Ever since they began to take an interest in lens grinding, the brothers Christiaan and Constantijn Huygens searched for high-quality glass to turn in to lenses. Historical research in combination with optical measurements on preserved lenses has allowed the verificationof the lenses ground by the brothers, and also provided information on who helped them with the necessary knowledge and material.

About one third of patients with epilepsy have seizures refractory to the medical treatment. Electrical stimulation mapping is the gold standard for the identification of “eloquent” areas prior to resection of epileptogenic tissue. However, it is time-consuming and may cause undesired side effects. Broadband gamma activity recorded with extraoperative electrocorticography during cognitive tasks may be an alternative to ESM but until now has not proven of definitive clinical value. Considering their role in cognition, the alpha and beta bands could further (...) improve the identification of eloquent cortex. We compared gamma, alpha and beta activity, and their combinations for the identification of eloquent cortical areas defined by ESM. Ten patients with intractable focal epilepsy participated in a delayed-match-to-sample task, where syllable sounds were compared to visually presented letters. We used a generalized linear model approach to find the optimal weighting of each band for predicting ESM-defined categories and estimated the diagnostic ability by calculating the area under the receiver operating characteristic curve. Gamma activity increased more in eloquent than in non-eloquent areas, whereas alpha and beta power decreased more in eloquent areas. Diagnostic ability of each band was close to 0.7 for all bands but depended on multiple factors including the time period of the cognitive task, the location of the electrodes and the patient’s degree of attention to the stimulus. We show that diagnostic ability can be increased by 3–5% by combining gamma and alpha and by 7.5–11% when gamma and beta were combined. We then show how ECoG power modulation from cognitive testing can be used to map the probability of eloquence in individual patients and how this probability map can be used in clinical settings to optimize ESM planning. We conclude that the combination of gamma and beta power modulation during cognitive testing can contribute to the identification of eloquent areas prior to ESM in patients with refractory focal epilepsy. (shrink)

The author argues that quantum theory admits a plurality of interpretations, each aiding further understanding of the theory, but also advocating specifically the Copenhagen Variant of the Modal Interpretation. That variant is applied to topics like the Einstein-Podolsky-Rosen paradox and the problem of 'identical' particles.

In our society, where interest in Buddhist meditation is expanding enormously, numerous scientific studies are now conducted on the neurophysiological effects of meditation practices and on the neural correlates of meditative states. However, very few studies have been conducted on the experience associated with contemplative practice: what it is like to meditate -- from moment to moment, at different stages of practice -- remains almost invisible in contemporary contemplative science. Recently, 'micro-phenomenological' interview methods have been developed to help us become (...) aware of lived experience and describe it with rigour and precision. The present article presents the results of a pilot project1 aimed at applying these methods to the description of meditative experience. The first part of the article describes these methods and their adjustment for the investigation of meditative experience. The second part provides micro- phenomenological descriptions of two processes of which meditation practice enables the practitioner to become aware: the process of losing contact with the current situation and generation of virtual ones in 'mind-wandering' episodes, and the process of emergence of a thought. The third part of the article highlights the interest such descriptions may have for practitioners and for teachers of meditation, defines the status of these results, and outlines directions for further research. (shrink)

In this target article the following hypotheses are discussed: (1) Colour is autonomous: a perceptuolinguistic and behavioural universal. (2) It is completely described by three independent attributes: hue, brightness, and saturation: (3) Phenomenologically and psychophysically there are four unique hues: red, green, blue, and yellow; (4) The unique hues are underpinned by two opponent psychophysical and/or neuronal channels: red/green, blue/yellow. The relevant literature is reviewed. We conclude: (i) Psychophysics and neurophysiology fail to set nontrivial constraints on colour categorization. (ii) Linguistic (...) evidence provides no grounds for the universality of basic colour categories. (iii) Neither the opponent hues red/green, blue/yellow nor hue, brightness, and saturation are intrinsic to a universal concept of colour. (iv) Colour is not autonomous. (shrink)

The Gesta Normannorum Ducum is one of the most important sources for the history of Normandy and England in the eleventh and twelfth centuries, and contains the earliest prose account of the Norman Conquest. It was written by a succession of authors, the first of whom was William of Jumieges, who wrote for William the Conqueror. Later historians, such as Orderic Vitalis and Robert of Torigni, interpolated and extended the chronicle as far as King Henry I. The later accretions reveal (...) much not only about changing attitudes towards the Norman invasion of England, but also about views of the early Viking foundations of Normandy.Elisabeth van Houts's two-volume edition is based on a study of all forty-seven extant manuscripts of the Gesta, including the earliest surviving copy of c. 1100, unknown until very recently. The full original text of William of Jumieges is supplied, as well as the integral text of the subsequent revisions and additions. Volume I contains Dr van Houts's introduction to the whole work, together with the text and translation of books i-iv. Volume II contains books v-viii. The edition forms an important contribution to our understanding of Anglo-Norman politics. (shrink)

