Originality has self-evident importance for science, but objectively measuring originality poses a formidable challenge. We conceptualise originality as the degree to which a scientific discovery... Show moreOriginality has self-evident importance for science, but objectively measuring originality poses a formidable challenge. We conceptualise originality as the degree to which a scientific discovery provides subsequent studies with unique knowledge that is not available from previous studies. Accordingly, we operationalise a new measure of originality for individual scientific papers building on the network betweenness centrality concept. Specifically, we measure the originality of a paper based on the directed citation network between its references and the subsequent papers citing it. We demonstrate the validity of this measure using survey information. In particular, we find that the proposed measure is positively correlated with the self-assessed theoretical originality but not with the methodological originality. We also find that originality can be reliably measured with only a small number of subsequent citing papers, which lowers computational cost and contributes to practical utility. The measure also predicts future citations, further confirming its validity. We further characterise the measure to guide its future use. Show less
In many countries the scientific funding system is shifting from an internal block funding model toward a competitive project funding model. However, there is growing concern that the competitive... Show moreIn many countries the scientific funding system is shifting from an internal block funding model toward a competitive project funding model. However, there is growing concern that the competitive project funding system favors relatively safe, conventional projects at the expense of risky, novel research. It is important to assess different funding models in order to design better funding systems for science. This paper empirically tests for differences in the novelty of funded outputs between internal block funding and competitive project funding, in the setting of Japan, where both funding models play a significant role. Combining survey data from a large sample of research projects in Japan and bibliometric information about the publications produced from these projects, we find that projects funded by competitive funds on average have higher novelty compared to those funded by internal block funds. However, such positive effects only hold for researchers with high status, such as senior and male researchers. In contrast, compared to internal block funding, competitive project funding has a negative relation to novelty for low status scientists (especially junior and female researchers). The findings suggest that the competitive project selection procedure is less receptive to novel ideas from researchers with low academic status and therefore discourages their novel research. These findings can serve as a warning about potential biases in competitive funding allocation procedures and suggest the importance of secure stable funding for allowing researchers with low status to pursue their novel ideas. Show less
Research which explores unchartered waters has a high potential for major impact but also carries a higher uncertainty of having impact. Such explorative research is often described as taking a novel. Show moreResearch which explores unchartered waters has a high potential for major impact but also carries a higher uncertainty of having impact. Such explorative research is often described as taking a novel approach. This study examines the complex relationship between pursuing a novel approach and impact. Viewing scientific research as a combinatorial process, we measure novelty in science by examining whether a published paper makes first-time-ever combinations of referenced journals, taking into account the difficulty of making such combinations. We apply this newly developed measure of novelty to all Web of Science research articles published in 2001 across all scientific disciplines. We find that highly novel papers, defined to be those that make more (distant) new combinations, deliver high gains to science: they are more likely to be a top 1% highly cited paper in the long run, to inspire follow-on highly cited research, and to be cited in a broader set of disciplines and in disciplines that are more distant from their “home” field. At the same time, novel research is also more risky, reflected by a higher variance in its citation performance. We also find strong evidence of delayed recognition of novel papers as novel papers are less likely to be top cited when using short time-windows. In addition, we find that novel research is significantly more highly cited in “foreign” fields but not in their “home” field. Finally, novel papers are published in journals with a lower Impact Factor, compared with non-novel papers, ceteris paribus. These findings suggest that science policy, in particular funding decisions which rely on bibliometric indicators based on short-term citation counts and Journal Impact Factors, may be biased against “high risk/high gain” novel research. The findings also caution against a mono-disciplinary approach in peer review to assess the true value of novel research. Show less
