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Traditional drill and practice (TD) and incremental rehearsal (IR) are two flashcard drill instructional methods previously\\u000a noted to improve wordrecognition. The current study sought to compare the effectiveness and efficiency of these two methods,\\u000a as assessed by next day retention assessments, under 2 conditions (i.e., opportunities to respond held constant across methods,\\u000a length of instructional session held constant across
Robert J. Volpe; Christina M. Mulé; Amy M. Briesch; Laurice M. Joseph; Matthew K. Burns
This is the entry page for participating in the WordRecognition Experiment. This study involves a series of wordrecognition trials in which participants are flashed a word either in the left or in the right hemifield and then identify the presented word. Performance is measured as the minimum presentation display time required for an individual to correctly identify the word.
|The visual wordrecognition literature has been dominated by the study of "monosyllabic" words in factorial experiments, computational models, and megastudies. However, it is not yet clear whether the behavioral effects reported for monosyllabic words generalize reliably to "multisyllabic" words. Hierarchical regression techniques were used to…
Lexical bias is a well-known factor affecting phonological categorization in spoken wordrecognition. The current study examined the interaction between lexical bias and dialect variation in spoken wordrecognition in noise. The stimulus materials were real English words in two regional American English dialects. To manipulate lexical bias, targetwords in the word- competitor condition were selected so that predicted
Cynthia G. Clopper; Janet B. Pierrehumbert; Terrin N. Tamati
The word shape analysis approach to text recognition is motivated by discoveries in psychological studies of the human reading process. It attempts to describe and compare the shape of the word as a whole object without trying to segment and recognize the individual characters, so it bypasses the errors committed in character segmentation and classification. However, the large number of classes and large variation and distortion expected in all patterns belonging to the same class make it difficult for conventional, accurate, pattern recognition approaches. A word shape analysis approach using ideal word patterns to overcome the difficulty and improve recognition performance is described in this paper. A special word pattern which characterizes a word class is extracted from different sample patterns of the word class and stored in memory. Recognition of a new word pattern is achieved by comparing it with the special pattern of each word class called ideal word pattern. The process of generating the ideal word pattern of each word class is proposed. The algorithm was tested on a set of machine printed gray scale word images which included a wide range of print types and qualities.
This article provides an overview of bilingualism research on visual wordrecognition in isolation and in sentence context. Many studies investigating the processing of words out-of-context have shown that lexical representations from both languages are activated when reading in one language (language-non-selective lexical access). A newly developed research line asks whether language-non-selective access generalizes to wordrecognition in sentence contexts, providing a language cue and/or semantic constraint information for upcoming words. Recent studies suggest that the language of the preceding words is insufficient to restrict lexical access to words of the target language, even when reading in the native language. Eye tracking studies revealing the time course of word activation further showed that semantic constraint does not restrict language-non-selective access at early reading stages, but there is evidence that it has a relatively late effect. The theoretical implications for theories of bilingual wordrecognition are discussed in light of the Bilingual Interactive Activation+ model (Dijkstra and van Heuven, 2002).
Assche, Eva Van; Duyck, Wouter; Hartsuiker, Robert J.
Most offline handwriting recognition approaches pro- ceed by segmenting words into smaller pieces (usually characters) which are recognized separately. The recog- nition result of a word is then the composition of the individually recognized parts. Inspired by results in cogni- tive psychology, researchers have begun to focus on holistic wordrecognition approaches. Here we present a holis- tic wordrecognition
Previous research has suggested that the initial portion of a word activates similar sounding words that compete for recognition. Other research has shown that the number of similar sounding words that are activated influences the speed and accuracy of recognition. Words with few neighbors are processed more quickly and accurately than words with many neighbors. The influences of the number of lexical competitors in the initial part of the word were examined in a shadowing and a lexical-decision task. Targetwords with few neighbors that share the initial phoneme were responded to more quickly than targetwords with many neighbors that share the initial phoneme. The implications of onset-density effects for models of spoken-wordrecognition are discussed.
In current study we examine how letter permutation affects in visual recognition of words for two orthographically dissimilar languages, Urdu and German. We present the hypothesis that recognition or reading of permuted and non-permuted words are two distinct mental level processes, and that people use different strategies in handling permuted words as compared to normal words. A comparison between reading behavior of people in these languages is also presented. We present our study in context of dual route theories of reading and it is observed that the dual-route theory is consistent with explanation of our hypothesis of distinction in underlying cognitive behavior for reading permuted and non-permuted words. We conducted three experiments in lexical decision tasks to analyze how reading is degraded or affected by letter permutation. We performed analysis of variance (ANOVA), distribution free rank test, and t-test to determine the significance differences in response time latencies for two classes of data. Results showed that the recognition accuracy for permuted words is decreased 31% in case of Urdu and 11% in case of German language. We also found a considerable difference in reading behavior for cursive and alphabetic languages and it is observed that reading of Urdu is comparatively slower than reading of German due to characteristics of cursive script.
Rashid, Sheikh Faisal; Shafait, Faisal; Breuel, Thomas M.
Research on hemispheric specialization in lateralized recognition tasks has examined a range of factors that may influence or interact with the left-right dominance of particular tasks. The divided visual field technique is a valuable strategy for examining hemispheric specialization across a range of abilities. This page offers information about how to use a divided visual field activity to illustrate hemispheric specialization.
Reading is a complex process that draws on a remarkable number of diverse perceptual and cognitive processes. In this review, I provide an overview of computational models of reading, focussing on models of visual wordrecognition-how we recognise individual words. Early computational models had 'toy' lexicons, could simulate only a narrow range of phenomena, and frequently had fundamental limitations, such as being able to handle only four-letter words. The most recent models can use realistic lexicons, can simulate data from a range of tasks, and can process words of different lengths. These models are the driving force behind much of the empirical work on reading. I discuss how the data have guided model development and, importantly, I also provide guidelines to help interpret and evaluate the contribution the models make to our understanding of how we read. PMID:24012145
According to a recent hypothesis, the prefrontal cortex has been proposed as the site of emotional memory integration, because it is sensitive to the recognition of emotional contents. In the present research, we explored the role of the dorsolateral prefrontal cortex (DLPFC) in memory recognition processes for positive versus negative emotional stimuli when old (target) and new (distractor, either semantically related or unrelated to the target) stimuli were presented. The role of the DLPFC was analysed using an rTMS (repeated transcranial magnetic stimulation) paradigm that induced increased cortical activation of the left DLPFC. The subjects were required to perform a task that consisted of two experimental phases (i.e., an encoding and a recognition phase) in which the targets and the distractors were presented and recognition performance was measured. rTMS stimulation was provided over the left DLPFC during the recognition phase. We found that the rTMS stimulation affected the memory recognition of positive emotional material. Moreover, related and unrelated distractors were discarded better when they were positively valenced, and a more significant effect (i.e., increased performance) was produced in response to related distractors. This result suggests that the activation of the left DLPFC favours the memory recognition of positive emotional information, and that such activation is able to induce a more appropriate selective process to distinguish target from distractor stimuli in the presence of more complex processes (related distractors). The valence model of emotional cue processing may explain this increased performance by demonstrating the distinct role of the left hemisphere in the retrieval of positive emotional information. PMID:22528734
THE HYPOTHESIS THAT WHEN ASSOCIATED PAIRS OF WORDS ARE PRESENTED, SPEED OF RECOGNITION WILL BE FASTER THAN WHEN NONASSOCIATED WORD PAIRS ARE PRESENTED OR WHEN A TARGETWORD IS PRESENTED BY ITSELF WAS TESTED. TWENTY UNIVERSITY STUDENTS, INITIALLY SCREENED FOR VISION, WERE ASSIGNED RANDOMLY TO ROWS OF A 5 X 5 REPEATED-MEASURES LATIN SQUARE DESIGN.…
According to the interactive activation framework proposed by McClelland and Rumelhart (1981), activation spreads both forward and backward between some levels of representation during visual wordrecognition. An important boundary condition, however, is that the spread of activation from lower to higher levels can be prevented (e.g., explicit letter processing during prime processing eliminates the well-documented semantic priming effect). Can the spread of activation from higher to lower levels also be prevented? This question was addressed with a choice task procedure in which subjects read a prime word and then responded to a target, performing either lexical decision or letter search depending on the color of the target. A semantic context effect was observed in lexical decision, providing evidence of semantic-level activation. In contrast, there was no semantic context effect in the letter search task, despite evidence of lexical involvement: Words were searched faster than nonwords. Further evidence of lexical involvement in the letter search task appeared in Experiment 2 in the form of greater identity priming for words than for nonwords. The results of these experiments are consistent with the conclusion that feedback from the semantic level to the lexical level can be blocked. Hence, between-level activation blocks can be instantiated in both bottom-up and top-down directions. PMID:11340855
We investigate the effects of word characteristics on episodic recognition memory using analyses that avoid Clark's (1973) "language-as-a-fixed-effect" fallacy. Our results demonstrate the importance of modeling word variability and show that episodic memory for words is strongly affected by item noise (Criss & Shiffrin, 2004), as measured by the…
Freeman, Emily; Heathcote, Andrew; Chalmers, Kerry; Hockley, William
activation of phonological and semantic information associated with words. In naming, they reflect differences in ease of articulating familiar versus unfamiliar pronunciations. Implications of these results concerning models of wordrecognition are discussed, focusing on how pseudohomophone effects can arise within models that do not incorporate word-specific representations, such as the M. S. Seidenberg and J. L. McClelland (1989) model.
Mark S. Seidenberg; Alan Petersen; Maryellen C. MacDonald; David C. Plaut
Sentence comprehension depends on continuous prediction of upcoming words. However, when and how contextual information affects the bottom-up streams of visual wordrecognition is unknown. This study examined the effects of word frequency and contextual predictability (cloze probability of a targetword embedded in the sentence) on N1, P200, and N400 components, which are related to various cognitive operations in early visual processing, perceptual decoding, and semantic processing. The data exhibited a significant interaction between predictability and frequency at the anterior N1 component. The predictability effect, in which the low predictability words elicited a more negative N1 than high predictability words, was only observed when reading a high frequency word. A significant predictability effect occurred during the P200 time window, in which the low predictability words elicited a less positive P200 than high predictability words. There is also a significant predictability effect on the N400 component; low predictability words elicited a greater N400 than high predictability words, although this effect did not interact with frequency. The temporal dynamics of the manner in which contextual information affects the visual wordrecognition is discussed. These findings support the interactive account, suggesting that contextual information facilitates visual-feature and orthographic processing in the early stage of visual word processing and semantic integration in the later stage.
Two cross-modal priming experiments investigated whether the representation of either an initial- or a final-embedded word may be activated when the longer carrier word is auditorily presented. Visual targets were semantically related either to the embedded word or to the carrier word or they were unrelated to the primes. A priming effect was found for semantic associates of the carrier
|Four eye-tracking experiments examined lexical competition in non-native spoken-wordrecognition. Dutch listeners hearing English fixated longer on distractor pictures with names containing vowels that Dutch listeners are likely to confuse with vowels in a target picture name ("pencil," given target "panda") than on less confusable distractors…
Thirty years of research has uncovered the broad principles that characterize spoken word processing across listeners. However, there have been few systematic investigations of individual differences. Such an investigation could help refine models of wordrecognition by indicating which processing parameters are likely to vary, and could also have important implications for work on language impairment. The present study begins to fill this gap by relating individual differences in overall language ability to variation in online wordrecognition processes. Using the visual world paradigm, we evaluated online spoken wordrecognition in adolescents who varied in both basic language abilities and non-verbal cognitive abilities. Eye movements to target, cohort and rhyme objects were monitored during spoken wordrecognition, as an index of lexical activation. Adolescents with poor language skills showed fewer looks to the target and more fixations to the cohort and rhyme competitors. These results were compared to a number of variants of the TRACE model (McClelland & Elman, 1986) that were constructed to test a range of theoretical approaches to language impairment: impairments at sensory and phonological levels; vocabulary size, and generalized slowing. None of the existing approaches were strongly supported, and variation in lexical decay offered the best fit. Thus, basic wordrecognition processes like lexical decay may offer a new way to characterize processing differences in language impairment. PMID:19836014
McMurray, Bob; Samelson, Vicki M; Lee, Sung Hee; Tomblin, J Bruce
In this thesis, three approaches were used for Automatic TargetRecognition (ATR). These approaches were shape, moment and Fourier generated features, Karhunen-Loeve Transform (KLT) generated features and Discrete Cosine Transform (DCT) generated features. The KLT approach was modelled after the face recognition research by Suarez, AFIT, and Turk and Pentland, MIT. A KLT is taken of a reduced covariance matrix, composed all three classes of targets, and the resulting eigenimages are used to reconstruct the original images. The reconstruction coefficients for each original image are found by taking the dot product of the original image with each eigenimage. These reconstruction coefficients were implemented as features into a three layer backprop with momentum network. Using the hold one-cut-out technique of testing data, the net could correctly differentiate the targets 100 percent of the time. Using standard features, the correct classification rate was 99.33 percent. The DCT was also taken of each image, and 16 low frequency Fourier components were kept as features. These recognition rates were compared to FFT results where each set contained the top five feature, as determined by a saliency test. The results proved that the DCT and the FFT were equivalent concerning classification of targets.
|Abbreviated CID W-22 lists were administered to normal and hearing-impaired adults to test the hypothesis that fewer judiciously chosen items can be used to test wordrecognition without compromising test accuracy. Results show that fewer items can be used if the words are sufficiently difficult and strict passing criteria are employed.…
A robust algorithm for offline cursive script recognition is described. The algorithm uses a generate-and-test paradigm to analyze cursive word images. The generate phase of the algorithm intelligently segments the word after analyzing certain structural features present in the word. The test phase determines the most likely character candidates among the segmentation points by using a recognition algorithm trained on generalized cursive letter shapes. In a sense, wordrecognition is done by sliding a variable sized window across the word looking for recognizable characters and strokes. The output of this system is a list of all plausible interpretations of the word. This list is then analyzed by a two-step contextual post- processor which first matches all of the interpretations to a supplied dictionary using a string matching algorithm. This eliminates the least likely interpretations. The remaining candidates are then analyzed for certain character spatial relationships (local reference line finder) to finally rank the dictionary. The system has the advantage of not requiring explicit word training yet is able to recognize many handwriting styles. This system is being successfully tested on a database of handwritten words extracted from live mail with dictionary sizes of up to 300 words. Planned extensions include developing a multilevel generate-and-test paradigm which can handle any type of handwritten word.
|Discusses the role of wordrecognition in reading comprehension. Defines seven strategies for wordrecognition--configuration, dictionary analysis, syllabication, structural analysis, sight words, context clues, and phonetic analysis--and provides activities for teaching each. (JPB)|
This paper reviews what is currently known about the sensory and perceptual input that is made available to the wordrecognition system by processes typically assumed to be related to speech sound perception. In the first section, we discuss several of the major problems that speech researchers have tried to deal with over the last thirty years. In the second section, we consider one attempt to conceptualize the speech perception process within a theoretical framework that equates processing stages with levels of linguistic analysis. This framework assumes that speech is processed through a series of analytic stages ranging from peripheral auditory processing, acoustic-phonetic and phonological analysis, to wordrecognition and lexical access. Finally, in the last section, we consider several recent approaches to spoken wordrecognition and lexical access. We examine a number of claims surrounding the nature of the bottom-up input assumed by these models, postulated perceptual units, and the interaction of different knowledge sources in auditory wordrecognition. An additional goal of this paper was to establish the need to employ segmental representations in spoken wordrecognition.
