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PubMed2006

Describing the impact of health research: a Research Impact Framework.

BACKGROUND: Researchers are increasingly required to describe the impact of their work, e.g. in grant proposals, project reports, press releases and research assessment exercises. Specialised impact assessment studies can be difficult to replicate and may require resources and skills not available to individual researchers. Researchers are often hard-pressed to identify and describe research impacts and ad hoc accounts do not facilitate comparison across time or projects. METHODS: The Research Impact Framework was developed by identifying potential areas of health research impact from the research impact assessment literature and based on research assessment criteria, for example, as set out by the UK Research Assessment Exercise panels. A prototype of the framework was used to guide an analysis of the impact of selected research projects at the London School of Hygiene and Tropical Medicine. Additional areas of impact were identified in the process and researchers also provided feedback on which descriptive categories they thought were useful and valid vis-à-vis the nature and impact of their work. RESULTS: We identified four broad areas of impact: I. Research-related impacts; II. Policy impacts; III. Service impacts: health and intersectoral and IV. Societal impacts. Within each of these areas, further descriptive categories were identified. For example, the nature of research impact on policy can be described using the following categorisation, put forward by Weiss: Instrumental use where research findings drive policy-making; Mobilisation of support where research provides support for policy proposals; Conceptual use where research influences the concepts and language of policy deliberations and Redefining/wider influence where research leads to rethinking and changing established practices and beliefs. CONCLUSION: Researchers, while initially sceptical, found that the Research Impact Framework provided prompts and descriptive categories that helped them systematically identify a range of specific and verifiable impacts related to their work (compared to ad hoc approaches they had previously used). The framework could also help researchers think through implementation strategies and identify unintended or harmful effects. The standardised structure of the framework facilitates comparison of research impacts across projects and time, which is useful from analytical, management and assessment perspectives.

Evaluation Studies as Topic↗

PubMed1986

Characteristics of verbal impairment in closed head injured patients.

One hundred twenty-five closed head injured postcoma patients in a rehabilitation medicine center underwent standardized aphasia tests to determine the presence and nature of verbal deficits. Mean time since injury for the group was 45 weeks. All patients evidenced linguistic impairment which was only apparent on testing, not in conversation. The population fell into three relatively equally sized groups: classic aphasia, dysarthria accompanied by linguistic deficits, and "subclinical" aphasic deficits. No patient with a history of coma after closed head injury was spared defective performance on selected language tasks. The patient groups reflected a severity continuum ranging from aphasia, the most severely impaired group, to the least impaired, the subclinical aphasia group. Further, closed head injured patients with a history of coma who manifest motor speech impairment (dysarthria) also manifest linguistic processing deficits. The study results suggest that linguistic functions are particularly vulnerable in severe head injury.

Adolescent↗

PubMed1998

Towards cooperative patient management through organizational and medical ontologies.

Within knowledge and data engineering a new research paradigm is emerging based on the Multi-Agent System (MAS) architectural framework, allowing human and software agents to interoperate and thus cooperate within common application areas. In such a framework, knowledgeable agents of heterogeneous nature, that possess diverse but at least partially compatible or inter-translatable conceptual views, or ontologies, modeling both their own expertise and the external environment, make somehow available their information resources or problem-solving abilities for cooperative processes addressing the construction of a new agent or the achievement of some common goal through a correlated execution of tasks. In this paper, we restrict our analysis to the case of an organization of cognitive agents, illustrated with examples from a prototypical healthcare MAS, that is, a so-called Distributed Healthcare Information System (D-HIS). The prototype makes use of an ontological library written in the standard language Ontolingua. An ongoing application of the methodology to the main problem of Clinical Practice Guidelines (GLs) computer-based dissemination and enforcement is described.

Artificial Intelligence↗

PubMed2003

Distinct brain representations for early and late learned words.

Recently there has been a renewed interest in cognitive psychology on the effects of the age of word acquisition (AoA) on lexical processing. In particular, it is currently unclear whether AoA or word frequency are better predictors of word recognition. To date no study has investigated the neural bases of the AoA effect or attempted to dissociate it from word frequency. We report a visual and an auditory event-related fMRI experiment investigating the influence of AoA and word frequency on neural activity, and show that AoA modulates brain areas that are not influenced by word frequency. The precuneus was activated for early learned words across auditory and visual presentation modalities. Additional activity in the auditory cortex was observed specifically for the reading of early acquired words. Late learned words, in contrast, led to a selective activation increase in lateral inferior frontal areas. These findings support models that suggest that early and late learned words are represented differently in the brain. They further allow to specify the nature of the representational differences, namely that early learned words are represented in the brain in a more sensory manner than late learned words.

