Motor-cortical beta oscillations are modulated by correctness of observed action

Contains fulltext : 73550.pdf (Publisher’s version ) (Closed access)How humans understand the intention of others’ actions remains controversial. Some authors have suggested that intentions are recognized by means of a motor simulation of the observed action with the mirror-neuron system [1–3]. Others emphasize that intention recognition is an inferential process, often called ‘‘mentalizing’’ or employing a ‘‘theory of mind,’’ which activates areas well outside the motor system [4–6]. Here, we assessed the contribution of brain regions involved in motor simulation and mentalizing for understanding action intentions via functional brain imaging. Results show that the inferior frontal gyrus (part of the mirror-neuron system) processes the intentionality of an observed action on the basis of the visual properties of the action, irrespective of whether the subject paid attention to the intention or not. Conversely, brain areas that are part of a ‘‘mentalizing’’ network become active when subjects reflect about the intentionality of an observed action, but they are largely insensitive to the visual properties of the observed action. This supports the hypothesis that motor simulation and mentalizing have distinct but complementary functions for the recognition of others’ intentions

Movement-Specific Repetition Suppression in Ventral and Dorsal Premotor Cortex during Action Observation

There are several models of premotor cortex contributions to sensorimotor behavior. For instance, the ventral premotor cortex (PMv) appears to be involved in processing visuospatial object properties for grasping, whereas the dorsal premotor cortex (PMd) is involved in using arbitrary rules to guide advance motor planning. These models have focused on individual movements. Here, we examine the premotor responses evoked during the processing of individual movements functionally embedded in an action. We tested whether processing hand–object interactions and action end states would differentially engage PMv and PMd. We used a repetition suppression (RS)–functional magnetic resonance imaging paradigm in which we independently manipulated the observed grip, the end position of the object (independent of its spatial location), and the hand trajectory. By comparing novel and repeated trials for each of these action components, we could isolate RS effects specific to each of them. Repeating the grasp component attenuated activity in right PMv, whereas repeating the end state of the action reduced blood oxygen level–dependent activity in the left PMd. These results suggest that PMv is involved in controlling the kinematic means of an appropriate hand–object interaction, whereas PMd is focused on specifying the desired end state of an action

Virtual Lesions of the IFG Abolish Response Facilitation for Biological and Non-Biological Cues

Humans are faster to perform a given action following observation of that same action. Converging evidence suggests that the human mirror neuron system (MNS) plays an important role in this phenomenon. However, the specificity of the neural mechanisms governing this effect remain controversial. Specialist theories of imitation suggest that biological cues are maximally capable of eliciting imitative facilitation. Generalist models, on the other hand, posit a broader role for the MNS in linking visual stimuli with appropriate responses. In the present study, we investigated the validity of these two theoretical approaches by disrupting the left and right inferior frontal gyrus (IFG) during the preparation of congruent (imitative) and incongruent (complementary) actions cued by either biological (hand) or non-biological (static dot) stimuli. Delivery of TMS over IFG abolished imitative response facilitation. Critically, this effect was identical whether actions were cued by biological or non-biological stimuli. This finding argues against theories of imitation in which biological stimuli are treated preferentially and stresses the notion of the IFG as a vital center of general perception–action coupling in the human brain

Changes in anti-viral effectiveness of interferon after dose reduction in chronic hepatitis c patients: a case control study

BACKGROUND: High dose interferon induction treatment of hepatitis C viral infection blocks viral production over 95%. Since dose reduction is often performed due to clinical considerations, the effect of dose reduction on hepatitis C virus kinetics was studied. METHODS: A new model that allowed longitudinal changes in the parameters of viral dynamics was used in a group of genotype-1 patients (N = 15) with dose reduction from 10 to 3 million units of interferon daily in combination with ribavirin, in comparison to a control group (N = 9) with no dose reduction. RESULTS: Dose reduction gave rise to a complex viral kinetic pattern, which could be only explained by a decrease in interferon effectiveness in blocking virion production. The benefit of the rapid initial viral decline following the high induction dose is lost after dose reduction. In addition, in some patients also the second phase viral decline slope, which is highly predictive of success of treatment, was impaired by the dose reduction resulting in smaller percentage of viral clearance in the dose reduction group. CONCLUSIONS: These findings, while explaining the failure of many induction schedules, suggest that for genotype-1 patients induction therapy should be continued till HCVRNA negativity in serum in order to increase the sustained response rate for chronic hepatitis C

Line-pack storage in biogas infrastructures at regional scale, a model approach

Previously, we reported on a biogas transport model; the model assesses transport costs in a grid with fishbone and star layout collecting biogas. Biogas collection from several digesters to a hub supports the efficient use of resources. A dedicated grid, used for transport, can serve as a form of biogas storage as well. So a model was developed to evaluate line-pack storage in a transport grid for different digester scale, number of digesters, region size, and grid type. Line-pack storage does not require additional investments, and variable costs consist of extra compression costs. In both fishbone lay-out and star lay-out estimated line-pack storage, costs are between 0.3 and 1.5 euroct m(-3)h(-1). In a star lay-out, line-pack storage volume increases with region size. In a fishbone lay-out, the maximum line-pack storage volume is small in both a small size region and in a large region, as a result of pipeline volume and pressure restriction. A comparison of storage costs shows that line-pack storage can compete on costs with pressureless storage, but pressurized pipes are preferred for seasonal storage. A method to describe enlargement of line-pack storage by increased investment in pipelines depending on maximum transport pressure is presented. Such enlargement by applying larger pipe diameters could be financially sensible

