SEARCH · PubMed Health

Results for “Scoring framework”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources

PubMed1999

The relationship of dysfunctional attitudes to personality in depressed patients.

AIM: To examine the relationship between dysfunctional attitudes and personality in depressed patients. METHOD: One hundred depressed patients completed both the Dysfunctional Attitudes Scale (DAS) and the Temperament and Character Inventory (TCI). RESULTS: Scores on the DAS correlated with duration of depression, age of onset of depression, age, harm avoidance and self-directedness. In a multiple regression analysis three measures explained 45% of the DAS score. These were duration of depression, reward dependence and self-directedness. In both the univariate analyses and multiple regression the strongest predictor of dysfunctional attitudes was the character dimension of self-directedness. CONCLUSION: The character dimension of self-directedness in the TCI which assesses an individuals' self-concept, relates highly with the dysfunctional attitudes score on the DAS. Given that the TCI assesses personality within a broader framework of a psychobiologic and developmental model, self-directedness may have a wider application as a measure of self-concept than the DAS.

Adult↗

PubMed2002

Development and validation of health-related quality of life measures for the knee.

Health-related quality of life is an individual's perception of his or her health and it is an important outcome measure for clinical research in orthopaedics. For clinical outcomes research related to the knee, measures of health-related quality of life should consider disability imposed by impairment of the knee. Health-related quality of life is measured by assembling questions to represent the construct of health-related quality of life. Validation of health-related quality of life requires evidence to support the interpretation and usefulness of the resulting score. The purpose of the current paper was to provide readers with a framework for identifying and selecting relevant clinical outcome measures that should be considered when designing clinical research related to the knee. The need to include reliable, valid, and responsive measures of health-related quality of life in clinical outcomes research related to the knee was discussed and the process for developing such measures was shown by describing the process used to develop the International Knee Documentation Committee Subjective Knee Form.

Biomechanical Phenomena↗

PubMed2006

Semi-supervised discovery of differential genes.

BACKGROUND: Various statistical scores have been proposed for evaluating the significance of genes that may exhibit differential expression between two or more controlled conditions. However, in many clinical studies to detect clinical marker genes for example, the conditions have not necessarily been controlled well, thus condition labels are sometimes hard to obtain due to physical, financial, and time costs. In such a situation, we can consider an unsupervised case where labels are not available or a semi-supervised case where labels are available for a part of the whole sample set, rather than a well-studied supervised case where all samples have their labels. RESULTS: We assume a latent variable model for the expression of active genes and apply the optimal discovery procedure (ODP) proposed by Storey (2005) to the model. Our latent variable model allows gene significance scores to be applied to unsupervised and semi-supervised cases. The ODP framework improves detectability by sharing the estimated parameters of null and alternative models of multiple tests over multiple genes. A theoretical consideration leads to two different interpretations of the latent variable, i.e., it only implicitly affects the alternative model through the model parameters, or it is explicitly included in the alternative model, so that the interpretations correspond to two different implementations of ODP. By comparing the two implementations through experiments with simulation data, we have found that sharing the latent variable estimation is effective for increasing the detectability of truly active genes. We also show that the unsupervised and semi-supervised rating of genes, which takes into account the samples without condition labels, can improve detection of active genes in real gene discovery problems. CONCLUSION: The experimental results indicate that the ODP framework is effective for hypotheses including latent variables and is further improved by sharing the estimations of hidden variables over multiple tests.

Algorithms↗

PubMed2006

Evaluating the performance of species richness estimators: sensitivity to sample grain size.

