39 resultados para stream of consciousness


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In spite of the inherent difficulties in achieving a biologically meaningful definition of consciousness, recent neurophysiological studies are starting to provide some insight in fundamental mechanisms associated with impaired consciousness in neurological disorders. Generalised seizures are associated with disruption of the default state network, a functional network of discrete brain areas, which include the fronto-parietal cortices. Subcortical contribution through activation of thalamocortical structures, as well as striate nuclei are also crucial to produce impaired consciousness in generalised seizures.

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The revolution in the foundations of physics at the beginning of the twentieth century suggested to several of its most prominent workers that biology was ripe for something similar. In consequence, a number of physicists moved into biology. They were highly influential in initiating a molecular biology in the 1950s. Two decades later it seemed to several of these migrants, and those they had influenced, that the major problems in molecular biology had been solved, and that it was time to move on to what seemed to them the final problem: the nervous system, consciousness, and the age-old mind-body problem. This paper reviews this "double migration" and shows how the hopes of the first generation of physicist-biologists were both realized and dashed. No new physical principles were discovered at work in the foundations of biology or neuroscience. On the other hand, the mind-set of those trained in physics proved immensely valuable in analyzing fundamental issues in both biology and neuroscience. It has been argued that the outcome of the molecular biology of the 1950s was a change in the concept of the gene from that of "a mysterious entity into that of a real molecular object" (Watson, 1965, p.6); the gates and channels which play such crucial roles in the functioning of nervous systems have been transformed in a similar way. Studies on highly simplified systems have also opened the prospect of finding the neural correlatives of numerous behaviors and neuropathologies. This increasing understanding at the molecular level is invaluable not only in devising rational therapies but also, by defining the material substrate of consciousness, in bringing the mind-body problem into sharper focus. Copyright © Taylor & Francis Inc.

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This research examines the relationship between 'race' and class in Britain. This is achieved by considering how these two concepts articulate in the overall structuring of class relationships in a society which is typified by the incorporatation of black labour into a majority white society, This relationship is examined through an investigation of those black workers who occupy a position in the objectively defined middle class. The basic theme underlying this research is that 'race, in the form of structural racism, plays a significant role at two levels. Firstly, it serves to structure the class position of black labour in Britain. Secondly, it serves to determine the type of race, class and political consciousness generated by black labour. The study was carried out in the London area. Occupation was used as an indicator of 'objective' class position when selecting respondents to be included in the two survey populations required for the research. A 'network' approach was used to actually locate the respondents. In-depth interviews were carried out with all the respondents. The study concludes that the concepts of 'race' and class are not independent of each other in the overall structuring of class relationships between black and white labour. It is argued that the inter-relationship identified between these two concepts serves to highlight the fact that the structural position of black labour, the type of consciousness generated and the type of decisions taken by those who took part in the research are to a large extent a result of the structural constraints deriving from the effects of structural racism in Britain.

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Insights from the stream of research on knowledge calibration, which refers to the correspondence between accuracy and confidence in knowledge, enable a better understanding of consequences of inaccurate perceptions of managers. This paper examines the consequences of inaccurate managerial knowledge through the lens of knowledge calibration. Specifically, the paper examines the antecedent role of miscalibration of knowledge in strategy formation. It is postulated that miscalibrated managers who overestimate external factors and display a high level of confidence in their estimates are likely to enact strategies that are relatively more evolutionary and incremental in nature, whereas miscalibrated managers who overestimate internal factors and display a high level of confidence in their estimates are likely to enact strategies that are relatively more discontinuous and disruptive in nature. Perspectives from social cognitive theory provide support for the underlying processes. The paper, in part, explains the paradox of the prevalence of inaccurate managerial perceptions and efficacious performance. It also advances the literature on strategy formation through the application of the construct of knowledge calibration.