Adolescent↗

PubMed1998

Functional disruption in the organization of the brain for reading in dyslexia.

Learning to read requires an awareness that spoken words can be decomposed into the phonologic constituents that the alphabetic characters represent. Such phonologic awareness is characteristically lacking in dyslexic readers who, therefore, have difficulty mapping the alphabetic characters onto the spoken word. To find the location and extent of the functional disruption in neural systems that underlies this impairment, we used functional magnetic resonance imaging to compare brain activation patterns in dyslexic and nonimpaired subjects as they performed tasks that made progressively greater demands on phonologic analysis. Brain activation patterns differed significantly between the groups with dyslexic readers showing relative underactivation in posterior regions (Wernicke's area, the angular gyrus, and striate cortex) and relative overactivation in an anterior region (inferior frontal gyrus). These results support a conclusion that the impairment in dyslexia is phonologic in nature and that these brain activation patterns may provide a neural signature for this impairment.

Brain↗

PubMed1981

Can practice result in the ability to divide attention between two complex language tasks? Comment on Hirst et al.

Several studies at the beginning of the century demonstrated that extensive practice enables subjects to adequately perform two language tasks presented simultaneously. This result was recently confirmed by Hirst et al. These authors concluded that practice eventually results in the ability to attend to both tasks simultaneously, since evidence shows that both primary and secondary tasks are processed semantically. Two arguments are presented showing that this conclusion is questionable. First, the processing of category and semantic relationships between words and sentences can be automatic. Second, the conclusion that true divided attention is possible after training can only be made if evaluated against several criteria of automatic performance. Hirst et al. reported data pertaining to only one of these criteria. Therefore this study is inconclusive and fails to elucidate the nature of the changes in processing that occur.

Attention↗

PubMed2002

Intelligibility of modified speech for young listeners with normal and impaired hearing.

Exposure to modified speech has been shown to benefit children with language-learning impairments with respect to their language skills (M. M. Merzenich et al., 1998; P. Tallal et al., 1996). In the study by Tallal and colleagues, the speech modification consisted of both slowing down and amplifying fast, transitional elements of speech. In this study, we examined whether the benefits of modified speech could be extended to provide intelligibility improvements for children with severe-to-profound hearing impairment who wear sensory aids. In addition, the separate effects on intelligibility of slowing down and amplifying speech were evaluated. Two groups of listeners were employed: 8 severe-to-profoundly hearing-impaired children and 5 children with normal hearing. Four speech-processing conditions were tested: (1) natural, unprocessed speech; (2) envelope-amplified speech; (3) slowed speech; and (4) both slowed and envelope-amplified speech. For each condition, three types of speech materials were used: words in sentences, isolated words, and syllable contrasts. To degrade the performance of the normal-hearing children, all testing was completed with a noise background. Results from the hearing-impaired children showed that all varieties of modified speech yielded either equivalent or poorer intelligibility than unprocessed speech. For words in sentences and isolated words, the slowing-down of speech had no effect on intelligibility scores whereas envelope amplification, both alone and combined with slowing-down, yielded significantly lower scores. Intelligibility results from normal-hearing children listening in noise were somewhat similar to those from hearing-impaired children. For isolated words, the slowing-down of speech had no effect on intelligibility whereas envelope amplification degraded intelligibility. For both subject groups, speech processing had no statistically significant effect on syllable discrimination. In summary, without extensive exposure to the speech processing conditions, children with impaired hearing and children with normal hearing listening in noise received no intelligibility advantage from either slowed speech or envelope-amplified speech.

Audiometry, Pure-Tone↗

PubMedDate not supplied

[Speech therapy for children with cleft lips and palates. I. Basic linguistic considerations].

According to several basic principals of hermeneutic theory (theory of understanding natural languages) we describe the major fields of language acquisition in which anomalies of CPL children often can be found. Besides phonation and articulation there are morphological, psychomotoric, onomatopoetic, and isotopic disorders. Also a delay of understanding by listening is often observed. Additionally some cofactors in psychodynamics of the family have to be respected. Defense mechanisms, somatization, and social symptomatization are described. Some examples from statistics and experimental psycholinguistics show, that a diagnosis of early language acquisition can't be found by comparing means (naive model of diagnosis). We show how to find out the multiple covariance of early language acquisition tests with the control groups. A final case study shows a typical process of CLP children's language acquisition.