1. Fifteen species richness estimators (three asymptotic based on species accumulation curves, 11 nonparametric, and one based in the species-area relationship) were compared by examining their performance in estimating the total species richness of epigean arthropods in the Azorean Laurisilva forests. Data obtained with standardized sampling of 78 transects in natural forest remnants of five islands were aggregated in seven different grains (i.e. ways of defining a single sample): islands, natural areas, transects, pairs of traps, traps, database records and individuals to assess the effect of using different sampling units on species richness estimations. 2. Estimated species richness scores depended both on the estimator considered and on the grain size used to aggregate data. However, several estimators (ACE, Chao 1, Jackknifel and 2 and Bootstrap) were precise in spite of grain variations. Weibull and several recent estimators [proposed by Rosenzweig et al. (Conservation Biology, 2003, 17, 864-874), and Ugland et al. (Journal of Animal Ecology, 2003, 72, 888-897)] performed poorly. 3. Estimations developed using the smaller grain sizes (pair of traps, traps, records and individuals) presented similar scores in a number of estimators (the above-mentioned plus ICE, Chao2, Michaelis-Menten, Negative Exponential and Clench). The estimations from those four sample sizes were also highly correlated. 4. Contrary to other studies, we conclude that most species richness estimators may be useful in biodiversity studies. Owing to their inherent formulas, several nonparametric and asymptotic estimators present insensitivity to differences in the way the samples are aggregated. Thus, they could be used to compare species richness scores obtained from different sampling strategies. Our results also point out that species richness estimations coming from small grain sizes can be directly compared and other estimators could give more precise results in those cases. We propose a decision framework based on our results and on the literature to assess which estimator should be used to compare species richness scores of different sites, depending on the grain size of the original data, and of the kind of data available (species occurrence or abundance data).

Animals↗

PubMed2004

A molecular linkage map with associated QTLs from a hulless x covered spring oat population.

In spring-type oat ( Avena sativa L.), quantitative trait loci (QTLs) detected in adapted populations may have the greatest potential for improving germplasm via marker-assisted selection. An F(6) recombinant inbred (RI) population was developed from a cross between two Canadian spring oat varieties: 'Terra', a hulless line, and 'Marion', an elite covered-seeded line. A molecular linkage map was generated using 430 AFLP, RFLP, RAPD, SCAR, and phenotypic markers scored on 101 RI lines. This map was refined by selecting a robust set of 124 framework markers that mapped to 35 linkage groups and contained 35 unlinked loci. One hundred one lines grown in up to 13 field environments in Canada and the United States between 1992 and 1997 were evaluated for 16 agronomic, kernel, and chemical composition traits. QTLs were localized using three detection methods with an experiment-wide error rate of approximately 0.05 for each trait. In total, 34 main-effect QTLs affecting the following traits were identified: heading date, plant height, lodging, visual score, grain yield, kernel weight, milling yield, test weight, thin and plump kernels, groat beta-glucan concentration, oil concentration, and protein. Several of these correspond to QTLs in homologous or homoeologous regions reported in other oat QTL studies. Twenty-four QTL-by-environment interactions and three epistatic interactions were also detected. The locus controlling the covered/hulless character ( N1) affected most of the traits measured in this study. Additive QTL models with N1 as a covariate were superior to models based on separate covered and hulless sub-populations. This approach is recommended for other populations segregating for major genes. Marker-trait associations identified in this study have considerable potential for use in marker-assisted selection strategies to improve traits within spring oat breeding programs.

Agriculture↗

PubMed1986

Assessment of neurological 'soft signs' in adolescents: reliability studies.

The validity and reliability of a scoring system for 'neurological soft signs' in teenagers was assessed. Six scales were adapted and fitted into the framework of a conventional neurological examination. The following emerged: each of the three multi-item scales had high internal consistency; inter-rater agreement on mirror movements of 'live' subjects was satisfactory; ratings of videotapes agreed among examiners for mirror movements and dysdiadochokinesis but not for choreiform movements; data-based cut-off scores defining present vs. absent were congruent with the ratings of outside neurologists; and each examiner was consistent in rating mirror movements and rapid alternating movements from videotapes over several months.

Adolescent↗

PubMed2006

Managing, profiling and analyzing a library of 2.6 million compounds gathered from 32 chemical providers.

The data for 3.8 million compounds from structural databases of 32 providers were gathered and stored in a single chemical database. Duplicates are removed using the IUPAC International Chemical Identifier. After this, 2.6 million compounds remain. Each database and the final one were studied in term of uniqueness, diversity, frameworks, 'drug-like' and 'lead-like' properties. This study also shows that there are more than 87 000 frameworks in the database. It contains 2.1 million 'drug-like' molecules among which, more than one million are 'lead-like'. This study has been carried out using 'ScreeningAssistant', a software dedicated to chemical databases management and screening sets generation. Compounds are stored in a MySQL database and all the operations on this database are carried out by Java code. The druglikeness and leadlikeness are estimated with 'in-house' scores using functions to estimate convenience to properties; unicity using the InChI code and diversity using molecular frameworks and fingerprints. The software has been conceived in order to facilitate the update of the database. 'ScreeningAssistant' is freely available under the GPL license.