In recent years, a new scientific field known as network science has been emerging. Network science is concerned with understanding the structure and properties of networks. One concept that is commonly used in describing a network is how the nodes in the network cluster together. The current research applied the idea of clustering to the study of how phonological neighbors influence visual wordrecognition. The results of 2 experiments converge to show that words with neighbors that are highly clustered (i.e., are closely related in terms of sound) are recognized more slowly than are those having neighbors that are less clustered. This result is explained in terms of the principles of interactive activation where the interplay between phoneme and phonological word units is affected by the neighborhood structure of the word. It is argued that neighbors in more clustered neighborhoods become more active and directly compete with the targetword, thereby slowing processing. PMID:23565783
In two eye-tracking experiments we examined whether wider discourse information helps the recognition of reduced pronunciations (e.g., "puter") more than the recognition of canonical pronunciations of spoken words (e.g., "computer"). Dutch participants listened to sentences from a casual speech corpus containing canonical and reduced targetwords.…
The bimodal interactive-activation model has been successfully applied to understanding the neurocognitive processes involved in reading words in alphabetic scripts, as reflected in the modulation of ERP components in masked repetition priming. In order to test the generalizability of this approach, in the present study we examined wordrecognition in a different writing system, the Japanese syllabary scripts hiragana and katakana. Native Japanese participants were presented with repeated or unrelated pairs of Japanese words in which the prime and targetwords were both in the same script (within-script priming, Exp. 1) or were in the opposite script (cross-script priming, Exp. 2). As in previous studies with alphabetic scripts, in both experiments the N250 (sublexical processing) and N400 (lexical-semantic processing) components were modulated by priming, although the time course was somewhat delayed. The earlier N/P150 effect (visual feature processing) was present only in "Experiment 1: Within-script priming", in which the prime and targetwords shared visual features. Overall, the results provide support for the hypothesis that visual wordrecognition involves a generalizable set of neurocognitive processes that operate in similar manners across different writing systems and languages, as well as pointing to the viability of the bimodal interactive-activation framework for modeling such processes. PMID:23378278
Participants read lists of words and then made recognition judgments to pairs of words, each of which consisted of a prime word and a test word. At issue was the effect of a semantic relationship between the prime word and the test word on the recognition judgment to the test word. Under standard recognition conditions, semantic priming impeded correct recognition judgments to new test words and had no effect on recognition judgments to old test words. The overall effect was to reduce the level of discrimination for recognition judgments to the test word. Under conditions in which familiarity assessment would be expected to play a greater role in judgments to old test words, semantic priming facilitated those judgments. The results are explained in terms of a dual process account of recognition.
Ngo, Catherine T.; Sargent, Jesse; Dopkins, Stephen
Toddlers’ and preschoolers’ knowledge of the phonological forms of words was tested in Spanish-learning, Catalan-learning, and bilingual children. These populations are of particular interest because of differences in the Spanish and Catalan vowel systems: Catalan has two vowels in a phonetic region where Spanish has only one. The proximity of the Spanish vowel to the Catalan ones might pose special learning problems. Children were shown picture pairs; the target picture’s name was spoken correctly, or a vowel in the targetword was altered. Altered vowels either contrasted with the usual vowel in Spanish and Catalan, or only in Catalan. Children’s looking to the target picture was used as a measure of wordrecognition. Monolinguals’ wordrecognition was hindered by within-language, but not non-native, vowel changes. Surprisingly, bilingual toddlers did not show sensitivity to changes in vowels contrastive only in Catalan. Among preschoolers, Catalan-dominant bilinguals but not Spanish-dominant bilinguals revealed mispronunciation sensitivity for the Catalan-only contrast. These studies reveal monolingual children’s robust knowledge of native-language vowel categories in words, and show that bilingual children whose two languages contain phonetically overlapping vowel categories may not treat those categories as separate in language comprehension.
Ramon-Casas, Marta; Swingley, Daniel; Sebastian-Galles, Nuria; Bosch, Laura
How do we map the rapid input of spoken language onto phonological and lexical representations over time? Attempts at psychologically-tractable computational models of spoken wordrecognition tend either to ignore time or to transform the temporal input into a spatial representation. TRACE, a connectionist model with broad and deep coverage of speech perception and spoken wordrecognition phenomena, takes the latter approach, using exclusively time-specific units at every level of representation. TRACE reduplicates featural, phonemic, and lexical inputs at every time step in a large memory trace, with rich interconnections (excitatory forward and backward connections between levels and inhibitory links within levels). As the length of the memory trace is increased, or as the phoneme and lexical inventory of the model is increased to a realistic size, this reduplication of time- (temporal position) specific units leads to a dramatic proliferation of units and connections, begging the question of whether a more efficient approach is possible. Our starting point is the observation that models of visual object recognition—including visual wordrecognition—have grappled with the problem of spatial invariance, and arrived at solutions other than a fully-reduplicative strategy like that of TRACE. This inspires a new model of spoken wordrecognition that combines time-specific phoneme representations similar to those in TRACE with higher-level representations based on string kernels: temporally independent (time invariant) diphone and lexical units. This reduces the number of necessary units and connections by several orders of magnitude relative to TRACE. Critically, we compare the new model to TRACE on a set of key phenomena, demonstrating that the new model inherits much of the behavior of TRACE and that the drastic computational savings do not come at the cost of explanatory power.
Hannagan, Thomas; Magnuson, James S.; Grainger, Jonathan
A fundamental challenge for the cognitive neuroscience of language is to capture the spatio-temporal patterns of brain activity that underlie critical functional components of the language comprehension process. We combine here psycholinguistic analysis, whole-head magnetoencephalography (MEG), the Mismatch Negativity (MMN) paradigm, and source localization techniques (Equivalent Current Dipole and L1-Minimum-Norm Current Estimates) to locate the process of spoken wordrecognition
Friedemann Pulvermuller; Yury Shtyrov; Risto J Ilmoniemi; William Marslen-Wilson
In several experiments, we compared behavioral and electrophysiological correlates of hemifield tachistoscopic presentations\\u000a of single words and nonwords for lexical decision in English and in Hebrew. The English task showed an overall right visual\\u000a field advantage for latency and accuracy, which was larger for targetwords than for nonwords, suggesting independent processing\\u000a in each hemisphere. The right hemisphere was more
A robust semantic priming effect typically occurs in visual wordrecognition if the prime is read before a response to the target. However, this effect is dramatically reduced if a letter search is performed on the prime prior to responding to the target. Three lexical decision experiments document the new observation that morphological priming is preserved following letter search on the prime. This dissociation between morphological and semantic priming following letter search can be understood in the context of an interactive activation framework. In addition, the implications of these results for connectionist and compound cue accounts of wordrecognition, as well as the issue of automaticity in wordrecognition, are discussed. PMID:9861715
Examined the recognition of English words by groups of native speakers of Italian who differed in age of arrival in Canada and amount of continued native language use. The dependent variable was the number of words correctly repeated in English sentences presented in noise. Significantly higher wordrecognition scores were obtained for early…
The value of Through the Wall Radar Imaging (TWRI) data collected with one system is limited when training the automatic targetrecognition classifier of a second system because of variation in the Point Spread Function (PSF). The target image is a function of both the scene reflectivity and the PSF, which is in turn a function of the imaging radar's
In this paper a method for analytic hand- written wordrecognition based on causal Markov random fields is described. The word models are hmms where each state corresponds to a letter modeled by a nshp-hmm (Markov field). The word models are built dynamically. Training is operated using Baum-Welch algorithm where the parameters are reestimated on the generated word models. The
Isoluminant stimuli are used increasingly often to investigate processes underlying visual wordrecognition. However, construction\\u000a of isoluminant stimuli is not straightforward, and inappropriate construction may have the result of misinforming theories\\u000a that relate wordrecognition to neurological function. To inform the use of isoluminant stimuli in studies of wordrecognition,\\u000a the present article details two experiments in which isoluminant stimuli
Timothy R. Jordan; Susan M. Sherman; Richard P. Tonkin
The purpose of this study was to determine differences in wordrecognition strategies used by good and poor readers. Twenty good readers and twenty poor readers were randomly selected from a fourth grade class and randomly assigned to levels of a five by five repeated-measures Latin Square design. All of the subjects were given two tasks to…
Clustering coefficient—a measure derived from the new science of networks—refers to the proportion of phonological neighbors of a targetword that are also neighbors of each other. Consider the words bat, hat, and can, all of which are neighbors of the word cat; the words bat and hat are also neighbors of each other. In a perceptual identification task, words with a low clustering coefficient (i.e., few neighbors are neighbors of each other) were more accurately identified than words with a high clustering coefficient (i.e., many neighbors are neighbors of each other). In a lexical decision task, words with a low clustering coefficient were responded to more quickly than words with a high clustering coefficient. These findings suggest that the structure of the lexicon, that is the similarity relationships among neighbors of the targetword measured by clustering coefficient, influences lexical access in spoken wordrecognition. Simulations of the TRACE and Shortlist models of spoken wordrecognition failed to account for the present findings. A framework for a new model of spoken wordrecognition is proposed.
We used eyetracking to examine how tonal versus segmental information influence spoken wordrecognition in Mandarin Chinese. Participants heard an auditory word and were required to identify its corresponding picture from an array that included the target item ("chuang2" "bed"), a phonological competitor (segmental: chuang1 "window"; cohort:…
|Three phoneme monitoring experiments examined the manner in which additional processing time influences spoken wordrecognition. Experiment 1a introduced a version of the phoneme monitoring paradigm in which a silent interval is inserted prior to the word-final target phoneme. Phoneme monitoring reaction time decreased as the silent interval…
LoCasto, Paul C.; Connine, Cynthia M.; Patterson, David
|In two eye-tracking experiments we examined whether wider discourse information helps the recognition of reduced pronunciations (e.g., "puter") more than the recognition of canonical pronunciations of spoken words (e.g., "computer"). Dutch participants listened to sentences from a casual speech corpus containing canonical and reduced target…
The purpose of this study was to examine the hypothesis that the attentional demands of wordrecognition covary with other measures of reading efficiency. Individual differences in efficiency were indexed by (a) speed and accuracy of lexical access, (b) obligatory activation of phonological codes, and (c) working memory capacity. The attentional demands of wordrecognition were measured with a dual-task
To test three hypotheses concerning fingerspelling's contribution to wordrecognition, 24 deaf children in three age groups (7-9, 10-12, and 13-15 years) were administered a vocabulary recognition test and a lexical decision task. Subjects' performance was measured by the number of words accurately identified and the response latency. Results did…
|Orthographic influences in spoken wordrecognition have been previously examined in alphabetic languages. However, it is unknown whether orthographic information affects spoken wordrecognition in Chinese, which has a clean dissociation between orthography (O) and phonology (P). The present study investigated orthographic effects using event…
A discrete-wordrecognition system utilizing a word dictionary and phonological rules is described. In this system, nine distinctive features are extracted from a discrete-word input. Segmentation is performed using these features. Segmentation errors are corrected by applying a phoneme connecting rule. The input word is transformed into an input feature matrix. The comparison of this matrix with the standard derived
|Balota et al. [Balota, D., Cortese, M., Sergent-Marshall, S., Spieler, D., & Yap, M. (2004). Visual wordrecognition for single-syllable words. "Journal of Experimental Psychology: General, 133," 283-316] studied lexical processing in word naming and lexical decision using hierarchical multiple regression techniques for a large data set of…
Accurate location of the endpoints of an isolated word is important for reliable and robust wordrecognition. The endpoint detection problem is nontrivial for nonstationary backgrounds where artifacts (i.e., nonspeech events) may be introduced by the speaker, the recording environment, and the transmission system. Several techniques for the detection of the endpoints of isolated words recorded over a dialed-up telephone
LORI F. LAMEL; LAWRENCE R. RABINER; AARON E. ROSENBERG; JAY G. WILPON
Based on the observation that the unpredictable nature of conversational speech makes it almost impossible to reliably model sequential word constraints, the notion of word set error criteria is proposed for improved recognition of spontaneous dialogs. The single-pass adaptive boosting (AB) algorithm enables the language model weights to be tuned using the word set error criteria. In the two-pass version
Previous research has shown that the number of phonologically similar items influences the processing of spoken words (e.g., Vitevitch, 2002; Vitevitch and Luce, 1998). The present experiment examines the influence of semantic similarity on the speed and accuracy of spoken wordrecognition using a lexical decision task. Semantic density refers to the number of words that are semantically associated to
|Most words in English are ambiguous between different interpretations; words can mean different things in different contexts. We investigate the implications of different types of semantic ambiguity for connectionist models of wordrecognition. We present a model in which there is competition to activate distributed semantic representations. The…
Rodd, Jennifer M.; Gaskell, M. Gareth; Marslen-Wilson, William D.