Semantics in the Motor System: Motor-Cortical Beta Oscillations Reflect Semantic Knowledge of End-Postures for Object Use

In the present EEG study we investigated whether semantic knowledge for object use is represented in motor-related brain areas. Subjects were required to perform actions with everyday objects and to maintain either a meaningful or a meaningless end posture with the object. Analysis of the EEG data focused on the beta-frequency band, as previous studies have indicated that the maintenance of a posture is reflected in stronger beta-oscillations. Time frequency analysis indicated that the execution of actions resulting in a meaningless compared to a meaningful end posture was accompanied by a stronger beta-desynchronization towards the end of the movement and a stronger subsequent beta-rebound after posture-onset. The effect in the beta-frequency band was localized to premotor, parietal and medial frontal areas and could not be attributed to differences in timing or movement complexity between meaningful and meaningless actions. Together these findings directly show that the motor system is differentially activated during the execution and maintenance of semantically correct or incorrect end postures. This suggests that semantic object knowledge is indeed represented in motor-related brain areas, organized around specific end postures associated with the use of objects

Potential advantages in heat and power production when biogas is collected from several digesters using dedicated pipelines - A case study in the "Province of West-Flanders" (Belgium)

In the case study “West-Flanders” costs of electricity and heat production are estimated if a dedicated biogas grid using pipelines would be implemented to centralize energy production in a region. Heat may not be used effectively at digester sites, e.g. because of a change in treatment of digestate. A large scale centralized combined heat and power (CHP) engine can produce additional electrical power at a hub, i.e. central collection point, and has lower specific costs compared to decentralized CHPs at digester sites. A biogas transport model is used to calculate transport costs in a grid. These costs, partly balanced by a scale advantage in CHP costs, are attributed to the additional electrical energy (80%) and heat (20%) produced. If the hub is at a digester site, costs of additional electricity can be as low as 4.0 €ct kWhe−1 and are in many cases below 12 €ct kWhe−1, i.e. in the same order of magnitude or lower than costs of electricity from biogas produced using separate CHPs at the different digester sites; costs of heat at the hub show to be lower than 1 €ct kWhth−1 assuming an effective heat use of 50%. In case a hub is situated at a location with high potential heat demand, i.e. a heat sink, transport of biogas from one digester only to a central located hub can provide 3.4 MWth of heat at 1.95 €ct kWhth−1. For such a centrally located hub additional electrical energy costs show to be slightly higher, but with three or more digesters these costs are lower than 20 €ct kWhe−1 and heat costs are around 0.5 €ct kWhth−1. With a centralized hub more renewable energy is produced, i.e. a more efficient use of biomass feedstock. It is concluded that costs for additional electricity and heat can be at a competing level and scale advantages in a CHP can be a driver to collect biogas at a hub using a biogas grid

Learning to use novel objects: A training study on the acquisition of novel action representations

Many studies have suggested that the motor system is organized in a hierarchical fashion, around the prototypical end location associated with using objects. However, most studies supporting the hierarchical view have used well-known actions and objects that are highly over-learned. Accordingly, at present it is unclear if the hierarchical principle applies to learning the use of novel objects as well. In the present study we found that when learning to use a novel object subjects acquired an action representation of the end location associated with using the object, as evidenced by slower responses in an action observation task, when the object was presented at an incorrect end location. By showing the importance of knowledge about end locations when learning to use a novel object, the present study suggests that end locations are a fundamental organizing feature of the human motor system

Epidemiology of chronic pain in the Netherlands

Chronic pain is very common but good data are scarce about the prevalence, incidence, diagnosis, severity, treatment, utilization of health care, and the impact of chronic pain on society, health care systems and the patient. Information about the epidemiology of chronic pain can help decision and policy makers decide about health budgets and prioritization, patient segmenting and budget fencing, and therapy budgets, including behavioural therapy and drug budgets. This report aims to provide epidemiological information about chronic pain in the Netherlands using the most representative, recent, comprehensive and valid studies. Out of 16 619 retrieved titles and abstracts, we selected 155 studies from the Netherlands that were relevant to the project questions. From these, we selected at least three studies per question that provided the most recent, representative and valid data

Eye–hand coordination during manual object transport with the affected and less affected hand in adolescents with hemiparetic cerebral palsy

In the present study we investigated eye–hand coordination in adolescents with hemiparetic cerebral palsy (CP) and neurologically healthy controls. Using an object prehension and transport task, we addressed two hypotheses, motivated by the question whether early brain damage and the ensuing limitations of motor activity lead to general and/or effector-specific effects in visuomotor control of manual actions. We hypothesized that individuals with hemiparetic CP would more closely visually monitor actions with their affected hand, compared to both their less affected hand and to control participants without a sensorimotor impairment. A second, more speculative hypothesis was that, in relation to previously established deficits in prospective action control in individuals with hemiparetic CP, gaze patterns might be less anticipatory in general, also during actions performed with the less affected hand. Analysis of the gaze and hand movement data revealed the increased visual monitoring of participants with CP when using their affected hand at the beginning as well as during object transport. In contrast, no general deficit in anticipatory gaze control in the participants with hemiparetic CP could be observed. Collectively, these findings are the first to directly show that individuals with hemiparetic CP adapt eye–hand coordination to the specific constraints of the moving limb, presumably to compensate for sensorimotor deficits