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Solution-processed semiconductors are in demand for present and next-generation optoelectronic technologies ranging from displays to quantum light sources because of their scalability and ease of integration into devices with diverse form factors. One of the central requirements for semiconductors used in these applications is a narrow photoluminescence (PL) line width. Narrow emission line widths are needed to ensure both color and single-photon purity, raising the question of what design rules are needed to obtain narrow emission from semiconductors made in solution. In this review, we first examine the requirements for colloidal emitters for a variety of applications including light-emitting diodes, photodetectors, lasers, and quantum information science. Next, we will delve into the sources of spectral broadening, including "homogeneous" broadening from dynamical broadening mechanisms in single-particle spectra, heterogeneous broadening from static structural differences in ensemble spectra, and spectral diffusion. Then, we compare the current state of the art in terms of emission line width for a variety of colloidal materials including II-VI quantum dots (QDs) and nanoplatelets, III-V QDs, alloyed QDs, metal-halide perovskites including nanocrystals and 2D structures, doped nanocrystals, and, finally, as a point of comparison, organic molecules. We end with some conclusions and connections, including an outline of promising paths forward.
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AIM: To explore patients' experiences with early rehabilitation in the intensive care unit and what they perceive to influence their participation. DESIGN: A qualitative design anchored in phenomenological and hermeneutical traditions utilizing in-depth interviews. METHODS: Thirteen patients were interviewed from 5 to 29 weeks following discharge from three units, in January-December 2022. Analysed using systematic text condensation and the pattern theory of self. Reporting adhered to consolidated criteria for reporting qualitative research. RESULTS: Interviews described four main categories: (1) A foreign body, how the participants experienced their dysfunctional and different looking bodies. (2) From crisis to reorientation, the transformation the participants experienced from a state of crisis to acceptance and the ability to look forwards, indicating how bodily dysfunctions are interlinked to breakdowns of the patients' selves and the reorganization process. (3) Diverse expectations regarding activity: ambiguous expectations communicated by the nurses. (4) Nurse-patient: a powerful interaction, highlighting the essential significance of positive expectations and tailored bodily and verbal interaction for rebuilding the patient's outwards orientation. CONCLUSION: Outwards orientation and reorganization of the self through a reduction in bodily dysfunctions, strengthening the patients' acceptance of the situation, providing tailored expectations and hands-on and verbal interaction appear to be fundamental aspects of patient participation in early rehabilitation. IMPLICATIONS: Insights into patients' perceptions show how dysfunctional bodies cloud individuals' perceptual fields, causing inwards orientation and negative thoughts concerning themselves, their capabilities, environment and future. This knowledge can improve nurses' ability to tailor care to promote optimal recovery for patients. PATIENT OR PUBLIC CONTRIBUTION: User representative contributed to the design of the study.
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Unidades de Cuidados Intensivos , Medicina , Humanos , Investigación Cualitativa , Pacientes , Alta del PacienteRESUMEN
As easy-to-grow quantum wells with narrow excitonic features at room temperature, two-dimensional (2D) Ruddleson-Popper perovskites are promising for realizing novel nanophotonic devices based on exciton-photon interactions. Here, we demonstrate a distinct hybrid exciton-photon Fano resonance in (C4H9NH3)2PbI4 thin films prepared via spin coating. Using a classical coupled-oscillator model and finite-difference time-domain simulations, we link the Fano interference to the coupling of the exciton with the Rayleigh-like scattering of the film microstructure. Combining colloidal plasmonic cavities with the 2D perovskite films, we demonstrate tuning of the Fano resonance. In combination with silver nanoparticles, the exciton-photon Fano interference couples to the in-plane plasmonic modes with indications of Rabi splitting. By creating a nanoparticle on mirror geometry, we address the out-of-plane excitonic component, reaching an intermediate coupling regime. These structures suggest possible photonic targets for biomolecular self-assembly applications.
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Nanopartículas del Metal , Compuestos de Calcio , Óxidos , Plata , TitanioRESUMEN
Categorization-based diagnosis, which endeavors to be consistent with the third-person, objective measures of science, is not always adequate with respect to problems concerning diagnostic accuracy, demarcation problems when there are comorbidities, well-documented problems of symptom amplification, and complications of stigmatization and looping effects. While psychiatric categories have proved useful and convenient for clinicians in identifying a recognizable constellation of symptoms typical for a particular disorder for the purposes of communication and eligibility for treatment regimes, the reification of these categories has without doubt had negative consequences for the patient and also for the general understanding of psychiatric disorders. We argue that a complementary, integrated framework that focuses on descriptive symptom-based classifications (drawing on phenomenological interview methods and narrative) combined with a more comprehensive conception of the human subject (found in the pattern theory of self), can not only offer a solution to some of the vexed issues of psychiatric diagnosis but also support more efficacious therapeutic interventions.
