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PubMed1994

Visual, orthographic, phonological, and lexical influences in reading.

The fuzzy logical model of perception (FLMP), used as a framework to analyze phenomena in reading, asserts that there are multiple influences on reading performance. Experiments on the dynamic interaction of letter information and orthographic context are presented. Previous results have supported the FLMP over a variety of interactive activation models. These findings indicated that lateral masking and the time course of processing must be accounted for in the theoretical prediction of letter and word recognition. A new finding is that the word superiority effect is not influenced by the nature of the backward masking stimulus, nor is it diminished with letter and word masks, contrary to the predictions of several extant explanations. The FLMP is extended to account for reaction time in reading. Perceptual recognition, naming, and lexical decision tasks reflect the influence of multiple sources of information. These include orthographic structure, spelling-to-speech correspondences, and word frequency. Reading can be productively analyzed as a prototypical pattern recognition situation in which the reader exploits multiple sources of information in perception and action.

Auditory Perception↗
PubMed1997

Featural evaluation, integration, and judgment of facial affect.

The paradigm of the fuzzy logical model of perception (FLMP) is extended to the domain of perception and recognition of facial affect. Two experiments were performed using a highly realistic computer-generated face varying on 2 features of facial affect. Each experiment used the same expanded factorial design, with 5 levels of brow deflection crossed with 5 levels of mouth deflection, as well as their corresponding half-face conditions, for a total stimulus set of 35 faces. Experiment 1 used a 2-alternative, forced-choice paradigm (either happy or angry), whereas Experiment 2 used 9 rating steps from happy to angry. Results indicate that participants evaluated and integrated information from both features to perceive affective expressions. Both choice probabilities and ratings showed that the influence of 1 feature was greater to the extent that the other feature was ambiguous. The FLMP fit the judgments from both experiments significantly better than an additive model. Our results question previous claims of categorical and holistic perception of affect.

Adolescent↗
PubMed1983

Evaluation and integration of visual and auditory information in speech perception.

Three experiments were carried out to investigate the evaluation and integration of visual and auditory information in speech perception. In the first two experiments, subjects identified /ba/ or /da/ speech events consisting of high-quality synthetic syllables ranging from /ba/ to /da/ combined with a videotaped /ba/ or /da/ or neutral articulation. Although subjects were specifically instructed to report what they heard, visual articulation made a large contribution to identification. The tests of quantitative models provide evidence for the integration of continuous and independent, as opposed to discrete or nonindependent, sources of information. The reaction times for identification were primarily correlated with the perceived ambiguity of the speech event. In a third experiment, the speech events were identified with an unconstrained set of response alternatives. In addition to /ba/ and /da/ responses, the /bda/ and /tha/ responses were well described by a combination of continuous and independent features. This body of results provides strong evidence for a fuzzy logical model of perceptual recognition.

Hearing↗
PubMed1991

Integration of orthographic and semantic information in memory retrieval.

Our central goal was to determine how multiple sources of information are evaluated and integrated during memory retrieval. An expanded factorial design was used to vary two sources of information independently of one another and to present each source alone. Subjects solved crossword-like puzzles with varying numbers of orthographic and semantic cues. The results of the experiment indicated that (a) performance is better given two sources of information relative to just one; (b) evaluation of each source of information provides continuous rather than just categorical (all-or-none) information; and (c) the two sources are integrated multiplicatively rather than simply used independently of one another as claimed by nonintegration models. A fuzzy logical model of perception (FLMP)-taken from the pattern recognition domain--gave a good description of the memory results. A single channel model, an averaging model, and an adding model produced poor descriptions of the results.

Adult↗
PubMed1995

Data fitting and detection theory: reply to Massaro and Oden (1995).

D. W. Massaro and G. C. Oden (1995) claimed that M. A. Pitt's (1995) data provide strong evidence in favor of independence, not interactivity, as argued by Pitt. Massaro and Oden's arguments rested on an evaluation of the fit of the fuzzy logical model of perception (FLMP) to the identification data and on criticisms of the detection theory analyses. In this reply, Pitt shows that the latter criticisms were unfounded and that the data-fitting demonstrations raised questions about FLMP's ability to capture the phenomenon of interest (i.e., lexical context effects).

