bluuebunny/crossref_metadata_2025 huggingface dataset:
Imitation as behaviour parsing
Authors: Byrne R.W.
Published: March 2003

Non–human great apes appear to be able to acquire elaborate skills partly by imitation, raising the possibility of the transfer of skill by imitation in animals that have only rudimentary mentalizing capacities: in contrast to the frequent assumption that imitation depends on prior understanding of others' intentions. Attempts to understand the apes' behaviour have led to the development of a purely mechanistic model of imitation, the ‘behaviour parsing’ model, in which the statistical regularities that are inevitable in planned behaviour are used to decipher the organization of another agent's behaviour, and thence to imitate parts of it. Behaviour can thereby beunderstood statisticallyin terms of its correlations (circumstances of use, effects on the environment) without understanding of intentions or the everyday physics of cause–and–effect. Thus, imitation of complex, novel behaviour may not require mentalizing, but conversely behaviour parsing may be a necessary preliminary to attributing intention and cause.
Electrophysiology and brain imaging of biological motion
Authors: Puce Aina , Perrett David
Published: March 2003

The movements of the faces and bodies of other conspecifics provide stimuli of considerable interest to the social primate. Studies of single cells, field potential recordings and functional neuroimaging data indicate that specialized visual mechanisms exist in the superior temporal sulcus (STS) of both human and non–human primates that produce selective neural responses to moving natural images of faces and bodies. STS mechanisms also process simplified displays of biological motion involving point lights marking the limb articulations of animate bodies and geometrical shapes whose motion simulates purposeful behaviour. Facial movements such as deviations in eye gaze, important for gauging an individual's social attention, and mouth movements, indicative of potential utterances, generate particularly robust neural responses that differentiate between movement types. Collectively such visual processing can enable the decoding of complex social signals and through its outputs to limbic, frontal and parietal systems the STS may play a part in enabling appropriate affective responses and social behaviour.
Teleological and referential understanding of action in infancy
Authors: Csibra Gergely
Published: March 2003

There are two fundamentally different ways to attribute intentional mental states to others upon observing their actions. Actions can be interpreted asgoal–directed, which warrants ascribing intentions, desires and beliefs appropriate to the observed actions, to the agents. Recent studies suggest that young infants also tend to interpret certain actions in terms of goals, and their reasoning about these actions is based on a sophisticated teleological representation. Several theorists proposed that infants rely on motion cues, such as self–initiated movement, in selecting goal–directed agents. Our experiments revealed that, although infants are more likely to attribute goals to self–propelled than to non–self–propelled agents, they do not need direct evidence about the source of motion for interpreting actions in teleological terms. The second mode of action–based mental state attribution interprets actions asreferential, and allows ascription of attentional states, referential intents, communicative messages, etc., to the agents. Young infants also display evidence of interpreting actions in referential terms (for example, when following others' gaze or pointing gesture) and are very sensitive to the communicative situations in which these actions occur. For example, young infants prefer faces with eye–contact and objects that react to them contingently, and these are the very situations that later elicit gaze following. Whether or not these early abilities amount to a ‘theory of mind’ is a matter of debate among infant researchers. Nevertheless, they represent skills that are vital for understanding social agents and engaging in social interactions.
Detecting agents
Authors: Johnson Susan C.
Published: March 2003

This paper reviews a recent set of behavioural studies that examine the scope and nature of the representational system underlying theory–of–mind development. Studies with typically developing infants, adults and children with autism all converge on the claim that there is a specialized input system that uses not only morphological cues, but also behavioural cues to categorize novel objects as agents. Evidence is reviewed in which 12– to 15–month–old infants treat certain non–human objects as if they have perceptual/attentional abilities, communicative abilities and goal–directed behaviour. They will follow the attentional orientation of an amorphously shaped novel object if it interacts contingently with them or with another person. They also seem to use a novel object's environmentally directed behaviour to determine its perceptual/attentional orientation and object–oriented goals. Results from adults and children with autism are strikingly similar, despite adults' contradictory beliefs about the objects in question and the failure of children with autism to ultimately develop more advanced theory–of–mind reasoning. The implications for a general theory–of–mind development are discussed.
A unifying computational framework for motor control and social interaction
Authors: Wolpert Daniel M. , Doya Kenji , Kawato Mitsuo
Published: March 2003

Recent empirical studies have implicated the use of the motor system during action observation, imitation and social interaction. In this paper, we explore the computational parallels between the processes that occur in motor control and in action observation, imitation, social interaction and theory of mind. In particular, we examine the extent to which motor commands acting on the body can be equated with communicative signals acting on other people and suggest that computational solutions for motor control may have been extended to the domain of social interaction.
Dressing the mind properly for the game
Authors: Sally David
Published: March 2003