|Word reading in alphabetic languages involves letter identification, independently of the format in which these letters are written. This process of letter "regularization" is sensitive to word context, leading to the recognition of a word even when numbers that resemble letters are inserted among other real letters (e.g., M4TERI4L). The present…
Molinaro, Nicola; Dunabeitia, Jon Andoni; Marin-Gutierrez, Alejandro; Carreiras, Manuel
Reports an error in "Coordination of wordrecognition and oculomotor control during reading: The role of implicit lexical decisions" by Wonil Choi and Peter C. Gordon (Journal of Experimental Psychology: Human Perception and Performance, 2013[Aug], Vol 39, 1032-1046). The graphs in Figures 1 and 2 are reversed. The online versions of this article have been corrected. (The following abstract of the original article appeared in record 2012-28751-001.) The coordination of word-recognition and oculomotor processes during reading was evaluated in eye-tracking experiments that examined how word skipping, where a word is not fixated during first-pass reading, is affected by the lexical status of a letter string in the parafovea and ease of recognizing that string. Ease of lexical recognition was manipulated through target-word frequency (Experiment 1) and through repetition priming between prime-target pairs embedded in a sentence (Experiment 2). Using the gaze-contingent boundary technique the targetword appeared in the parafovea either with full preview or with transposed-letter (TL) preview. The TL preview strings were nonwords in Experiment 1 (e.g., bilnk created from the target blink), but were words in Experiment 2 (e.g., sacred created from the target scared). Experiment 1 showed greater skipping for high-frequency than low-frequency targetwords in the full preview condition, but not in the TL preview (nonword) condition. Experiment 2 showed greater skipping for targetwords that repeated an earlier prime word than for those that did not, with this repetition priming occurring both with preview of the full target and with preview of the target's TL neighbor word. However, time to progress from the word after the target was greater following skips of the TL preview word, whose meaning was anomalous in the sentence context, than following skips of the full preview word whose meaning fit sensibly into the sentence context. Together, the results support the idea that coordination between word-recognition and oculomotor processes occurs at the level of implicit lexical decisions. (PsycINFO Database Record (c) 2013 APA, all rights reserved). PMID:23978215
Serial attention models of eye-movement control during reading were evaluated in an eye-tracking experiment that examined how lexical activation combines with visual information in the parafovea to affect word skipping (where a word is not fixated during first-pass reading). Lexical activation was manipulated by repetition priming created through prime-target pairs embedded within a sentence. The boundary technique (Rayner, 1975) was used to determine whether the targetword was fully available during parafoveal preview or whether it was available with transposed letters (e.g., Herman changed to Hreman). With full parafoveal preview, the targetword was skipped more frequently when it matched the earlier prime word (i.e., was repeated) than when it did not match the earlier prime word (i.e., was new). With transposed-letter (TL) preview, repetition had no effect on skipping rates despite the great similarity of the TL preview string to the targetword and substantial evidence that TL strings activate the words from which they are derived (Perea & Lupker, 2003). These results show that lexically based skipping is based on full recognition of the letter string in parafoveal preview and does not involve using the contextual constraint to compensate for the reduced information available from the parafovea. These results are consistent with models of eye-movement control during reading in which successive words in a text are processed 1 at a time (serially) and in which wordrecognition strongly influences eye movements. PMID:22686842
The present study investigated the effects of word-recognition training on the word-recognition processing of learners of English as a foreign language (EFL). Providing 7-week word-recognition training, the study examined whether such training improves EFL learners' word-recognition performance. The main aspects of this study concerned word…
Children with hyperlexia read words spontaneously before the age of five, have impaired comprehension on both listening and reading tasks, and have wordrecognition skill above expectations based on cognitive and linguistic abilities. One student with hyperlexia and another student with higher wordrecognition than comprehension skills who started to read words at a very early age were followed over several years from the primary grades through high school when both were completing a second-year Spanish course. The purpose of the present study was to examine the foreign language (FL) wordrecognition, spelling, reading comprehension, writing, speaking, and listening skills of the two students and another high school student without hyperlexia. Results showed that the student without hyperlexia achieved higher scores than the hyperlexic student and the student with above average wordrecognition skills on most FL proficiency measures. The student with hyperlexia and the student with above average wordrecognition skills achieved higher scores on the Spanish proficiency tasks that required the exclusive use of phonological (pronunciation) and phonological/orthographic (wordrecognition, spelling) skills than on Spanish proficiency tasks that required the use of listening comprehension and speaking and writing skills. The findings provide support for the notion that wordrecognition and spelling in a FL may be modular processes and exist independently of general cognitive and linguistic skills. Results also suggest that students may have stronger FL learning skills in one language component than in other components of language, and that there may be a weak relationship between FL wordrecognition and oral proficiency in the FL. PMID:20563785
Abstract Recall of emotion words is superior to neutral words. Prior work reported in this journal (Anooshian & Hertel, 1994) found that this effect was absent in a second language. Words in a second language may thus lack the emotional associations of words acquired in childhood. To determine whether memory,probes may be generally useful for assessing emotionality effects in a
This paper focuses on the extent to which the development of ESL (English as a Second Language) wordrecognition skills mimics\\u000a similar trajectories in same-aged EL1 (English as a First Language) children, and the extent to which phonological processing\\u000a skills and rapid naming can be used to predict wordrecognition performance in ESL children. Two cohorts of Grade 1 ESL
Esther Geva; Zhoreh Yaghoub-Zadeh; Barbara Schuster
Recognition memory for spoken words was investigated with a continuous recognition memory task. Independent variables were number of intervening words (lag) between initial and subsequent presentations of a word, total number of talkers in the stimulus set, and whether words were repeated in the same voice or a different voice. In Experiment 1, recognition judgments were based on word identity
Thomas J. Palmeri; Stephen D. Goldinger; David B. Pisoni
|The present work aims at demonstrating that visual training associated with the act of reading modifies the way we perceive printed words. As reading does not train all parts of the retina in the same way but favors regions on the side in the direction of scanning, visual wordrecognition should be better at retinal locations that are frequently…
Although the definitive source of the left hemisphere's superiority for visual wordrecognition remains illusive, some argue that the left (LH) and right (RH) hemispheres engage different strategies during early perceptual processes involved in stimulus encoding. In particular, it is proposed that the LH treats a word as a unitary perceptual group whereas the RH processes the letters comprising a
Annukka K. Lindell; Isabel Arend; Robert Ward; Jennifer Norton; Jennifer Wathan
Recognition and retrieval of historical handwritten material is an unsolved problem. We propose a novel approach to recognizing and retrieving handwritten manuscripts, based upon word image classification as a key step. Decision trees with normalized pixels as features form the basis of a highly accurate AdaBoost classifier, trained on a corpus of word images that have been resized and sampled
An approach to handprinted wordrecognition is described. The approach is based on the use of generating multiple possible segmentations of a word image into characters and matching these segmentations to a lexicon of candidate strings. The segmentation process uses a combination of connected component analysis and distance transform-based, connected character splitting. Neural networks are used to assign character confidence
Paul D. Gader; Michael W. Whalen; Margaret Ganzberger; Dan Hepp
|This dissertation investigates the role of grammatical gender facilitation and inhibition in second language (L2) learners' spoken wordrecognition. Native speakers of languages that have grammatical gender are sensitive to gender marking when hearing and recognizing a word. Gender facilitation refers to when a given noun that is preceded by an…
A parallel distributed processing model of visual wordrecognition and pronunciation is described. The model consists of sets of orthographic and phonological units and an interlevel of hidden units. Weights on connections between units were modified during a training phase using the back-propagation learning algorithm. The model simulates many aspects of human performance, including (a) differences between words in terms
|Examines contributions of vowel signs in reading Hebrew on memory and comprehension. Finds that vowel signs speeded up recognition memory of words in third graders, and improved recall of words printed in the context of mixed lists in sixth graders. Finds also that vowelization improved memory and comprehension of some prose texts. (RS)|
In the context of targetrecognition in sensor networks, the requirement of adding intelligence largely corre- sponds to the capability of recognizing unknown tar- gets, i.e., targets without any a priori information, and of modifying the knowledge base dynamically to incor- porate the newly discovered knowledge. In this paper, a collaborative unknown targetrecognition algorithm is presented. The algorithm involves
The paper proposed a novel automatic targetrecognition (ATR) system for classification of three types of ground vehicles in the moving and stationary target acquisition and recognition (MSTAR) public release database. First MSTAR image chips are represented as fine and raw feature vectors, where raw features compensate for the target pose estimation error that corrupts fine image features. Then, the
In models of visual wordrecognition that incorporate an interactive activation framework, activation spreads from orthographic and phonological units to semantic units and from semantic units back to phonological and orthographic units. The present research examined whether semantic feedback changes over the time course of lexical processing and as a function of stimulus quality. Using a mediated priming paradigm, prime-targetword pairs were associatively related (frog-toad), homophonically mediated (frog-towed), or orthographically mediated (frog-told). Evidence of semantic feedback to both orthography and phonology was found when the prime duration was 146 ms (Experiment 1) and only to phonology when the prime duration was 253 ms (Experiment 2a). However, when the prime duration was 253 ms and targetwords were degraded (Experiment 2b), feedback spread only to orthography. The results suggest that the dynamics of semantic feedback change as the function of processing demands in the visual wordrecognition system. PMID:23505963
Reimer, Jason F; Lorsbach, Thomas C; Bleakney, Dana M; McKinney, Scott P
Some previous studies of visual wordrecognition have reported an interaction between visual field and word length (measured by number of letters), such that recognition is affected more by word length for words presented in the left than for words presented in the right visual field. However, when manipulating serial position of letters in words…
In this paper, preliminary considerations and some experimental results are presented in an effort to design Very Large Vocabulary Recognition (VLVR) systems. We will first consider the applicability of current recognition techniques and argue their inade...
|Speeded visual word naming and lexical decision performance are reported for 2,428 words for young adults and healthy older adults. Hierarchical regression techniques were used to investigate the unique predictive variance of phonological features in the onsets, lexical variables (e.g., measures of consistency, frequency, familiarity,…
Balota, David A.; Cortese, Michael J.; Sergent-Marshall, Susan D.; Spieler, Daniel H.; Yap, Melvin J.
This paper describes the speaker-independent spoken wordrecognition system for a large size vocabulary. Speech is analyzed by the filter bank, from whose logarithmic spectrum the 11 features are extracted every 10 ms. Using the features the speech is first segmented and the primary phoneme recognition is carried out for every segment using the Bayes decision method. After correcting errors
The present study investigated the relationship between rapid recognition of individual words (WordRecognition Test) and two measures of contextual reading: (1) grade-level Passage Reading Test (IRI passage) and (2) performance on standardized STAR Reading Test. To establish if time of presentation on the wordrecognition test was a factor in…
In the present PET study, we examined brain activity related to processing of pictures and printed words in episodic memory. Our goal was to determine how the perceptual format of objects (verbal versus pictorial) is reflected in the neural organization of episodic memory for common objects. We investigated this issue in relation to encoding and recognition with a particular focus on medial temporal-lobe (MTL) structures. At encoding, participants saw pictures of objects or their written names and were asked to make semantic judgments. At recognition, participants made yes-no recognition judgments in four different conditions. In two conditions, target items were pictures of objects; these objects had originally been encoded either in picture or in word format. In two other conditions, target items were words; they also denoted objects originally encoded either as pictures or as words. Our data show that right MTL structures are differentially involved in picture processing during encoding and recognition. A posterior MTL region showed higher activation in response to the presentation of pictures than of words across all conditions. During encoding, this region may be involved in setting up a representation of the perceptual information that comprises the picture. At recognition, it may play a role in guiding retrieval processes based on the perceptual input, i.e. the retrieval cue. Another more anterior right MTL region was found to be differentially involved in recognition of objects that had been encoded as pictures, irrespective of whether the retrieval cue provided was pictorial or verbal in nature; this region may be involved in accessing stored pictorial representations. Our results suggest that left MTL structures contribute to picture processing only during encoding. Some regions in the left MTL showed an involvement in semantic encoding that was picture specific; others showed a task-specific involvement across pictures and words. Together, our results provide evidence that the involvement of some but not all MTL regions in episodic encoding and recognition is format specific. PMID:11194410
Köhler, S; Moscovitch, M; Winocur, G; McIntosh, A R
Automatic targetrecognition (ATR) algorithms have offered the promise of recognizing items of military importance over the past 20 years. It is the experience of the authors that greater ATR success would be possible if the ATR were used to 'aid' the human operator instead of automatically 'direct' the operator. ATRs have failed not due to their probability of detection versus false alarm rate, but to neglect of the human component. ATRs are designed to improve overall throughput by relieving the human operator of the need to perform repetitive tasks like scanning vast quantities of imagery for possible targets. ATRs are typically inserted prior to the operator and provide cues, which are then accepted or rejected. From our experience at three field exercises and a current operational deployment to the Bosnian theater, this is not the best way to get total system performance. The human operator makes decisions based on learning, history of past events, and surrounding contextual information. Loss of these factors by providing imagery, latent with symbolic cues on top of the original imagery, actually increases the workload of the operator. This paper covers the lessons learned from the field demonstrations and the operational deployment. The reconnaissance and intelligence community's primary use of an ATR should be to establish prioritized cues of potential targets for an operator to 'pull' from and to be able to 'send' targets identified by the operator for a 'second opinion.' The Army and Air Force are modifying their exploitation workstations over the next 18 months to use ATRs, which operate in this fashion. This will be the future architecture that ATRs for the reconnaissance and intelligence community should integrate into.
Previous work has shown that German-learning 7-9-month-old infants recognize function words (Hoehle and Weissenborn, 2003). English-learning infants recognize function words around 10.5-11 months (Schafer et al. 1998; Shady, 1996; Shi et al., 2003, 2004), and the highly frequent determiner ``the'' at 8 months (Shi et al., 2004). The present study investigates French-learning infants' recognition of function words. As French is a syllable-timing language, the fuller syllabic status may allow infants to recognize function words earlier than English-learning infants. Syntactically and morphologically, functional elements occur more systematically in French than in English, providing reliable statistical cues to functor segmentation. Using a preferential looking procedure, we familiarized 8-month-olds with a target function word (``des,'' ``la,'' ``mes'' or ``ta''), and tested them with phrases containing the target versus a non-target. Results showed that infants' looking time to the phrases containing the targets versus those containing the non-targets differed significantly. Thus, infants recognized the target functors in continuous speech. As the targets included both high-frequency (``des,'' ``la'') and low-frequency (``mes,'' ``ta'') function words, we suggest that infants may begin segmenting high-frequency functors at an even younger age. The implications of early processing of function words to language acquisition will be discussed.
The context in which a word occurs could influence either the actual decoding of the word or a postrecognition judgment of\\u000a the relatedness of word and context. In this research, we investigated the loci of contextual effects that occur in lexical\\u000a priming, when prime and targetwords are related along different dimensions. Both lexical decision and naming tasks were used
Mark S. Seidenberg; Gloria S. Waters; Michael Sanders; Pearl Langer
Reports two sets of lexical priming experiments in which the morphological, semantic, and orthographic relationships between primes and targets are varied in three SOA conditions. Results showed that morphological structure plays a significant role in early visual recognition of English words that is independent of both semantic and orthographic…
Rastle, Kathleen; Davis, Matt H.; Marslen-Wilson, William D.; Tyler, Lorraine K.
Advanced mammalian target identification derived from the perception of target's manifold and measurement manifolddistance. It does not rely on object's segmented accuracy, not depend on target's variety model, and adapt to a range of changes on targets. In this paper, based on the existed manifold learning algorithm, set up a new bionic automatic targetrecognition model, discussed the targets manifold knowledge acquisition and the knowledge expression architecture, gave a manifold knowledge-based new method for automatic targetrecognition. Experiments show that the new method has a strong adaptability to targets various transform, and has a very high correctly identification probability.
In the foreseeable future, automatic targetrecognition (ATR) systems are going to become an integral part of targeting systems. How these ATRs interact with operators is clearly going to influence overall system accuracy. The objective of the two studies...
The paper describes a search procedure that, given a set of alternate models for each word of a small vocabulary isolated words recognizer, selects the set of models that minimizes the expected number of errors. The reported results show that the number of errors that occur on the test set by using the best set of models selected from the
Speeded visual word naming and lexical decision performance are reported for 2,428 words for young adults and healthy older adults. Hierarchical regression techniques were used to investigate the unique predictive variance of phonological features in the onsets, lexical variables (e.g., measures of consistency, frequency, familiarity, neighborhood size, and length), and semantic variables (e.g., imageability and semantic connectivity). The influence of
David A. Balota; Michael J. Cortese; Susan D. Sergent-Marshall; Daniel H. Spieler; Melvin J. Yap
Response time (RT) distributions obtained from 3 wordrecognition experiments were analyzed by fitting an ex-Gaussian function to the empirical data to determine the main effects and interactive influences of word frequency, repetition, and lexicality on the nature of the underlying distributions. The ex-Gaussian analysis allows one to determine if a manipulation simply shifts the response time (RT) distribution, produces
|The purpose of this study was to determine the relation between wordrecognition errors made at a letter-sound pattern level on a word list and on a curriculum-based measurement oral reading fluency measure (CBM-ORF) for typical and struggling elementary readers. The participants were second, third, and fourth grade typical and struggling readers…
Flynn, Lindsay J.; Hosp, John L.; Hosp, Michelle K.; Robbins, Kelly P.
A number of studies have examined the acoustic differences between infant-directed speech (IDS) and adult-directed speech, suggesting that the exaggerated acoustic properties of IDS might facilitate infants’ language development. However, there has been little empirical investigation of the acoustic properties that infants use for word learning. The goal of this study was thus to examine how 19-month-olds’ wordrecognition is affected by three acoustic properties of IDS: slow speaking rate, vowel hyper-articulation, and wide pitch range. Using the intermodal preferential looking procedure, infants were exposed to half of the test stimuli (e.g., Where’s the book?) in typical IDS style. The other half of the stimuli were digitally altered to remove one of the three properties under investigation. After the targetword (e.g., book) was spoken, infants’ gaze toward target and distractor referents was measured frame by frame to examine the time course of wordrecognition. The results showed that slow speaking rate and vowel hyper-articulation significantly improved infants’ ability to recognize words, whereas wide pitch range did not. These findings suggest that 19-month-olds’ wordrecognition may be affected only by the linguistically relevant acoustic properties in IDS.