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In the current global economic climate, international HRM is facing unprecedented pressure to become more innovative, effective and efficient. New discourses are emerging around the application of information technology, with 'e-HR' (electronic-enablement of Human Resources), self-service portals and promises of improved services couched as various HR 'value propositions'. This study explores these issues through our engagement with the emergent stream of 'critical' HRM, the broader study of organizational discourse and ethical management theories. We have found that while there is growing research into the take-up of e-HR applications, there is a dearth of investigation into the impact of e-HR on the people involved; in particular, the (re)structuring of social relations between HR functions and line managers in the move away from face-to-face HR support services, to more technology-mediated 'self-service' relationships. We undertake a close reading of personal narratives from a multinational organization, deploying a critical discourse lens to examine different dimensions of e-HR and raise questions about the strong technocratic framing of the international language of people management, shaping line manager enactment of e-HR duties. We argue for a more reflexive stance in the conceptualization e-HR, and conclude with a discussion about the theoretical and practical implications of our study, limitations and suggestions for future research. © 2014 © 2014 Taylor & Francis.

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When people monitor a visual stream of rapidly presented stimuli for two targets (T1 and T2), they often miss T2 if it falls into a time window of about half a second after T1 onset—the attentional blink (AB). We provide an overview of recent neuroscientific studies devoted to analyze the neural processes underlying the AB and their temporal dynamics. The available evidence points to an attentional network involving temporal, right-parietal and frontal cortex, and suggests that the components of this neural network interact by means of synchronization and stimulus-induced desynchronization in the beta frequency range. We set up a neurocognitive scenario describing how the AB might emerge and why it depends on the presence of masks and the other event(s) the targets are embedded in. The scenario supports the idea that the AB arises from ‘‘biased competition’’, with the top–down bias being generated by parietal–frontal interactions and the competition taking place between stimulus codes in temporal cortex.

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Service innovations in retailing have the potential to benefit consumers as well as retailers. This research models key factors associated with the trial and continuous use of a specific self-service technology (SST), the personal shopping assistant (PSA), and estimates retailer benefits from implementing that innovation. Based on theoretical insights from prior SST studies, diffusion of innovation literature, and the technology acceptance model (TAM), this study develops specific hypotheses and tests them on a sample of 104 actual users of the PSA and 345 nonusers who shopped at the retail store offering the PSA device. Results indicate that factors affecting initial trial are different from those affecting continuous use. More specifically, consumers' trust toward the retailer, novelty seeking, and market mavenism are positively related to trial, while technology anxiety hinders the likelihood of trying the PSA. Perceived ease of use of the device positively impacts continuous use while consumers' need for interaction in shopping environments reduces the likelihood of continuous use. Importantly, there is evidence on retailer benefits from introducing the innovation since consumers using the PSA tend to spend more during each shopping trip. However, given the high costs of technology, the payback period for recovery of investments in innovation depends largely upon continued use of the innovation by consumers. Important implications are provided for retailers considering investments in new in-store service innovations. Incorporation of technology within physical stores affords opportunities for the retailer to reduce costs, while enhancing service provided to consumers. Therefore, service innovations in retailing have the potential to benefit consumers as well as retailers. This research models key factors associated with the trial and continuous use of a specific SST in the retail context, the PSA, and estimates retailer benefits from implementing that innovation. In so doing, the study contributes to the nascent area of research on SSTs in the retail sector. Based on theoretical insights from prior SST studies, diffusion of innovation literature, and the TAM, this study develops specific hypotheses regarding the (1) antecedent effects of technological anxiety, novelty seeking, market mavenism, and trust in the retailer on trial of the service innovation; (2) the effects of ease of use, perceived waiting time, and need for interaction on continuous use of the innovation; and (3) the effect of use of innovation on consumer spending at the store. The hypotheses were tested on a sample of 104 actual users of the PSA and 345 nonusers who shopped at the retail store offering the PSA device, one of the early adopters of PSA in Germany. Data were analyzed using logistic regression (antecedents of trial), multiple regression (antecedents of continuous use), and propensity score matching (assessing retailer benefits). Results indicate that factors affecting initial trial are different from those affecting continuous use. More specifically, consumers' trust toward the retailer, novelty seeking, and market mavenism are positively related to trial, while technology anxiety hinders the likelihood of trying the PSA. Perceived ease of use of the device positively impacts continuous use, while consumers' need for interaction in shopping environments reduces the likelihood of continuous use. Importantly, there is evidence on retailer benefits from introducing the innovation since consumers using the PSA tend to spend more during each shopping trip. However, given the high costs of technology, the payback period for recovery of investments in innovation depends largely upon continued use of the innovation by consumers. Important implications are provided for retailers considering investments in new in-store service innovations. The study contributes to the literature through its (1) simultaneous examination of antecedents of trial and continuous usage of a specific SST, (2) the demonstration of economic benefits of SST introduction for the retailer, and (3) contribution to the stream of research on service innovation, as against product innovation.