Humans↗
PubMed2004

Modeling the effects of choice-set size on the processing of letters and words.

Letters and words are better identified when there are fewer available choices. How do readers use choice-set restrictions? By analyzing new experimental data and previously reported data, the author shows that Bayes theorem-based models overestimate readers' use of choice-set restrictions. This result is discordant with choice-similarity models such as R. D. Luce's (1963a) similarity choice model, G. Keren and S. Baggen's (1981) letter recognition model, and D. W. Massaro and G. C. Oden's (1979) fuzzy logical model of perception. Other models posit that choice restrictions affect accuracy only by improving guessing (e.g., J. L. McClelland & D. E. Rumelhart's, 1981, interactive activation model). It is shown that these models underestimate readers' use of choice-set restrictions. Restriction of choice set does improve perception of letters and words, but not optimally. Decision models that may be able to explain this phenomenon are discussed.

Attention↗
PubMed1988

Ambiguity in perception and experimentation.

Bruno and Cutting (1988) varied four monocular cues to perceived depth in a factorial design. Subjects judged the distance between test objects. Given main effects in the analysis of variance, the authors concluded that the perceivers integrated the four different sources of information, as opposed to simply selecting a single source. Given no interactions in the analysis of variance, the authors concluded that the integration process was additive rather than multiplicative. The ambiguity inherent in Bruno and Cutting's experiments and analyses is discussed. As presented, their results did not provide evidence for integration of depth cues or evidence for additivity, independence, and parallel processing of the cues. An additional analysis of the distribution of the rating judgments given by their subjects, however, provides some evidence for integration of the cues. The fuzzy logical model of perception (FLMP) is extended to describe perceptual recognition of depth. The model assumes independence of the cues during feature evaluation and a nonadditive integration process in which the least ambiguous cues have the greatest impact on the judgment. The FLMP is contrasted with a model assuming additivity of the cues. Because both models describe the results equally well, it remains for future researchers to provide definitive tests between the models.

Cues↗
PubMed2003

Postacute management of patients with spinal cord injury due to metastatic tumour disease: survival and efficacy of rehabilitation.

STUDY DESIGN: Retrospective study utilising clinical records and public administration databases. OBJECTIVES: This study was performed to analyse the clinical presentation and survival rate of individuals with spinal cord injury (SCI) due to spinal metastasis after primary treatment, and to evaluate the efficacy of rehabilitative efforts. SETTING: Spinal Cord Injury Unit, University Hospital, Heidelberg. METHODS: A total of 68 consecutive patients were included. Demographics, clinical data, tumour type, level and completeness of SCI, initial treatment, functional independence measure (FIM) and survival time were derived from hospital and public administration databases. Cox regression and fuzzy logic rule generation were used for statistical analysis. RESULTS: Of the 68 patients, 66 patients died 11 months (median, interquartile range (IQR) 4-29 months) after the onset of neurological symptoms at an average age of 58 years. The functional independence measure (FIM) score describing the general clinical and functional status proved to be the most reliable prognostic factor of survival. Other more specific parameters (eg tumour type or level of lesion) did not have such an impact. In total, 51 patients completed the rehabilitation programme within 50 days (median, IQR 27-99 days). The FIM score improved from 62 at admission to 84 at discharge. CONCLUSION: The clinical and functional status is a valuable prognostic factor for survival. Since institutionalised rehabilitative efforts are effective, this group of patients should be accepted into such a program.

Adolescent↗
PubMed2005

Precipitation, pH and metal load in AMD river basins: an application of fuzzy clustering algorithms to the process characterization.

In the present work, Acid Mine Drainage (AMD) processes in the Chorrito Stream, which flows into the Cobica River (Iberian Pyrite Belt, Southwest Spain) are characterized by means of clustering techniques based on fuzzy logic. Also, pH behavior in contrast to precipitation is clearly explained, proving that the influence of rainfall inputs on the acidity and, as a result, on the metal load of a riverbed undergoing AMD processes highly depends on the moment when it occurs. In general, the riverbed dynamic behavior is the response to the sum of instant stimuli produced by isolated rainfall, the seasonal memory depending on the moment of the target hydrological year and, finally, the own inertia of the river basin, as a result of an accumulation process caused by age-long mining activity.