Game theory as a theoretical and empirical approach to interaction has spread from economics to psychology, political science, sociology and biology. Numerous social interactions—foraging, talking, trusting, coordinating, competing—can be formally represented in a game with specific rules and strategies. These same interactions seem to rely on an interweaving of mental selves, but an effective strategy need not depend on explicit strategizing and higher mental capabilities, as less sentient creatures or even lines of software can play similar games. Human players are distinct because we are less consistent and our choices respond to elements of the setting that appear to be strategically insignificant. Recent analyses of this variable response have yielded a number of insights into the mental approach of human players: we often mentalize, but not always; we are endowed with social preferences; we distinguish among various types of opponents; we manifest different personalities; we are often guided by security concerns; and our strategic sophistication is usually modest.
Action generation and action perception in imitation: an instance of the ideomotor principle
Authors: Wohlschläger Andreas , Gattis Merideth , Bekkering Harold
Published: March 2003

We review a series of behavioural experiments on imitation in children and adults that test the predictions of a new theory of imitation. Most of the recent theories of imitation assume a direct visual–to–motor mapping between perceived and imitated movements. Based on our findings of systematic errors in imitation, the new theory of goal–directed imitation (GOADI) instead assumes that imitation is guided by cognitively specified goals. According to GOADI, the imitator does not imitate the observed movement as a whole, but rather decomposes it into its separate aspects. These aspects are hierarchically ordered, and the highest aspect becomes the imitator's main goal. Other aspects become sub–goals. In accordance with the ideomotor principle, the main goal activates the motor programme that is most strongly associated with the achievement of that goal. When executed, this motor programme sometimes matches, and sometimes does not, the model's movement. However, the main goal extracted from the model movement is almost always imitated correctly.
Mathematical modelling of animate and intentional motion
Authors: Rittscher Jens , Blake Andrew , Hoogs Anthony , Stein Gees
Published: March 2003

Our aim is to enable a machine to observe and interpret the behaviour of others. Mathematical models are employed to describe certain biological motions. The main challenge is to design models that are both tractable and meaningful. In the first part we will describe how computer vision techniques, in particular visual tracking, can be applied to recognize a small vocabulary of human actions in a constrained scenario. Mainly the problems of viewpoint and scale invariance need to be overcome to formalize a general framework. Hence the second part of the article is devoted to the question whether a particular human action should be captured in a single complex model or whether it is more promising to make extensive use of semantic knowledge and a collection of low–level models that encode certain motion primitives. Scene context plays a crucial role if we intend to give a higher–level interpretation rather than a low–level physical description of the observed motion. A semantic knowledge base is used to establish the scene context. This approach consists of three main components: visual analysis, the mapping from vision to language and the search of the semantic database. A small number of robust visual detectors is used to generate a higher–level description of the scene. The approach together with a number of results is presented in the third part of this article.
What imitation tells us about social cognition: a rapprochement between developmental psychology and cognitive neuroscience
Authors: Meltzoff Andrew N. , Decety Jean
Published: March 2003

Both developmental and neurophysiological research suggest a common coding between perceived and generated actions. This shared representational network is innately wired in humans. We review psychological evidence concerning the imitative behaviour of newborn human infants. We suggest that the mechanisms involved in infant imitation provide the foundation for understanding that others are ‘like me’ and underlie the development of theory of mind and empathy for others. We also analyse functional neuroimaging studies that explore the neurophysiological substrate of imitation in adults. We marshal evidence that imitation recruits not only shared neural representations between the self and the other but also cortical regions in the parietal cortex that are crucial for distinguishing between the perspective of self and other. Imitation is doubly revealing: it is used by infants to learn about adults, and by scientists to understand the organization and functioning of the brain.
Models of dyadic social interaction
Authors: Griffin Dale , Gonzalez Richard
Published: March 2003

We discuss the logic of research designs for dyadic interaction and present statistical models with parameters that are tied to psychologically relevant constructs. Building on Karl Pearson's classic nineteenth–century statistical analysis of within–organism similarity, we describe several approaches to indexing dyadic interdependence and provide graphical methods for visualizing dyadic data. We also describe several statistical and conceptual solutions to the ‘levels of analytic’ problem in analysing dyadic data. These analytic strategies allow the researcher to examine and measure psychological questions of interdependence and social influence. We provide illustrative data from casually interacting and romantic dyads.
Social capital in the success of knowledge workers
Authors: Tymon Walter G. , Stumpf Stephen A.
Published: March 2003

The concept of social capital will be key to individual and organizational success throughout the twenty‐first century. Social capital is the stock of accumulated resources that one can access based on the relationships that can aid or be leveraged in accomplishing an end or furthering a pursuit. Several attributes of social capital are explored that distinguish it from other forms of capital; namely, physical, financial, human, market, intellectual, and knowledge capital. These attributes considered are capital’s transferability, controllability, fungibility, entropy, and synergy. Implications for career development and one’s ability to contribute to organization effectiveness are discussed, as well as management practices affecting the development of social capital. Concludes with propositions for future research.
Importance of person‐organization fit to job seekers
Authors: Backhaus Kristin
Published: March 2003

