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PubMed2006

Bringing history to life: simulating landmark experiments in psychology.

The course in history of psychology can be challenging for students, many of whom enter it with little background in history and faced with unfamiliar names and concepts. The sheer volume of material can encourage passive memorization unless efforts are made to increase student involvement. As part of a trend toward experiential history, historians of science have begun to supplement their lectures with demonstrations of classic physics experiments as a way to bring the history of science to life. Here, the authors report on computer simulations of five landmark experiments from early experimental psychology in the areas of reaction time, span of attention, and apparent motion. The simulations are designed not only to permit hands-on replication of historically important results but also to reproduce the experimental procedures closely enough that students can gain a feel for the nature of early research and the psychological processes being studied.

Computer Simulation↗
PubMed2004

Inspiratory flow limitation in obstructive sleep apnoea patients.

Patients suffering from the obstructive sleep apnoea syndrome (OSAS) experience nocturnal episodes of upper airway obstruction resulting in recurrent oxygen desaturations and arousals. Methods to quantify the nocturnal obstructive events are of interest for characterizing this prevalent sleep disorder. In a study published in this issue of Clinical Science, Bloch and co-workers propose the computation of a new index for objectively quantifying the degree of flow limitation in patients with OSAS. The results obtained in a bench test and in a pilot study in patients suggest that the flow limitation index proposed may help to better characterize the disturbed breathing events undergone by patients with OSAS.

Airway Obstruction↗
PubMed2000

From image segmentation to anti-textons.

We apply the 'patchwork engine' (PE; van Tonder and Ejima, 2000 Neural Networks forthcoming) to encode spaces between textons in an attempt to find a suitable feature representation of anti-textons [Williams and Julesz, 1991, in Neural Networks for Perception volume 1: Human and Machine Perception Ed. H Wechsler (San Diego, CA: Academic Press); 1992, Proceedings of the National Academy of Sciences of the USA 89 6531-6534]. With computed anti-textons it is possible to show that tessellation and distribution of anti-textons can differ from that of textons depending on the ratio of texton size to anti-texton size. From this we hypothesise that variability of anti-textons can enhance texture segregation, and test our hypothesis in two psychophysical experiments. Texture segregation asymmetry is the topic of the first test. We found that targets on backgrounds with regular anti-textons segregate more strongly than on backgrounds with highly variable anti-textons. This neatly complements other explanations for texture segregation asymmetry (e.g. Rubenstein and Sagi, 1990 Journal of the Optical Society of America A 7 1632-1643). Second the relative significance of textons and anti-textons in human texture segregation is investigated for a limited set of texture patterns. Subjects consistently judged a combination of texton and anti-texton gradients as more conspicuous than texton-only gradients, and judged texton-only gradients as being more conspicuous than anti-texton-only gradients. In the absence of strong texton gradients the regularity versus irregularity of anti-textons agrees with perceived texture segregation. Using PE outputs as anti-texton features thus enabled the conception of various useful tests on texture segregation. The PE is originally intended as a general image segmentation method based on symmetry axes. With this paper we therefore hope to relate anti-textons with visual processing in a wider sense.

Contrast Sensitivity↗
PubMed2004

User-controlled mapping of significant literatures.

We apply a version of our web-based literature-mapping system to PNAS for 1971-2002, as indexed by the National Library of Medicine and the Institute for Scientific Information. Given a single input term from a user, a medical subject heading, a cocited author, or a cocited journal, PNASLINK rapidly displays views in which that term and the other 24 terms that most frequently co-occur with it in a bibliographic database are interrelated in ways suggesting fruitful combinations for document retrieval. The interrelationships are produced by two algorithms, pathfinder networks and Kohonen-style self-organizing maps. PNASLINK displays are themselves interactive interfaces that can retrieve documents from digital libraries (e.g., PNAS Online). This style of visualizing knowledge domains is called "localized" because it does not attempt to map the indexing of literatures in full but concentrates on the top terms in an "associative thesaurus" reflecting user interests. It also permits swift remappings, as the user recognizes terms worth pursuing. PNASLINK is illustrated with maps drawn from the literature of population genetics. Some comparative and evaluative comments are added, one from a domain expert indicating that the face validity of the system may be tempered by insufficient specificity in the indexing terms being mapped.