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Trastornos Mentales/diagnóstico , Psicopatología/métodos , Comorbilidad , Humanos , Trastornos Mentales/patologíaRESUMEN
We distinguish between three philosophical views on the neuroscience of predictive models: predictive coding (associated with internal Bayesian models and prediction error minimization), predictive processing (associated with radical connectionism and 'simple' embodiment) and predictive engagement (associated with enactivist approaches to cognition). We examine the concept of active inference under each model and then ask how this concept informs discussions of social cognition. In this context we consider Frith and Friston's proposal for a neural hermeneutics, and we explore the alternative model of enactivist hermeneutics.
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Debates about neonatal imitation remain more open than Keven & Akins (K&A) imply. K&A do not recognize the primacy of the question concerning differential imitation and the links between experimental designs and more or less plausible theoretical assumptions. Moreover, they do not acknowledge previous theorizing on spontaneous behavior, the explanatory power of entrainment, and subtle connections with social cognition.
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Conducta Imitativa , Habla , Relaciones Interpersonales , Conducta SocialRESUMEN
The main question that Firestone & Scholl (F&S) pose is whether "what and how we see is functionally independent from what and how we think, know, desire, act, and so forth" (sect. 2, para. 1). We synthesize a collection of concerns from an interdisciplinary set of coauthors regarding F&S's assumptions and appeals to intuition, resulting in their treatment of visual perception as context-free.
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Intuición , Percepción Visual , Humanos , Visión OcularRESUMEN
I evaluate several attempts to integrate standard theories of social cognition, either theory theory or simulation theory, with aspects of interaction theory, and especially with the concept of direct social perception. I refer to these as new hybrid theories of social cognition. One of the new hybrids accomplishes the integration only by weakening the concept of mindreading or by understanding mindreading as targeting the shared situation rather than the other's mental states. Hybrids that attempt to accommodate the idea of direct perception of mental states grant a phenomenological directness only by maintaining tacit (theory-based) inferences on the subpersonal level. If such inferential processes are thought to be extra-perceptual, then perception is neither sufficient nor direct for an understanding of intentions and emotions. Moreover, insistence on top-down inferential processes trades off against the possibility of plasticity in the perceptual system itself. I suggest that a better model than a hybrid theory would be a pluralist one. A pluralist approach to social cognition would treat theoretical inference, simulation, direct perception, interactive skills, etc. as different strategies. The real challenge is to work out a pluralist account of subpersonal processes.
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Teoría Psicológica , Percepción Social , Teoría de la Mente/fisiología , Pensamiento/fisiología , HumanosRESUMEN
Although post-cognitivist approaches have shaken the status quo by emphasising the dynamic interactions among the brain, the body, and the environment in cognition, mainstream psychological theories continue to view concepts as primarily representational or skull-bound mental phenomena. As a result, the dynamics of action and the possible impact of material culture on conceptual thinking are poorly understood. In this paper, we explore the process and meaning of conceptual thinking from a material engagement perspective. We argue that conceptual thinking is not a matter of forming representations in the head but something we do-a way of engaging with materiality. Conceptual thinking is conceptual thinging, namely a kind of unmediated practical knowledge that individuals put into play when they engage, in a general way, with and through the world. In this sense, we propose that conceptual thinking is instantiated in the dynamic coordination of bodily practices and artefacts in sociomaterial activities. To elucidate this perspective, we introduce seven principles defining conceptual thinking within an ecological-enactive framework of cognition.
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Concepts of empathy, sympathy and compassion are often confused in a variety of literatures. This article proposes a pattern-theoretic approach to distinguishing compassion from empathy and sympathy. Drawing on psychology, Western philosophy, affective neuroscience, and contemplative science, we clarify the nature of compassion as a specific pattern of dynamically related factors that include physiological, cognitive, and affective processes, relational/intersubjective processes, and motivational/action tendencies. We also show that the dynamic nature of the compassion pattern is reflected in neuroscientific findings, as well as in compassion practice. The pattern theory of compassion allows us to make several clear distinctions between compassion, empathy, and sympathy.