Automatic targetrecognition (ATR) in hyperspectral imagery is a challenging problem due to recent advances of remote sensing instruments which have significantly improved sensor's spectral resolution. As a result, small and subtle targets can be uncovered and extracted from image scenes, which may not be identified by prior knowledge. In particular, when target size is smaller than pixel resolution, target
STUDIES of primates1 and of patients with brain lesions2 have shown that the visual system represents the external world in regions and pathways specialized to compute visual features and attributes. For example, object recognition is performed by a ventral pathway located in the inferior portion of the temporal lobe3. We studied visual processing of words and word-like stimuli (letter-strings) by
In this introduction to the special issue on sublexical representations in visual wordrecognition, we briefly discuss the importance of research that attempts to describe the functional units that intervene between low-level perceptual processes and access to whole-word representations in long-term memory. We will comment on how the different contributions to this issue add to our growing knowledge of the
Two separate studies were designed to investigate the effect of reading the first word of a pair on the speed of recognizing the second. One study drew its subjects from the college level; the other from the fourth grade. A Scientific Prototype Three-Channel Tachistoscope was used, and an erasing image was flashed immediately following the…
This paper presents an approach related to automated recognition of small features of movable targets including fast moving objects such as airplanes, etc. Small features recognition is a challenging problem in both fields: pattern recognition of particular configurations and of complexes comprising a number of configurations. Specific target details, although well characterized by their features are often arranged in an elaborated way which makes the recognition task very difficult and welcomes new ideas (approaches). On the other hand, the variety of small characters (features) is intrinsically linked to the technology development of the identified targets and is unavoidable. Due to the complexity of possible technological designs, the feature representation is one of the key issues in optical pattern recognition. A flexible hierarchical prediction modeling is proposed with application examples.
It is widely believed that orthographic processing implies an approximate, flexible coding of letter position, as shown by relative-position and transposition priming effects in visual wordrecognition. These findings have inspired alternative proposals about the representation of letter position, ranging from noisy coding across the ordinal positions to relative position coding based on open bigrams. This debate can be cast within the broader problem of learning location-invariant representations of written words, that is, a coding scheme abstracting the identity and position of letters (and combinations of letters) from their eye-centered (i.e., retinal) locations. We asked whether location-invariance would emerge from deep unsupervised learning on letter strings and what type of intermediate coding would emerge in the resulting hierarchical generative model. We trained a deep network with three hidden layers on an artificial dataset of letter strings presented at five possible retinal locations. Though word-level information (i.e., word identity) was never provided to the network during training, linear decoding from the activity of the deepest hidden layer yielded near-perfect accuracy in location-invariant wordrecognition. Conversely, decoding from lower layers yielded a large number of transposition errors. Analyses of emergent internal representations showed that word selectivity and location invariance increased as a function of layer depth. Word-tuning and location-invariance were found at the level of single neurons, but there was no evidence for bigram coding. Finally, the distributed internal representation of words at the deepest layer showed higher similarity to the representation elicited by the two exterior letters than by other combinations of two contiguous letters, in agreement with the hypothesis that word edges have special status. These results reveal that the efficient coding of written words-which was the model's learning objective-is largely based on letter-level information. PMID:24065939
It is widely believed that orthographic processing implies an approximate, flexible coding of letter position, as shown by relative-position and transposition priming effects in visual wordrecognition. These findings have inspired alternative proposals about the representation of letter position, ranging from noisy coding across the ordinal positions to relative position coding based on open bigrams. This debate can be cast within the broader problem of learning location-invariant representations of written words, that is, a coding scheme abstracting the identity and position of letters (and combinations of letters) from their eye-centered (i.e., retinal) locations. We asked whether location-invariance would emerge from deep unsupervised learning on letter strings and what type of intermediate coding would emerge in the resulting hierarchical generative model. We trained a deep network with three hidden layers on an artificial dataset of letter strings presented at five possible retinal locations. Though word-level information (i.e., word identity) was never provided to the network during training, linear decoding from the activity of the deepest hidden layer yielded near-perfect accuracy in location-invariant wordrecognition. Conversely, decoding from lower layers yielded a large number of transposition errors. Analyses of emergent internal representations showed that word selectivity and location invariance increased as a function of layer depth. Word-tuning and location-invariance were found at the level of single neurons, but there was no evidence for bigram coding. Finally, the distributed internal representation of words at the deepest layer showed higher similarity to the representation elicited by the two exterior letters than by other combinations of two contiguous letters, in agreement with the hypothesis that word edges have special status. These results reveal that the efficient coding of written words—which was the model's learning objective—is largely based on letter-level information.
The exploratory research reported in this study was designed to initiate research in reading that includes children who have cognitive disabilities other than learning disabilities. Forty children, whose wordrecognition level was at the second-grade level, were assessed for knowledge of letter names, letter sounds, and rime recognition for high and low frequency targetwords and nonwords. Of these children,
We address the targetrecognition problem by focusing on intermediate-level vision. Early biological vision extracts edges and contours of various lengths. High-level recognition is either view or template-based, which is fragile with respect to lighting,...
|Although it is assumed that semantics is a critical component of visual wordrecognition, there is still much that we do not understand. One recent way of studying semantic processing has been in terms of semantic neighbourhood (SN) density, and this research has shown that semantic neighbours facilitate lexical decisions. However, it is not…
|Past findings were reviewed with psychometric results and clinical observations of seven children with unusually precocious word-recognition skills and otherwise multiple significant developmental deviations. Implications concerning the syndrome of hyperlexia and how the behavior pattern may disrupt the acquisition of appropriate modalities of…
|A study involving a high-school student with hyperlexia and a student with above average wordrecognition skills, found they scored higher on Spanish proficiency tasks that required the exclusive use of phonological and phonological/orthographic skills than on Spanish proficiency tasks requiring listening comprehension and speaking and writing…
Seven children who had unusually precocious word-recognition skills and otherwise had multiple significant developmental deviations were identified. Past findings are reviewed along with psychometric results and clinical observations of the seven hyperlexic children. Implications concerning the syndrome of hyperlexia and how this behavioral pattern may disrupt the acquisition of appropriate modalities of communication are discussed. PMID:7133911
An attempt is made to isolate the assumptions that make a connectionist approach to visual wordrecognition distinctive. These include the commitment to distributed representations, the claim that there is no distinction between lexical and nonlexical systems in the naming task, and the claim that it is possible to map from orthography to meaning without using localized representations. It is
|Purpose: The purpose of this study was to assess the time course of spoken wordrecognition in 2-year-old children who use cochlear implants (CIs) in quiet and in the presence of speech competitors. Method: Children who use CIs and age-matched peers with normal acoustic hearing listened to familiar auditory labels, in quiet or in the presence of…
Grieco-Calub, Tina M.; Saffran, Jenny R.; Litovsky, Ruth Y.
|Reports an error in "Context and spoken wordrecognition in a novel lexicon" by Kathleen Pirog Revill, Michael K. Tanenhaus and Richard N. Aslin ("Journal of Experimental Psychology: Learning, Memory, and Cognition," 2008[Sep], Vol 34, 1207-1223). Figure 9 was inadvertently duplicated as Figure 10. Figure 9 in the original article was correct.…
Revill, Kathleen Pirog; Tanenhaus, Michael K.; Aslin, Richard N.
In this paper we compare a standard HMM based recognizer to a highly parameter efficient hybrid denoted hidden neural network (HNN). The comparison was done on a speaker independent command wordrecognition task aimed at car hands-free applications. Monophone based HMM and HNN recognizers were initially trained on clean Wall Street Journal British English data. Evaluation of these baseline models
|An exploratory investigation was made of cross-modality matching within the context of wordrecognition skills among beginning adult readers. The specific aim of the study was to assess the possibility that a deficit in cross-modality matching might be potentially useful as a diagnostic and predictive indicator of the rate at which adults learn…
|Three eye movement studies with novel lexicons investigated the role of semantic context in spoken wordrecognition, contrasting 3 models: restrictive access, access-selection, and continuous integration. Actions directed at novel shapes caused changes in motion (e.g., looming, spinning) or state (e.g., color, texture). Across the experiments,…
Revill, Kathleen Pirog; Tanenhaus, Michael K.; Aslin, Richard N.
Recent work (Vitevitch & Luce, 1998) investigating the role of phonotactic information in spoken wordrecognition suggests the operation of two levels of representation, each having distinctly different consequences for processing. The lexical level is marked by competitive effects associated with similarity neighborhood activation, whereas increased probabilities of segments and sequences of segments facilitate processing at the sublexical level. We
The consequences for the process of spoken wordrecognition of changes-in- progress in the sound system of New Zealand English are investigated in a semantic priming experiment. For example, semantic associates of both beer (ie. wine) and bear (ie. hug) are facilitated after subjects have heard (bi\\\\), while only hug is primed by (be\\\\). This result reflects the asymmetry found
This study examined the capability of the left hemisphere (LH) and the right hemisphere (RH) to perform a visual recognition task independently as formulated by the Direct Access Model (Fernandino, Iacoboni, & Zaidel, 2007). Healthy native Hebrew speakers were asked to categorize nouns and non-words (created from nouns by transposing two middle…
Nemrodov, Dan; Harpaz, Yuval; Javitt, Daniel C.; Lavidor, Michal
Visual speech perception has become a topic of considerable interest to speech researchers. Previous research has demonstrated that perceivers neurally encode and use speech information from the visual modality, and this information has been found to facilitate spoken wordrecognition in tasks such as lexical decision (Kim, Davis, & Krins, 2004). In this paper, we used a cross-modality repetition priming
Adam B. Buchwald; Stephen J. Winters; David B. Pisoni
A parallel distributed processing model of visual wordrecognition and pronunciation and of the acquisition of these skills is described. The model consists of a set of orthographic units used to code letter strings, a set of hidden units, and a set of ph...
Past findings were reviewed with psychometric results and clinical observations of seven children with unusually precocious word-recognition skills and otherwise multiple significant developmental deviations. Implications concerning the syndrome of hyperlexia and how the behavior pattern may disrupt the acquisition of appropriate modalities of…
In this paper, we present how appearance-based features can be used for the recognition of words in American sign language (ASL) from a video stream. The features are extracted without any segmenta- tion or tracking of the hands or head of the signer, which avoids pos- sible errors in the segmentation step. Experiments are performed on a database that consists
Brown (1976) has provided an analysis of the effect of the memorability of an item on the confidence with which it is accepted or rejected in a test of recognition or recall. When the subject has no clear recollection of the inclusion of an item in an input list, he is assumed to evaluate its memorability in the context of
Two visual-world experiments evaluated the time course and use of orthographic information in spoken-wordrecognition using printed words as referents. Participants saw 4 words on a computer screen and listened to spoken sentences instructing them to click on one of the words (e.g., "Click on the word bead"). The printed words appeared 200 ms…
Because of large variations involved in handwritten words, the recognition problem is very difficult. Hidden Markov models (HMM) have been widely and successfully used in speech processing and recognition. Recently HMM has also been used with some success in recognizing handwritten words with presegmented letters. In this paper, a complete scheme for totally unconstrained handwritten wordrecognition based on a
This paper proposes a new framework for extracting facial features based on the bag of words method, and applies it to face and facial expression recognition. Recently, the bag of words method has been successfully used in object recognition. However, for recognition problems of facial images, the orderless collection of local patches in bag of words method cannot provide strongly
|In two eye-tracking experiments in Italian, we investigated how acoustic information and stored knowledge about lexical stress are used during the recognition of tri-syllabic spoken words. Experiment 1 showed that Italians use acoustic cues to a word's stress pattern rapidly in wordrecognition, but only for words with antepenultimate stress.…
A quasi-experimental design was used to investigate the impact of Picture Communication Symbols (PCS) on sight wordrecognition by young children identified as 'at risk' for academic and social-behavior difficulties. Ten pre-primer and 10 primer Dolch words were presented to 23 students in the intervention group and 8 students in the control group during interactive games. Assessments occurred at four
This study assessed how lexical factors associated with vocabulary growth influence spoken wordrecognition by preschoolers, elementary-school children, and adults. Word frequency effects in gating and word repetition tasks were minimal, whereas age-of-acquisition and neighborhood density effects were found for all listeners. For word repetition, children displayed more of an advantage for the recognition of early-acquired items from sparse vs
Victoria M. Garlock; Amanda C. Walley; Jamie L. Metsala
The present study aimed at testing theoretical predictions of the fuzzy-trace theory about true and false recognition. The effects of semantic relatedness and study opportunity on true and false recognition of words from Deese, Roediger, McDermott lists (J. Deese, 1959; D. R. Read, 1996; H. L. Roediger & K. B. McDermott, 1995) were evaluated in 7- to 12-year-old children (N = 151). Instead of a traditional analysis of variance, the authors used a relatively novel statistical analysis technique, latent class factor analysis, to test the hypotheses pertaining to the effect of semantic relatedness and study opportunity on children's true and false recognition given their low or high verbatim-trace and gist-trace level. The results showed that variation in true recognition of targetwords from semantically related and unrelated word lists that were either studied once or repeated could be explained well by variation in verbatim-trace and gist-trace level. Variation in false recognition of semantically related distractors also could be explained by variation in gist-trace level, but the recollection-rejection hypothesis was not confirmed. The variable age was positively but weakly related to gist-trace level, but no significant relationship was found between age and verbatim-trace level. PMID:20438256
FPGAs can be used to build systems for automatic targetrecognition (ATR) that achieve an order of magnitude increase in performance over systems built using general purpose processors. This improvement is possible because the bit-level operations that comprise much of the ATR computational burden map extremely efficiently into FPGAs, and because the specificity of ATR target templates can be leveraged
John Villasenor; Brian Schoner; Kang-Ngee Chia; Charles Zapata; Hea Joung Kim; Chris Jones; Shane Lansing; Bill Mangione-Smith
Recognition without identification (RWI) refers to people's ability to discriminate studied from unstudied items when the items themselves fail to be identified, as when people fail to identify words from fragments. We sought to identify the ERP correlates of word fragment RWI in an effort to better understand its underlying mechanisms; in so doing, we also examined the ERP correlates of word identification failure vs. success. We found the ERP correlate of the RWI effect to be the N300; greater negativity was shown for unidentified fragments of studied words than for unidentified fragments of unstudied words between 300-325 ms post test fragment onset. We further separated the ERPs according to whether subjects showed the behavioral RWI effect or not; the N300 effect emerged only among those subjects who showed the behavioral effect, suggesting that the N300 is related to the behavioral effect itself. With regard to the ERP correlates of word identification failure vs. success, we found very early indicators of later word identification success vs. failure (starting at 125 ms) that were independent of priming. These early effects may be preconscious markers of downstream word identification success vs. failure. We also found a later persistent negativity associated with successfully identified words that we propose to be associated with executive function and possibly the successful suppression of irrelevant words that might initially come to mind when attempting to complete a unique word fragment; word fragment identification failure may sometimes be due to a failure to suppress irrelevant or incorrect words. PMID:21827776
Ryals, Anthony J; Yadon, Carly A; Nomi, Jason S; Cleary, Anne M
Previous tests of toddlers’ phonological knowledge of familiar words using wordrecognition tasks have examined syllable onsets but not word-final consonants (codas). However, there are good reasons to suppose that children’s knowledge of coda consonants might be less complete than their knowledge of onset consonants. To test this hypothesis, the present study examined 14- to 21-month-old children’s knowledge of the phonological forms of familiar words by measuring their comprehension of correctly-pronounced and mispronounced instances of those words using a visual fixation task. Mispronunciations substituted onset or coda consonants. Adults were tested in the same task for comparison with children. Children and adults fixated named targets more upon hearing correct pronunciations than upon hearing mispronunciations, whether those mispronunciations involved the word’s initial or final consonant. In addition, detailed analysis of the timing of adults’ and children’s eye movements provided clear evidence for incremental interpretation of the speech signal. Children’s responses were slower and less accurate overall, but children and adults showed nearly identical temporal effects of the placement of phonological substitutions. The results demonstrate accurate encoding of consonants even in words children cannot yet say.
