101 research outputs found
Preservationism in the Epistemology of Memory
No full textPreservationism states that memory preserves the justification of the beliefs it preserves. More precisely: if S formed a justified belief that p at t1 and retains in memory a belief that p until t2, then S's belief that p is prima facie justified via memory at t2. Preservationism is an unchallenged orthodoxy in the epistemology of memory. Advocates include Sven Bernecker, Tyler Burge, Alvin Goldman, Gilbert Harman, Michael Huemer, Matthew McGrath, and Thomas Senor. I develop three dilemmas for it, in part by drawing on research in cognitive psychology. The dilemmas centre on preservationism's implications for certain cases involving either stored beliefs, forgotten evidence, or recollection failure. Each dilemma shows that preservationism either is false or lacks key support
Preservationism in the Epistemology of Memory
No full textPreservationism states that memory preserves the justification of the beliefs it preserves. More precisely: if S formed a justified belief that p at t1 and retains in memory a belief that p until t2, then S's belief that p is prima facie justified via memory at t2. Preservationism is an unchallenged orthodoxy in the epistemology of memory. Advocates include Sven Bernecker, Tyler Burge, Alvin Goldman, Gilbert Harman, Michael Huemer, Matthew McGrath, and Thomas Senor. I develop three dilemmas for it, in part by drawing on research in cognitive psychology. The dilemmas centre on preservationism's implications for certain cases involving either stored beliefs, forgotten evidence, or recollection failure. Each dilemma shows that preservationism either is false or lacks key support
Metacognition as Evidence for Evidentialism
No full textMetacognition is the monitoring and controlling of cognitive processes. I examine the role of metacognition in ‘ordinary retrieval cases’, cases in which it is intuitive that via recollection the subject has a justified belief. Drawing on psychological research on metacognition, I argue that evidentialism has a unique, accurate prediction in each ordinary retrieval case: the subject has evidence for the proposition she justifiedly believes. But, I argue, process reliabilism has no unique, accurate predictions in these cases. I conclude that ordinary retrieval cases better support evidentialism than process reliabilism. This conclusion challenges several common assumptions. One is that non-evidentialism alone allows for a naturalized epistemology, i.e., an epistemology that is fully in accordance with scientific research and methodology. Another is that process reliabilism fares much better than evidentialism in the epistemology of memory
Iron deficiency and human hypoxia physiology
No full textThis thesis is concerned with a very common disorder of iron homeostasis: iron deficiency. The specific focus is the manner in which iron deficiency influences physiological responses to hypoxia in humans. This work is predicated on observations made over many decades in vitro and in vivo, suggesting that variations in the bioavailability of iron have important consequences for certain biological processes known to depend on oxygen availability.
Three separate but related studies together form the basis for this thesis. The first two, Study A and Study B, adopt a similar approach in recruiting healthy volunteers who differ according to iron status, yielding iron-deficient and iron-replete groups in both cases. In Study A, the behaviour of the pulmonary circulation is investigated during a sustained hypoxic exposure, before and after an intravenous infusion of iron. In Study B, skeletal muscle metabolism is explored, both at the level of high-energy phosphate metabolism and the integrated physiological responses to exercise on a cycle ergometer. In the third study, Study C, a different approach is taken, recruiting patients with chronic obstructive pulmonary disease (COPD), and exploring the prevalence and associations of iron deficiency in this condition.
Chapters 2 and 3 describe experiments using sustained hypoxia in a normobaric chamber, during which the pulmonary circulation is assessed non-invasively using Doppler echocardiography. These reveal augmented hypoxic pulmonary vasoconstriction (HPV) in iron-deficient individuals, who also exhibit greater sensitivity to the effects of an infusion of intravenous iron. Additionally, the way in which certain circulating mediators important for iron haemostasis change over the course of these hypoxic exposures, and how iron status influences these responses, is explored.
Chapter 4 reports the findings of experiments using 31P-magnetic resonance spectroscopy and cardiopulmonary exercise testing, which demonstrate abnormal whole-body metabolism in iron-deficient individuals during large muscle-mass exercise, despite the absence of a clear defect in mitochondrial oxidative phosphorylation. Intravenous iron is found to have significant effects to alter the lactate threshold in healthy individuals, but the effects are more striking in iron-deficient individuals. Collectively, these experiments imply that iron deficiency promotes a more glycolytic phenotype.
