132,674 research outputs found
Exploration and Exploitation of Victorian Science in Darwin's Reading Notebooks
Search in an environment with an uncertain distribution of resources involves
a trade-off between exploitation of past discoveries and further exploration.
This extends to information foraging, where a knowledge-seeker shifts between
reading in depth and studying new domains. To study this decision-making
process, we examine the reading choices made by one of the most celebrated
scientists of the modern era: Charles Darwin. From the full-text of books
listed in his chronologically-organized reading journals, we generate topic
models to quantify his local (text-to-text) and global (text-to-past) reading
decisions using Kullback-Liebler Divergence, a cognitively-validated,
information-theoretic measure of relative surprise. Rather than a pattern of
surprise-minimization, corresponding to a pure exploitation strategy, Darwin's
behavior shifts from early exploitation to later exploration, seeking unusually
high levels of cognitive surprise relative to previous eras. These shifts,
detected by an unsupervised Bayesian model, correlate with major intellectual
epochs of his career as identified both by qualitative scholarship and Darwin's
own self-commentary. Our methods allow us to compare his consumption of texts
with their publication order. We find Darwin's consumption more exploratory
than the culture's production, suggesting that underneath gradual societal
changes are the explorations of individual synthesis and discovery. Our
quantitative methods advance the study of cognitive search through a framework
for testing interactions between individual and collective behavior and between
short- and long-term consumption choices. This novel application of topic
modeling to characterize individual reading complements widespread studies of
collective scientific behavior.Comment: Cognition pre-print, published February 2017; 22 pages, plus 17 pages
supporting information, 7 pages reference
Neural signals encoding shifts in beliefs
Dopamine is implicated in a diverse range of cognitive functions including cognitive flexibility, task switching, signalling novel or unexpected stimuli as well as advance information. There is also longstanding line of thought that links dopamine with belief formation and, crucially, aberrant belief formation in psychosis. Integrating these strands of evidence would suggest that dopamine plays a central role in belief updating and more specifically in encoding of meaningful information content in observations. The precise nature of this relationship has remained unclear. To directly address this question we developed a paradigm that allowed us to decompose two distinct types of information content, information-theoretic surprise that reflects the unexpectedness of an observation, and epistemic value that induces shifts in beliefs or, more formally, Bayesian surprise. Using functional magnetic-resonance imaging in humans we show that dopamine-rich midbrain regions encode shifts in beliefs whereas surprise is encoded in prefrontal regions, including the pre-supplementary motor area and dorsal cingulate cortex. By linking putative dopaminergic activity to belief updating these data provide a link to false belief formation that characterises hyperdopaminergic states associated with idiopathic and drug induced psychosis
Final report TransForum WP-046 : images of sustainable development of Dutch agriculture and green space
In the project âImages of sustainable development of Dutch agriculture and green spaceâ three PhD candidates studied the topic of images in sustainable development. Frans Hermans focused on the topic of societal images and their role and influence in innovation projects. The title of his subproject was âSocial learning for sustainability in dynamic agricultural innovation networks.â Joost Vervoort explored the topic of âvisualisationâ, that is, using and producing images for specific purposes, in the context of innovation projects and programmes, in a subproject called âStep into the system: interactive media strategies for the exchange of insights on social-ecological change.â Finally, Dirk van Apeldoorn took a complex adaptive systems approach to images. He modelled various agro-ecosystems to compare images of those systems with the behaviour of those systems. His subproject was called âModeling resilience of agro-ecosystems.
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A journey into the heart the US-Mexico borderlands reveals a world of ancient rivers, mud, and brick.Radio-Television-Fil
Dialogical encounter argument as a source of rigour in the practice based PhD
This paper distinguishes between three views of argument: âargument as structure,â âargument as confrontationâ and âargument as dialogical encounter.â Empirical studies of the criteria that examiners bring to the assessment of PhDs are cited. The studies provide evidence that qualities that align one or other of the three modes of argument figure significantly in the criteria that examiners bring to the assessment process. Embedded in the studies are respondentsâ comments that suggest that the range of conceptions of argument held by PhD examiners is broad. Explicit use of the term âargumentâ is often made in reference to a minimal concept of argument ÂŹâ âargument as structure.â However, the reported comments indicate a significant bias towards qualities associated with concepts of argument that lie somewhere along the spectrum between âargument as confrontationâ and âargument as dialogical encounterâ as a marker of quality in PhD research. Drawing on the work of Hans Georg Gadamer the paper will explore the possibilities opened up by adopting the view of âargument as dialogical encounterâ in the context of the PhD. In particular I consider the issue of how PhD projects be structured so as to support the construction of arguments appropriate to practice based research in design?
Keywords:
Argument; Gadamer; Hermeneutics; Rigour; Practice Based Research; Phd Examination</p
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Eye-tracking the emergence of attentional anchors in a mathematics learning tablet activity
Little is known about micro-processes by which sensorimotor interaction gives rise to conceptual development. Per embodiment theory, these micro-processes are mediated by dynamical attentional structures. Accordingly this study investigated eye-gaze behaviors during engagement in solving tablet-based bimanual manipulation tasks designed to foster proportional reasoning. Seventy-six elementary- and vocational-school students (9-15 yo) participated in individual task-based clinical interviews. Data gathered included action-logging, eye-tracking, and videography. Analyses revealed the emergence of stable eye-path gaze patterns contemporaneous with first enactments of effective manipulation and prior to verbal articulations of manipulation strategies. Characteristic gaze patterns included consistent or recurring attention to screen locations that bore non-salient stimuli or no stimuli at all yet bore invariant geometric relations to dynamical salient features. Arguably, this research validates empirically hypothetical constructs from constructivism, particularly reflective abstraction
âOtherâ or âone of usâ?: the porn user in public and academic discourse
The consumption of sexually explicit media has long been a matter of public and political concern. It has also been a topic of academic interest. In both these arenas a predominantly behaviourist model of effects and regulation has worked to cast the examination of sexually explicit texts and their consumption as a debate about harm. The broader area of investigation remains extraordinarily undeveloped.
Sexually explicit media is a focus of interest for academics because of the way it âspeaksâ sex and sexuality for its culture. In this paper I examine existing and emerging figures of the porn consumer, their relation to ways of thinking and speaking about pornography, and the implications of these for future work on porn consumption.
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Using term clouds to represent segment-level semantic content of podcasts
Spoken audio, like any time-continuous medium, is notoriously difficult to browse or skim without support of an interface providing semantically annotated jump points to signal the user where to listen in. Creation of time-aligned metadata by human annotators is prohibitively expensive, motivating the investigation of representations of segment-level semantic content based on transcripts
generated by automatic speech recognition (ASR). This paper
examines the feasibility of using term clouds to provide users with a structured representation of the semantic content of podcast episodes. Podcast episodes are visualized as a series of sub-episode segments, each represented by a term cloud derived from a transcript
generated by automatic speech recognition (ASR). Quality of
segment-level term clouds is measured quantitatively and their utility is investigated using a small-scale user study based on human labeled segment boundaries. Since the segment-level clouds generated from ASR-transcripts prove useful, we examine an adaptation of text tiling techniques to speech in order to be able to generate segments as part of a completely automated indexing and structuring system for browsing of spoken audio. Results demonstrate that the segments generated are comparable with human selected segment boundaries
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