Environmental Monitoring↗
PubMed1999

Speech perception in perceivers with hearing loss: synergy of multiple modalities.

Although we would expect that the role of visible speech in multimodal speech perception would have the greatest relevance to individuals with hearing impairment, relatively few analytic studies have been done with these participants. Their adequate understanding of spoken language usually requires information from several modalities or other sources of information. The framework of the fuzzy logical model of perception (FLMP) is used to assess how individuals with hearing impairment evaluate and integrate multiple sources of information. Given this framework, a distinction can be made between information and information processing. Within this framework, we can ask what information differences and information-processing differences exist among individuals with normal hearing and those with hearing impairment. Four experimental studies from the literature are analyzed to address these questions. Test items are presented under both unimodal and bimodal conditions. Of central interest is the nature of the bimodal performance as a function of the unimodal performance. The findings show that, although information differences obviously exist across different populations, their information processing involved in pattern recognition appears to be the same and is well described by the FLMP.

Adolescent↗
PubMed2000

Effects of facial paralysis and audiovisual information on stop place identification.

This study investigated how listeners' perceptions of bilabial and lingua-alveolar voiced stops in auditory (A) and audiovisual (AV) presentation modes were influenced by articulatory function in a girl with bilateral facial paralysis (BFP) and a girl with normal facial movement (NFM). The Fuzzy Logic Model of Perception (FLMP) was used to make predictions about listeners' identifications of stop place based on assumptions about the nature (clear, ambiguous, or conflicting) of the A or AV cues produced by each child during /b/ and /d/ CV syllables. As predicted, (a) listeners' identification scores for NFM were very high and reliable, regardless of presentation mode or stop place, (b) listeners' identification scores for BFP were high for lingua-alveolar place, regardless of presentation mode, but more variable and less reliable than for NFM; significantly lower (overall at a chance level) for bilabial place in the A mode; and lowest for bilabial place in the AV mode. Conflicting visual cues for stop place for BFP's productions of /bV/ syllables influenced listeners' perceptions, resulting in most of her bilabial syllables being misidentified in the AV mode. F2 locus equations for each child's /bV/ and /dV/ syllables showed patterns similar to those reported by previous investigators, but with less differentiation between stop place for BFP than NFM. These acoustic results corresponded to the perceptual results obtained. (That is, when presented with only auditory information, on average, listeners perceived BFP's target /b/ syllables to be near the boundary between /b/ and /d/.)

Adult↗
PubMed1998

Ultrasound transmission speed and ultrasound bone profile score (UBPS) of the phalanges in normal women and women with osteoporosis.

The distal metaphysis of the first phalanx of the fingers II-V is, like the vertebral body, a useful site for the measurement of mineralisation and structure of the bone because of the simultaneous presence of compact and trabecular bone. With an ultrasound device (DBM sonic 1200, IGEA, Italy), we measured the adSOS (the amplitude dependent speed of sound) and the UBPS (ultrasound bone profile score), a score which is calculated from the graphic traces of the receiving probe with an expert system which uses fuzzy-logic at phalanges II-IV, as well as bone mineral density (BMD) at lumbar spine using dual X-ray absorptiometry (DXA). Precision of the measurements was as follows: adSOS: short-time-CV% = 0.576, long-time-CV% = 1.1, SCV% = 5.9, RMSSD% = 1.825. UBPS: short-time CV% = 5.95. There was no correlation between adSOS or UBPS and lumbar BMD (DXA). There was a significant positive correlation between adSOS and UBPS, r = 0.804 (p<0.00001). The validity of adSOS and UBPS was examined in 25 young and healthy women (mean age: 33.4 year), 15 postmenopausal healthy women (mean age: 58.5 years), 17 women with osteopenia, (mean age: 52.4 years), as defined by a t-score between -1 to -2.5 SD as lumbar BMD (DXA), and 20 women with osteoporosis and vertebral fractures (mean age: 61.4 years). We compared the healthy postmenopausal women and the women with osteoporotic vertebral fractures, the z-score of the adSOS was below minus 1.5 SD and UBPS was below 40, sensitivity was 0.7 for adSOS, and 0.85 for UBPS, with a specificity 0.97 for adSOS, and of 0.93 for UBPS; positive predictive value: adSOS: 0.93, UBPS: 0.85. AdSOS declined with age (r= 0.694, p=0.021); the UBPS was not age dependent (r=-0.15, p = n.s.). The ROC-curve shows a value of 0.96 for adSOS and 0.94 for UBPS. AdSOS and UBPS could discriminate well between the healthy controls and the women with osteopenia or vertebral fractures (p<0.00001). These results show that adSOS and UBPS are precise parameters to be measured at the phalanges. The detection level of pathological changes in osteoporosis are similar between adSOS and lumbar BMD (DXA) and improved by using the UBPS. This might be explained by the influence of structural changes in bone on UBPS, rather than change in bone mineral alone. Prospective studies have to clarify the role of adSOS and UBPS in fracture prediction.