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Visual sensitivity, defined as the “susceptibility toward experiencing seizures, which are triggered by the physical characteristics of visual stimuli and not by their perceptual properties,”1 can manifest in the context of various forms of generalized or focal, idiopathic or symptomatic epilepsies.2 We report a patient with no family or personal history of epilepsy who presented episodes of loss of consciousness exclusively triggered by visual stimuli unrelated to their emotional content, in which we have documented EEG-EKG characteristics suggestive of a neurally mediated syncope.

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The 'attentional blink' (AB) reflects a limitation in the ability to identify multiple items in a stream of rapidly presented information. Repetitive transcranial magnetic stimulation (rTMS), applied to a site over the right posterior parietal cortex, reduced the magnitude of the AB to visual stimuli, whilst no effect of rTMS was found when stimulation took place at a control site. The data confirm that the posterior parietal cortex may play a critical role in temporal as well as spatial aspects of visual attention.

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Few works address methodological issues of how to conduct strategy-as-practice research and even fewer focus on how to analyse the subsequent data in ways that illuminate strategy as an everyday, social practice. We address this gap by proposing a quantitative method for analysing observational data, which can complement more traditional qualitative methodologies. We propose that rigorous but context-sensitive coding of transcripts can render everyday practice analysable statistically. Such statistical analysis provides a means for analytically representing patterns and shifts within the mundane, repetitive elements through which practice is accomplished. We call this approach the Event Database (EDB) and it consists of five basic coding categories that help us capture the stream of practice. Indexing codes help to index or categorise the data, in order to give context and offer some basic information about the event under discussion. Indexing codes are descriptive codes, which allow us to catalogue and classify events according to their assigned characteristics. Content codes are to do with the qualitative nature of the event; this is the essence of the event. It is a description that helps to inform judgements about the phenomenon. Nature codes help us distinguish between discursive and tangible events. We include this code to acknowledge that some events differ qualitatively from other events. Type events are codes abstracted from the data in order to help us classify events based on their description or nature. This involves significantly more judgement than the index codes but consequently is also more meaningful. Dynamics codes help us capture some of the movement or fluidity of events. This category has been included to let us capture the flow of activity over time.

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The introduction situates the ‘hard problem’ in its historical context and argues that the problem has two sides: the output side (the Kant-Eccles problem of the freedom of the Will) and the input side (the problem of qualia). The output side ultimately reduces to whether quantum mechanics can affect the operation of synapses. A discussion of the detailed molecular biology of synaptic transmission as presently understood suggests that such affects are unlikely. Instead an evolutionary argument is presented which suggests that our conviction of free agency is an evolutionarily induced illusion and hence that the Kant-Eccles problem is itself illusory. This conclusion is supported by well-known neurophysiology. The input side, the problem of qualia, of subjectivity, is not so easily outflanked. After a brief review of the neurophysiological correlates of consciousness (NCC) and of the Penrose-Hameroff microtubular neuroquantology it is again concluded that the molecular neurobiology makes quantum wave-mechanics an unlikely explanation. Instead recourse is made to an evolutionarily- and neurobiologically-informed panpsychism. The notion of an ‘emergent’ property is carefully distinguished from that of the more usual ‘system’ property used by most dual-aspect theorists (and the majority of neuroscientists) and used to support Llinas’ concept of an ‘oneiric’ consciousness continuously modified by sensory input. I conclude that a panpsychist theory, such as this, coupled with the non-classical understanding of matter flowing from quantum physics (both epistemological and scientific) may be the default and only solution to the problem posed by the presence of mind in a world of things.