Databases, Bibliographic↗
PubMed2004

Tracking evolving communities in large linked networks.

We are interested in tracking changes in large-scale data by periodically creating an agglomerative clustering and examining the evolution of clusters (communities) over time. We examine a large real-world data set: the NEC CiteSeer database, a linked network of >250,000 papers. Tracking changes over time requires a clustering algorithm that produces clusters stable under small perturbations of the input data. However, small perturbations of the CiteSeer data lead to significant changes to most of the clusters. One reason for this is that the order in which papers within communities are combined is somewhat arbitrary. However, certain subsets of papers, called natural communities, correspond to real structure in the CiteSeer database and thus appear in any clustering. By identifying the subset of clusters that remain stable under multiple clustering runs, we get the set of natural communities that we can track over time. We demonstrate that such natural communities allow us to identify emerging communities and track temporal changes in the underlying structure of our network data.

Cluster Analysis↗
PubMed1995

Review of the organized support network for infertility patients in licensed units in the UK.

In acknowledging that 'counselling is generally recognized as beneficial', the Human Fertilization and Embryology Authority (HFEA) Code of Practice requires that all infertility units provide counselling facilities to be available for patients. In this study, we intended to evaluate the support and counselling services made available by the licensed units in the UK. A questionnaire consisting of 30 questions was designed and sent to every licensed treatment unit in the UK. The data were coded on a nominal scale and, using a data entry program, loaded onto a computer. Using the Statistical Package for the Social Sciences program, a non-parametric frequency analysis was performed. Associations were examined with cross-tabulations and chi 2 analysis. A total of 62 units (61.4%) responded to the questionnaire, from both the private and National Health Service sectors. Of these, 95% have their own counsellor, most of whom (84%) practised on the premises. One-third of these counsellors had a dual role, mainly as nurses, social workers or in administration; 98.6% were trained in counselling, with only 28% having either the Certificate or Diploma in Counselling. One-third (32.2%) of centres charged for counselling, with only 13 units indicating their charges. The majority of centres (78.8%) do not actively follow-up patients after counselling and one-quarter (25.5%) did not have a specific counselling room. Over two-thirds (68.4%) of centres described their support network as adequate. The results of this survey suggest that, although the requirements of the HFEA Code of Practice are being adhered to reasonably well, overall patient uptake of counselling is low.(ABSTRACT TRUNCATED AT 250 WORDS)

England↗
PubMed2006

Spectators & spectacles: nurses, midwives and visuality.

AIM: In this paper we reflect on how linear perspective vision influences the practice of nurses and midwives and to advance understanding of clinical practice in technologically intensive environments through examination of drawings by nurses and midwives and through critical analysis. BACKGROUND: There is increasing emphasis on vision in Western culture, and both nurses and midwives spend a great deal of time observing their clinical environment(s). Healthcare practitioners work increasingly in image-based realities and nurses rely on visual skills. Vision and visual representation are central to our practice and are important to examine because we look often at technology to assess people and care. DISCUSSION: The world in which we practise is one of meaning(s). Technological development is transformative in nature and produces changes that alter the way(s) we give care. Amongst all this change, it is unclear how we practise in environments characterized by increasing technology and it is unknown how nursing and midwifery practice alter as a result. CONCLUSION: Simple drawings included in this paper highlight an important and shared experience of clinical practice(s). They emphasize the importance and scope of the visual sense and expose practitioner behaviour that has enormous implications for current and future professional development and person-focussed care provision. Experiences described in this paper require further examination and highlight substantial changes to nurse-patient relationships, health care and the way we practise.

Attitude of Health Personnel↗