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Empatía , Teoría Psicológica , Empatía/fisiología , Humanos , Motivación/fisiologíaRESUMEN
Mental disorders are increasingly understood as involving complex alterations of self that emerge from dynamical interactions of constituent elements, including cognitive, bodily, affective, social, narrative, cultural and normative aspects and processes. An account of self that supports this view is the pattern theory of self (PTS). The PTS is a non-reductive account of the self, consistent with both embodied-enactive cognition and phenomenological psychopathology; it foregrounds the multi-dimensionality of subjects, stressing situated embodiment and intersubjective processes in the formation of the self-pattern. Indications in the literature already demonstrate the viability of the PTS for formulating an alternative methodology to better understand the lived experience of those suffering mental disorders and to guide mental health research more generally. This article develops a flexible methodological framework that front-loads the self-pattern into a minimally structured phenomenological interview. We call this framework 'Examination of Self Patterns' (ESP). The ESP is unconstrained by internalist or externalist assumptions about mind and is flexibly guided by person-specific interpretations rather than pre-determined diagnostic categories. We suggest this approach is advantageous for tackling the inherent complexity of mental health, the clinical protocols and the requirements of research.
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Photoluminescence intermittency remains one of the biggest challenges in realizing perovskite quantum dots (QDs) as scalable single photon emitters. We compare CsPbBr3 QDs capped with different ligands, lecithin, and a combination of oleic acid and oleylamine, to elucidate the role of surface chemistry on photoluminescence intermittency. We employ widefield photoluminescence microscopy to sample the blinking behavior of hundreds of QDs. Using change point analysis, we achieve the robust classification of blinking trajectories, and we analyze representative distributions from large numbers of QDs (Nlecithin = 1308, Noleic acid/oleylamine = 1317). We find that lecithin suppresses blinking in CsPbBr3 QDs compared with oleic acid/oleylamine. Under common experimental conditions, lecithin-capped QDs are 7.5 times more likely to be nonblinking and spend 2.5 times longer in their most emissive state, despite both QDs having nearly identical solution photoluminescence quantum yields. We measure photoluminescence as a function of dilution and show that the differences between lecithin and oleic acid/oleylamine capping emerge at low concentrations during preparation for single particle experiments. From experiment and first-principles calculations, we attribute the differences in lecithin and oleic acid/oleylamine performance to differences in their ligand binding equilibria. Consistent with our experimental data, density functional theory calculations suggest a stronger binding affinity of lecithin to the QD surface compared to oleic acid/oleylamine, implying a reduced likelihood of ligand desorption during dilution. These results suggest that using more tightly binding ligands is a necessity for surface passivation and, consequently, blinking reduction in perovskite QDs used for single particle and quantum light experiments.
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The notion of an enactive system requires thinking about the brain in a way that is different from the standard computational-representational models. In evolutionary terms, the brain does what it does and is the way that it is, across some scale of variations, because it is part of a living body with hands that can reach and grasp in certain limited ways, eyes structured to focus, an autonomic system, an upright posture, etc. coping with specific kinds of environments, and with other people. Changes to any of the bodily, environmental, or intersubjective conditions elicit responses from the system as a whole. On this view, rather than representing or computing information, the brain is better conceived as participating in the action.
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Cognición/fisiología , Relaciones Interpersonales , Neuronas Espejo/fisiología , Percepción Social , Teoría de la Mente/fisiología , HumanosRESUMEN
The concept of minimal self-consciousness or "minimal self" is equivalent to a very basic form of first-person, pre-reflective self-awareness, which includes bodily self-awareness, and is related to phenomenal experience (qualia) and sentience. This phenomenological concept plays a role in characterizations of the senses of ownership and agency; in recent debates about Buddhist conceptions of the no-self; in explanations of illusions such as the Rubber Hand Illusion; as well as in characterizations of schizophrenia as a self-disorder. Despite its relevance to these complex investigations, a number of theorists have recently pointed out that the concept is not well defined. In order to provide some clarification about the notion of minimal self and how it relates to bodily and sensory processes this paper reaches back to the ideas expressed in a famous medieval thought experiment proposed in the 11th century: Avicenna's Flying Man argument. The paper then provides a review of some of the contemporary debates about the minimal self, pointing especially to questions about the role of bodily and social processes.