Combinatorial Chemistry Techniques↗

PubMed2026

SeqQC-former: A sequence-quality fusion framework for QC-aware review prioritization of candidate somatic SNVs in cancer genomics.

The accurate prioritization of candidate somatic single-nucleotide variants (SNVs) remains a challenge due to the substantial variability in sequencing quality across genomic loci. SeqQC-Former is a sequence-quality fusion framework that integrates the local nucleotide context with read-level quality-control (QC) covariates derived from matched tumor-normal sequencing data. This integration generates QC-aware prioritization scores for the downstream review of candidate variants. Unlike conventional variant callers, SeqQC-Former is designed not to infer biological truth but to support post-calling review and prioritization under heterogeneous sequencing conditions. The framework was trained and evaluated on a SEQC2-derived dataset comprising 89,447 candidate loci, including 1378 positive and 88,069 negative loci. In chromosome-held-out validation, which aims to reduce potential genomic-position leakage, SeqQC-Former demonstrated strong discrimination (AUROC = 0.9479; AUPRC = 0.9448), indicating good generalization to previously unseen chromosomes. Given that the SEQC2-derived labels contain QC-associated information; these results should be interpreted as an evaluation of QC-aware prioritization capability rather than an independent validation of biological variant correctness. Ablation analyses revealed that structured QC covariates provided the dominant predictive signal under the current SEQC2-derived labeling regime. SeqQC-Former achieved a significantly higher AUROC than classical machine-learning baselines, as determined by DeLong's test (p < 0.01). Application to 53,164 glioblastoma variants demonstrated that external predictions were sensitive to QC scaling and threshold selection, underscoring that model outputs should be interpreted as QC-dependent prioritization scores rather than calibrated probabilities or definitive biological classifications. Overall, SeqQC-Former offers a reproducible post-calling QC-aware prioritization framework for large-scale somatic SNV review and underscores the importance of explicitly modeling sequencing-quality information when interpreting structured cancer genomics datasets.

Humans↗

PubMed1992

The contribution of constructional accuracy and organizational strategy to nonverbal recall in schizophrenia and chronic alcoholism.

The Rey-Osterrieth complex figure was used to assess the separate influences of the constructional accuracy and the organizational strategy employed while copying the figure on the later, incidental recall of the figure. We tested a model, which hypothesized that subjects who copied the main framework of the figure holistically would be more likely to achieve good copy accuracy scores and to reproduce the figure more accurately at recall than subjects who used a piecemeal approach during copy. Subjects included 68 detoxified, chronic alcoholics (ALC), 28 patients with schizophrenia (SZ), and 69 normal control subjects (NCS). The results showed that the ALC and the SZ groups, on average, had lower accuracy and strategy scores at copy than did the NCS group, and furthermore, that the combined contributions of copy accuracy and copy strategy accounted for group differences at recall. A path analysis revealed that, for all three groups, copy strategy had a significant direct effect on copy accuracy. Moreover, copy accuracy and copy strategy made independent contributions to recall accuracy within the ALC and NCS groups; by contrast, within the SZ group, copy strategy made an independent contribution to recall performance but copy accuracy did not. These results suggest that (1) organizational strategy can influence constructional accuracy at both copy and recall; (2) copy accuracy and strategy have the potential to influence recall independently; and (3) the recall deficit in ALC could be attributed to abnormalities in both accuracy and strategy at copy, whereas in SZ it could be attributed only to strategy abnormalities. The deficits observed on the complex figure test in the ALC and SZ were primarily nonmnemonic and were related to ability in figure construction and organizational strategy.

Adult↗

PubMed2006

[Malnutrition in pediatric oncology: prevalence and screening].