Chapter 5 explores iron deficiency in COPD, a condition in which pulmonary vascular disease, hypoxia and skeletal muscle dysfunction coexist, and examines some of the difficulties in assessing iron status in the setting of a chronic inflammatory disorder. Iron deficiency is found to be common, and unexpectedly associated with significantly more severe hypoxaemia, in patients with COPD. Possible reasons for these findings, and their clinical implications, are considered.
Chapter 6 provides a summary of the main conclusions to be drawn from the studies presented in this thesis.</p
Note sur la frise de l'Érechtheion : le sujet de MAcr 1073
No full textΤο θραύσμα της ζωφόρου του Ερεχθείου ΜΑκρ 1073, για το οποίο πληρώθηκαν εκατό δραχμές στον καλλιτέχνη, παριστάνει στο πρώτο επίπεδο ένα νέο άνδρα ο οποίος δεν γράφει σε πινακίδα αλλά σχεδιάζει στο έδαφος, δραστηριότητα που σχετίζεται μάλλον με τα παρακείμενα πρόσωπα : δύο γυναίκες κοντά σε άμαξα που σύρεται από δύο ημίονους.The fragment of the Erechtheion frieze MAcr 1073, whose author was paid a hundred drachmes, depicts a young man in the foreground, not writing on a tablet, but drawing on the ground, an activity no doubt related to the adjacent figures: two women near a cart pulled by two mules.Le fragment de la frise de l'Érechtheion MAcr 1073, payé cent drachmes à son auteur, représente, au premier plan, un jeune homme non pas en train d'écrire sur une tablette, mais de dessiner sur le sol, activité sans doute en rapport avec les figures adjacentes : deux femmes près d'une voiture tirée par deux mules.Holtzmann Bernard. Note sur la frise de l'Érechtheion : le sujet de MAcr 1073. In: Bulletin de correspondance hellénique. Volume 124, livraison 1, 2000. pp. 221-226
Eliminating the Problem of Stored Beliefs
No full textThe problem of stored beliefs is that of explaining how non-occurrent, seemingly justified beliefs are indeed justified. Internalism about epistemic justification, the view that one’s mental life alone determines what one is justified in believing, allegedly cannot solve this problem. This paper provides a solution. It asks: Does having a belief that p require having a special relation to a mental representation that p? If the answer is yes, then there are no stored beliefs, and so there is no problem. Drawing on extensive research in cognitive psychology, this paper argues that memory doesn’t store the representations required for stored belief, and we don’t bear the special relation to anything memory does store. On the leading “no” answer, a belief is roughly a set of dispositions. This paper argues that a justified belief is then best understood as a set of dispositions. Since these dispositions are mental, internalism can count the right stored beliefs as justified
Remembering trauma in epistemology
No full textThis paper explores some surprising effects of psychological trauma on memory and develops the puzzle of observer memory for trauma. Memory for trauma tends to have a third-person perspective, or observer perspective. But it appears observer memory, by having a novel visual point of view, tends to misrepresent the past. And many find it plausible that if a memory type tends to misrepresent, it cannot yield knowledge of, or justification for believing, details of past events. But it is also plausible that, with respect to details of past trauma, observer memory can yield knowledge or justification. I argue for a novel set of views that offers a way out of the puzzle: observer memory does tend to misrepresent, but it still has epistemic power regarding details of the past, although with special limits; but observer memory for trauma has other epistemic powers too, in that it allows for a kind of self-awareness
Internalism and the Problem of Stored Beliefs
No full textA belief is stored if it is in no way before the subject’s mind. The problem of stored beliefs is that of satisfactorily explaining how the stored beliefs which seem justified are indeed justified. In this paper I challenge the two main internalist attempts to solve this problem. Internalism about epistemic justification, at a minimum, states that one’s mental life alone determines what one is justified in believing. First I dispute the attempt from epistemic conservatism, which states that believing justifies retaining belief. Then I defend the attempt from dispositionalism, which assigns a justifying role to dispositions, from some key objections. But by drawing on cognitive psychological research I show that, for internalism, the problem of stored beliefs remains
Internalism and the Problem of Stored Beliefs
No full textA belief is stored if it is in no way before the subject’s mind. The problem of stored beliefs is that of satisfactorily explaining how the stored beliefs which seem justified are indeed justified. In this paper I challenge the two main internalist attempts to solve this problem. Internalism about epistemic justification, at a minimum, states that one’s mental life alone determines what one is justified in believing. First I dispute the attempt from epistemic conservatism, which states that believing justifies retaining belief. Then I defend the attempt from dispositionalism, which assigns a justifying role to dispositions, from some key objections. But by drawing on cognitive psychological research I show that, for internalism, the problem of stored beliefs remains
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