Modulation of Brain Activity during Action Observation: Influence of Perspective, Transitivity and Meaningfulness

The coupling process between observed and performed actions is thought to be performed by a fronto-parietal perception-action system including regions of the inferior frontal gyrus and the inferior parietal lobule. When investigating the influence of the movements' characteristics on this process, most research on action observation has focused on only one particular variable even though the type of movements we observe can vary on several levels. By manipulating the visual perspective, transitivity and meaningfulness of observed movements in a functional magnetic resonance imaging study we aimed at investigating how the type of movements and the visual perspective can modulate brain activity during action observation in healthy individuals. Importantly, we used an active observation task where participants had to subsequently execute or imagine the observed movements. Our results show that the fronto-parietal regions of the perception action system were mostly recruited during the observation of meaningless actions while visual perspective had little influence on the activity within the perception-action system. Simultaneous investigation of several sources of modulation during active action observation is probably an approach that could lead to a greater ecological comprehension of this important sensorimotor process

Procjena utjecaja modernizacije i novih tehnoloških procesa na izloženost buci u aluminijskoj industriji

The aim of this study was to assess to which extent modernisation of an aluminium production complex reduced occupational noise hazard for jobs with the highest potential of exposure. Periodical measurements of noise level were taken at the same workplaces using the same method, before and after modernisation of all plants. The results were compared with the recommended standard. After modernisation, the noise was significantly reduced in all sections of all plants. The greatest reduction was measured in the foundry. After modernisation, the portion of workplaces with excessive noise level dropped significantly (chi-square=21.315; p<0.0001) from 78.4 % to 13 %. Noise remained a problem in ingot casting and dross skimming section. In the anode plant, noise remained a problem in the green mill section where noise intensities generated by mills and vibrocompactors varied from 95 dB(A) to 102 dB(A). In the electrolysis plant, the portion of workplaces with extensive noise dropped from 77.8 % to 39.3 % after modernisation (p=0.0019). Noise remains to be a problem at the anode covering section where levels rise up to 100 dB(A). The modernisation of the factory has considerably reduced the noise level in the working environment of all plants, but it can not be reduced completely.Cilj je rada procijeniti utjecaj modernizacije tehnološkog procesa proizvodnje aluminija na prisutnost i razinu buke štetne za zdravlje radnika u radnom okolišu. U tu svrhu uspoređivani su rezultati periodičkih mjerenja razine buke prije i nakon modernizacije. Mjerenja intenziteta buke provedena su na istim radnim mjestima i istom metodom tijekom radnih smjena i uspoređeni s važećim nacionalnim standardom. Nakon modernizacije tvornice u svim odjelima proizvodnih pogona značajno se smanjila razina buke, kao i broj radnih mjesta na kojima su radnici izloženi prekomjernoj buci. Najbolji rezultati postignuti su u ljevaonici, gdje se broj radnih mjesta s prekomjernom razinom buke, tj. razinom buke višom od 90 dB(A) smanjio sa 78.4 % na 13 %. Na radnim mjestima gdje se izlijevaju ingoti i skida šljaka buka je i dalje prekomjerna. U pogonu anoda prekomjerna je buka i dalje prisutna pri proizvodnji sirovih anoda, gdje razina buke zbog rada mlinova i vibrokompresora varira od 95 dB(A) do 102 dB(A). U pogonu elektrolize buka viša od 100 dB(A) izmjerena je pri zasipanju anoda. Iako je modernizacijom tvornice i unaprjeđenjem tehnološkog procesa značajno reducirana razina buke, nije ju moguće u cijelosti ukloniti