UNLABELLED: Algorithms for nutritional pediatric support have been proposed in a French national nutritional framework program. However, they are not specific for oncology. With the pediatric nutritional risk score (PNRS) all children with cancer have a high risk of malnutrition, but a systematic nutritional support is not possible for all of them. AIM: Estimation of malnutrition prevalence and identification of predictive factors of major weight loss during treatment defined by a weight loss more than 5% within 1 month, 7.5% within 3 months, 10% within 6 months. POPULATION AND METHODS: This historical study included children registered with a solid tumor in 2002 in an oncology pediatric unit. Data collected at diagnosis were weight, height, PNRS, the Lansky functional score, tumor type. Furthermore weight, height, and major weight loss were collected at each cure of chemotherapy and during evolution. Malnutrition at diagnosis was defined using the weight for height ratio. Relations between major weight loss and risks factors were estimated using logistic regression. RESULTS: Seventy children were included, 16 (22.9%) were malnourished at admission. During chemotherapy, 29 (41.4%) children experienced a major weight loss. Odds ratio of those who were malnourished at diagnosis was not significantly higher in comparison to well-nourished children. Children with a high risk of malnutrition are those affected by Ewing tumor, B lymphom, head and neck localisations, osteosarcomas, metastatic cancers, or cancers treated by high dose chemotherapy with stem cell rescue. For these 29 (41.4%) children the major weight loss odds ratio was 5.9 [IC95% 2.0-16.7]. CONCLUSION: Taking into account others factors with items of PNRS allows to screen children with an higher risk of a major weight loss during treatment and to enhance nutritional care plan for them.

Adolescent↗

PubMed2006

Measuring improved targeting of health interventions to the poor in the context of a community-randomised trial in rural India.

In spite of growing interest in socioeconomic differentials in health outcomes and access to health services, little has been written about methodologies for assessing the impact of equity-enhancing policies or programs. This paper describes three methodological challenges involved in designing a randomised trial with an equity outcome, and how these were met in a trial of alternative strategies to improving the uptake of benefits of a health insurance scheme among its poorest members. The Vimo SEWA trial is nested within a community-based insurance scheme in rural India. While conducting this trial, three methodological problems were encountered: (i) measuring poverty (or "wealth", or "socioeconomic status") (ii) assessing beneficiaries against an appropriate reference standard population and (iii) settling on an appropriate equity measure as an outcome indicator. These problems are likely to arise in any policy or program assessment that has an equity outcome. In the Vimo SEWA trial, the socioeconomic status of beneficiaries (claimants) is assessed relative to that of all scheme members living in same sub-district by applying a rapid assessment questionnaire--which reduces to an integrated index of socioeconomic status--to both a random sample of members in each sub-district, and to all claimants. The results are used to estimate the full distribution of socioeconomic status of members in each sub-district, with each member given a rank score between 0 and 100. Interpolation is used to estimate the rank scores of claimants relative to the membership base. The primary outcome measure for the trial is the mean socioeconomic rank score of claimants. In developing country settings, using an index of socioeconomic status is simpler than assessing household income or the value of household consumption. It is also relatively straightforward to compare the socioeconomic status of health program beneficiaries with a relevant reference population, although two independent surveys are required. Expressing relative wealth on a scale from zero to 100 is conceptually appealing, and the mean value of this rank score provides an equity-specific outcome measure readily integrated into the usual analytic framework for cluster-randomised trials.

Developing Countries↗

PubMed2006

Validating the bipolar spectrum in the French National EPIDEP Study: overview of the phenomenology and relative prevalence of its clinical prototypes.