This study investigates the importance of person‐organization fit to job seekers. The study hypothesizes that as job experience increases, importance of fit will also increase. Further, it hypothesizes that desire for personal control will be positively associated with importance of fit. Results suggest that while number of years of work experience is not related to the importance placed on person‐organization fit, having an experience of perceiving poor fit with an organization does relate to the importance placed on fit in future job searches. Findings also suggest that desire for personal control is positively associated with importance placed on fit. The study suggests that disposition as well as situational factors influence the assessment of organizational attractiveness.
A social psychological model of women’s gender‐typed occupational mobility
Authors: Chang Tracy F.H.
Published: March 2003

This study develops a social psychological model to account for women’s gender‐typed occupational mobility. The model delineates that occupational gender composition affects women’s psychological experience (experience of sex discrimination, self‐efficacy, and gender role ideology), and that this psychological experience, in turn, contributes to their mobility between male‐dominated and female‐dominated occupations. Using the National Longitudinal Surveys (NLS) of Young Women data, the study finds that occupational gender composition affects women’s report of experience of sex discrimination but not self‐efficacy or gender role ideology. Self‐efficacy contributes to women’s gender‐typed occupational mobility, but experience of sex discrimination and gender role ideology do not. The direction for future research is discussed.
Benchmarking performance indices: pitfalls and solutions
Authors: Maleyeff John
Published: March 2003

Many organizations include benchmarking as a component of their performance management system. Often, a performance index is used to quantify the ability of an organizational entity to operate successfully. Benchmarking a performance index is done inappropriately when statistical methods are employed that ignore sample size effects or use aggregate performance data over a period during which changes occurred within the organization. Benchmarking will also be ineffective when invalid targets are employed. When benchmarking is done incorrectly, customer satisfaction may actually decline due to gaming and poor morale among employees. Based on the philosophy of W. Edwards Deming, the techniques of statistical process control (SPC), and basic undergraduate statistics, a system is described for effectively benchmarking a performance index. Examples are presented to illustrate the pitfalls that exist in many performance management systems and to explain the system presented for effective benchmarking.
A multi‐level causal model for best practices in project management
Authors: Loo Robert
Published: March 2003

This paper presents a multi‐level causal model for best practices in project management based upon the literature, especially empirical studies of competencies and project management. The model emphasizes the roles of technical project management skills and interpersonal or people skills as inputs to the model. Next, the model stresses the important roles of organizational facilitators and inhibitors, that is, moderator variables (e.g. project management systems and supportive senior management) in influencing project outcomes. The model addresses the outcome variables of technical competencies (e.g. planning and controlling) and people competencies (e.g. interpersonal communication and conflict management skills). Finally, the model recognizes the important role of feedback for corrective actions and reinforcing best practices, that is, organizational learning.
TQM practices and organizational performances of SMEs in Malaysia
Authors: Sadiq Sohail M. , Boon Hoong Teo
Published: March 2003

This paper examines and compares the total quality management (TQM) practices and organizational performances of small to medium enterprises (SMEs) with and without ISO 9000 certification in Malaysia. A quality measurement framework is developed for this paper based on the critical success factors of the TQM program. Empirical research was carried out to determine the difference, if any, in the TQM implementation and organizational performances of SMEs with and without ISO 9000 certification. The quality measurement framework developed for this paper provides a benchmark of TQM practices for SMEs, which are in the early implementation stage of the quality program and this is proposed as a quality checklist for SMEs to improve and focus on specific areas of their respective quality program. Results based on testing the mean differences between firms with and without ISO 9000 certification indicate that there are significant differences in performances between certified and non‐certified firms, supporting the hypothesis that ISO 9000 certification contributes to a higher organizational performance. Other findings based on the impact of length of operation on performance are also reported. The paper discusses the implications of this. Limitations of the study are highlighted and further research directions are suggested.
Multicast‐based online auctions: a performance perspective
Authors: Liu Hong , Wang Shouhong , Fei Teng
Published: March 2003

Online auctions on the Internet have become popular. However, the communication techniques currently used in the online auction industry are primarily based on unicast technology. Unicast‐based online auctions suffer from unbearable delay of the communication between the auctioneer and bidders. Recently, multicast is changing the Internet environment, and is penetrating to the online auction field. This study describes a model for multicast‐based online auctions. The laboratory experiments demonstrate that the communication performance of multicast‐based online auctions is significantly better than that of traditional unicast‐based auctions.
Benchmarking as an enabler of business excellence in the South African financial sector
Authors: Vermeulen W.
Published: March 2003