Child↗

PubMed2005

Iatrogenic harm caused by diagnostic errors in fibrodysplasia ossificans progressiva.

BACKGROUND: Little is known about diagnostic errors for a disease worldwide. Such errors could alter the disease's natural history, especially if unwarranted interventions cause irreversible harm. Fibrodysplasia ossificans progressiva (FOP), a rare, autosomal dominant genetic disease characterized by episodes of permanent heterotopic ossification of soft tissues, occurs worldwide without racial, ethnic, or geographic predilection. There is no effective treatment, and soft-tissue trauma (eg, biopsies, surgical procedures, intramuscular injections, or mandibular blocks for dental procedures) and viral illnesses are likely to induce episodes of rapidly progressive heterotopic ossification, with resultant permanent loss of motion in the affected area. Accurate diagnoses can be made on the basis of the clinical findings of tumor-like swellings on the head, neck, back, or shoulders and characteristic short great toes with hallux valgus-like malformations and missing interphalangeal joints. On the basis of conversations with numerous individuals with FOP, we suspected that diagnostic errors with FOP are common and often associated with inappropriate and harmful diagnostic and therapeutic procedures. OBJECTIVE: To document the frequency of diagnostic errors with FOP and complications resulting from misdiagnoses. DESIGN: A questionnaire requesting detailed demographic, diagnostic, and treatment information was sent to all 269 patient-members of the International FOP Association; the sampling frame included > 90% of all known FOP patients worldwide. We received 138 replies (51% response) from 25 countries. The age range was 2 to 71 years; there were 78 female subjects and 60 male subjects. In addition, to assess the availability and adequacy of information about FOP, we reviewed 184 English-language textbooks in relevant specialties published in the past 20 years. RESULTS: Incorrect diagnoses were given initially to 87% of individuals with FOP. This astonishing rate of diagnostic errors occurred worldwide, regardless of ethnicity, geographic background, or misdiagnosing physician's specialty. The most common incorrect diagnosis was cancer (32%). The mean period from the onset of symptoms to correct diagnosis was 4.1 years, and the median number of physicians consulted before the correct diagnosis of FOP was 6. For 67% of patients, unnecessary invasive procedures (biopsies) were performed; 68% received inappropriate therapies. Forty-nine percent of all patients reported permanent loss of mobility resulting from invasive medical interventions that caused posttraumatic ossification. Notably, only 8% of the 184 textbooks that were reviewed contained adequate descriptions of FOP, including the caution that trauma can accelerate the process of heterotopic ossification. CONCLUSIONS: Diagnostic errors and inappropriate medical procedures, which may lead to permanent harm, can alter the natural history of a disease. In FOP, the astonishing rates of diagnostic errors and inappropriate invasive medical procedures likely result from lack of physician awareness because of failure of information transfer.

Adolescent↗

PubMed2007

Representing word meaning and order information in a composite holographic lexicon.

The authors present a computational model that builds a holographic lexicon representing both word meaning and word order from unsupervised experience with natural language. The model uses simple convolution and superposition mechanisms (cf. B. B. Murdock, 1982) to learn distributed holographic representations for words. The structure of the resulting lexicon can account for empirical data from classic experiments studying semantic typicality, categorization, priming, and semantic constraint in sentence completions. Furthermore, order information can be retrieved from the holographic representations, allowing the model to account for limited word transitions without the need for built-in transition rules. The model demonstrates that a broad range of psychological data can be accounted for directly from the structure of lexical representations learned in this way, without the need for complexity to be built into either the processing mechanisms or the representations. The holographic representations are an appropriate knowledge representation to be used by higher order models of language comprehension, relieving the complexity required at the higher level.

Association↗

PubMed1980

Neuropsychological deficits in Cushing's syndrome.

In contrast to well documented reports of medical symptoms in Cushing's syndrome (an endocrine disorder with the hallmark of corticoid overproduction), vague and infrequent references to associated mental changes reflect the subjective nature of previous clinical studies of psychological symptoms. This report presents neuropsychological test findings of 35 Cushing's syndrome patients before initiation of medical therapy, and documents the frequency, nature, and severity of deficits. Performances on the Michigan Neuropsychological Test Battery revealed equivocal or no signs of neuropsychological deficits in 13 patients. Ten other patients had few and mild deficits, eight had moderate and more frequent signs of impairment, and four had frequent and marked deficits in language and nonlanguage tests of higher (cognitive) and/or lower (sensory and/or motor) level cerebral functions. The findings thus indicate varying degrees of diffuse bilateral cerebral dysfunction in two thirds of this population. Impairment was more frequent and severe in nonverbal visual-ideational and visual memory functions. This pattern of deficits is similar to that in patients with other types of diffuse bilateral neuropathological processes such as toxicity, anoxia, and infectious cerebral disorders.