BACKGROUND: Few studies have been undertaken to ascertain the feasibility of using the bipolar (BP) spectrum in clinical practice. The only systematic national study is the French EPIDEP Study of consecutive inpatients and outpatients presenting with major depressive episodes (MDE). The protocol was developed in 1994 and implemented in 1995; publication of its first data began in 1998. This report provides the complete data set of the EPIDEP. METHODS: Forty-eight psychiatrists, practicing in 15 sites in four regions of France (Paris, Besançon, Bordeaux and Marseille), were all trained on a common protocol based on DSM-IV criteria for MDE (n=537) subdivided into BP-I (history of mania), BP-II (history of hypomania), as well as extended definitions of the "softer spectrum" beyond BP-I and BP-II. Measures tapping into this spectrum included the Hypomania Checklist (HCA), the cyclothymic (CT), depressive (DT) and hyperthymic (HT) temperament scales. These measures and course permitted post-hoc assignment of MDE in the bipolar spectrum, based in part on the Akiskal, H.S., Pinto, O., 1999. [The evolving bipolar spectrum: Prototypes I, II, III, IV. Psychiatr. Clin. North Am. 22, 517-534] proposal: depression with history of spontaneous hypomanic episodes (DSM-IV, BP-II), cyclothymic depressions (BP-II(1/2)), antidepressant-associated hypomania (BP-III) and hyperthymic depressions (BP-IV). < > was thereby limited to an exclusion diagnosis for the remainder of MDE. LIMITATION: In the clinical setting, psychiatrists cannot be entirely blind to the observations in the various clinical evaluations and instruments. However, the systematic multisite collection of such data tended to minimize any such biases. RESULTS: After excluding patients lost to follow-up, among 493 presenting with MDE with complete data files, the BP-II rate was estimated at index at 20%; 1 month later, systematic probing for hypomania doubled the rate of BP-II to 39%. The comparison between BP-II and UP showed differential phenomenology, such as hypersomnia, increased psychomotor activation, guilt feelings and suicidal thoughts in BP-II. Related data demonstrated the importance of CT in further qualifying of MDE to define a distinct, more severe ("darker") BP-II(1/2) variant of BP-II. Moreover, BP-III, arising from DT and associated with antidepressants, emerged as a valid soft bipolar variant on the basis of the phenomenology of hypomania and bipolar family history. Finally, we found preliminary evidence for the inclusion of BP-IV into the bipolar spectrum, its total hypomania score falling intermediate between BP-II and strict UP. Using this broader diagnostic framework, the bipolar spectrum (the combined "hard" BP-I phenotype, BP-II and the soft spectrum) accounted for 65% of MDE. CONCLUSION: The EPIDEP study achieved its objectives by demonstrating the feasibility of identifying the bipolar spectrum at a national level, and refining its phenomenology through rigorous clinical characterization and validation of bipolar spectrum subtypes, including MDE with brief hypomanias, cyclothymia and hyperthymia. The spectrum accounted for two out of three MDE, making "strict UP" less prevalent than BP as redefined herein. Our findings were anticipated by Falret, who in 1854 had predicted that many melancholic patients in the community would 1 day be classified in his circular group. We also confirmed Baillarger's observation in the same year that episodes (in this study, hypomanic episodes) could last as short as 2 days. Our findings deriving from a systematic French national database a century and a half later invite major shifts in clinical and public health services, as well as in the future conduct of psychopharmacologic trials. In this respect, the systematic training of clinicians in four regions of France represents a national resource for affective disorders and can serve as a model to effect change in diagnostic practice in other countries.

Adolescent↗

PubMed2006

A new approach to the assessment of the quality of predictions of transcription factor binding sites.

In this paper, we describe a novel method called Secondary Verification which assesses the quality of predictions of transcription factor binding sites. This method incorporates a distribution of prediction scores over positive examples (i.e. the actual binding sites) and is shown to be superior to p-value, routinely used statistical significance assessment, which uses only a distribution of prediction scores over background sequences. We also discuss how to integrate both distributions into a framework called Secondary Verification Assessment method which evaluates the quality of a model of a transcription factor. Based on that we create a hybrid representation of a transcription factor: we select the description (with or without dependencies) which is best for the transcription factor considered.

Algorithms↗

PubMed2005

Predicting oligomeric assemblies: N-mers a primer.

Multi-protein complexes play key roles in many biological processes. However, since the structures of these assemblies are hard to resolve experimentally, the detailed mechanism of how they work cooperatively in the cell has remained elusive. Similarly, recent advances on in silico prediction of protein-protein interactions have so far avoided this difficult problem. In this paper, we present a general algorithm to predict molecular assemblies of homo-oligomers. Given the number of N-mers and the 3D structure of one monomer, the method samples all the possible symmetries that N-mers can be assembled. Based on a scoring function that clusters the low free energy structures at each binding interface, the algorithm predicts the complex structure as well as the symmetry of the protein assembly. The method is quite general and does not involve any free parameters. The algorithm has been implemented as a public server and integrated to the protein-protein complex prediction server ClusPro. Using this application, we validated predictions for trimers, tetramers (discriminating between dimer of dimers and 4-fold symmetry structures), pentamers and hexamers (discriminating between trimer of dimers, dimer of trimers, and 6-fold symmetry structures), for a total of 107 assemblies. For 85% of the multimers, the server predicts the complex structure within an average rms deviation of 2A from the full crystal. For complexes that involve more than one binding interface, the cluster size at each surface provides a strong indication as to which interface forms first. With improving scoring functions and computer power, our multimer docking approach could be used as a framework to address the more general problem of multi-protein assemblies.

Algorithms↗

PubMed1997

Response bias affects perceptual asymmetry scores and performance measures on a dichotic listening task.