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This article aims to show that there is an alternative way to explain human action with respect to the bottlenecks of the psychology of decision making. The empirical study of human behaviour from mid-20th century to date has mainly developed by looking at a normative model of decision making. In particular Subjective Expected Utility (SEU) decision making, which stems from the subjective expected utility theory of Savage (1954) that itself extended the analysis by Von Neumann and Morgenstern (1944). On this view, the cognitive psychology of decision making precisely reflects the conceptual structure of formal decision theory. This article shows that there is an alternative way to understand decision making by recovering Newell and Simon's account of problem solving, developed in the framework of bounded rationality, and inserting it into the more recent research program of embodied cognition. Herbert Simon emphasized the importance of problem solving and differentiated it from decision making, which he considered a phase downstream of the former. Moreover according to Simon the centre of gravity of the rationality of the action lies in the ability to adapt. And the centre of gravity of adaptation is not so much in the internal environment of the actor as in the pragmatic external environment. The behaviour adapts to external purposes and reveals those characteristics of the system that limit its adaptation. According to Simon (1981), in fact, environmental feedback is the most effective factor in modelling human actions in solving a problem. In addition, his notion of problem space signifies the possible situations to be searched in order to find that situation which corresponds to the solution. Using the language of embodied cognition, the notion of problem space is about the possible solutions that are enacted in relation to environmental affordances. The correspondence between action and the solution of a problem conceptually bypasses the analytic phase of the decision and limits the role of symbolic representation. In solving any problem, the search for the solution corresponds to acting in ways that involve recursive feedback processes leading up to the final action. From this point of view, the new term enactive problem solving summarizes this fusion between bounded and embodied cognition. That problem solving involves bounded cognition means that it is through the problem solver's enactive interaction with environmental affordances, and especially social affordances that it is possible to construct the processes required for arriving at a solution. Lastly the concept of enactive problem solving is also able to explain the mechanisms underlying the adaptive heuristics of rational ecology. Its adaptive function is effective both in practical and motor tasks as well as in abstract and symbolic ones.
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Clinical and neuroscientific evidence indicates that transdiagnostic processes contribute to the generation and maintenance of psychopathological symptoms and disorders. Rigidity (inflexibility) appears a core feature of most transdiagnostic pathological processes. Decreasing rigidity may prove important to restore and maintain mental health. One of the primary domains in which rigidity and flexibility plays a role concerns the self. We adopt the pattern theory of self (PTS) for a working definition of self. This incorporates the pluralist view on self as constituted by multiple aspects or processes, understood to constitute a self-pattern, i.e. processes organized in non-linear dynamical relations across a number of time scales. The use of mindfulness meditation in the format of Mindfulness Based Interventions (MBIs) has been developed over four decades in Clinical Psychology. MBIs are promising as evidence-based treatments, shown to be equivalent to gold-standard treatments and superior to specific active controls in several randomized controlled trials. Notably, MBIs have been shown to target transdiagnostic symptoms. Given the hypothesized central role of rigid, habitual self-patterns in psychopathology, PTS offers a useful frame to understand how mindfulness may be beneficial in decreasing inflexibility. We discuss the evidence that mindfulness can alter the psychological and behavioral expression of individual aspects of the self-pattern, as well as favour change in the self-pattern as a whole gestalt. We discuss neuroscientific research on how the phenomenology of the self (pattern) is reflected in associated cortical networks and meditation-related alterations in cortical networks. Creating a synergy between these two aspects can increase understanding of psychopathological processes and improve diagnostic and therapeutic options.
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In this paper I address what has been called the integration problem in psychiatry. This problem is tied to conceptions of causality and explanatory levels in our understanding of mind. I take an interdisciplinary enactive perspective to develop a 3-fold method for exploring the dynamics of integration, based on a concept of dynamical causation and a non-hierarchical (level-free) notion of gestalt. I also consider Autism Spectrum Disorder (ASD) as a test case.
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In this paper I examine a set of exceptional aesthetic experiences that remove us from our pragmatic everyday life and involve a specific type of unaffordability. I then extend this notion of unaffordability to experiences of awe and its relation to the sublime. My analysis is guided by considerations of the phenomenologically inspired enactivist approach that supports an affordance-based accounts of aesthetic experience. I review some recent neurophenomenological studies of the experience of awe, and I then sketch out a phenomenology of awe as it approaches the sublime.
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We review different analytic approaches to narratives by those with psychopathological conditions, and we suggest that the interpretation of such narratives are complicated by a variety of phenomenological and hermeneutical considerations. We summarize an empirical study of narrative distance in narratives by non-pathological subjects, and discuss how the results can be interpreted in two different ways with regard to the issue of dissociation.