394 research outputs found

    Phylogenetic reorganization of the basal ganglia: A necessary, but not the only, bridge over a primate Rubicon of acoustic communication

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    In this response to commentaries, we revisit the two main arguments of our target article. Based on data drawn from a variety of research areas – vocal behavior in nonhuman primates, speech physiology and pathology, neurobiology of basal ganglia functions, motor skill learning, paleoanthropological concepts – the target article, first, suggests a two-stage model of the evolution of the crucial motor prerequisites of spoken language within the hominin lineage: (1) monosynaptic refinement of the projections of motor cortex to brainstem nuclei steering laryngeal muscles, and (2) subsequent “vocal-laryngeal elaboration” of cortico-basal ganglia circuits, driven by human-specific FOXP2 mutations. Second, as concerns the ontogenetic development of verbal communication, age-dependent interactions between the basal ganglia and their cortical targets are assumed to contribute to the time course of the acquisition of articulate speech. Whereas such a phylogenetic reorganization of cortico-striatal circuits must be considered a necessary prerequisite for ontogenetic speech acquisition, the 30 commentaries – addressing the whole range of data sources referred to – point at several further aspects of acoustic communication which have to be added to or integrated with the presented model. For example, the relationships between vocal tract movement sequencing – the focus of the target article – and rhythmical structures of movement organization, the connections between speech motor control and the central-auditory and central-visual systems, the impact of social factors upon the development of vocal behavior (in nonhuman primates and in our species), and the interactions of ontogenetic speech acquisition – based upon FOXP2-driven structural changes at the level of the basal ganglia – with preceding subvocal stages of acoustic communication as well as higher-order (cognitive) dimensions of phonological development. Most importantly, thus, several promising future research directions unfold from these contributions – accessible to clinical studies and functional imaging in our species as well as experimental investigations in nonhuman primates

    Systemarchitektur und Fahrmanöver zum sicheren Anhalten modularer automatisierter Fahrzeuge

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    Maschinelle Systeme übernehmen einen immer größer werdenden Anteil der dynamischen Fahraufgabe automatisierter Fahrzeuge. Funktionale Degradationen können die Fähigkeiten dieser Systeme negativ beeinflussen, sodass sie die Fahraufgabe nicht weiter erfüllen können. In diesen Fällen wird bei höher automatisierten Systemen die Fahraufgabe von einer maschinellen Rückfallebene übernommen. Im Rahmen des Forschungsprojekts UNICARagil wird eine modulare und dienstbasierte funktionale Fahrzeugarchitektur entwickelt, für die in diesem Beitrag die Anforderungen und die Systemarchitektur einer geeigneten funktionalen Rückfallebene vorgestellt werden und der weitere Forschungsbedarf hinsichtlich der erforderlichen Fähigkeiten der Teilfunktionen, ihrer gegenseitigen Abhängigkeiten und der Absicherung der Teil- und Gesamtfunktionen erläutert wird

    Approach to Maintain a Safe State of an Automated Vehicle in Case of Unsafe Desired Behavior

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    For automated driving, higher levels of automation pose new challenges in terms of safety. In this paper, we develop a generic behavior safety framework that maintains a safe vehicle state even in case of system failures. It is applicable to different configurations of automated driving system architectures. We verify the designed generic behavior safety framework by applying it to two different architectures from both projects PRORETA 5 and UNICARagil. The previously defined safety requirements are met with both applications, which indicates that the developed generic safety framework is also valid for other configurations of automated driving systems

    Reward system and temporal pole contributions to affective evaluation during a first person shooter video game

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    <p>Abstract</p> <p>Background</p> <p>Violent content in video games evokes many concerns but there is little research concerning its rewarding aspects. It was demonstrated that playing a video game leads to striatal dopamine release. It is unclear, however, which aspects of the game cause this reward system activation and if violent content contributes to it. We combined functional Magnetic Resonance Imaging (fMRI) with individual affect measures to address the neuronal correlates of violence in a video game.</p> <p>Results</p> <p>Thirteen male German volunteers played a first-person shooter game (<it>Tactical Ops: Assault on Terror</it>) during fMRI measurement. We defined success as eliminating opponents, and failure as being eliminated themselves. Affect was measured directly before and after game play using the Positive and Negative Affect Schedule (PANAS). Failure and success events evoked increased activity in visual cortex but only failure decreased activity in orbitofrontal cortex and caudate nucleus. A negative correlation between negative affect and responses to failure was evident in the right temporal pole (rTP).</p> <p>Conclusions</p> <p>The deactivation of the caudate nucleus during failure is in accordance with its role in reward-prediction error: it occurred whenever subject missed an expected reward (being eliminated rather than eliminating the opponent). We found no indication that violence events were directly rewarding for the players. We addressed subjective evaluations of affect change due to gameplay to study the reward system. Subjects reporting greater negative affect after playing the game had less rTP activity associated with failure. The rTP may therefore be involved in evaluating the failure events in a social context, to regulate the players' mood.</p