Adult↗

PubMed2001

Syntactic and semantic processing in the healthy and aphasic human brain.

A syntactic and a semantic task were performed by German-speaking healthy subjects and aphasics with lesions in the dominant left hemisphere. In both tasks, pictures of objects were presented that had to be classified by pressing buttons. The classification was into grammatical gender in the syntactic task (masculine or feminine gender?) and into semantic category in the semantic task (man- or nature made?). Behavioral data revealed a significant Group by Task interaction, with aphasics showing most pronounced problems with syntax. Brain event-related potentials 300-600 ms following picture onset showed different task-dependent laterality patterns in the two groups. In controls, the syntax task induced a left-lateralized negative ERP, whereas the semantic task produced more symmetric responses over the hemispheres. The opposite was the case in the patients, where, paradoxically, stronger laterality of physiological brain responses emerged in the semantic task than in the syntactic task. We interpret these data based on neuro-psycholinguistic models of word processing and current theories about the roles of the hemispheres in language recovery.

Adult↗

PubMed2002

Are seizures harmful: what can we learn from animal models?

Epilepsy is a brain disease that requires distributed neuronal networks for its expression. Several characteristics of epilepsy, including its natural history, the latency between an initial insult and the first manifestation of seizures, the complex interaction of seizures with development as a function of developmental stage, the modulating effect of systemic physiological responses, and the fact that seizures are ultimately defined by a combination of electrical and behavioral criteria all suggest that epilepsy should ideally be studied in an intact whole animal preparation. Such preparations offer the ability to study acute and chronic changes in brain structure and function after single or repeated seizures. Animal models have major limitations, however, including strain specificity, difficulty in isolating potentially confounding variables, a relative lack of accessible higher cortical functions, such as language and abstract processing, and shorter lifespans that may be insufficient to allow the complete expression of seizure-related injury. Information we have learned from animal studies includes a broad understanding of the chemical, molecular and anatomic consequences of seizures, including their temporal and spatial relationships to each other, and information on the consequences of seizures as a function of development. Recent studies have cast light on potential mechanisms of resistance to seizure-induced injury in the developing brain. In the future, we can anticipate that animal models will continue to be useful, especially when whole-animal preparations are used to generate material for detailed in vitro examination.

Animals↗

PubMed2003

Electrophysiological correlates of prosody and punctuation.

Psycholinguistic models of sentence parsing are primarily based on reading rather than auditory processing data. Moreover, both prosodic information and its potential orthographic equivalent, i.e., punctuation, have been largely ignored until recently. The unavailability of experimental online methods is one likely reason for this neglect. Here I give an overview of six event-related brain potential (ERP) studies demonstrating that the processing of both prosodic boundaries in natural speech and commas during silent reading can determine syntax parsing immediately. In ERPs, speech boundaries and commas reliably elicit a similar online brain response, termed the Closure Positive Shift (CPS). This finding points to a common mechanism, suggesting that commas serve as visual triggers for covert phonological phrasing. Alternative CPS accounts are tested and the relationship between the CPS and other ERP components, including the P600/SPS, is addressed.

Adolescent↗

PubMed1998

When theories of speech meet the real world.