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Combined bioreaction separation studies have been carried out for the first time on a moving port semi-continuous counter-current chromatographic reactor-separator (SCCR-S1) consisting of twelve 5.4cm id x 75cm long columns packed with calcium charged cross-linked polystyrene resin (KORELA V07C). The inversion of sucrose to glucose and fructose in the presence of the enzyme invertase and the biochemIcal synthesis of dextran and fructose from sucrose in the presence of the enzyme dextransucrase were investigated. A dilute stream of the appropriate enzyme in deionised water was used as the eluent stream. The effect of switch time, feed concentration, enzyme activity, eluent rate and enzyme to feed concentration ratio on the combined bioreaction-separation were investigated. For the invertase reaction, at 20.77% w/v sucrose feed concentrations complete conversions were achieved. The enzyme usage was 34% of the theoretical enzyme amount needed to convert an equivalent amount of sucrose over the same time period when using a conventional fermenter. The fructose rich (FRP) and glucose rich (GRP) product purities obtained were over 90%. By operating at 35% w/v sucrose feed concentration and employing the product splitting and recycling techniques, the total concentration and purity of the GRP increased from 32% w/v to 4.6% and from 92.3% to 95% respectively. The FRP concentration also increased from 1.82% w/v to 2.88% w/v. A mathematical model was developed for the combined reaction-separation and used to simulate the continuous inversion of sucrose and product separation using the SCCR-S1. In the biosynthesis of dextran studies, 52% conversion of a 2% w/v sucrose concentration feed was achieved. An average dextran molecular weight of 4 millIon was obtained in the dextran rich (DRP) product stream. The enzyme dextransucrase was purifed successfully using centrifugation and ultrafiltration techniques.

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This is the second part of a review of the work of quantum physicists on the ‘hard part’ of the problem of mind. After an introduction which sets the scene and a brief review of contemporary work on the neural correlates of consciousness (NCC) the work of four prominent modern investigators is examined: J.C. Eccles/Friedrich Beck; Henry Stapp; Stuart Hameroff/Roger Penrose; David Bohm. With the exception of David Bohm, all attempt to show where in the brain’s microstructure quantum affects could make themselves felt. It is reluctantly concluded that none have neurobiological plausibility. They are all instances, to paraphrase T.H. Huxley, of a beautiful hypothesis destroyed by ugly facts. David Bohm does not attempt to fit his new quantum physics to contemporary neurobiology but instead asks for a radical rethink of our conventional scientific paradigm. He suggests that we should look towards developing a ‘pan-experientialism’ or ‘dual-aspect monism’ where consciousness goes ‘all the way down’ and that the ‘hard problem’ is not soluble within the framework of ideas provided by ‘classical’ natural science.

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In recent years, much interest has focused on the significance of inducing not only systemic immunity but also good local immunity at susceptible mucosal surfaces. A new field of mucosal immunity has been established as information accumulates on gut-associated lymphoid tissue, bronchus-associated lymphoid tissue and nasal-associated lymphoid tissue (GALT, BALT and NALT, respectively) and on their role in both local and systemic immune responses. This project, following the line of investigation started by other workers, was designed to study the use of microspheres to deliver antigens by the mucosal routes (oral and nasal). Antigen-containing microspheres were prepared with PLA and PLGA, by either entrapment within the particles or adsorption onto the surface. The model protein antigens used in this work were mainly tetanus toxoid (TT), bovine serum albumin (BSA) and γ-globulins.In vitro investigations included the study of physicochemical properties of the particulate carriers as well as the assessment of stability of the antigen molecules throughout the formulation procedures. Good loading efficiencies were obtained with both formulation techniques, which did not affect the immunogenicity of the antigens studied. The influence of the surfactant employed on the microspheres' surface properties was demonstrated as well as its implications on the adsorption of proteins. Preparations containing protein adsorbed were shown to be slightly more hydrophobic than empty PLA microspheres, which can enhance the uptake of particles by the antigen presenting cells that prefer to associate with hydrophobic surfaces. Systemic and mucosal immune responses induced upon nasal, oral and intramuscular administration have been assessed and, when appropriate, compared with the most widely used vaccine adjuvant, aluminium hydroxide. The results indicate that association of TT with PLA microspheres through microencapsulation or adsorption procedures led to an enhancement of specific mucosal IgA and IgG and systemic IgG responses to the mucosal delivered antigens. Particularly, nasal administration of TT produced significantly higher serum levels of specific IgG in test animals, as compared to control groups, suggesting that this is a potential route for vaccination. This implies the uptake and transfer of particles through the nasal mucosa, which was further demonstrated by the presence in the blood stream of latex particles as early as 10 min after nasal administration.