    Characterization of a CdZnTe detector for a low-power CubeSat application

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    We report spectral and imaging performance of a pixelated CdZnTe detector custom designed for the MeVCube project: a small Compton telescope on a CubeSat platform. MeVCube is expected to cover the energy range between 200 keV and 4 MeV, with a sensitivity comparable to the one of the last generation of larger satellites. In order to achieve this goal, an energy resolution of few percent in full width at half maximum (FWHM) and a 3-D spatial resolution of few millimeters for the individual detectors are needed. The severe power constraints present in small satellites require very low power read-out electronics for the detector. Our read-out is based on the VATA450.3 ASIC developed by Ideas, with a power consumption of only 0.25 mW/channel, which exhibits good performance in terms of dynamic range, noise and linearity. A 2.0 cm× 2.0 cm× 1.5 cm CdZnTe detector, with a custom 8 × 8 pixel anode structure read-out by a VATA450.3 ASIC, has been tested. A preliminary read-out system for the cathode, based on a discrete Amptek A250F charge sensitive pre-amplifier and a DRS4 ASIC, has been implemented. An energy resolution around 3% FWHM has been measured at a gamma energy of 662 keV; at 200 keV the average energy resolution is 6.5%, decreasing to ≲ 2% at energies above 1 MeV. A 3-D spatial resolution of ≈ 2 mm is achieved in each dimension.Peer Reviewe

    Characterization of a CdZnTe detector for a low-power CubeSat application

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    We report spectral and imaging performance of a pixelated CdZnTe detector custom designed for the \emph{MeVCube} project: a small Compton telescope on a CubeSat platform. \emph{MeVCube} is expected to cover the energy range between 200  keV200\;\mathrm{keV} and 4  MeV4\;\mathrm{MeV}, with performance comparable to the last generation of larger satellites. In order to achieve this goal, an energy resolution of few percent in full width at half maximum (FWHM) and a 33-D spatial resolution of few millimeters for the individual detectors are needed. The severe power constraints present in small satellites require very low power read-out electronics for the detector. Our read-out is based on the VATA450.3 ASIC developed by \emph{Ideas}, with a power consumption of only 0.25  mW/channel0.25\;\mathrm{mW/channel}, which exhibits good performance in terms of dynamic range, noise and linearity. A 2.0  cm×2.0  cm×1.5  cm2.0\;\mathrm{cm} \times 2.0\;\mathrm{cm} \times 1.5\;\mathrm{cm} CdZnTe detector, with a custom 8×88 \times 8 pixel anode structure read-out by a VATA450.3 ASIC, has been tested. A preliminary read-out system for the cathode, based on a discrete \emph{Amptek} A250F charge sensitive pre-amplifier and a DRS4 ASIC, has been implemented. An energy resolution around 3%3\% FWHM has been measured at a gamma energy of 662  keV662\;\mathrm{keV}; at 200  keV200\;\mathrm{keV} the average energy resolution is 6.5%6.5\%, decreasing to 2%\lesssim 2\% at energies above 1  MeV1\;\mathrm{MeV}. A 33-D spatial resolution of 2mm\approx 2\,\mathrm{mm} is achieved

    Collision avoidance in persons with homonymous visual field defects under virtual reality conditions

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    AbstractThe aim of the present study was to examine the effect of homonymous visual field defects (HVFDs) on collision avoidance of dynamic obstacles at an intersection under virtual reality (VR) conditions. Overall performance was quantitatively assessed as the number of collisions at a virtual intersection at two difficulty levels. HVFDs were assessed by binocular semi-automated kinetic perimetry within the 90° visual field, stimulus III4e and the area of sparing within the affected hemifield (A-SPAR in deg2) was calculated. The effect of A-SPAR, age, gender, side of brain lesion, time since brain lesion and presence of macular sparing on the number of collisions, as well as performance over time were investigated. Thirty patients (10 female, 20 male, age range: 19–71years) with HVFDs due to unilateral vascular brain lesions and 30 group-age-matched subjects with normal visual fields were examined. The mean number of collisions was higher for patients and in the more difficult level they experienced more collisions with vehicles approaching from the blind side than the seeing side. Lower A-SPAR and increasing age were associated with decreasing performance. However, in agreement with previous studies, wide variability in performance among patients with identical visual field defects was observed and performance of some patients was similar to that of normal subjects. Both patients and healthy subjects displayed equal improvement of performance over time in the more difficult level. In conclusion, our results suggest that visual-field related parameters per se are inadequate in predicting successful collision avoidance. Individualized approaches which also consider compensatory strategies by means of eye and head movements should be introduced
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