| 1. |
- Bianchi, Michele, et al.
(författare)
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Poly(3,4‐ethylenedioxythiophene)‐Based Neural Interfaces for Recording and Stimulation: Fundamental Aspects and In Vivo Applications
- 2022
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Ingår i: Advanced Science. - : John Wiley & Sons. - 2198-3844. ; 9:12
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Forskningsöversikt (refereegranskat)abstract
- Next‐generation neural interfaces for bidirectional communication with the central nervous system aim to achieve the intimate integration with the neural tissue with minimal neuroinflammatory response, high spatio‐temporal resolution, very high sensitivity, and readout stability. The design and manufacturing of devices for low power/low noise neural recording and safe and energy‐efficient stimulation that are, at the same time, conformable to the brain, with matched mechanical properties and biocompatibility, is a convergence area of research where neuroscientists, materials scientists, and nanotechnologists operate synergically. The biotic–abiotic neural interface, however, remains a formidable challenge that prompts for new materials platforms and innovation in device layouts. Conductive polymers (CP) are attractive materials to be interfaced with the neural tissue and to be used as sensing/stimulating electrodes because of their mixed ionic‐electronic conductivity, their low contact impedance, high charge storage capacitance, chemical versatility, and biocompatibility. This manuscript reviews the state‐of‐the‐art of poly(3,4‐ethylenedioxythiophene)‐based neural interfaces for extracellular recording and stimulation, focusing on those technological approaches that are successfully demonstrated in vivo. The aim is to highlight the most reliable and ready‐for‐clinical‐use solutions, in terms of materials technology and recording performance, other than spot major limitations and identify future trends in this field.
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| 2. |
- Boehler, Christian, et al.
(författare)
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Tutorial: guidelines for standardized performance tests for electrodes intended for neural interfaces and bioelectronics
- 2020
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Ingår i: Nature Protocols. - : Springer Nature. - 1754-2189 .- 1750-2799. ; 15:11, s. 3557-3578
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Forskningsöversikt (refereegranskat)abstract
- Implantable neural interfaces advance the possibilities for neuroscientists to study the brain. They are also promising for use in a multitude of bioelectronic therapies. Electrode technology plays a central role in these developments, as the electrode surfaces form the physical interfaces between technology and the biological targets. Despite this, a common understanding of how electrodes should best be evaluated and compared with respect to their efficiency in recording and stimulation is currently lacking. Without broadly accepted performance tests, it is difficult to rank the many suggestions for electrode materials available in the literature, or to identify where efforts should be focused to advance the field most efficiently. This tutorial critically discusses the most relevant performance tests for characterization of neural interface electrodes and explains their implementation, interpretation and respective limitations. We propose a unified standard to facilitate transparent reporting on electrode performance, promote efficient scientific process and ultimately accelerate translation into clinical practice.
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| 3. |
- Falck-Ytter, Terje, 1979-
(författare)
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From Actions to Faces : Studies of Social Perception in Typical and Atypical Development
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis consists of three eye-tracking studies of social perception in children. Study I and Study II investigated action perception in typically developing infants and preschoolers with Autism Spectrum Disorder (ASD), respectively. Study III investigated face perception in children with ASD. Do infants come to understand others’ actions by a Mirror Neuron System (MNS) that maps others’ actions onto motor plans for similar actions? In Study I, we measured the eye movements while participants observed video clips of an actor's hand placing toys into a bucket. Adults and twelve-month-old infants looked at the bucket before the hand reached it, predicting the goal of the action. This predictive performance was linked to seeing a hand-object interaction. Six-month-olds failed to predict the goal of the action. The development in prediction skills coincides with the age at which infants learn to perform the action themselves. This supports the view that the MNS forms the basis of important social competences such as predicting others' actions. According to the MNS theory of ASD, a failure to map others’ actions onto motor plans for similar actions underlies the social symptoms defining the disorder. In Study II, children with ASD as well as typically developing children and adults were shown the same stimuli as used in Study I. At odds with the theory, all groups used strikingly similar predictive eye movements in action observation. Gaze was reactive in a self-propelled condition, suggesting that prediction is linked to seeing a hand-object interaction. This study does not support the view that ASD is characterized by a global dysfunction in the MNS. Face processing is another core social competence, and research has suggested that many individuals with ASD have face processing impairments. In Study III, we showed faces to young children with ASD and related their looking performance to their behavioural symptoms. Our findings suggest that the socio-communicative information transmitted from faces is processed in a piecemeal fashion in young children with ASD. Much of the variability in face scanning could be explained by individual differences in socio-communicative skills.
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| 4. |
- Metta, Giorgio, et al.
