Automatic object-based spatial selection depends on the distribution of sustained attention

Several space-based and object-based attention studies suggest these selection mechanisms may be voluntarily deployed, depending on task parameters and the attentional scope of the observer. Here, we sought to elucidate factors related to involuntary deployment of object-mediated space-based attention through two experiments. Experiment 1 used a modified flanker task where a target and nearby distractor were presented within the same or different object frames, such that an object-based attentional spread should be detrimental to performance. Results showed the presence of a flanker effect with no significant difference in magnitude between grouping conditions, indicating participants may have uniformly used a diffused attentional spotlight regardless of object segmentation. In a second experiment, we manipulated the extent of the observer’s sustained attentional scope via an inducer task to determine whether object-based selection depends on the initial spotlight size. The results revealed object-based effects solely when attention narrowly encompassed the target, but not when it was widened to include the distracting flanker. This suggests the deployment of object-based attention may occur when spatial attention is initially focused narrowly. Because selecting the whole object frame directly interfered with task goals, we conclude that object-based attention may not always fully conform to relevant task goals or operate in a goal-oriented manner. We discuss these results in the context of existing literature while proposing a reconciliation of previously inconsistent findings of object-based selection.

Tanulók- és sportolók motoros-képességeinek fejlesztése és felmérése labdás játékok esetén

Kutatásunk célja egy olyan komplex hardver- szoftverrendszer létrehozása volt, amelynek segítségével megállapítható a technika elsajátításának hatékonysága labdás játékok esetén például egy kézilabdázó dobási pontosságának és dobóerejének mérése révén. A szemből és oldalnézetből készített felvételek alapján, a mozgó objektum képkockánkénti elmozdulásából számítható a labda sebessége és pozíciója a képelemzés eszközeinek segítségével. Különös figyelmet fordítottunk az eszköz költséghatékony megvalósítására, valamint fontosnak tartottuk az egyszerű kezelhetőséget a telepítés és a mérés folyamán egyaránt. Mindezt a megfelelő hardver és szoftver technológiák kiválasztásán túl az is biztosítja, hogy nem igényel külön hardver eszközt a kezelése, mivel az edzők vagy a testnevelők saját mobileszközükről férhetnek hozzá a rendszer szolgáltatásaihoz. Az egyszerű kezelhetőséget a telepítés és a mérés folyamán egyaránt szem előtt tartottuk. Ez a technológia mind módszertani szempontból, mind motivációs eszközként is figyelmet érdemel, akár edzéseken, akár az iskolai testnevelés órákon. A fenti szempontok figyelembevételével a Raspberry Pi 3B+, a hozzá csatlakozó Raspberry Pi Camera V2-es modelljére (Raspberry Pi) és az ESP32 Cam-ra (ESP32), mint hardver komponensekre esett a választásunk. A kezelőfelületet pedig egy webes alkalmazás biztosítja, amelyen keresztül megfelelő hitelesítési folyamatot követően elérhetők a rendszer szolgáltatásai. ----- Developement and measurement of ballplayers’ motoric skills ----- Our research aimed to create a complex hardware-software system that can be used to determine the effectiveness of the technique in ball games, for example by measuring the throwing accuracy and throwing power of a handball player. Based on the shots taken from the front and side views, the speed and position of the ball can be calculated from the displacement of the moving object frame by frame using image analysis tools. We paid special attention to the cost-effective implementation of the device, and we considered it important to be easy to use during both installation and measurement. In addition to selecting the right hardware and software technologies, this is ensured by the fact that it does not require a separate hardware device to manage, as coaches or physical educators can access the system's services from their mobile devices. Ease of use was kept in mind during both installation and measurement. This technology deserves attention both from a methodological point of view and as a motivational tool, whether in training or school physical education classes. Considering the above considerations, we chose the Raspberry Pi 3B+ with a Raspberry Pi Camera V2 model and the ESP32 Cam as hardware components. The user interface is provided by a web application through which the system services can be accessed after a proper authentication process.

Reverse Validation Based Adaptive Particle Filter Algorithm for Object Tracking

To improves tracking drift which often occurs in adaptive tracking, an algorithm based on the fusion of tracking and detection is proposed in this paper. Firstly, tracking object frame by frame via color histogram and particle filtering. Secondly, reversely validating the tracking result based on particle filtering. Finally, relocating the object based on SIFT features matching and voting when drift occurs. Object appearance model is updated at the same time. The algorithm can not only sense tracking drift but also relocate the object whenever needed. Experimental results demonstrate that this algorithm outperforms state-of-the-art algorithms on many challenging sequences.

Calculating rotational motion in discrete element modelling of arbitrary shaped model objects

Application of the discrete element method (DEM) to real scale engineering problems involving three‐dimensional modelling of large, non‐spherical particles must consider the inertia tensor and temporal change in the orientation of the particles when calculating the rotational motion. This factor has commonly been neglected in discrete element modelling although it will significantly influence the dynamic behaviour of non‐spherical particles. In this paper two methods, vector transformation and tensor transformation, for calculation of the rotational motion of particles in response to applied moments are presented. The methods consider the inertia tensor and the local object frame of arbitrary shaped particles and suggest solutions for the non‐linear Euler equations for calculation of their rotational motion. They are discussed with respect to implementation into a discrete element code and assessed in terms of their accuracy and computational efficiency.

Observations on Stroboscopic Induced Motion

Subject-relative explanations of motion induction state that induced motion is the result of a misperceived shift of the median plane of the visual field of the subject. This theory does not require relative motion of the spot and frame, in the classical spot-and-frame condition, only asymmetrical stimulation. Three experiments are reported in which stroboscopic induced motion was investigated. The experimental arrangement was unconventional in that the induced object (spot) was presented only during the interstimulus interval between the exposures of the inducing object (frame). This allowed differentiation of the duration of the induced movement and that of the inducing one. In the first experiment it was demonstrated that perception of induced motion depends upon the duration of the interstimulus interval between the presentations of the inducing frame. In the second experiment it was shown that the perceived velocity of the induced movement can be different from that of the inducing one and depends on the duration of exposure of the induced object. In the third experiment a stimulus display was created in which the apparent displacement of an object and its induced motion are incongruous. The results are incompatible with subject-relative displacement as the sole determining factor of motion induction and they present some difficulties for the hypothesis that induced motion is the result of the apportionment of the objective displacement of the frame.