Benchmarking is the process of identifying, understanding, and adapting outstanding practices from within the organization or from other businesses to help improve performance. The importance of benchmarking as an enabler of business excellence has necessitated an in‐depth investigation into the current state of benchmarking in South Africa. This research project highlighted the fact that the respondents realized the importance of benchmarking, but that various problems exist regarding the effective implementation of benchmarking. Based on the research findings, recommendations for achieving success are suggested.
Optimization Strategies for DNA Microarray-Based Detection of Bacteria with 16S rRNA-Targeting Oligonucleotide Probes
Authors: Peplies Jörg , Glöckner Frank Oliver , Amann Rudolf
Published: March 2003

The usability of the DNA microarray format for the specific detection of bacteria based on their 16S rRNA genes was systematically evaluated with a model system composed of six environmental strains and 20 oligonucleotide probes. Parameters such as secondary structures of the target molecules and steric hindrance were investigated to better understand the mechanisms underlying a microarray hybridization reaction, with focus on their influence on the specificity of hybridization. With adequate hybridization conditions, false-positive signals could be almost completely prevented, resulting in clear data interpretation. Among 199 potential nonspecific hybridization events, only 1 false-positive signal was observed, whereas false-negative results were more common (17 of 41). Subsequent parameter analysis revealed that this was mainly an effect of reduced accessibility of probe binding sites caused by the secondary structures of the target molecules. False-negative results could be prevented and the overall signal intensities could be adjusted by introducing a new optimization strategy called directed application of capture oligonucleotides. The small number of false-positive signals in our data set is discussed, and a general optimization approach is suggested. Our results show that, compared to standard hybridization formats such as fluorescence in situ hybridization, a large number of oligonucleotide probes with different characteristics can be applied in parallel in a highly specific way without extensive experimental effort.
Dr D G James FRCP and the Fellowship of Postgraduate Medicine
Authors: Cook G C
Published: March 2003

Dr D G James recently retired as Vice President of the Fellowship of Postgraduate Medicine. The following article is based on a speech given at a dinner at the Athenaeum Club on 10 October 2002 to thank Dr James for his contributions to the Fellowship of Postgraduate Medicine over 50 years.
Thallium poisoning: emphasis on early diagnosis and response to haemodialysis
Authors: Misra U K , Kalita J , Yadav R K , Ranjan P
Published: March 2003

Thallium poisoning is known for its diverse manifestations and these can delay the diagnosis if a clear history of poisoning is not forthcoming. A 42 year old man presented on the third day of illness with flaccid quadriparesis and paresthesia, which were confused with Guillain-Barré syndrome. Because of associated loose motions, skin lesions, and liver and kidney dysfunction arsenic poisoning was considered. In the second week he developed ophthalmoplegia, nystagmus, and neck tremor and later developed alopecia, and thallium poisoning was suspected. His serum thallium level on the 18th day of illness was 40 980 μg/ml. He was subjected to haemodialysis, potassium supplementation, laxatives, and B complex supplementation. He showed significant improvement after haemodialysis and at three months he was able to walk with support. At six months of follow up he was independent for activities of daily living. Severe paresthesia, ophthalmoplegia, cerebellar and extrapyramidal signs, and alopecia are highly suggestive of thallium poisoning. Haemodialysis may be effective even in the third week of poisoning.
Simultaneous bilateral spontaneous pneumothorax in a patient with recurrent, extraosseous multiple myeloma
Authors: Peters F , Cathomas G , Rothen M , Thurnheer R , Rutishauser J
Published: March 2003

A patient with simultaneous bilateral spontaneous pneumothorax (SBSP) due to pulmonary and pleural manifestations of recurrent multiple myeloma is presented. The patient died in shock of unknown cause. The diagnosis was suspected from pleural fluid examination showing an exudate with numerous plasmocytes. Macroscopically and histologically, the visceral organs and the bone marrow were infiltrated with multiple monoclonal proliferations of plasma cells staining positively for IgG and lambda chains.

SBSP is a rare condition and may be caused by trauma, parenchymal lung disease, infections, or neoplasms. This is the first report of SBSP caused by pleuropulmonary infiltration of multiple myeloma.
Roth’s spots: an unusual presentation of HIV
Authors: Vose M J , Charles S J
Published: March 2003

A 46 year old Nigerian man presented with a four week history of progressive bilateral visual loss. He had been unwell, with weight loss, fever, and night sweats for six months. Dilated fundoscopy revealed macular haemorrhages and diffuse Roth’s spots. The patient was found to be severely anaemic and a bone marrow aspirate revealed a T cell lymphoma with a decreased CD4+ T cell count. The patient consented for testing for HIV which proved positive.
D-lactic acidosis secondary to short bowel syndrome
Authors: Zhang D L , Jiang Z W , Jiang J , Cao B , Li J S
Published: March 2003