(författare)
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The iCub humanoid robot : An open-systems platform for research in cognitive development
- 2010
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Ingår i: Neural Networks. - : Elsevier BV. - 0893-6080 .- 1879-2782. ; 23:8-9, s. 1125-1134
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Tidskriftsartikel (refereegranskat)abstract
- We describe a humanoid robot platform - the iCub - which was designed to support collaborative research in cognitive development through autonomous exploration and social interaction. The motivation for this effort is the conviction that significantly greater impact can be leveraged by adopting an open systems policy for software and hardware development. This creates the need for a robust humanoid robot that offers rich perceptuo-motor capabilities with many degrees of freedom, a cognitive capacity for learning and development, a software architecture that encourages reuse & easy integration, and a support infrastructure that fosters collaboration and sharing of resources. The iCub satisfies all of these needs in the guise of an open-system platform which is freely available and which has attracted a growing community of users and developers. To date, twenty iCubs each comprising approximately 5000 mechanical and electrical parts have been delivered to several research labs in Europe and to one in the USA.
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| 5. |
- Vernon, David, 1958-, et al.
(författare)
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Desiderata for developmental cognitive architectures
- 2016
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Ingår i: Biologically Inspired Cognitive Architectures. - : Elsevier. - 2212-683X .- 2212-6848. ; 18, s. 116-127
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Tidskriftsartikel (refereegranskat)abstract
- This paper complements Ron Sun’s influential Desiderata for Cognitive Architectures by focussing on the desirable attributes of a biologically-inspired cognitive architecture for an agent with a capacity for autonomous development. Ten desiderata are identified, dealing with value systems & motives, embodiment, sensorimotor contingencies, perception, attention, prospective action, memory, learning, internal simulation, and constitutive autonomy. These desiderata are motivated by studies in developmental psychology, cognitive neuroscience, and enactive cognitive science. All ten focus on the ultimate aspects of cognitive development — why a feature is necessary and what it enables — rather on than the proximate mechanisms by which it can be realized. As such, the desiderata are for the most part neutral regarding the paradigm of cognitive science — cognitivist or emergent — that is adopted when designing a cognitive architecture. Where some element of a desideratum is specific to a particular paradigm, this is noted.
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| 6. |
- Vomero, Maria, et al.
(författare)
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Conformable polyimide-based μECoGs : Bringing the electrodes closer to the signal source
- 2020
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Ingår i: Biomaterials. - : Elsevier. - 0142-9612 .- 1878-5905. ; 255
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Tidskriftsartikel (refereegranskat)abstract
- Structural biocompatibility is a fundamental requirement for chronically stable bioelectronic devices. Newest neurotechnologies are increasingly focused on minimizing the foreign body response through the development of devices that match the mechanical properties of the implanted tissue and mimic its surface composition, often compromising on their robustness. In this study, an analytical approach is proposed to determine the threshold of conformability for polyimide-based electrocorticography devices. A finite element model was used to quantify the depression of the cortex following the application of devices mechanically above or below conformability threshold. Findings were validated in vivo on rat animal models. Impedance measurements were performed for 40 days after implantation to monitor the status of the biotic/abiotic interface with both conformable and non-conformable implants. Multi-unit activity was then recorded for 12 weeks after implantation using the most compliant device type. It can therefore be concluded that conformability is an essential prerequisite for steady and reliable implants which does not only depend on the Young's modulus of the device material: it strongly relies on the relation between tissue curvature at the implantation site and corresponding device's thickness and geometry, which eventually define the moment of inertia and the interactions at the material-tissue interface.
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| 7. |
- Vomero, Maria, et al.
(författare)
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On the longevity of flexible neural interfaces: Establishing biostability of polyimide-based intracortical implants
- 2022
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Ingår i: Biomaterials. - : Elsevier. - 0142-9612 .- 1878-5905. ; 281
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Tidskriftsartikel (refereegranskat)abstract
- Flexible neural implants are extremely favored, as the most successful strategy to promote probe-tissue integration and avoid severe gliosis relies on reducing the mechanical mismatch between probe and brain tissue. But what are the realistic requirements for achieving chronic recording stability? What are the critical dimensions and main factors determining glial scar-free device integration? To answer these questions, two types of hair-sized polyimide-based flexible intracortical (PIXI) arrays were fabricated, differing only in their cross-sectional area. Chronic tissue reaction to both types was evaluated in rats, and in different implantation setups. Interfacial stresses were found to play a critical role in long-term tissue integration. Still, all the devices provided high quality chronic recordings of single units and inflammatory gene expression was not significantly upregulated for larger devices. Our study points out that the most relevant factor in eliciting FBR is played by mechanical probe-tissue interactions, that polyimide is well tolerated by the tissue, and that a holistic design - considering material properties, geometrical dimensions and assembling techniques - is the key towards longevity and long-term performance of intracortical probes. The optimization of only one parameter did not yet lead to the successful translation of research accomplishments into chronic preclinical and clinical applications.
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