This dissertation shows that the subjective experience of surprise and curiosity depends on where people are in their process of making sense. Part 1 focusses on surprise. It shows that to study... Show moreThis dissertation shows that the subjective experience of surprise and curiosity depends on where people are in their process of making sense. Part 1 focusses on surprise. It shows that to study surprise it is key to take the temporal dynamics of sense-making into account and to distinguish surprise (i.e., the response to the unexpectedness of an event) from the state that follows it after sense-making (i.e., the response to the valence of the event). Part 2 focusses on curiosity. It shows that anticipation is a key factor for how it feels to be curious. The closer people are to the resolution, the more they anticipate discovering new information, the more negative feelings of deprivation are reduced. Moreover, the more people anticipate that they can deal with complex novel things, the more curious they will become. Taken together, the findings in this dissertation show that people first need to master a situation of "not knowing" before they can appreciate it. Show less
The main goal of this work is to develop a method that, operating on top of an Evolutionary Algorithm, increases its likeliness of finding innovative solutions. This likeliness is laid out to be... Show moreThe main goal of this work is to develop a method that, operating on top of an Evolutionary Algorithm, increases its likeliness of finding innovative solutions. This likeliness is laid out to be increased with the diversity of the solutions found, provided that they are of sufficient quality. The developed method needs to be applicable in a scenario in which the search is required to be started from a single, fixed solution. Therefore, a scheme is envisioned in which the search is performed in a sequential fashion, zooming in on a locally-optimal solution, and then exploring for a new potentially high-quality region based on a memory of solutions encountered earlier in the search. Two exploration criteria, one using an archive of earlier solutions as memory and the other deriving from a surrogate model trained on earlier solutions, were established to be worthwhile for integration into quality-based search. The resulting schemes were applied to a real-world airfoil optimization task, showing both to perform better than the baseline method of multiple standard optimization runs. The model-based approach delivers the best results, in the sense that it finds more solutions, more diverse solutions, and better-quality solutions than the baseline method. Show less
Veen, R. van der; Boshuizen, M.C.S.; Kloet, E.R. de 2013
Rationale Glucocorticoid hormones facilitate sensitization to repeated administration of psychostimulants, an effect that is mediated by glucocorticoid receptors (GRs). It is still unclear, however... Show moreRationale Glucocorticoid hormones facilitate sensitization to repeated administration of psychostimulants, an effect that is mediated by glucocorticoid receptors (GRs). It is still unclear, however, at which stage of psychomotor sensitization are stress and GR-mediated effects involved.Objectives In the present study, we have tested the hypothesis that GR-mediated effects during the phase of repeated amphetamine injections play a crucial role in the long-term expression of sensitization. For this purpose, we used DBA/2 mice, an inbred strain commonly used for the study of stress effects on psychostimulant sensitization.Methods Animals were treated with the GR antagonist mifepristone (200 mg/kg) at 2.5 h before each daily injection of amphetamine (2.5 mg/kg) or saline in a 5-day protocol. The amphetamine or saline injections were given in the home or a novel context. This was followed by a 2.5-week withdrawal period, without any drug delivery. Following the withdrawal period, two low-dose amphetamine challenges (1.25 mg/kg) were given subsequently, without additional mifepristone.Results The animals receiving amphetamine in the novel context showed a higher expression of sensitization at challenge as compared to those in the home condition. Mifepristone treatment influenced locomotor response to repeated amphetamine injections, but this effect during the initial phase did not affect the expression of sensitization after a withdrawal period.Conclusion Our results indicate that GR-related processes during the initial phase of sensitization are involved in, but not crucial for, the development of long-term sensitization. Show less
Adrenal corticosterone secretion of newborn mice rapidly desensitizes to repeated maternal absence. The present study investigated the effects of novelty exposure, maternal care and genotype on... Show moreAdrenal corticosterone secretion of newborn mice rapidly desensitizes to repeated maternal absence. The present study investigated the effects of novelty exposure, maternal care and genotype on this phenomenon. Maternal separation (MS) took place on postnatal days (pnd) 3-5. In Wistar rats, the degree of novelty in the MS-environment was varied by exposing pups to: (i) "home separation": pups remained in the home cage: (ii) "novel separation": pups were placed individually in a novel cage. Maternal care was recorded on pnd 1 to 4. To investigate the effect of genotype, we also examined Long Evans in the "home separation" condition. Basal and stress-induced ACTH and corticosterone levels were measured. Adrenal tyrosine hydroxylase (TH) and melanocortin receptor-2 (MCR-2) proteins served as markers for adrenal function.We show, in both rat strains, that the rise in plasma corticosterone induced by a single 8 h-MS on pnd 5 was abolished, when this separation procedure had also been performed on pnd 3 and 4. Habituation to maternal absence occurred irrespective of housing conditions. However, pups in the "home separation" condition received less maternal care upon reunion than those placed in the "novel separation". These "home separation" pups appeared more responsive to a subsequent acute novelty-stressor, and their adrenal TH and MCR-2 were higher. Long Evans rats appeared more stress responsive than the Wistars, in the home separation condition.In conclusion, separation environment, maternal care and genotype do not affect adrenal desensitization to repeated 8 h-MS itself, but may modulate the adrenal stress-responsiveness of separated pups. (C) 2011 Elsevier Inc. All rights reserved. Show less