Objective: Clock variance is an important statistic in many clinical and developmental studies. Existing methods require a large number of trials for accurate clock variability assessment, which is problematic in studies using clinical or either young or aged participants. Furthermore, these existing methods often implicitly convolute clock and memory processes, making it difficult to disentangle whether the clock or memory system are driving the observed deviations. Here we assessed whether twenty repeated productions of a well-engrained interval (1 second), a task (...) that does not incorporate memory updating nor the processing of feedback, could provide an accurate assessment of clock variability. Method: Sixty-eight undergraduate students completed two tasks: a 1-second production task in which they were asked to produce a 1-second duration by ending a tone by a keypress, and a multi-duration reproduction task. Durations presented in the reproduction task were tones lasting 1.17, 1.4 and 1.68 seconds. No feedback was presented in either task, and the order of presentation was counterbalanced between participants. Results: The observed central tendency in the reproduction task was better explained by models including the measures of clock variability derived from the 1-second production task than by models without it. Three clock variability measures were calculated for each participant (standard deviation, root mean squared residuals (RMSR) from an estimated linear slope, and RMSR scaled by mean production duration). The model including the scaled RMSR was prefered over the alternative models, and no notable effects of the order of presentation were observed. These results suggest that (1) measures of variability should account for drift, (2) the presentation of another timing task before a 1-second production task did not influence the assessment of the clock variability, and (3) the observed variability adheres to the scalar property and predicts temporal performance, and is thus a usable index of clock variability. Conclusion: This study shows that just 20 repeated productions of 1 second provide a reliable index of clock variability. As administering this task is fast and easy, it could prove to be useful in a large variety of developmental and clinical populations. (shrink)

Background Since the enactment of the euthanasia law in the Netherlands, there has been a lively public debate on assisted dying that may influence the way patients talk about euthanasia and physician-assisted suicide with their physicians and the way physicians experience the practice of EAS. Aim To show what developments physicians see in practice and how they perceive the influence of the public debate on the practice of EAS. Methods We conducted a secondary analysis of in-depth interviews with 28 Dutch (...) physicians who had experience with a complex case of EAS. Respondents were recruited both by the network of physicians working for SCEN as well as via a national questionnaire, wherein participating physicians could indicate their willingness to be interviewed. Results Three themes came up in analysing the interviews. First, the interviewed physicians experienced a change in what patients would expect from them: from a role as an involved caregiver to being the mere performer of EAS. Second, interviewees said that requests for EAS based on non-medical reasons came up more frequently and wondered if EAS was the right solution for these requests. Last, respondents had the impression that the standards of EAS are shifting and that the boundaries of the EAS regulation were stretched. Conclusions The perceived developments could make physicians less willing to consider a request for EAS. Our results also raise questions about the role of physicians and of EAS in society. (shrink)

: According to a consensus of psycho-physiological and philosophical theories, color sensations (or qualia) are generated in a cerebral "space" fed from photon-photoreceptor interaction (producing "metamers") in the retina of the eye. The resulting "space" has three dimensions: hue (or chroma), saturation (or "purity"), and brightness (lightness, value or intensity) and (in some versions) is further structured by primitive or landmark "colors"—usually four, or six (when white and black are added to red, yellow, green and blue). It has also been (...) proposed that there are eleven semantic universals—labeling the previous six plus the "intermediaries" of orange, pink, brown, purple, and gray. There are many versions of this consensus, but they all aim to provide ontological, epistemological and semantic blueprints for the brute fact of the reality of color ordained by Nature (evolution). In contrast to this consensus, we have argued that "seeing color" is not a matter of light waves impacting on our eyes, producing sensations to be categorized and labeled in the "color space" in the brain. While electrochemical events may unproblematically be regarded as the causal precondition for seeing color, the reception of sensations in "the color space" as semantically labeled natural categories, kinds, or information, is a "just so" story: it is Wittgenstein's beetle in a box. In contrast we consider that the authority of this consensus might better be regarded not as the result of the truth-tracking of nature, but as the sociohistorical outcome of philosophical presuppositions, scientific theories, experimental practices, technological apparatus, and their feed forward into the lifeworld. The question we shall therefore explore is whether, or to what extent, we ourselves are changed, as the conditions of production of color science change. Thus we are doing a kind of anthropology at two levels: of color science itself (and its effect on our own lifeworld), and of those studied by the "anthropology of color". As befits this stance we are agnostic about the theoretical entities of color science (cf. van Fraassen 2001), and within this new context, we propose to cross-cut object-and-subject, organism-and-environment (the bedrock of color science) in socio-historical ways. Our approach is in part inspired by, but not the same as, that of Gibson, in that we wish to pursue the notion of "social affordances" (Burmudez 1995). We suggest that color has become a naturalization through science-based technologies, which, through praxes and materializations, have become the perceptual and cultural entities that structure experience and understanding in the lifeworld. It is this naturalization that we shall refer to and characterize as "the historically inflected exosomatic organ". Consequently we shall explore the historical ontology of "color" without assuming an underlying biological constant (Dupré 2001). In part 1 we show the flimsiness of the evidence for the three dimensions of color, borrowed from physics, and fine-tuned to a "standard observer" (a "spectral creature" with a phenomenal "color space"). In part 2 we address the structuring of hue through the development of color circles and color spaces. This is followed by a review of the evidence for unique hues. Again the evidence is shown to be flimsy. We then show that an isolated domain of color is a particular kind of model, not a "natural given". In part 3, after reviewing what is referred to as "the isomorphy thesis," we discuss the exemplary case study of Berlin and Kay (1969). This illustrates the pull of stadial models presupposed by their evolutionary theory of color language. The Berlin and Kay paradigm proposes that American English color terms are incorrigible and can provide the universal metalanguage. We conclude by presenting an alternative account, namely that we ourselves are changed as the conditions of production of color science change. We argue that it is better to regard "seeing-color" as a historically inflected exosomatic organ that provides social affordances for those trained to grasp them. (shrink)