A 12 year old boy presented with 11 episodes of weakness, ataxia, nausea, slurred speech, dehydration, and sometimes severe lethargy bordering on coma. A year previously the boy had small intestinal resections leaving 20 cm of small bowel remaining. D-lactic acidosis was diagnosed on the basis of a D-lactate level of 5.23 mmol/l. The clinical presentation of the disease is recurrent episodes of unusual neurological manifestations and severe metabolic acidosis. The diagnosis is dependent on the presentations and the plasma D-lactate level. Development of the syndrome seems to be the effect of the accumulation of D-lactic acid.
Hydatid cyst of liver
Authors: Kumar M J , Toe K , Banerjee R D
Published: March 2003

Hydatid disease of the liver is still endemic in certain parts of the world. The diagnosis of non-complicated hydatid cyst of the liver depends on clinical suspicion. Ultrasonography and computed tomography, the most important diagnostic tools, are helpful for determining the complications and planning treatment. The modern treatment of hydatid cyst of the liver varies from surgical intervention to percutaneous drainage or medical therapy. Surgery is still the treatment of choice and can be performed by the conventional or laparoscopic approach. Percutaneous drainage and treatment of the cyst with hypertonic saline or alcohol seems to be a good alternative to surgery in selected cases.
The sweet cake that reaches parts other cakes can’t!
Authors: Hussain R M
Published: March 2003

This is a case report of a previously healthy woman of 56 years who presented with a life threatening tetraparesis, severe hypokalaemia, hypertension, and raised muscle enzymes. The cause of was finally found to be unusual and very much “local”. Initial inquiry into her drug history was negative until she was made aware that herbal remedies could cause serious adverse reactions. She then mentioned that she had been eating a large number of “Pontefract cakes” (a liquorice sweet) for the management of her chronic constipation. This case highlights the importance of asking about herbal remedies when taking a drug history in all patients, including those admitted as medical emergencies.
Present treatment options for atrial fibrillation
Authors: Lairikyengbam S K S , Anderson M H , Davies A G
Published: March 2003

Atrial fibrillation is the commonest sustained cardiac arrhythmia. It accounts for >35% of all hospital admissions for cardiac arrhythmias in the United States. The presence of atrial fibrillation increases the mortality of a population by up to twofold. The risk of stroke increases from 1.5% in patients with atrial fibrillation from 50–59 years of age to up to 23.5% for such patients aged 80–89 years. Although the diagnosis of atrial fibrillation is usually straightforward, effective treatment is not. This article will discuss how rhythm control of atrial fibrillation can best be achieved, the controversy over the rhythm versus rate control, the maintenance of sinus rhythm with antiarrhythmic drugs after cardioversion, and prevention of thromboembolism. Finally, the recent advances in various non-pharmacological approaches for the treatment of atrial fibrillation will be highlighted.
Juvenile myoclonic epilepsy: under-appreciated and under-diagnosed
Authors: Renganathan R , Delanty N
Published: March 2003

Juvenile myoclonic epilepsy (JME) is a hereditary, idiopathic, generalised epilepsy and is found in 5%–11% of patients with epilepsy. It is characterised by myoclonic jerks, occasional generalised tonic-clonic seizures, and sometimes absence seizures. JME continues to be under-appreciated and under-diagnosed. Accurate diagnosis is important as it usually responds well to treatment with appropriate anticonvulsants and misdiagnosis often results in unnecessary morbidity. In addition lifelong therapy is usually indicated as the natural history is one of relapse off treatment, even after a prolonged seizure-free period.
Migraine, memory loss, and “multiple sclerosis ”. Neurological features of the antiphospholipid (Hughes’) syndrome
Authors: Hughes G R V
Published: March 2003

The antiphospholipid syndrome (APS, Hughes’ syndrome), first described in 1983, is a prothrombotic disease in which neurological events feature prominently. Strokes, transient ischaemic attacks, and headaches (including migraine) are important complications. However, it is clear that other neurological symptoms, including diplopia, memory loss, ataxia, and “multiple sclerosis-like” features are common. A notable feature of Hughes’ syndrome is the clinical response to anticoagulants; features such as headache and memory loss often improving dramatically with appropriate warfarin dosage. APS may well become recognised as an important (and potentially treatable) cause of neurological disease.
Management of stroke
Authors: Mc Govern R , Rudd A
Published: March 2003

This article outlines the current evidenced based practice for stroke care. It outlines many of the recommendations in the National Clinical Guidelines for Stroke published by the Royal College of Physicians. It also covers all aspects of multidisciplinary stroke care from initial assessment and acute treatment to rehabilitation strategies and management of complications. The article concludes with an examination of the latest evidence for secondary prevention of cerebrovascular disease.
Are district general hospital patients with unstable angina at a disadvantage?
Authors: Miller C , Lipscomb K , Curzen N
Published: March 2003

Objective

To determine whether patients with non-ST elevation acute coronary syndromes requiring coronary angiography and revascularisation have inferior access to these services if admitted to district general hospitals (DGHs) compared with similar patients admitted to a base hospital containing a tertiary cardiac centre.