Voice recognition software is hardly new--attempts at capturing spoken words and turning them into written text have been available to consumers for about two decades. But what was once an expensive and highly unreliable tool has made great strides in recent years, perhaps most recognized in programs such as Nuance's Dragon NaturallySpeaking…
Two experiments tested language switching effects with bilingual participants in a priming paradigm with masked primes (duration of 50 ms in Experiment 1 and 100 ms in Experiment 2). Participants had to monitor targetwords for animal names, and ERPs were recorded to critical (non-animal) words in L1 and L2 primed by unrelated words from the same or the other language. Both experiments revealed language priming (switching) effects that depended on target language. For targetwords in L1, most of the language switch effect appeared in the N400 ERP component, with L2 primes generating a more negative going wave than L1 primes. For L2 targetwords, on the other hand, the effects of a language switch appeared mainly in an earlier ERP component (N250) peaking at approximately 250 ms post-target onset, and showing greater negativity following an L1 prime than an L2 prime. This is the first evidence for fast-acting language-switching effects occurring in the absence of overt task switching.
Chauncey, Krysta; Grainger, Jonathan; Holcomb, Phillip J.
When do children first represent word forms without experimental training or contextual support? Both English- and Welsh-learning children were tested, replicating Halle and Boysson-Bardies (1994: French, 11 months.). Twelve children acquiring English showed word-form recognition by 11 months (Vihman et al., in press); 12 Welsh children showed the effect at 12 months but a separate sample of 12 tested at 11 months did not (Vihman and DePaolis, 1999). A subsequent study of 16 children using event-related potentials (ERPs) showed word-form recognition within 250 ms for English at 11 months (Thierry et al., 2003). Attempts to locate the age of onset longitudinally proved problematic: Repeated tests of single samples of English and Welsh monolingual children (12 each) at 9, 10, 11, and 12 months showed that infant episodic memory interferes sufficiently with longitudinal observation based on a single set of stimuli to preclude drawing any conclusions. Cross-sectional samples of monolingual English and Welsh children (24 each) are currently being tested at 9 to12 months, using both head turn and ERPs, as are English/Welsh bilingual children at 11 months. These studies should yield solid information as to the age of onset of spontaneous word form representation. [ESRC support is gratefully acknowledged.
The present study investigated the electrophysiological correlates of morphological processing in Chinese compound word reading using a delayed repetition priming paradigm. Participants were asked to passively view lists of two-character compound words containing prime-target pairs separated by a few items. In a Whole Word repetition condition, the prime and target were the same real words (e.g., , manager-manager). In a Constituent repetition condition, the prime and target were swapped in terms of their constituent position (e.g., , the former is a pseudo-word and the later means nurse). Two ERP components including N200 and N400 showed repetition effects. The N200 showed a negative shift upon repetition in the Whole Word condition but this effect was delayed for the Constituent condition. The N400 showed comparable amplitude reduction across the two priming conditions. The results reveal different aspects of morphological processing with an early stage associated with N200 and a late stage with N400. There was also a possibility that the N200 effect reflect general cognitive processing, i.e., the detection of low-probability stimuli.
Du, Yingchun; Hu, Weiping; Fang, Zhuo; Zhang, John X.
The present study investigated the electrophysiological correlates of morphological processing in Chinese compound word reading using a delayed repetition priming paradigm. Participants were asked to passively view lists of two-character compound words containing prime-target pairs separated by a few items. In a Whole Word repetition condition, the prime and target were the same real words (e.g., , manager-manager). In a Constituent repetition condition, the prime and target were swapped in terms of their constituent position (e.g., , the former is a pseudo-word and the later means nurse). Two ERP components including N200 and N400 showed repetition effects. The N200 showed a negative shift upon repetition in the Whole Word condition but this effect was delayed for the Constituent condition. The N400 showed comparable amplitude reduction across the two priming conditions. The results reveal different aspects of morphological processing with an early stage associated with N200 and a late stage with N400. There was also a possibility that the N200 effect reflect general cognitive processing, i.e., the detection of low-probability stimuli. PMID:24068994
Du, Yingchun; Hu, Weiping; Fang, Zhuo; Zhang, John X
Adults of varying reading comprehension skill learned a set of previously unknown rare English words (e.g., gloaming) in three different learning conditions in which the type of word knowledge was manipulated. The words were presented in one of three conditions: (1) orthography-to-meaning (no phonology); (2) orthography-to-phonology (no meaning); and (3) phonology-to-meaning (no orthography). Following learning, participants made meaning judgments on the learned words, familiar known words, and unpresented (unlearned) rare words while their ERPs were recorded. The behavioral results showed no significant effects of comprehension skill on meaning judgment performance. Contrastingly, the ERP results indicated comprehension skill differences in P600 amplitude; high-skilled readers showed stronger familiarity effects for learned words, whereas less-skilled readers did not distinguish between learned words, familiar words, and unlearned words. Evidence from the P600 and N400 illustrated superior learning of meaning when meaning information was coupled with orthography rather than phonology. These results suggest that the availability of word knowledge (orthography, phonology, and meaning) at learning affects subsequent word identification processes when the words are encountered in a new context.
Balass, Michal; Nelson, Jessica R.; Perfetti, Charles A.
Functional magnetic resonance imaging (fMRI) was used to gain more insight in the mechanism underlying a decline in recognition memory function with age. Twelve young (23-27 years) and 12 older (63-67 years) healthy men performed two types of word encoding tasks, in which words were either incidentally or intentionally encoded for storage in memory. After a 30min delay, participants performed a recognition task. Older participants were less accurate and slower than young on the recognition task. In the both groups, successful retrieval was accompanied by activation in the left inferior frontal gyrus, left precentral gyrus and right cerebellum. Older participants showed additional activity in the bilateral medial prefrontal gyrus and right parahippocampal gyrus. Correlational analyses showed that only the additional parahippocampal activation correlated positively with task performance in the older but not young participants, suggesting that activation in this area served the purpose of functional compensation. The additional activation in the medial prefrontal cortex, on the other hand, was explained in terms of increased conflict, that is, reduced distinction between target and distracter words leading to increased simultaneous activity of both response tendencies. In a comparison between incidentally and intentionally remembered words the young group showed additional activation in the right middle occipital gyrus. This last result was explained in terms of strategic differences between the young and older group. PMID:16757006
van der Veen, Frederik M; Nijhuis, Frouke A P; Tisserand, Danielle J; Backes, Walter H; Jolles, Jelle
Off-line recognition of handwriting may be achieved using simplified profiles of word shapes. These profiles consist of approximations of the word's upper and lower contour. Training and recognition are based on n-gram extraction and identification. The lexicons used extend to 16,000 words
|This article presents a theory of visual wordrecognition that assumes that, in the tasks of word identification, lexical decision, and semantic categorization, human readers behave as optimal Bayesian decision makers. This leads to the development of a computational model of wordrecognition, the Bayesian reader. The Bayesian reader successfully…
This article presents a theory of visual wordrecognition that assumes that, in the tasks of word identification, lexical decision, and semantic categorization, human readers behave as optimal Bayesian decision makers. This leads to the development of a computational model of wordrecognition, the Bayesian reader. The Bayesian reader successfully…
The split fovea theory proposes that visual wordrecognition of centrally presented words is mediated by the splitting of the foveal image, with letters to the left of fixation being projected to the right hemisphere (RH) and letters to the right of fixation being projected to the left hemisphere (LH). Two lexical decision experiments aimed to elucidate wordrecognition processes
Michal Lavidor; Adrian Hayes; Richard Shillcock; Andrew W. Ellisb
We address the problem of adaptive waveform design for extended targetrecognition in cognitive radar networks. A closed-loop active targetrecognition radar system is extended to the case of a centralized cognitive radar network, in which a generalized likelihood ratio (GLR) based sequential hypothesis testing (SHT) framework is employed. Using Doppler velocities measured by multiple radars, the target aspect angle for each radar is calculated. The joint probability of each target hypothesis is then updated using observations from different radar line of sights (LOS). Based on these probabilities, a minimum correlation algorithm is proposed to adaptively design the transmit waveform for each radar in an amplitude fluctuation situation. Simulation results demonstrate performance improvements due to the cognitive radar network and adaptive waveform design. Our minimum correlation algorithm outperforms the eigen-waveform solution and other non-cognitive waveform design approaches.
We address the problem of adaptive waveform design for extended targetrecognition in cognitive radar networks. A closed-loop active targetrecognition radar system is extended to the case of a centralized cognitive radar network, in which a generalized likelihood ratio (GLR) based sequential hypothesis testing (SHT) framework is employed. Using Doppler velocities measured by multiple radars, the target aspect angle for each radar is calculated. The joint probability of each target hypothesis is then updated using observations from different radar line of sights (LOS). Based on these probabilities, a minimum correlation algorithm is proposed to adaptively design the transmit waveform for each radar in an amplitude fluctuation situation. Simulation results demonstrate performance improvements due to the cognitive radar network and adaptive waveform design. Our minimum correlation algorithm outperforms the eigen-waveform solution and other non-cognitive waveform design approaches. PMID:22163464
|This study investigated the effects of left and right intracranial tumors on picture and wordrecognition memory. We hypothesized that left hemispheric (LH) patients would exhibit greater wordrecognition memory impairment than right hemispheric (RH) patients, with no significant hemispheric group picture recognition memory differences. The LH…
Goldstein, Bram; Armstrong, Carol L.; Modestino, Edward; Ledakis, George; John, Cameron; Hunter, Jill V.
In this activity about neuron/target muscle recognition (page 44 of the PDF), learners arranged in two rows facing away from each other use string to simulate neural development. The lesson guide, part of NASA's "The Brain in Space: A Teacher's Guide with Activities for Neuroscience" includes background information and evaluation strategies.
Automatic targetrecognition (ATR) based on the emerging technology of Compressed Sensing (CS) can considerably improve accuracy, speed and cost associated with these types of systems. An image based ATR algorithm has been built upon this new theory, which can perform target detection and recognition in a low dimensional space. Compressed dictionaries (A) are formed to include rotational information for a scale of interest. The algorithm seeks to identify y(test sample) as a linear combination of the dictionary elements : y=Ax, where A ? Rnxm(n<target. The algorithm can reject clutter and background, which are part of the input image. The detection and recognition problems are solved by finding the sparse-solution to the undetermined system y=Ax via Orthogonal Matching Pursuit (OMP) and l1 minimization techniques. Visible and MWIR imagery collected by the Army Night Vision and Electronic Sensors Directorate (NVESD) was utilized to test the algorithm. Results show an average detection and recognition rates above 95% for targets at ranges up to 3Km for both image modalities.
In this paper, we propose a method for online Farsi handwritten wordsrecognition. At first, words are broken to their sub-words. Each sub-word is made of some strokes. The sign of the sub-word is found from the positions and shapes of its sub-strokes. After that, we classify sub-words according to their signs. Some online features are extracted from the main-stroke
Monocular tachistoscopic wordrecognition performance as a function of word placement to the right or left of fixation was studied in 20 seventh grade children. Half the subjects possessed normal reading skills, while the other half read at a third grade level. Words directed to the left cerebral hemisphere (right field words) were recognized significantly more often (P < 0.005)
This paper describes and evaluates a new technique for measuring confidence in word strings produced by speech recognition systems. It detects misrecognized and out-of-vocabulary words in spontaneous spoken dialogs. The system uses multiple, diverse knowl...
Cross-modal semantic priming and phoneme monitoring experiments investigated processing of word-final nonreleased stop consonants (e.g., kit may be pronounced /kit/ or /ki/), which are common phonological variants in American English. Both voiced /d/ and voiceless /t/ segments were presented in release and no-release versions. A cross-modal semantic priming task (Experiment 1) showed comparable priming for /d/ and /t/ versions. A second set of stimuli ending in /s/ were presented as intact, missing /s/, or with a mismatching final segment and showed significant but reduced priming for the latter two conditions. Experiment 2 showed that phoneme monitoring reaction time for release and no-release words and onset mismatching stimuli (derived pseudowords) increased as acoustic-phonetic similarity to the intended word decreased. The results suggest that spoken wordrecognition does not require special mechanisms for processing no-release variants. Rather, the results can be accounted for by means of existing assumptions concerning probabilistic activation that is based on partial activation. PMID:11424652
Analyses of lexical decision studies revealed that (a) older (O) adults' mean semantic priming effect was 1.44 times that of younger (Y) adults, (b) regression lines describing the relations between older and younger adults' latencies in related (O = 1.54 Y-112 and unrelated conditions (O = 1.50 Y-93) were not significantly different, and (c) that there was a proportional relation between older and younger adults' priming effects (O = 1.48 Y-2). Analyses of word-naming studies yielded similar results. Analyses of delayed pronunciation data (Balota & Duchek, 1988) revealed that wordrecognition was 1.47 times slower in older adults, whereas older adults' output processes were only 1.26 times slower. Overall, analyses of whole latencies and durations of component processes provide converging evidence for a general slowing factor of approximately 1.5 for lexical information processing. PMID:1610515
Five hyperlexic boys (4-5 to 10-1 years), who had been diagnosed with infantile autism or pervasive developmental delay in early childhood, were evaluated. Measures of intelligence, single-wordrecognition and comprehension, and picture naming were administered to determine the precocity or deficiency of reading recognition and comprehension, the underlying mechanisms of oral reading, and possible parallels with the acquired dyslexia subtypes. The results indicated that hyperlexia may be operationalized as unexpected reading precocity as compared to IQ; however, reading comprehension was not unexpectedly deficient. The phonological route to reading appeared to be preferred to the lexical route, and the overall pattern of performance most closely paralleled that of the surface dyslexic subtype. PMID:3651809
We propose a novel automatic targetrecognition (ATR) system for classification of three types of ground vehicles in the MSTAR public release database. First, each image chip is pre-processed by extracting fine and raw feature sets, where raw features compensate for the target pose estimation error that corrupts fine image features. Then, the chips are classified by using the adaptive boosting (AdaBoost) algorithm with the radial basis function (RBF) net as the base learner. Since the RBF net is a binary classifier, we decompose our multiclass problem into a set of binary ones through the error-correcting output codes (ECOC) method, specifying a dictionary of code words for the set of three possible classes. AdaBoost combines the classification results of the RBF net for each binary problem into a code word, which is then "decoded" as one of the code words (i.e., ground-vehicle classes) in the specified dictionary. Along with classification, within the AdaBoost framework, we also conduct efficient fusion of the fine and raw image-feature vectors. The results of large-scale experiments demonstrate that our ATR scheme outperforms the state-of-the-art systems reported in the literature.
Speech perception requires listeners to integrate multiple cues that each contribute to judgments about a phonetic category. Classic studies of trading relations assessed the weights attached to each cue, but did not explore the time-course of cue-integration. Here we provide the first direct evidence that asynchronous cues to both voicing (b/p) and manner (b/w) contrasts become available to the listener at different times during spoken wordrecognition. Using the Visual World paradigm, we show that the probability of eye movements to pictures of target and competitor objects diverge at different points in time after the onset of the targetword. These points of divergence correspond to the availability of early (voice-onset-time or formant transition slope) and late (vowel length) cues to voicing and manner contrasts. These results support a model of cue-integration in which phonetic cues are used for lexical access as soon as they are available.
McMurray, Bob; Clayards, Meghan A.; Tanenhaus, Michael K.; Aslin, Richard N.