Absorptiometry, Photon↗
PubMed1999

[Endothelial evaluation of corneal transplants by digital imaging].

BACKGROUND: Evaluation of corneal graft endothelium in organ culture comprises judgement of cell area, cell form and cell density by phase contrast microscopy after cell border swelling in hypotonic solution. Up to now, cell density has been determined via counting cells by hand within a fixed frame on polaroid images regarding the magnification factor. It was the purpose of this paper to establish a facilitated and reliable method for endothelial cell count by digital imaging and to compare it with our standard procedure of endothelial cell count by hand. MATERIAL AND METHODS: After cell border swelling in hypotonic solution endothelial images are recorded by a digital camera that is connected to a computer system where the grey scale images are processed into binary images using specialized enhancement and thresholding techniques. A fuzzy logic based computer program was developed in order to differentiate between single and multiple objects, i.e. living and necrotic cells. This digital imaging system determines endothelial cell density automatically and offers the possibility to correct the data in any case of misinterpretation. Twenty corneal grafts were evaluated with this system by two experienced investigators and the results were compared with endothelial cell count by hand. RESULTS: Using the new system, intra- and interindividual variability of endothelial cell count was statistically significantly lower compared with evaluation by hand. Furthermore, less time for evaluation and documentation was necessary. CONCLUSIONS: In a reduced period of time endothelial cell density of corneal grafts in organ culture can be determined reliably and reproducibly with the new digital imaging system if the possibility of data correction is used in case of misinterpretation. In the future, the necessity of corrections should be reduced and the use of multiple fixed frames should further improve quality control of corneal grafts.

Cell Count↗
PubMed2001

Experiences of otoneurological expert system for vertigo.

We have developed an OtoNeurological Expert system (ONE) to aid the diagnostics of vertigo, to assist teaching and to implement the database for research. The database contains detailed information on the patient history, signs and test results necessary for the diagnostic work with vertiginous patients. The pattern recognition method was used in the reasoning process. Questions regarding symptoms, signs and test results are weighted and scored for each disease, and the most likely disease is recognized from the defined disease profiles. Uncertainties in reasoning, caused by missing information, were solved with a method resembling fuzzy logic. We have also applied adaptive computer applications, such as genetic algorithms and decision trees, in the reasoning process. In the validation the expert system ONE proved to be a sound decision maker, by solving 65% of the cases correctly, while the physicians' mean was 69%. To improve the expert system ONE further, a follow-up should be implemented for the patients, to ease the diagnostic work of some difficult diseases. The six diseases were detected with high accuracy also with adaptive learning methods and discriminant analysis. An expert system is a practical tool in otoneurology. We aim to construct a hybrid program for the reasoning, where the best reasoning method for each disease is used.

Decision Making↗
PubMed1996

Automated scoring of micronuclei in binucleated human lymphocytes.