Design

Prospective, consecutive monitoring of all patients with acute coronary syndromes accepted by the tertiary cardiac centre for angiography and revascularisation over a three month period (1 April to 30 June 2002).

Participants

All patients accepted for angiography from DGHs and from within the base hospital with a diagnosis of acute coronary syndromes.

Setting

Tertiary cardiac facility (Manchester Heart Centre at Manchester Royal Infirmary (MRI)).

Main outcome measure

Time waited from referral to angiography and revascularisation.

Results

A total of 184 patients with a diagnosis of non-ST elevation acute coronary syndromes underwent angiography with a view to revascularisation. Of these, 89 (48%) were admitted initially to MRI and 95 (52%) were admitted to a feeder DGH. DGH patients waited significantly longer from admission to angiography than MRI patients (median 13 days (25th-75th percentiles 7–19) v 5 days (3–8) respectively; p<0.0005). DGH patients therefore also waited longer from admission to revascularisation (15 days (6–20) v 6 days (3–9) respectively). Once transferred into the Manchester Heart Centre, DGH patients underwent angiography within a median of 1 day (1–2). More DGH patients than those from MRI underwent both coronary artery bypass grafting (21 (22%) v 8 (9%) respectively; p=0.015) and percutaneous coronary intervention (44 (46%) v 32 (36%) respectively; p=NS).

Conclusion

Patients admitted to feeder DGHs with non-ST elevation acute coronary syndromes wait significantly longer for access to invasive coronary assessment and revascularisation than similar patients admitted in the hospital that incorporates the tertiary cardiac centre. This inequity of access is determined by postcode rather than clinical priority.
Illumination of x-rays: the usual lights exposed
Authors: Blackshaw G R J C , Gostling J A , Appleton B N , Pearce N , Thomas G V , Lewis W G
Published: March 2003

Aims

Faced with pressure of work and limited resource, doctors frequently use the nearest available light to examine x-ray films. The aim of this study was to examine the relative intensities of hospital light sources, and to compare these with the light intensity guidelines (1500 to 3000 candelas) of the British Institute of Radiology.

Methods

The relative intensities of seven hospital light sources were examined using a standard light meter at a constant 30 cm from the source. A control group of 10 individual consultant’s x-ray viewing boxes were compared with six other ward based light sources.

Results

Only two light sources approached the British Institute of Radiology light intensity x-ray viewing criteria: the x-ray viewing boxes of consultant radiologists with a median light intensity of 3503 candelas (χ2=13.3, df 1; p=0.0001), and daylight from north facing windows with a median of 1464 candelas when overcast (χ2=8.571, df 1; p=0.003) and 4669 candelas in sunshine (χ2= 6.364, df 1; p=0.0001).

Conclusion

Few hospital light sources met the British Institute of Radiology guidelines. The long held high regard of artists for northern light appears justified even in the environment of a British district general hospital.
Signal Strength Determines the Nature of the Relationship Between Perception and Working Memory
Authors: Sheth Bhavin R. , Shimojo Shinsuke
Published: March 2003

Neurophysiological and behavioral studies have shown that perception and memory share neural substrates and functional properties. But are perception and the active working memory of a stimulus one and the same? To address this question in the spatial domain, we compared the percept and the working memory of the position of a target stimulus embedded within a surround of moving dots. Motion in a particular direction after the target's offset biased the memory of target location in the same direction. However, motion simultaneous with a high-contrast, perceptually strong target biased the percept of target location in the opposite direction. Thus, perception and working memory can be modified by motion in qualitatively different ways. Manipulations to strengthen the memory trace had no effect on the direction of the memory bias, indicating that memory signal strength can never equal that of the percept of a strong stimulus. However, the percept of a weak stimulus was biased in the direction of motion. Thus, although perception and working memory are not inherently different, they can differ behaviorally depending on the strength of the perceptual signal. Understanding how a changing surround biases neural representations in general, and postsensory processes in particular, can help one understand past reports of spatial mislocalization.
Dissociating Hippocampal versus Basal Ganglia Contributions to Learning and Transfer
Authors: Myers Catherine E. , Shohamy Daphna , Gluck Mark A. , Grossman Steven , Kluger Alan , Ferris Steven , Golomb James , Schnirman Geoffrey , Schwartz Ronald
Published: March 2003