Two theories of speech--one quite conventional, the other much less so--account very differently for the biological advantage of speech over writing/reading. The guiding assumption of the more conventional theory is that the elements of speech are sounds, and that these are served by processes of motor control and auditory perception that are in no way specialized for language. Accordingly, there must be a cognitive stage, beyond action and perception, where the motor and auditory representations are somehow invested with linguistic significance. On the conventional view, then, the sounds of speech are just like the letters of the alphabet. Neither has more than an arbitrary relation to language, hence the difference between them is trivially a matter of which of the equally large gaps between signal and message needs to be bridged. On the less conventional theory, the ultimate constituents of speech are not sounds, but articulatory gestures. Having evolved exclusively in the service of language, they form a natural class, a phonetic modality. Being phonetic to begin with, they do not require to be made so by cognitive translation. And that, very simply, is the advantage of speech over writing/reading. Speech has the corollary advantage that it is managed by a module biologically adapted to circumvent limitations of tongue and ear by automatically coarticulating the constituent gestures and coping with the complex acoustic consequences. But a result is that awareness of phonetic structure is not normally a product of having learned to speak: The module "spells"--that is, sequences phonetic segments--for the speaker and recovers the segments for the listener, leaving both in the dark about the way that is done; the gestural representations are immediately phonetic in nature, precluding the cognitive translation that would bring them to notice; and coarticulation destroys all correspondence in segmentation between acoustic and phonetic structures, making it that much harder to demonstrate the alphabetic nature of speech at the acoustic surface. Accordingly, special difficulty in becoming literate might be caused by a weakness of the phonetic module, for that would produce primary representations of a fragile sort, with the consequence that they would be that much harder to bring to awareness--as is required if they are to serve writers and readers as the units of an alphabetic script--and also that much less able to bear the weight of working memory.

Awareness↗

PubMed2004

General conditions for predictivity in learning theory.

Developing theoretical foundations for learning is a key step towards understanding intelligence. 'Learning from examples' is a paradigm in which systems (natural or artificial) learn a functional relationship from a training set of examples. Within this paradigm, a learning algorithm is a map from the space of training sets to the hypothesis space of possible functional solutions. A central question for the theory is to determine conditions under which a learning algorithm will generalize from its finite training set to novel examples. A milestone in learning theory was a characterization of conditions on the hypothesis space that ensure generalization for the natural class of empirical risk minimization (ERM) learning algorithms that are based on minimizing the error on the training set. Here we provide conditions for generalization in terms of a precise stability property of the learning process: when the training set is perturbed by deleting one example, the learned hypothesis does not change much. This stability property stipulates conditions on the learning map rather than on the hypothesis space, subsumes the classical theory for ERM algorithms, and is applicable to more general algorithms. The surprising connection between stability and predictivity has implications for the foundations of learning theory and for the design of novel algorithms, and provides insights into problems as diverse as language learning and inverse problems in physics and engineering.

Algorithms↗

PubMed1996

'Identities ascertained': British ophthalmology in the first half of the nineteenth century.

The paper takes its cue from the work on specialization and American ophthalmology by George Rosen (1944). Where Rosen's account was inspired by sociology, this paper gives a non-teleological account of medical specialization through a cultural history of ophthalmology. The cultural nature of the ophthalmic epidemics motivated practitioners to study the eye in earnest. These practitioners had to surmount obstacles intrinsic to the medical culture: the division between physicians and surgeons, hostility to specialisms, and the association with quackery. Practitioners justified their interests through the management of history, the association with philanthropy, and the construction of a father-figure. New interest in the eye was partly legitimated by the use of existing discourses, both philosophical and religious, that offered practitioners motivating languages to describe their practice. Specialization was effected through varying combinations of elements: emotional and intellectual investment in the eye, the advocacy of further research, and the explicit prosecution of specialties. The process depended upon generalist enthusiasm for the eye, and specialists' championing of generalist medicine. Specialization is a continual cultural process in a constant balancing act with the generalist tendency in medicine.

History, 19th Century↗

PubMed1999

Folklore associated with dying in the west of Ireland.

The warm welcome for modern advances in the care of the dying should not exclude the past in which there is much to be learned from the skills of our ancestors. A bilingual two-year qualitative research project into traditions associated with dying and death was undertaken. Research began in the archives available in the internationally recognized university folklore departments of Ireland and Scotland. This was augmented by 40 indepth personal interviews with Gaelic- and English-speaking residents in rural communities of both countries, recalling local customs and practices in the care of the dying. This paper reports the Irish experience; the collection of data in Scotland continues. From this study, several main themes emerged. Death was seen and accepted as a natural continuation of life, simply a step into the spirit world. In view of people's oneness with nature and the spiritual world, death was not to be feared. Traditions were unique to each area even down to the precise number of candles used at the sickbed. People understood the signs and symptoms of dying and were skilled in alleviating the distress of both relatives and the dying; and, in this, language was important in capturing and expressing the philosophy of these people. The acceptance of death as the one truism of life was facilitated by the strong faith and prayer of people for whom, in the celebration of death, humour was never far away. In their grief, the community was supported by the loose formality of the wake (torramh), funeral procession, keening (caoineadh) and music. In all these, the men and women of the community and its leaders had distinct and respected roles to play.

Attitude to Death↗