 yr) novices and experts (precision mechanics) performed a force maintenance and a force modulation task. Results showed that whereas the amplitude of force variability did not differ across groups in the maintenance tasks, in the modulation task it was higher for late middle-aged novices than for experts and higher for both these groups than for young participants. Within both tasks and for all groups, stochastic fluctuations were lowest where the deterministic influence was smallest. However, although all groups showed similar dynamics underlying force control in the maintenance task, a group effect was found for deterministic and stochastic fluctuations in the modulation task. The latter findings imply that both components were involved in the observed group differences in the variability of force fluctuations in the modulation task. These findings suggest that between groups the general characteristics of the dynamics do not differ in either task and that force control is more affected by age than by expertise. However, expertise seems to counteract some of the age effects.NEW & NOTEWORTHY Stochastic and deterministic dynamical components contribute to force production. Dynamical signatures differ between force maintenance and cyclic force modulation tasks but hardly between age and expertise groups. Differences in both stochastic and deterministic components are associated with group differences in behavioral variability, and observed behavioral variability is more strongly task dependent than person dependent.

Salient and sudden sensory events generate a remarkably large response in the human brain, the vertex wave (VW). The VW is coupled with a modulation of a voluntarily-applied isometric force. In the present study, we tested whether the VW is also related to executing high-precision movements. The execution of a voluntary high-precision movement remains relatively independent of the brain activity reflected by the preceding VW. The apparent relationship between the positive VW and movement onset time is explained by goal-related but stimulus-independent neural activities. These results highlight the need to consider such goal-related but stimulus-independent neural activities when attempting to relate event-related potential amplitude with perceptual and behavioural performance.Salient and fast-rising sensory events generate a large biphasic vertex wave (VW) in the human electroencephalogram (EEG). We recently reported that the VW is coupled with a modulation of concomitantly-applied isometric force. In the present study, in five experiments, we tested whether the VW is also related to high-precision visuomotor control. We obtained three results. First, the saliency-induced increase in VW amplitude was paralleled by a modulation in two of the five extracted movement parameters: a reduction in the onset time of the voluntary movement (P 0.005) and an increase in movement accuracy (P 0.005). Second, spontaneous trial-by-trial variability in vertex wave amplitude, for a given level of stimulus saliency, was positively correlated with movement onset time (P 0.001 in four out of five experiments). Third, this latter trial-by-trial correlation was explained by a widespread EEG negativity independent of the occurrence of the positive VW, although overlapping in time with it. These results indicate that (i) the execution of a voluntary high-precision movement remains relatively independent of the neural processing reflected by the preceding VW, with (ii) the exception of movement onset time, for which saliency-based contextual effects are dissociated from trial-by-trial effects. These results also indicate that (iii) attentional effects can produce spurious correlations between event-related potentials (ERPs) and behavioural measures. Although sudden salient stimuli trigger characteristic EEG responses coupled with distinct reactive components within an ongoing isometric task, the results of the present study indicate that the execution of a subsequent voluntary movement appears largely protected from such saliency-based modulation, with the exception of movement onset time.

We report on results from the fully diode-pumped chirped-pulse amplification laser system Polaris. Pulses were amplified to a maximum energy of 54.2 J before compression. These pulses have a full width at half-maximum spectral bandwidth of 18 nm centered at 1033 nm and are generated at a repetition rate of 0.02 Hz. To the best of our knowledge, these are the most energetic broadband laser pulses generated by a diode-pumped laser system so far. Due to the limited size of our vacuum compressor, only attenuated pulses could be compressed to a duration of 98 fs containing an energy of 16.7 J, which leads to a peak power of 170 TW. These pulses could be focused to a peak intensity of 1.3×1021 W/cm2. Having an ultra-high temporal contrast of 1012 with respect to amplified spontaneous emission these laser pulses are well suited for high-intensity laser–matter experiments.

There are well-documented differences in the way that people typically perform identical motor tasks with their dominant and the nondominant arms. According to Yadav and Sainburg's ( Neuroscience 196: 153–167, 2011) hybrid-control model, this is because the two arms rely to different degrees on impedance control versus predictive control processes. Here, we assessed whether differences in limb control mechanisms influence the rate of feedforward compensation to a novel dynamic environment. Seventy-five healthy, right-handed participants, divided into four subsamples depending on the arm (left, right) and direction of the force field (ipsilateral, contralateral), reached to central targets in velocity-dependent curl force fields. We assessed the rate at which participants developed predictive compensation for the force field using intermittent error-clamp trials and assessed both kinematic errors and initial aiming angles in the field trials. Participants who were exposed to fields that pushed the limb toward ipsilateral space reduced kinematic errors more slowly, built up less predictive field compensation, and relied more on strategic reaiming than those exposed to contralateral fields. However, there were no significant differences in predictive field compensation or kinematic errors between limbs, suggesting that participants using either the left or the right arm could adapt equally well to novel dynamics. It therefore appears that the distinct preferences in control mechanisms typically observed for the dominant and nondominant arms reflect a default mode that is based on habitual functional requirements rather than an absolute limit in capacity to access the controller specialized for the opposite limb.

We present few-femtosecond shadowgraphic snapshots taken during the non-linear evolution of the plasma wave in a laser wakefield accelerator with transverse synchronized few-cycle probe pulses. These snapshots can be directly associated with the electron density distribution within the plasma wave and give quantitative information about its size and shape. Our results show that self-injection of electrons into the first plasma wave period is induced by a lengthening of the first plasma period. Three dimensional particle in cell simulations support our observations., Comment: 5 pages, 4 figures

Efficient motor control requires motor planning. Age-related changes in motor control are well described, e.g. increased movement variability and greater antagonistic muscle co-activation, as well as less functional and less regional specific brain activation. However, less is known about age-related changes in motor planning. By use of transcranial magnetic stimulation we investigated differences in corticomotor facilitation during motor planning in 17 young (25 ± 3 years) and 17 older healthy adults (70 ± 13 years) in a delayed movement paradigm for wrist movements. Motor evoked potentials (MEPs) were recorded for the flexor and extensor carpi radialis during movement preparation of wrist flexion and extension as well as during rest. We found that MEPs were less specifically facilitated during planning in older as compared to younger adults, as indicated by an Age × Condition × Muscle interaction. Young participants showed significantly facilitated MEPs in the respective muscle needed for wrist flexion or extension. By contrast MEPs in older participants were less specifically modulated. We conclude that age relates to dedifferentiated activation of the primary motor cortex already during preparation of distinct movements which might contribute to less efficient motor control in older adults.