Based on prior animal and computational models, we propose a double dissociation between the associative learning deficits observed in patients with medial temporal (hippocampal) damage versus patients with Parkinson's disease (basal ganglia dysfunction). Specifically, we expect that basal ganglia dysfunction may result in slowed learning, while individuals with hippocampal damage may learn at normal speed. However, when challenged with a transfer task where previously learned information is presented in novel recombinations, we expect that hippocampal damage will impair generalization but basal ganglia dysfunction will not. We tested this prediction in a group of healthy elderly with mild-to-moderate hippocampal atrophy, a group of patients with mild Parkinson's disease, and healthy controls, using an “acquired equivalence” associative learning task. As predicted, Parkinson's patients were slower on the initial learning but then transferred well, while the hippocampal atrophy group showed the opposite pattern: good initial learning with impaired transfer. To our knowledge, this is the first time that a single task has been used to demonstrate a double dissociation between the associative learning impairments caused by hippocampal versus basal ganglia damage/dysfunction. This finding has implications for understanding the distinct contributions of the medial temporal lobe and basal ganglia to learning and memory.
A Computational Study into the Evolution of Dual-Route Dynamics for Affective Processing
Authors: Dulk Paul den , Heerebout Bram T. , Phaf R. Hans
Published: March 2003

The evolutionary justification by LeDoux (1996) for his dual-route model of fear processing was analyzed computationally by applying genetic algorithms to artificial neural networks. The evolution was simulated of a neural network controlling an agent that gathered food in an artificial world and that was occasionally menaced by a predator. Connections could not change in the agent's “lifetime,” so there was no learning in the simulations. Only if the smells of food and predator were hard to distinguish and the fitness reflected time pressures in escaping from the predator did the type of dual processing postulated by LeDoux emerge in the surviving agents. Processing in the “quick and dirty” pathway of the fear system ensured avoidance of both predators and food, but a distinction between food and predator was made only in the long pathway. Elaborate processing inhibited the avoidance reaction and reversed it into an approach reaction to food, but strengthened the avoidance reaction to predators (and more finely tuned the direction of escape). It is suggested that “computational neuroethology” (Beer, 1990) may help constrain reasoning in evolutionary psychology, particularly when applied to specific neurobiological models, and in the future may even generate new hypotheses for cognitive neuroscience.
Visual Selective Behavior Can Be Triggered by a Feed-Forward Process
Authors: VanRullen Rufin , Koch Christof
Published: March 2003

The ventral visual pathway implements object recognition and categorization in a hierarchy of processing areas with neuronal selectivities of increasing complexity. The presence of massive feedback connections within this hierarchy raises the possibility that normal visual processing relies on the use of computational loops. It is not known, however, whether object recognition can be performed at all without such loops (i.e., in a purely feed-forward mode). By analyzing the time course of reaction times in a masked natural scene categorization paradigm, we show that the human visual system can generate selective motor responses based on a single feed-forward pass. We confirm these results using a more constrained letter discrimination task, in which the rapid succession of a target and mask is actually perceived as a distractor. We show that a masked stimulus presented for only 26 msec—and often not consciously perceived—can fully determine the earliest selective motor responses: The neural representations of the stimulus and mask are thus kept separated during a short period corresponding to the feed-forward “sweep.” Therefore, feedback loops do not appear to be “mandatory” for visual processing. Rather, we found that such loops allow the masked stimulus to reverberate in the visual system and affect behavior for nearly 150 msec after the feed-forward sweep.
Enhanced Pitch Sensitivity in Individuals with Autism: A Signal Detection Analysis
Authors: Bonnel Anna , Mottron Laurent , Peretz Isabelle , Trudel Manon , Gallun Erick , Bonnel Anne-Marie
Published: March 2003

Past research has shown a superiority of participants with high-functioning autism over comparison groups in memorizing picture-pitch associations and in detecting pitch changes in melodies. A subset of individuals with autism, known as “musical savants,” is also known to possess absolute pitch. This superiority might be due to an abnormally high sensitivity to fine-grained pitch differences in sounds. To test this hypothesis, psychoacoustic tasks were devised so as to use a signal detection methodology. Participants were all musically untrained and were divided into a group of 12 high-functioning individuals with autism and a group of 12 normally developing individuals. Their task was to judge the pitch of pure tones in a “same-different” discrimination task and in a “high-low” categorization task. In both tasks, the obtained psychometric functions revealed higher pitch sensitivity for subjects with autism, with a more pronounced advantage over control participants in the categorization task. These findings confirm that pitch processing is enhanced in “high-functioning” autism. Superior performance in pitch discrimination and categorization extends previous findings of enhanced visual performance to the auditory domain. Thus, and as predicted by the enhanced perceptual functioning model for peaks of ability in autism (Mottron & Burack, 2001), autistic individuals outperform typically developing population in a variety of low-level perceptual tasks.
Lateralization of Prefrontal Activity during Episodic Memory Retrieval: Evidence for the Production-Monitoring Hypothesis
Authors: Cabeza Roberto , Locantore Jill K. , Anderson Nicole D.
Published: March 2003