Although previous research has established that multiple top-down factors guide the identification of words during speech processing, the ultimate range of information sources that listeners integrate from different levels of linguistic structure is still unknown. In a set of experiments, we investigate whether comprehenders can integrate information from the 2 most disparate domains: pragmatic inference and phonetic perception. Using contexts that trigger pragmatic expectations regarding upcoming coreference (expectations for either he or she), we test listeners' identification of phonetic category boundaries (using acoustically ambiguous words on the /hi/?/?i/ continuum). The results indicate that, in addition to phonetic cues, wordrecognition also reflects pragmatic inference. These findings are consistent with evidence for top-down contextual effects from lexical, syntactic, and semantic cues, but they extend this previous work by testing cues at the pragmatic level and by eliminating a statistical-frequency confound that might otherwise explain the previously reported results. We conclude by exploring the time course of this interaction and discussing how different models of cue integration could be adapted to account for our results. PMID:22250908
The ability to recognize spoken words interrupted by silence was investigated with young normal-hearing listeners and older listeners with and without hearing impairment. Targetwords from the revised SPIN test by Bilger et al. [J. Speech Hear. Res. 27(1), 32–48 (1984)] were presented in isolation and in the original sentence context using a range of interruption patterns in which portions of speech were replaced with silence. The number of auditory “glimpses” of speech and the glimpse proportion (total duration glimpsed/word duration) were varied using a subset of the SPIN targetwords that ranged in duration from 300 to 600?ms. The words were presented in isolation, in the context of low-predictability (LP) sentences, and in high-predictability (HP) sentences. The glimpse proportion was found to have a strong influence on wordrecognition, with relatively little influence of the number of glimpses, glimpse duration, or glimpse rate. Although older listeners tended to recognize fewer interrupted words, there was considerable overlap in recognition scores across listener groups in all conditions, and all groups were affected by interruption parameters and context in much the same way.
We used ERPs to investigate the time course of interactions between lexical semantic and sublexical visual word form processing during wordrecognition. Participants read sentence-embedded pseudowords that orthographically resembled a contextually supported real word (e.g., "She measured the flour so she could bake a ceke…") or did not (e.g., "She measured the flour so she could bake a tont…") along with nonword consonant strings (e.g., "She measured the flour so she could bake a srdt…"). Pseudowords that resembled a contextually supported real word ("ceke") elicited an enhanced positivity at 130 msec (P130), relative to real words (e.g., "She measured the flour so she could bake a cake…"). Pseudowords that did not resemble a plausible real word ("tont") enhanced the N170 component, as did nonword consonant strings ("srdt"). The effect pattern shows that the visual wordrecognition system is, perhaps, counterintuitively, more rapidly sensitive to minor than to flagrant deviations from contextually predicted inputs. The findings are consistent with rapid interactions between lexical and sublexical representations during wordrecognition, in which rapid lexical access of a contextually supported word (CAKE) provides top-down excitation of form features ("cake"), highlighting the anomaly of an unexpected word "ceke." PMID:21981670
|Empirical work and models of visual wordrecognition have traditionally focused on group-level performance. Despite the emphasis on the prototypical reader, there is clear evidence that variation in reading skill modulates wordrecognition performance. In the present study, we examined differences among individuals who contributed to the English…
Yap, Melvin J.; Balota, David A.; Sibley, Daragh E.; Ratcliff, Roger
This study focused on developmental wordrecognition strategies used by first language (L1) English readers of second language (L2) Japanese. There were two proficiency groups of Japanese learners. The study considered whether or not wordrecognition strategies are developmental and whether or not L1 orthographic interference (i.e., involvement of…
|The nature of wordrecognition difficulties in developmental dyslexia is still a topic of controversy. We investigated the contribution of phonological processing deficits and uncertainty to the wordrecognition difficulties of dyslexic children by mathematical diffusion modeling of visual and auditory lexical decision data. The first study…
Zeguers, Maaike H. T.; Snellings, Patrick; Tijms, Jurgen; Weeda, Wouter D.; Tamboer, Peter; Bexkens, Anika; Huizenga, Hilde M.
This article first presents a conception of wordrecognition involving both phonological and orthographic processes. Three different explanations about the origin of orthographic processes in wordrecognition are then discussed. These explanations are: (1) differences in orthographic memory, (2) differences in phonological processes and (3) differences in leisure time reading. In accord with the third explanation, it is argued that
|Many studies in bilingual visual wordrecognition have demonstrated that lexical access is not language selective. However, research on bilingual wordrecognition in the auditory modality has been scarce, and it has yielded mixed results with regard to the degree of this language nonselectivity. In the present study, we investigated whether…
Lagrou, Evelyne; Hartsuiker, Robert J.; Duyck, Wouter
Several parametric representations of the acoustic signal were compared with regard to wordrecognition performance in a syllable-oriented continuous speech recognition system. The vocabulary included many phonetically similar monosyllabic words, therefore the emphasis was on the ability to retain phonetically significant acoustic information in the face of syntactic and duration variations. For each parameter set (based on a mel-frequency cepstrum,
This paper presents visual detection and recognition of flying targets (e.g. planes, missiles) based on automatically extracted shape and object texture information, for application areas like alerting, recognition and tracking. Targets are extracted based on robust background modeling and a novel contour extraction approach, and object recognition is done by comparisons to shape and texture based query results on a
Levente Kovács; Ákos Utasi; Andrea Kovács; Tamás Szirányi
This paper describes the results of our work in designing a system for large-vocabulary wordrecognition of continuous speech. We generalize the use of context-dependent Hidden Markov Models (HMM) of phonemes to take into account word-dependent coarticulatory effects, Robustness is assured by smoothing the detailed word-dependent models with less detailed but more robust models. We describe training and recognition algorithms
Yen-Lu Chow; Richard Schwartz; Salim Roucos; Owen Kimball; P. Price; F. Kubala; M. Dunham; M. Krasner; J. Makhoul
|Across 3 different wordrecognition tasks, distributional analyses were used to examine the joint effects of stimulus quality and word frequency on underlying response time distributions. Consistent with the extant literature, stimulus quality and word frequency produced additive effects in lexical decision, not only in the means but also in the…
Purpose: To construct a table for upper and lower limits of the 95% critical range for changes in wordrecognition scores obtained with monosyllabic word lists (of lengths 10, 25, 50, and 100 words) using newly available methods. Although such a table has been available for nearly 30 years (A. R. Thornton & M. J. M. Raffin, 1978), the earlier…
|Purpose: To construct a table for upper and lower limits of the 95% critical range for changes in wordrecognition scores obtained with monosyllabic word lists (of lengths 10, 25, 50, and 100 words) using newly available methods. Although such a table has been available for nearly 30 years (A. R. Thornton & M. J. M. Raffin, 1978), the earlier…
|The present study investigated whether the balance of neighborhood distribution (i.e., the way orthographic neighbors are spread across letter positions) influences visual wordrecognition. Three word conditions were compared. Word neighbors were either concentrated on one letter position (e.g.,nasse/basse-lasse-tasse-masse) or were unequally…
Robert, Christelle; Mathey, Stephanie; Zagar, Daniel
The government of Bangladesh introduced national ID cards in 2008 for all peoples of age 18 years and above. This card is now a de-facto identity document and finds diverse applications in vote casting, bank account opening, telephone subscribing as well as in many real life transactions and security checking. To get real fruits of this versatile ID card, automated retrieving and recognition of an independent person from this extra large national database is an ultimate necessity. This work is the first step to fill this gap in making the recognition in automated fashion. Here we have investigated an image analysis technique to extract the words that will be used in subsequent recognition steps. At first scanned ID card image is used as an input into the computer system and then the target text region is separated from the picture region. The text region is used for separation of lines and words on the basis of the vertical and horizontal projections of image intensity, respectively. Experimentation using real national ID cards confirms the effectiveness of our technique.
Akhter, Md. Rezwan; Bhuiyan, Md. Hasanuzzaman; Uddin, Mohammad Shorif
Listeners identified a phonetically balanced set of consonant-vowel-consonant (CVC) words and nonsense syllables in noise at four signal-to-noise ratios. The identification scores for phonemes and syllables were analyzed using the j-factor model [Boothroyd and Nittrouer, J. Acoust. Soc. Am. 84, 101-114 (1988)], which measures the perceptual independence of the parts of a whole. Results indicate that nonsense CVC syllables are perceived as having three independent phonemes, while words show j=2.34 independent units. Among the words, high-frequency words are perceived as having significantly fewer independent units than low-frequency words. Words with dense phonetic neighborhoods are perceived as having 0.5 more independent units than words with sparse neighborhoods. The neighborhood effect in these data is due almost entirely to density as determined by the initial consonant and vowel, demonstrated in analyses by subjects and items, and correlation analyses of syllable recognition with the neighborhood activation model [Luce and Pisoni, Ear Hear. 19, 1-36 (1998)]. The j factors are interpreted as measuring increased efficiency of the perception of word-final consonants of words in sparse neighborhoods during spoken wordrecognition.
A fuzzy expert system for selected Arabic sub-wordsrecognition is presented in this paper. For each sub-word pattern, membership values are determined for a number of fuzzy sets defined on the features extracted from the pattern. These sub-words consist of two characters and are written cursively, so, the first step is to segment the sub-words into two objects, main and
A normative study was conducted using the Deese\\/Roediger–McDermott paradigm (DRM) to obtain false recognition for 60 six-word\\u000a lists in Spanish, designed with a completely new methodology. For the first time, lists included words (e.g., bridal, newlyweds, bond, commitment, couple, to marry) simultaneously associated with three critical words (e.g., love, wedding, marriage). Backward associative strength between lists and critical words was
Automatic targetrecognition that relies on rapid feature extraction of real-time target from photo-realistic imaging will enable efficient identification of target patterns. To achieve this objective, Cross-plots of binary patterns are explored as potential signatures for the observed target by high-speed capture of the crucial spatial features using minimal computational resources. Targetrecognition was implemented based on the proposed pattern recognition concept and tested rigorously for its precision and recall performance. We conclude that Cross-plotting is able to produce a digital fingerprint of a target that correlates efficiently and effectively to signatures of patterns having its identity in a target repository.
According to current models, spoken wordrecognition is driven by the phonological properties of the speech signal. However, several studies have suggested that orthographic information also influences recognition in adult listeners. In particular, it has been repeatedly shown that, in the lexical decision task, words that include rimes with inconsistent spellings (e.g., /-ip/ spelled -eap or -eep) are disadvantaged, as compared with words with consistent rime spelling. In the present study, we explored whether the orthographic consistency effect extends to tasks requiring people to process words beyond simple lexical access. Two different tasks were used: semantic and gender categorization. Both tasks produced reliable consistency effects. The data are discussed as suggesting that orthographic codes are activated during wordrecognition, or that the organization of phonological representations of words is affected by orthography during literacy acquisition. PMID:19293108
Peereman, Ronald; Dufour, Sophie; Burt, Jennifer S
|Clustering coefficient--a measure derived from the new science of networks--refers to the proportion of phonological neighbors of a targetword that are also neighbors of each other. Consider the words "bat", "hat", and "can", all of which are neighbors of the word "cat"; the words "bat" and "hat" are also neighbors of each other. In a perceptual…
Clustering coefficient--a measure derived from the new science of networks--refers to the proportion of phonological neighbors of a targetword that are also neighbors of each other. Consider the words "bat", "hat", and "can", all of which are neighbors of the word "cat"; the words "bat" and "hat" are also neighbors of each other. In a perceptual…
|Reports on a study in which subjects heard the beginnings of spoken words, followed by increasingly larger segments of word-onset information until the words could be correctly identified. Results are discussed in terms of word-initial phonology as a trigger for response activation. (34 references) (Author/OD)|
People can discriminate real words from nonwords even when the latter are orthographically and phonologically word-like, presumably because words activate specific lexical and\\/or semantic information. We investigated the neural correlates of this identification process using event-related functional magnetic resonance imaging (fMRI). Participants performed a visual lexical decision task under conditions that encouraged specific word identification: Nonwords were matched to words
J. R. Binder; K. A. McKiernan; M. E. Parsons; C. F. Westbury; E. T. Possing; J. N. Kaufman; L. Buchanan
Three eye movement studies with novel lexicons investigated the role of semantic context in spoken wordrecognition, contrasting three models: restrictive access, access-selection and continuous integration. Actions directed at novel shapes caused changes in motion (e.g., looming, spinning, etc.) or state (color, texture, etc.). Across the experiments, novel names for the actions and the shapes varied in frequency, cohort density, and whether the cohorts referred to actions (Experiment 1) or shapes with action-congruent or incongruent affordances (Experiments 2 and 3). Experiment 1 demonstrated effects of frequency and cohort competition from both displayed and non-displayed competitors. In Experiment 2 a biasing context induced an increase in anticipatory eye movements to congruent referents and reduced the probability of looks to incongruent cohorts, without the delay predicted by access-selection models. In Experiment 3, context did not reduce competition from non-displayed incompatible neighbors as predicted by restrictive access models. We conclude that the results are most consistent with continuous integration models.
Revill, Kathleen Pirog; Tanenhaus, Michael K.; Aslin, Richard N.
Three eye movement studies with novel lexicons investigated the role of semantic context in spoken wordrecognition, contrasting 3 models: restrictive access, access-selection, and continuous integration. Actions directed at novel shapes caused changes in motion (e.g., looming, spinning) or state (e.g., color, texture). Across the experiments, novel names for the actions and the shapes varied in frequency, cohort density, and whether the cohorts referred to actions (Experiment 1) or shapes with action-congruent or action-incongruent affordances (Experiments 2 and 3). Experiment 1 demonstrated effects of frequency and cohort competition from both displayed and non-displayed competitors. In Experiment 2, a biasing context induced an increase in anticipatory eye movements to congruent referents and reduced the probability of looks to incongruent cohorts, without the delay predicted by access-selection models. In Experiment 3, context did not reduce competition from non-displayed incompatible neighbors as predicted by restrictive access models. The authors conclude that the results are most consistent with continuous integration models. PMID:18763901
Revill, Kathleen Pirog; Tanenhaus, Michael K; Aslin, Richard N
The role of morphological, semantic, and form-based factors in the early stages of visual wordrecognition was investigated across different SOAs in a masked priming paradigm, focusing on English derivational morphology. In a first set of experiments, stimulus pairs co-varying in morphological decomposability and in semantic and orthographic relatedness were presented at three SOAs (36, 48, and 72 ms). No effects of orthographic relatedness were found at any SOA. Semantic relatedness did not interact with effects of morphological decomposability, which came through strongly at all SOAs, even for pseudo-suffixed pairs such as archer-arch. Derivational morphological effects in masked priming seem to be primarily driven by morphological decomposability at an early stage of visual wordrecognition, and are independent of semantic factors. A second experiment reversed the order of prime and target (stem-derived rather than derived-stem), and again found that morphological priming did not interact with semantic relatedness. This points to an early segmentation process that is driven by morphological decomposability and not by the structure or content of central lexical representations.