One of the goals of computerized tutoring systems is to optimize the learning of facts. Over a hundred years of declarative memory research have identified two robust effects that can improve such systems: the spacing and the testing effect. By making optimal use of both and adjusting the system to the individual learner using cognitive models based on declarative memory theories, such systems consistently outperform traditional methods (Van Rijn, Van Maanen, & Van Woudenberg, 2009). This adjustment process is driven by (...) a continuously updated estimate of the rate of forgetting for each item and learner on the basis of the learner's accuracy and response time. In this study, we investigated to what extent these estimates of individual rates of forgetting are stable over time and across different materials. We demonstrate that they are stable over time but not across materials. Even though most theories of human declarative memory assume a single underlying rate of forgetting, we show that, in practice, it makes sense to assume different materials are forgotten at different rates. If a computerized, adaptive fact‐learning system allowed different rates of forgetting for different materials, it could adapt to individual learners more readily. (shrink)

In recent papers Hans Halvorson has offered a critique of the semantic view of theories, showing that theories may be the same although the corresponding sets of models are different and, conversely, that theories may be different although the corresponding sets of models are the same. This critique will be assessed, first, as it pertains to issues concerning scientific models in the empirical sciences and, second, independent of any concern with empirical science.

Introduction: In The Netherlands, physicians have to be convinced that the patient suffers unbearably and hopelessly before granting a request for euthanasia. The extent to which general practitioners (GPs), consulted physicians and members of the euthanasia review committees judge this criterion similarly was evaluated. Methods: 300 GPs, 150 consultants and 27 members of review committees were sent a questionnaire with patient descriptions. Besides a “standard case” of a patient with physical suffering and limited life expectancy, the descriptions included cases in (...) which the request was mainly rooted in psychosocial or existential suffering, such as fear of future suffering or dependency. For each case, respondents were asked whether they recognised the case from their own practice and whether they considered the suffering to be unbearable. Results: The cases were recognisable for almost all respondents. For the “standard case” nearly all respondents were convinced that the patient suffered unbearably. For the other cases, GPs thought the suffering was unbearable less often (2–49%) than consultants (25–79%) and members of the euthanasia review committees (24–88%). In each group, the suffering of patients with early dementia and patients who were “tired of living” was least often considered to be unbearable. Conclusions: When non-physical aspects of suffering are central in a euthanasia request, there is variance between and within GPs, consultants and members of the euthanasia committees in their judgement of the patient’s suffering. Possible explanations could be differences in their roles in the decision-making process, differences in experience with evaluating a euthanasia request, or differences in views regarding the permissibility of euthanasia. (shrink)

SummaryIntense, sustained nursing lengthens inter-birth intervals and is causally linked with low natural fertility. However, in traditional settings, the effects of such nursing on fertility are difficult to disentangle from those of nutrition. Results from an prospective, direct observational study of reproductive function in well-nourished Amele women who nurse intensively and persistently but who also have high fertility are here presented. Endocrine measures show that ovarian activity resumes by median 11·0 months postpartum. Median duration of postpartum amenorrhoea is 11·3 months, (...) time to next conception is 19·0 months, and the inter-birth interval is 28·0 months. Average life time fertility is 6·8. High fertility in Amele women is due both to refractoriness of reproductive function to suckling stimuli, and to maintenance of equivalent age-specific fertility rates across the reproductive life span. (shrink)

Research on value congruence rests on the assumption that values denote desirable behaviors and ideals that employees and organizations strive to approach. In the present study, we develop and test the argument that a more complete understanding of value congruence can be achieved by considering a second type of congruence based on employees’ and organizations’ counter-ideal values. We examined this proposition in a time-lagged study of 672 employees from various occupational and organizational backgrounds. We used difference scores as well as (...) polynomial regression and response surface analyses to test our hypotheses. Consistent with our hypotheses, results reveal that counter-ideal value congruence has unique relations to employees’ trust in the organization that go beyond the effects of ideal value congruence. We discuss theoretical and practical implications of this expanded perspective on value congruence. (shrink)

The method of positron emission tomography illustrates the circular logic popular in subtractive neuroimaging and linear reductive cognitive psychology. Both require that strictly feed-forward, modular, cognitive components exist, before the fact, to justify the inference of particular components from images after the fact. Also, both require a "true" componential theory of cognition and laboratory tasks, before the fact, to guarantee reliable choices for subtractive contrasts. None of these possibilities are likely. Consequently, linear reductive analysis has failed to yield general, reliable, (...) componential accounts. (shrink)