We propose a new hypothesis concerning the lateralization of prefrontal cortex (PFC) activity during verbal episodic memory retrieval. The hypothesis states that the left PFC is differentially more involved in semantically guided information production than is the right PFC, and that the right PFC is differentially more involved in monitoring and verification than is the left PFC. This “production-monitoring hypothesis” differs from the existing “systematic-heuristic hypothesis,” which proposes that the left PFC is primarily involved in systematic retrieval operations, and the right PFC in heuristic retrieval operations. To compare the two hypotheses, we measured PFC activity using positron emission tomography (PET) during the performance of four episodic retrieval tasks: stem cued recall, associative cued recall, context recognition (source memory), and item recognition. Recall tasks emphasized production processes, whereas recognition tasks emphasized monitoring processes. Stem cued recall and context-recognition tasks underscored systematic operations, whereas associative cued recall and item-recognition tasks underscored heuristic operations. Consistent with the production-monitoring hypothesis, the left PFC was more activated for recall than for recognition tasks and the right PFC was more activated for recognition than for recall tasks. Inconsistent with the systematic-heuristic hypothesis, the left PFC was more activated for heuristic than for systematic tasks and the right PFC showed the converse result. Additionally, the study yielded activation differences outside the PFC. In agreement with a previous recall/recognition PET study, anterior cingulate, cerebellar, and striatal regions were more activated for recall than for recognition tasks, and the converse occurred for posterior parietal regions. A right medial temporal lobe region was more activated for stem cued recall and context recognition than for associative cued recall and item recognition, possibly reflecting perceptual integration. In sum, the results provide evidence for the production-monitoring hypothesis and clarify the role of different brain regions typically activated in PET and functional magnetic resonance imaging (fMRI) studies of episodic retrieval.
Distinct Patterns of Neural Modulation during the Processing of Conceptual and Syntactic Anomalies
Authors: Kuperberg Gina R. , Holcomb Phillip J. , Sitnikova Tatiana , Greve Douglas , Dale Anders M. , Caplan David
Published: March 2003

The aim of this study was to gain further insights into how the brain distinguishes between meaning and syntax during language comprehension. Participants read and made plausibility judgments on sentences that were plausible, morpho-syntactically anomalous, or pragmatically anomalous. In an event-related potential (ERP) experiment, morphosyntactic and pragmatic violations elicited significant P600 and N400 effects, respectively, replicating previous ERP studies that have established qualitative differences in processing conceptually and syntactic anomalies. Our main focus was a functional magnetic resonance imaging (fMRI) study in which the same subjects read the same sentences presented in the same pseudorandomized sequence while performing the same task as in the ERP experiment. Rapid-presentation event-related fMRI methods allowed us to estimate the hemodynamic response at successive temporal windows as the sentences unfolded word by word, without assumptions about the shape of the underlying response function. Relative to nonviolated sentences, the pragmatic anomalies were associated with an increased hemodynamic response in left temporal and inferior frontal regions and a decreased response in the right medial parietal cortex. Relative to nonviolated sentences, the morphosyntactic anomalies were associated with an increased response in bilateral medial and lateral parietal regions and a decreased response in left temporal and inferior frontal regions. Thus, overlapping neural networks were modulated in opposite directions to the two types of anomaly. These fMRI findings document both qualitative and quantitative differences in how the brain distinguishes between these two types of anomalies. This suggests that morphosyntactic and pragmatic information can be processed in different ways but by the same neural systems.
Aristotelian Piety
Authors: Broadie Sarah
Published: March 2003

Aristotle seems to omit discussing the virtue piety. Such an omission should surprise us. Piety is not covertly dealt with under the more general heading of justice, nor under that of philia. But piety does make a veiled appearance at NE X.8, 1179a22-32. Many interpreters have refused to take this passage seriously, but this is shown to be a mistake.
HASTY, theArabidopsisortholog of exportin 5/MSN5, regulates phase change and morphogenesis
Authors: Bollman Krista M. , Aukerman Milo J. , Park Mee-Yeon , Hunter Christine , Berardini Tanya Z. , Poethig R. Scott
Published: March 2003

Loss-of-function mutations of HASTY (HST) affect many different processes in Arabidopsis development. In addition to reducing the size of both roots and lateral organs of the shoot, hstmutations affect the size of the shoot apical meristem, accelerate vegetative phase change, delay floral induction under short days, adaxialize leaves and carpels, disrupt the phyllotaxis of the inflorescence, and reduce fertility. Double mutant analysis suggests that HST acts in parallel toSQUINT in the regulation of phase change and in parallel toKANADI in the regulation of leaf polarity. Positional cloning demonstrated that HST is the Arabidopsis ortholog of the importin β-like nucleocytoplasmic transport receptors exportin 5in mammals and MSN5 in yeast. Consistent with a potential role in nucleocytoplasmic transport, we found that HST interacts with RAN1 in a yeast two-hybrid assay and that a HST-GUS fusion protein is located at the periphery of the nucleus. HST is one of at least 17 members of the importin-βfamily in Arabidopsis and is the first member of this family shown to have an essential function in plants. The hst loss-of-function phenotype suggests that this protein regulates the nucleocytoplasmic transport of molecules involved in several different morphogenetic pathways, as well as molecules generally required for root and shoot growth.