A dichotic listening paradigm discussed by Sidtis and Bryden (Neuropsychologia, 1978, 16, 627-632) allows one to present non-verbal as well as verbal material. This paradigm also permits signal-detection analyses to separate response biases from discrimination abilities. The present study used Sidtis' (Neuropsychologia, 1981, 19, 103-112) Complex Tone Task as an example of the paradigm. Employing signal-detection analyses, we demonstrated that commonly used performance and asymmetry indices are confounded by response bias. Several indices based on signal-detection measures are suggested to replace current widely used measures. As pointed out by Bryden and Sprott (Neuropsychologia, 1981, 19, 571-581), currently the usefulness of a perceptual asymmetry score is mainly determined by mathematical and statistical properties rather than by a theoretical framework. Thus, the choice of a particular index based on signal-detection theory is arbitrary. The present results and those of Katsuki et al. (Journal of Speech and Hearing Research, 1984, 27, 444-448) suggest that the confounding effect of response bias may be present in a variety of experiments investigating lateral processing.

Adolescent↗

PubMed2001

Radiation hybrid comparative mapping between human chromosome 17 and porcine chromosome 12 demonstrates conservation of gene order.

A comparative study of human chromosome 17 (HSA17) and pig chromosome 12 (SSC12) was conducted using both somatic cell hybrid panel (SCHP) and radiation hybrid (RH) panel analysis. Sequences from an expressed sequence tag (EST) project in pig reproduction were examined and six genes and ESTs originally believed to map to HSA17 were selected for this study. The genes/ESTs were TATA box binding protein-associated factor (TAF2N/RBP56), alpha-2-plasmin inhibitor (SERPINF2/PLI), H3 histone family 3B (H3F3B), aminopeptidase puromycin sensitive (NPEPPS), an expressed sequence tag (ESTMI015) and P311 protein (P311). The SCHP analysis mapped five genes/ESTs (TAF2N, H3F3B, SERPINF2, NPEPPS and ESTMI015) to SSC12q11-q15 and SSC12p11-p15 with 100% concordance, and assigned P311 to SSC2 (1/2q24)-q29 with 100% concordance. Radiation hybrid analysis of all six genes confirmed the SCHP mapping results, with average retention frequency of 25%. Recent human sequence data demonstrated that P311 is actually located on HSA5q. As HSA5q and SSC2q show conserved syntenic regions predicted from bi-directional painting, our P311 mapping data is consistent with these results. An expanded comparative SSC12 RH map integrating the five new type I markers and 23 previously mapped loci was established using a LOD score threshold of 4.8. The gene order of the five genes/ESTs on the SSC12 framework RH map (H3F3B-ESTMI015-NPEPPS-TAF2N-SERPINF2) is identical to the HSA17 GB4 map but with inversion of the map as conventionally drawn.

Animals↗

PubMed2004

Causal analysis of individual change using the difference score.

Causal analysis of change in time-related characteristics such as health or disease is an increasingly important area of epidemiology. Change is often analyzed using data from 2 waves of a longitudinal study, using the difference score--the difference between the scores at the 2 waves--as the outcome in a regression model. In this article, I show how and when causal analysis of change can be performed using simple linear regression models of continuous difference scores. Not only do causal analyses require making adjustments for confounding bias, but also for the shape of individual "growth curves"--the way in which each individual's score changes over time. In practice, the type of growth curve is critical to determining whether age or start score or neither is included in the regression model. For valid analyses, both sets of adjustments require assumptions based on prior theory that cannot be tested using the study data; choosing to make adjustments using variables based solely on observed associations with the difference score can give misleading results. However, analysts can state their assumptions clearly using this framework and put them up for rigorous scientific scrutiny. The approach is illustrated by an application to data from the Whitehall II study of British civil servants.

Age Factors↗

PubMed2000

Linear classification of low-resolution EEG patterns produced by imagined hand movements.

Electroencephalograph (EEG)-based brain-computer interfaces (BCI's) require on-line detection of mental states from spontaneous EEG signals. In this framework, surface Laplacian (SL) transformation of EEG signals has proved to improve the recognition scores of imagined motor activity. The results we obtained in the first year of an European project named adaptive brain interfaces (ABI) suggest that: 1) the detection of mental imagined activity can be obtained by using the signal space projection (SSP) method as a classifier and 2) a particular type of electrodes can be used in such a BCI device, reconciling the benefits of SL waveforms and the need for the use of few electrodes. Recognition of mental activity was attempted on both raw and SL-transformed EEG data from five healthy people performing two mental tasks, namely imagined right and left hand movements.

Adult↗