Manual and automatic scoring of micronuclei (MN) in binucleated human lymphocytes (BNC) were compared after irradiation of whole blood samples. The blood samples were irradiated with X-ray doses (1, 2 or 3 Gy) and stained with Giemsa. The preparation technique was optimized in such a way that acceptable conditions (cell density, contrast) were obtained for both scoring procedures. To estimate the quality of automatic micronucleus detection, two researchers who had different experience in scoring MN (6 months and 5 years) analysed the samples independently from each other. Automatic scoring was carried out with a digital image analysis system and the recognition procedure was divided into two parts. The BNC positions were detected with low microscope magnification (100x), and the recognition of micronuclei within the cytoplasm of the classified BNC was carried out at high magnification (630x). A fuzzy logic classification system as well as two different segmentation steps (preclassification and postclassification) made it possible that about 94% of all automatically recognized BNC were classified correctly). On the other hand, the classification system was optimized in such a way that false positive decisions were minimized (95% of automatically recognized micronuclei were classified correctly). Failure to recognize micronuclei (8.5%-25% false negatives) was mainly due to extremely small micronuclei, poor contrast with respect to the cytoplasm, and aggregation of micronuclei especially at higher doses.

Automation↗
PubMed1991

Crossmodal integration in the identification of consonant segments.

Although speechreading can be facilitated by auditory or tactile supplements, the process that integrates cues across modalities is not well understood. This paper describes two "optimal processing" models for the types of integration that can be used in speechreading consonant segments and compares their predictions with those of the Fuzzy Logical Model of Perception (FLMP, Massaro, 1987). In "pre-labelling" integration, continuous sensory data is combined across modalities before response labels are assigned. In "post-labelling" integration, the responses that would be made under unimodal conditions are combined, and a joint response is derived from the pair. To describe pre-labelling integration, confusion matrices are characterized by a multidimensional decision model that allows performance to be described by a subject's sensitivity and bias in using continuous-valued cues. The cue space is characterized by the locations of stimulus and response centres. The distance between a pair of stimulus centres determines how well two stimuli can be distinguished in a given experiment. In the multimodal case, the cue space is assumed to be the product space of the cue spaces corresponding to the stimulation modes. Measurements of multimodal accuracy in five modern studies of consonant identification are more consistent with the predictions of the pre-labelling integration model than the FLMP or the post-labelling model.

Attention↗
PubMed2000

An intelligent diabetes software prototype: predicting blood glucose levels and recommending regimen changes.

Maintaining optimal blood glucose (BG) control is difficult for type 1 diabetes mellitus (T1DM) patients when typical daily regimens of food, insulin and exercise are altered. Artificial intelligence (AI) systems consisting of treatment algorithms calibrated through large datasets of patient specific information may offer a solution. Such a system can predict BG level changes resulting from regimen disturbances and recommend regimen changes for compensation. A software prototype based on neural network, fuzzy logic, and expert system concepts was developed and evaluated to determine feasibility and efficacy of a patient specific prediction model. BG data are the primary driver for adapting existing functions to patient specific prediction algorithms. Mean absolute percent error (MAPE) between actual and predicted BG values from inputs of daily insulin, food, and exercise information for an T1DM test subject was 10.5% using a calibrated model. The prototype is limited by the requirement for a rigid testing schedule, human error and situational circumstances such as alcohol consumption, illness, infection, stress, and significant hormonal imbalances. No significant conclusions regarding model validity can be drawn due to limited evaluation process and subject sample size, although the prototype has demonstrated viability as a learning tool for diabetes patients. Increased impetus for further development of this prototype and similar AI models may materialize when more effective diagnostic and data capture tools become available to reduce testing and improve accuracy of the model with more input data.

Algorithms↗
PubMed1993

Pilot study of an expert system adviser for controlling general anaesthesia.

RESAC (real time expert system for advice and control), has been developed to advise on the concentration of inhaled volatile anaesthetics during anaesthesia. It merges clinical information and on-line measurements using Bayesian inference and fuzzy logic. This paper describes a clinical trial in seven patients after initial development of the knowledge base and the human computer interface. Evaluation of the performance of RESAC included analysis of questionnaire responses. Anaesthetists were confident enough to follow the dosage advice given by RESAC in most of the patients.

Adult↗