Marslen-Wilson, William D.; Bozic, Mirjana; Randall, Billi
In this paper, we present a novel method to extract stroke order independent information from online data. This information, which we term pseudo-online, conveys relevant information on the offline representation of the word. Based on this information, a combination of classification decisions from online and pseudo-online cursive word recognizers is performed to improve the recognition of online cursive words. One of the most valuable aspects of this approach with respect to similar methods that combine online and offline classifiers for wordrecognition is that the pseudo-online representation is similar to the online signal and, hence, wordrecognition is based on a single engine. Results demonstrate that the pseudo-online representation is useful as the combination of classifiers perform better than those based solely on pure online information. PMID:15875790
The task of identifying objects in images is a common requirement for many image processing systems. The identification of these objects (also called models) is in some contexts called automatic targetrecognition (ATR). TargetRecognition algorithms are well suited to hardware field programmable gate array (FPGA) implementations because of their extensive use of bit- level operations and their amenability to
The present study examined how contextual learning and in particular emotionality conditioning impacts the neural processing of words, as possible key factors for the acquisition of words' emotional connotation. 21 participants learned on five consecutive days associations between meaningless pseudowords and unpleasant or neutral pictures using an evaluative conditioning paradigm. Subsequently, event-related potentials were recorded while participants implicitly processed the learned emotional relevance in a lexical decision paradigm. Emotional and neutral words were presented together with the conditioned pseudowords and a set of new pseudowords. Conditioned and new pseudowords differed in the late positive complex. Emotionally and neutrally conditioned stimuli differed in an early time window (80-120 ms) and in the P300. These results replicate ERP effects known from emotion wordrecognition and indicate that contextual learning and in particular evaluative conditioning is suitable to establish emotional associations in words, and to explain early ERP effects in emotion wordrecognition. PMID:23291494
|Three experiments were conducted to investigate how syntactic-category and semantic information is processed in visual wordrecognition. The stimuli were two-character Chinese words in which semantic and syntactic-category ambiguities were factorially manipulated. A lexical decision task was employed in Experiment 1, whereas a semantic…
|Spoken wordrecognition, during gating, appears intact in specific language impairment (SLI). This study used gating to investigate the process in adolescents with autism spectrum disorders plus language impairment (ALI). Adolescents with ALI, SLI, and typical language development (TLD), matched on nonverbal IQ listened to gated words that varied…
Sentence comprehension (SC) studies in typical and impaired readers suggest that reading for meaning involves more extensive brain activation than reading isolated words. Thus far, no reading disability\\/dyslexia (RD) studies have directly controlled for the wordrecognition (WR) components of SC tasks, which is central for understanding comprehension processes beyond WR. This exper- iment compared SC to WR in 29,
S. L. Rimrodt; A. M. Clements-Stephens; K. R. Pugh; S. M. Courtney; P. Gaur; J. J. Pekar
Four tachistoscopic forced-choice recognition experiments (with 153 paid volunteers) explored the flexibility of processes underlying word perception. Stimuli were words, orthographically regular but unfamiliar pseudowords, and orthographically irregular nonsense strings. In Exps I and II, Ss knew that several kinds of stimuli would occur in each block of trials and that one kind would occur more often than the others.
Thomas H. Carr; Brian J. Davidson; Harold L. Hawkins
This paper compares the word error rate of a speech recognizer using several signal processing front ends based on auditory properties. Front ends were compared with a control mel filter bank (MFB) based cepstral front end in clean speech and with speech degraded by noise and spectral variability, using the TI-105 isolated word database. MFB recognition error rates ranged from
Charles R. Jankowski Jr; Hoang-Doan H. Vo; Richard P. Lippmann
Three experiments were conducted to investigate how syntactic-category and semantic information is processed in visual wordrecognition. The stimuli were two-character Chinese words in which semantic and syntactic-category ambiguities were factorially manipulated. A lexical decision task was employed in Experiment 1, whereas a semantic relatedness…
Explored genetic and environmental etiologies of individual differences in printed wordrecognition and related skills in identical and fraternal twin 8- to 18-year-olds. Found evidence for moderate genetic influences common between IQ, phoneme awareness, and word-reading skills and for stronger IQ-independent genetic influences that were common…
Tasks of word reading in Chinese and English; nonverbal IQ; speeded naming; and units of syllable onset (a phoneme measure), syllable, and tone detection awareness were administered to 211 Hong Kong Chinese children ages 4 and 5. In separate regression equations, syllable awareness was equally associated with Chinese and English wordrecognition. In contrast, syllable onset awareness was uniquely associated
|Three experiments assessed the contributions of age-of-acquisition (AoA) and frequency to visual wordrecognition. Three databases were created from electronic journals in chemistry, psychology and geology in order to identify technical words that are extremely frequent in each discipline but acquired late in life. In Experiment 1, psychologists…
Stadthagen-Gonzalez, Hans; Bowers, Jeffrey S.; Damian, Markus F.
Recognition of a spoken word phonological variant—schwa vowel deletion (e.g., corporate ? corp’rate)— was investigated in vowel detection (absent\\/present) and syllable number judgment (two or three syllables) tasks. Variant\\u000a frequency corpus analyses (Patterson, LoCasto, & Connine, 2003) were used to select words with either high or low schwa vowel\\u000a deletion rates. Speech continua were created for each word in which
Cynthia M. Connine; Larissa J. Ranbom; David J. Patterson
We investigated the visual wordrecognition ability of M.T., a young boy with surface dyslexia, by means of a paradigm that measures performance as a function of the eye fixation position within the word, known as the “viewing-position effect” paradigm. In well-achieving readers, the viewing-position effect is mainly determined by factors affecting letter visibility and by lexical constraints on word
Matthieu Dubois; Pierre Lafaye De Micheaux; Marie-Pascale Noël; Sylviane Valdois
Previous work has shown that German-learning 7-9-month-old infants recognize function words (Hoehle and Weissenborn, 2003). English-learning infants recognize function words around 10.5-11 months (Schafer et al. 1998; Shady, 1996; Shi et al., 2003, 2004), and the highly frequent determiner ``the'' at 8 months (Shi et al., 2004). The present study investigates French-learning infants' recognition of function words. As French is
Four experiments are reported that investigate processing of mispronounced words for which the phonological form is inconsistent with the graphemic form (words spelled with silent letters). Words produced as mispronunciations that are consistent with their spelling were more confusable with their citation form counterpart than mispronunciations that are inconsistent with their spelling in a same\\/different task. Cross-modal repetition priming for
|Four experiments are reported that investigate processing of mispronounced words for which the phonological form is inconsistent with the graphemic form (words spelled with silent letters). Words produced as mispronunciations that are consistent with their spelling were more confusable with their citation form counterpart than mispronunciations…
Four experiments are reported that investigate processing of mispronounced words for which the phonological form is inconsistent with the graphemic form (words spelled with silent letters). Words produced as mispronunciations that are consistent with their spelling were more confusable with their citation form counterpart than mispronunciations…
Subjects were presented with the French words “dure” and “douce” (hard and soft) uttered in either a hard or a soft intonation. When the task was to recognise the word, no ear difference was observed in reaction times. However, when the phonologically similar words “dune” and “douze” (sand-hill and twelve) were presented and uttered in the same intonations, there was
This paper proposes a new isolated wordrecognition technique based on a combination of instantaneous and dynamic features of the speech spectrum. This technique is shown to be highly effective in speaker-independent speech recognition. Spoken utterances are represented by time sequences of cepstrum coefficients and energy. Regression coefficients for these time functions are extracted for every frame over an approximately
In this paper speech theories and some methodological concerns about feature extraction and classification techniques widely used in speech recognition system are surveyed and discussed. The shortage of isolated word speech recognition is addressed as compared to its phoneme-based counterpart. This paper could be regarded as a very early stage towards methodology establishment in searching for better accuracy and less
M. A. Yusnita; M. P. Paulraj; Sazali Yaacob; Shahriman Abu Bakar; A. Saidatul; Ahmad Nazri Abdullah
|Seeks to discover whether listening to songs over an extended period of time contributes to a greater integration of words and music in memory among preschool children. Finds more accurate recognition of songs performed without text when they had heard them previously with texts and that melodic content influenced song-recognition ability. (DSK)|
Feierabend, John M.; Saunders, T. Clark; Getnick, Pamela E.; Holahan, John M.
Target and pattern recognition systems are in widespread use. Efforts have been made in all areas of pattern recognition to increase the performance of these systems. Feature extraction, feature selection, and classification are the major aspects of a tar...
Robust real-time recognition of multiple targets with varying pose requires heavy computational loads, which are often too demanding to be performed online at the sensor location. Thus an important problem is the performance of ATR algorithms on highly-compressed video sequences transmitted to a remote facility. We investigate the effects of H.264 video compression on correlation-based recognition algorithms. Our primary test bed is a collection of fifty video sequences consisting of long-wave infrared (LWIR) and mid-wave infrared (MWIR) imagery of ground targets. The targets are viewed from an aerial vehicle approaching the target, which introduces large amounts of scale distortion across a single sequence. Each sequence is stored at seven different levels of compression, including the uncompressed version. We employ two different types of correlation filters to perform frame-by-frame targetrecognition: optimal tradeoff synthetic discriminant function (OTSDF) filters and a new scale-tolerant filter called fractional power Mellin radial harmonic (FPMRH) filters. In addition, we apply the Fisher metric to compressed target images to evaluate target class separability and to estimate recognition performance as a function of video compression rate. Targets are centered and cropped according to ground truth data prior to separability analysis. We compare our separability estimates with the actual recognition rates achieved by the best correlation filter for each sequence. Numerical results are provided for several targetrecognition examples.
Kerekes, Ryan A.; Vijaya Kumar, B. V. K.; Sims, S. Richard F.
This study tests the hypothesis that function words are among the earliest word forms segmented by preverbal infants. In a visual fixation procedure, French-learning 8-month-old infants were familiarized to a function word, mes or ta. All infants were then tested with passages containing mes vs. ta. Looking times during the presentation of the two passage types were expected to differ
In a series of experiments, the authors investigated the effects of talker variability on children’s wordrecognition. In Experiment 1, when stimuli were presented in the clear, 3- and 5-year-olds were less accurate at identifying words spoken by multiple talkers than those spoken by a single talker when the multiple-talker list was presented first. In Experiment 2, when words were presented in noise, 3-, 4-, and 5-year-olds again performed worse in the multiple-talker condition than in the single-talker condition, this time regardless of order; processing multiple talkers became easier with age. Experiment 3 showed that both children and adults were slower to repeat words from multiple-talker than those from single-talker lists. More important, children (but not adults) matched acoustic properties of the stimuli (specifically, duration). These results provide important new information about the development of talker normalization in speech perception and spoken wordrecognition.
We examined the effects of sensorimotor experience in two visual wordrecognition tasks. Body-object interaction (BOI) ratings were collected for a large set of words. These ratings assess perceptions of the ease with which a human body can physically interact with a word's referent. A set of high BOI words (e.g., "mask") and a set of low BOI…
Siakaluk, Paul D.; Pexman, Penny M.; Aguilera, Laura; Owen, William J.; Sears, Christopher R.
|We examined the effects of sensorimotor experience in two visual wordrecognition tasks. Body-object interaction (BOI) ratings were collected for a large set of words. These ratings assess perceptions of the ease with which a human body can physically interact with a word's referent. A set of high BOI words (e.g., "mask") and a set of low BOI…
Siakaluk, Paul D.; Pexman, Penny M.; Aguilera, Laura; Owen, William J.; Sears, Christopher R.
A novel recognition method is proposed to relax the heavy requirement of training set size in the radar High Resolution Range Profile (HRRP) targetrecognition. Firstly, the statistical characteristic of HRRP's frequency spectrum is analyzed and considered to be a wide-sense stationary process. Then a linear dynamic model is introduced to describe the frequency spectrum amplitude and an Expectation Maximization
Wang Penghui; Du Lan; Pan Mian; Zhang Xuefeng; Liu Hongwei
Much research has explored how spoken wordrecognition is influenced by the architecture and dynamics of the mental lexicon (e.g., Luce and Pisoni, 1998; McClelland and Elman, 1986). A more recent question is whether the processes underlying wordrecognition are unique to the auditory domain, or whether visually perceived (lipread) speech may also be sensitive to the structure of the mental lexicon (Auer, 2002; Mattys, Bernstein, and Auer, 2002). The current research was designed to test the hypothesis that both aurally and visually perceived spoken words are isolated in the mental lexicon as a function of their modality-specific perceptual similarity to other words. Lexical competition (the extent to which perceptually similar words influence recognition of a stimulus word) was quantified using metrics that are well-established in the literature, as well as a statistical method for calculating perceptual confusability based on the phi-square statistic. Both auditory and visual spoken wordrecognition were influenced by modality-specific lexical competition as well as stimulus word frequency. These findings extend the scope of activation-competition models of spoken wordrecognition and reinforce the hypothesis (Auer, 2002; Mattys et al., 2002) that perceptual and cognitive properties underlying spoken wordrecognition are not specific to the auditory domain. In addition, the results support the use of the phi-square statistic as a better predictor of lexical competition than metrics currently used in models of spoken wordrecognition.
Empirical work and models of visual wordrecognition have traditionally focused on group-level performance. Despite the emphasis on the prototypical reader, there is clear evidence that variation in reading skill modulates wordrecognition performance. In the present study, we examined differences between individuals who contributed to the English Lexicon Project (http://elexicon.wustl.edu), an online behavioral database containing nearly four million wordrecognition (speeded pronunciation and lexical decision) trials from over 1,200 participants. We observed considerable within- and between-session reliability across distinct sets of items, in terms of overall mean response time (RT), RT distributional characteristics, diffusion model parameters (Ratcliff, Gomez, & McKoon, 2004), and sensitivity to underlying lexical dimensions. This indicates reliably detectable individual differences in wordrecognition performance. In addition, higher vocabulary knowledge was associated with faster, more accurate wordrecognition performance, attenuated sensitivity to stimuli characteristics, and more efficient accumulation of information. Finally, in contrast to suggestions in the literature, we did not find evidence that individuals were trading-off in their utilization of lexical and nonlexical information.
Yap, Melvin J.; Balota, David A.; Sibley, Daragh E.; Ratcliff, Roger
We examined cortical activity in early blind during wordrecognition memory. Nine participants were blind at birth and one by 1.5years. In an event-related design, we studied blood oxygen level-dependent responses to studied ("old") compared to novel ("new") words. Presentation mode was in Braille or spoken. Responses were larger for identified "new" words read with Braille in bilateral lower and higher tier visual areas and primary somatosensory cortex. Responses to spoken "new" words were larger in bilateral primary and accessory auditory cortex. Auditory cortex was unresponsive to Braille words and occipital cortex responded to spoken words but not differentially with "old"/"new" recognition. Left dorsolateral prefrontal cortex had larger responses to "old" words only with Braille. Larger occipital cortex responses to "new" Braille words suggested verbal memory based on the mechanism of recollection. A previous report in sighted noted larger responses for "new" words studied in association with pictures that created a distinctiveness heuristic source factor which enhanced recollection during remembering. Prior behavioral studies in early blind noted an exceptional ability to recall words. Utilization of this skill by participants in the current study possibly engendered recollection that augmented remembering "old" words. A larger response when identifying "new" words possibly resulted from exhaustive recollecting the sensory properties of "old" words in modality appropriate sensory cortices. The uniqueness of a memory role for occipital cortex is in its cross-modal responses to coding tactile properties of Braille. The latter possibly reflects a "sensory echo" that aids recollection. PMID:22251836
Background The existence and function of unilateral hemispheric projections within foveal vision may substantially affect foveal wordrecognition. The purpose of this research was to reveal these projections and determine their functionality. Methodology Single words (and pseudowords) were presented to the left or right of fixation, entirely within either foveal or extrafoveal vision. To maximize the likelihood of unilateral projections for foveal displays, stimuli in foveal vision were presented away from the midline. The processing of stimuli in each location was assessed by combining behavioural measures (reaction times, accuracy) with on-line monitoring of hemispheric activity using event-related potentials recorded over each hemisphere, and carefully-controlled presentation procedures using an eye-tracker linked to a fixation-contingent display. Principal Findings Event-related potentials 100–150 ms and 150–200 ms after stimulus onset indicated that stimuli in extrafoveal and foveal locations were projected unilaterally to the hemisphere contralateral to the presentation hemifield with no concurrent projection to the ipsilateral hemisphere. These effects were similar for words and pseudowords, suggesting this early division occurred before wordrecognition. Indeed, event-related potentials revealed differences between words and pseudowords 300–350 ms after stimulus onset, for foveal and extrafoveal locations, indicating that wordrecognition had now occurred. However, these later event-related potentials also revealed that the hemispheric division observed previously was no longer present for foveal locations but remained for extrafoveal locations. These findings closely matched the behavioural finding that foveal locations produced similar performance each side of fixation but extrafoveal locations produced left-right asymmetries. Conclusions These findings indicate that an initial division in unilateral hemispheric projections occurs in foveal vision away from the midline but is not apparent, or functional, when foveal wordrecognition actually occurs. In contrast, the division in unilateral hemispheric projections that occurs in extrafoveal locations is still apparent, and is functional, when extrafoveal wordrecognition takes place.
