A prominent view holds that perception and memory are distinguished at least partly by their temporal orientation: Perception functions to represent the present, while memory functions to represent the past. Call this view perceptual presentism. This chapter critically examines perceptual presentism in light of contemporary perception science. I adduce evidence for three forms of perceptual sensitivity to the past: (i) shaping perception by past stimulus exposure, (ii) recruitment of mnemonic representations in perceptual processing, and (iii) perceptual representation of present objects (...) as possessing past properties. I argue that forms (i) and (ii) are consistent with perceptual presentism, while form (iii) poses a genuine threat to the view. While the empirical case for form (iii) remains inconclusive, I suggest that the most serious challenges to perceptual presentism derive from representations that integrate mnemonic and present-tensed elements in the performance of canonical perceptual functions, such as perceiving object continuity over time. (shrink)

The third book of Lucretius' great poem on the workings of the universe is devoted entirely to expounding the implications of Epicurus' dictum that death does not matter, 'is nothing to us'. The soul is not immortal: it no more exists after the dissolution of the body than it had done before its birth. Only if this fact is accepted can men rid themselves of irrational fears and achieve the state of ataraxia, freedom from mental disturbance, on which the Epicurean (...) definition of pleasure was based. To present this case Lucretius deploys the full range of poetic and rhetorical registers, soberly prohibitive, artfully decorative or passionately emotive as best suits his argument, reinforcing it with vivid and compelling imagery. This new edition has been completely revised, with a considerably enlarged Commentary and a new supplementary introduction taking account of the great amount of new scholarship of the last forty years. (shrink)

Purpose Prescription stimulant use as “cognitive enhancers” has been described among undergraduate college students. However, the use of prescription stimulants among future health care professionals is not well characterized. This study was designed to determine the prevalence of prescription stimulant misuse among students at an academic health sciences center. -/- Method Electronic surveys were e-mailed to 621 medical, pharmacy, and respiratory therapy students at East Tennessee State University for four consecutive weeks in fall 2011. Completing the survey was voluntary and (...) anonymous. Surveys asked about reasons for, frequency of, and side effects of nonprescription misuse of prescription stimulants. Given the sensitive material, an opportunity to win one of ten $50 gift cards was used as an incentive. -/- Results Three hundred seventy-two (59.9%) students completed the survey from three disciplines (47.6% medical, 70.5% pharmacy, and 57.6% respiratory therapy). Overall, 11.3% of responders admitted to misusing prescription stimulants. There was more misuse by respiratory therapy students, although this was not statistically significant (10.9% medicine, 9.7% pharmacy, 26.3% respiratory therapy; P = .087). Reasons for prescription stimulant misuse included to enhance alertness/ energy (65.9%), to improve academic performance (56.7%), to experiment (18.2%), and to use recreationally/get high (4.5%). -/- Conclusions Prescription stimulant misuse was prevalent among participating students, but further research is needed to describe prevalence among future health care workers more generally. The implications and consequences of such misuse require further study across professions with emphasis on investigating issues of academic dishonesty (e.g., “cognitive enhancement”), educational quality, and patient safety or health care quality. (shrink)

The thymus is a unique primary lymphoid organ that supports the production of self‐tolerant T‐cells essential for adaptive immunity. Intrathymic microenvironments are microanatomically compartmentalised, forming defined cortical, and medullary regions each differentially supporting critical aspects of thymus‐dependent T‐cell maturation. Importantly, the specific functional properties of thymic cortical and medullary compartments are defined by highly specialised thymic epithelial cells (TEC). For example, in the medulla heterogenous medullary TEC (mTEC) contribute to the enforcement of central tolerance by supporting deletion of autoreactive T‐cell (...) clones, thereby counterbalancing the potential for random T‐cell receptor generation to contribute to autoimmune disease. Recent advances have further shed light on the pathways and mechanisms that control heterogeneous mTEC development and how differential mTEC functionality contributes to control self‐tolerant T‐cell development. Here we discuss recent findings in relation to mTEC development and highlight examples of how mTEC diversity contribute to thymus medulla function. (shrink)

This book presents a wide range of thinking about how the discipline of philosophy has engaged and might in the future engage with the profound questions raised by rapidly shifting methods of communication. Although social media and telecommunications have dramatically altered the daily lives of people, and no technology has enjoyed the same rapid success as that of the mobile phone, the philosophical underpinnings and consequences of these changes have been insufficiently explored. Clustered in six sections, this book addresses major (...) questions of interest to the thoughtful professional. Section I considers ontology: How should we consider emerging media and what are the categories through which we can organize and understand this new realm of social reality. Section II investigates human nature and its relationship to the social transformations that are occurring through new media. It also considers and compares historical methods of communication such as paper. In Section III, questions of time, narrative voice, and emotions are assessed in relation to emerging media. General issues concerning emergence of meaning, philosophy of mind, artificial intelligence, and agency are the focus of Section IV. Symbols and speech acts—including the philosophical ramifications of the communication process itself as viewed through emerging technologies—represent the key concerns of Section V. Section VI probes various interpersonal, institutional, and political/power dimensions stemming from new systems of communication. A coda points forward to outstanding open questions, calling for further research to be done. The book represents a seminal contribution assembling original thoughts from both leading and rising scholars of the field. (shrink)