Rather than emitting pulses, passive radar systems rely on illuminators of opportunity, such as TV and FM radio, to illuminate potential targets. These systems are particularly attractive since they allow receivers to operate without emitting energy, rendering them covert. Many existing passive radar systems estimate the locations and velocities of targets. This paper focuses on adding an automatic targetrecognition
JPL is developing a comprehensive Automatic TargetRecognition (ATR) system that consists of an innovative anomaly detection preprocessing module and an automatic training targetrecognition module. The anomaly detection module is trained with an imaging data feature retrieved from an imaging sensor suite that represents the states of the normalcy model. The normalcy model is then trained from a self-organizing learning system over a period of time and fed into the anomaly detection module for scene anomaly monitoring and detection. The "abnormal" event detection will be sent to a human operator for further investigation responses. The targetrecognition will be continuously updated with the "normal' input sensor data. The combination of the anomaly detection preprocessing module to the re-trainable targetrecognition processor will result in a dynamic ATR system that is capable of automatic detection of anomaly event and provide an early warning to a human operator for in-time warning and response.
The purpose of this research is to demonstrate the application of decision analysis (DA) techniques to the decisions made throughout the lifecycle of Automatic TargetRecognition (ATR) technology development. This work is accomplished in the hopes of impr...
Targetrecognition and identification in battlefields has been a crucial determinant to the ultimate success or failure of modern military campaigns. Since World War II, the Identification of Friend or Foe (IFF) systems installed in radar systems have ser...
With the advantages of stealthiness, all weather effectiveness, visible targetrecognition and long affect distance, infrared thermal imaging system play important role in scouting, aiming and tracking. In order to eliminate influences of thermal camouflage to traditional intensity infrared thermal imaging system, we proposed design method of ARM based infrared camouflage targetrecognition system. Considering the measurement of Stokes parameters, we analyzed design method of polarized image acquisition module, designed ARM core board and its data connection with other devices, adopted LCD to display polarization image computed out by ARM. We also studied embedded Linux platform and polarized image processing program based on this platform, finally actualized the design method of ARM based infrared camouflage targetrecognition system. Results of our experiment show that data stream can be successfully transmitted between modules of the system and the platform we used is fast enough to run polarized image processing program. It's an effective method of using ARM to actualize infrared camouflage targetrecognition system.
Synthetic Aperture Radar (SAR) imaging and Automatic TargetRecognition (ATR) of moving targets pose a significant challenge due to the inherent difficulty of focusing moving targets. As a result, ATR of moving targets has recently received increased interest. High Range Resolution (HRR) radar mode offers an approach for recognizing moving targets by forming focused HRR profiles with significantly enhanced target-to-(clutter+noise)
This study explored recognition memory performance for novel versus familiar words in Alzheimer's disease (AD) patients and normal controls (NCs), using an adaptation of E. Tulving and N. Kroll's (1995) procedure. Results showed that both groups exhibited more hits and more false alarms for familiar than for novel words. The groups did not differ in the recognition of familiar words, reflecting preserved familiarity processes in AD. However, AD patients made more false alarms than NCs in the recognition of novel words, reflecting impairment of recollection processes in AD. A positron emission tomography analysis of clinico-metabolic correlations in AD patients showed a correlation between recognition of novel words and right hippocampal activity, whereas recognition of familiar words was more related to metabolic activity in the left posterior orbitofrontal cortex. PMID:12597083
Lekeu, Françoise; Van der Linden, Martial; Degueldre, Christian; Lemaire, Christian; Luxen, André; Franck, Georges; Moonen, Gustave; Salmon, Eric
Stem homographs are pairs of words with the same orthographic description of their stem but which are semantically and morphologically unrelated (e.g. in Spanish: rata\\/rato (rat\\/moment)). In priming tasks, stem homographs produce inhibition, unlike morphologically related words (loca\\/loco (madwoman\\/madman)) which produce facilitation. An event-related potentials study was conducted to compare morphological and stem homographic priming effects. The results show a
Horacio Barber; Alberto Dom??nguez; Manuel de Vega
Infants’ abilities to discriminate native and non-native phonemes have been extensively investigated in monolingual learners, demonstrating a transition from language-general to language-specific sensitivities over the first year after birth. However, these studies have mostly been limited to the study of vowels and consonants in monolingual learners. There is relatively little research on other types of phonetic segments, such as lexical tone, even though tone languages are very well represented across languages of the world. The goal of the present study is to investigate how Mandarin Chinese-English bilingual learners contend with non-phonemic pitch variation in English spoken wordrecognition. This is contrasted with their treatment of phonemic changes in lexical tone in Mandarin spoken wordrecognition. The experimental design was cross-sectional and three age-groups were sampled (7.5 months, 9 months and 11 months). Results demonstrated limited generalization abilities at 7.5 months, where infants only recognized words in English when matched in pitch and words in Mandarin that were matched in tone. At 9 months, infants recognized words in Mandarin Chinese that matched in tone, but also falsely recognized words that contrasted in tone. At this age, infants also recognized English words whether they were matched or mismatched in pitch. By 11 months, infants correctly recognized pitch-matched and - mismatched words in English but only recognized tonal matches in Mandarin Chinese.
In this work we concentrate on generating compound words with high order n-gram information for speech recognition. In most existing compound words generation methods, only bi-gram information is considered. They are successful for improving the performance of bi-gram models but doesn't work well in higher order n-gram cases. Since nowadays 3gram and 4-gram language models are commonly used, here we
The release-from-competition (RFC) effect, inwhich a difficult concurrent memory task speedspronunciation of low-frequency irregular wordsbut slows pronunciation of other word types,has been interpreted as strong support for thedual-route approach to wordrecognition. However, attempts to replicate this effect havenot produced consistent results. Besides,attempts at replication have mostly beenlimited to skilled readers of English. Thepresent research attempted to replicate the RFCeffect
Infants prefer to listen to happy speech. To assess influences of speech affect on early lexical processing, 7.5- and 10.5-month-old infants were familiarized with one word spoken with happy affect and another with neutral affect and then tested on recognition of these words in fluent passages. Infants heard all passages either with happy affect or with neutral affect. Contrary to
This paper develops wordrecognition methods for historical handwritten cursive and printed documents. It employs a powerful segmentation-free letter detection method based upon joint boosting with histogram-of-gradients features. Ecient inference on an ensemble of hidden Markov models can select the most probable se- quence of candidate character detections to recognize complete words in ambiguous handwritten text, drawing on character n-gram
In most current models of wordrecognition, the wordrecognition process is assumed to be driven by the activation of letter units (i.e., that letters are the perceptual units in reading). An alternative possibility is that the wordrecognition process is driven by the activation of grapheme units, that is, that graphemes, rather than letters, are the perceptual units in reading. If so, there must be representational units for multiletter graphemes like CH and PH, which play a key role in this process. We examined this idea in four masked priming experiments. Primes were created by transposing, replacing entirely, or removing one component of either multiletter graphemes or two adjacent letters that each represented a grapheme, using both English and Spanish stimuli. In none of the experiments was there any evidence of differential priming effects depending on whether the two letters being manipulated formed a single grapheme or formed two separate graphemes. These data are most consistent with the idea that multiletter graphemes have no special status at the earliest stages of word processing and, therefore, that wordrecognition is, indeed, driven by the activation of units for individual letters. PMID:22309089
Lupker, Stephen J; Acha, Joana; Davis, Colin J; Perea, Manuel
Under natural conditions, listeners use both auditory and visual speech cues to extract meaning from speech signals containing many sources of variability. However, traditional clinical tests of spoken wordrecognition routinely employ isolated words or sentences produced by a single talker in an auditory-only presentation format. The more central cognitive processes used during multimodal integration, perceptual normalization and lexical discrimination that may contribute to individual variation in spoken wordrecognition performance are not assessed in conventional tests of this kind. In this paper, we review our past and current research activities aimed at developing a series of new assessment tools designed to evaluate spoken wordrecognition in children who are deaf or hard of hearing. These measures are theoretically motivated by a current model of spoken wordrecognition and also incorporate “real-world” stimulus variability in the form multiple talkers and presentation formats. The goal of this research is to enhance our ability to estimate real-world listening ability and to predict benefit from sensory aid use in children with varying degrees of hearing loss.
MicroRNAs (miRNAs) are short non-coding RNAs that regulate gene expression in plants and animals. Although their biological importance has become clear, how they recognize and regulate target genes remains less well understood. Here, we systematically evaluate the minimal requirements for functional miRNA–target duplexes in vivo and distinguish classes of target sites with different functional properties. Target sites can be grouped
Julius Brennecke; Alexander Stark; Robert B. Russell; Stephen M. Cohen
This paper utilizes game-theoretic principles in the automatic recognition of unknown radar targets. This study uses a non-cooperative matching game where pure strategies are associated with specific items to be matched, and agreement between possible hypotheses represents the payoff gained when playing a certain strategy against an opponent who is playing another strategy. The targetrecognition approach attempts to match scattering centers of an unknown target with those of library targets as competing strategies. The algorithm is tested using real radar data representing scattering from commercial aircraft models. Radar data of library targets at various azimuth positions are matched against an unknown radar target signature at a specific aspect angle. Computer simulations provide an estimate of the error rates in scenarios of additive Gaussian noise corrupting target signatures.
Tulving and Thomson recently contradicted the generation-recognition theory of recall with the phrase 'recognition failure of recallable words.' This phrase, however, is not an admissable summary of their experiments. The word 'light' in the cue-target pa...
A simulation experiment was performed to determine the effects of TV camera lens field of view and target size upon air-to-ground targetrecognition via closed-circuit television. Measures of performance were probability of correct targetrecognition, range of correct recognition, and proportion of errors committed. As the field of view decreased, (1) probability of correct recognition decreased (P < .01), (2)
The boundary paradigm, in combination with parafoveal masks, is the main technique for studying parafoveal preprocessing during reading. The rationale is that the masks (e.g., strings of X's) prevent parafoveal preprocessing, but do not interfere with foveal processing. A recent study, however, raised doubts about the neutrality of parafoveal masks. In the present study, we explored this issue by means of fixation-related brain potentials (FRPs). Two FRP conditions presented rows of five words. The task of the participant was to judge whether the final word of a list was a “new” word, or whether it was a repeated (i.e., “old”) word. The critical manipulation was that the final word was X-masked during parafoveal preview in one condition, whereas another condition presented a valid preview of the word. In two additional event-related brain potential (ERP) conditions, the words were presented serially with no parafoveal preview available; in one of the conditions with a fixed timing, in the other word presentation was self-paced by the participants. Expectedly, the valid-preview FRP condition elicited the shortest processing times. Processing times did not differ between the two ERP conditions indicating that “cognitive readiness” during self-paced processing can be ruled out as an alternative explanation for differences in processing times between the ERP and the FRP conditions. The longest processing times were found in the X-mask FRP condition indicating that parafoveal X-masks interfere with foveal wordrecognition.
|In two experiments, poor and normal Dutch readers, matched for reading age, were presented with visual matching tasks on a computer screen. In the first experiment, word and pseudoword letter strings were used. Poor readers needed more time to decode uppercase/lowercase pairs, especially when the pairs consisted of pseudowords. Experiment 2…
Toddlers’ and preschoolers’ knowledge of the phonological forms of words was tested in Spanish-learning, Catalan-learning, and bilingual children. These populations are of particular interest because of differences in the Spanish and Catalan vowel systems: Catalan has two vowels in a phonetic region where Spanish has only one. The proximity of the Spanish vowel to the Catalan ones might pose special
Marta Ramon-Casas; Daniel Swingley; Núria Sebastián-Gallés; Laura Bosch
Although it is generally believed that the representational characteristics of verbal stimuli (typescript or speaker's voice, for example) persist for a very brief time in sensory memory, some recent studies suggest that such characteristics may persist much longer. The present experiments show that words are recognized faster and more accurately when they are re-presented in the same voice. This same-voice
In this study, we investigate the processing of morphologically complex words in Danish using auditory lexical decision. We document a second critical point in auditory comprehension in addition to the Uniqueness Point (UP), namely the point at which competing morphological continuation forms of the base cease to be compatible with the input,…
|Although previous research has established that multiple top-down factors guide the identification of words during speech processing, the ultimate range of information sources that listeners integrate from different levels of linguistic structure is still unknown. In a set of experiments, we investigate whether comprehenders can integrate…
Models of morphological processing make different predictions about whether morphologically complex written words are initially decomposed and recognized on the basis of their morphemic subunits or whether they can directly be accessed as whole words and at what point semantics begin to influence morphological processing. In this study, we used unprimed and masked primed lexical decision to compare truly suffixed
Most theories of spoken word identification assume that variable speech signals are matched to canonical representations in memory. To achieve this, idiosyncratic voice details are first normalized, allowing direct comparison of the input to the lexicon. This investigation assessed both explicit and implicit memory for spoken words as a function of speakers' voices, delays between study and test, and levels
DARPA/Air Force Research Laboratory Moving and Stationary Target Acquisition and Recognition (MSTAR) program is developing state-of-the-art model based vision approach to Synthetic Aperture Radar (SAR) Automatic TargetRecognition (ATR). The model-based approach requires using off-line developed target models in an on-line hypothesize-and-test manner to compare predicted target signatures with image data and output target reports. Central to this model-based ATR is the PEMS (Predict-Extract-Match-Search) subsystem. The Search module is critical to PEMS by providing intelligent control to traverse the hypothesis feature space. A major MSTAR goal is to demonstrate robust ATR for variations in targets including partially hidden targets. This paper will provide an update on the technology being developed under MSTAR and the status of this model based ATR research, specifically concentrating on the Search Module.
|Method: Complete psychometric functions for phoneme and wordrecognition scores at 8 signal-to-noise ratios from -15 dB to 20 dB were generated for the first 10, 20, and 25, as well as all 50, three-word presentations of the Tri-Word or Computer Assisted Speech Recognition Assessment (CASRA) Test (Gelfand, 1998) based on the results of 12…
Method: Complete psychometric functions for phoneme and wordrecognition scores at 8 signal-to-noise ratios from -15 dB to 20 dB were generated for the first 10, 20, and 25, as well as all 50, three-word presentations of the Tri-Word or Computer Assisted Speech Recognition Assessment (CASRA) Test (Gelfand, 1998) based on the results of 12…
Spoken wordrecognition involves the activation of multiple word candidates on the basis of the initial speech input--the "cohort"--and selection among these competitors. Selection may be driven primarily by bottom-up acoustic-phonetic inputs or it may be modulated by other aspects of lexical representation, such as a word's meaning…
Zhuang, Jie; Randall, Billi; Stamatakis, Emmanuel A.; Marslen-Wilson, William D.; Tyler, Lorraine K.
|The present study addressed the issue of syllable activation during visual recognition of French words. In addition, it was investigated whether word orthographic information underlies syllable effects. To do so, words were selected according to the frequency of their first syllable (high versus low) and the frequency of the orthographic…
|Spoken wordrecognition involves the activation of multiple word candidates on the basis of the initial speech input--the "cohort"--and selection among these competitors. Selection may be driven primarily by bottom-up acoustic-phonetic inputs or it may be modulated by other aspects of lexical representation, such as a word's meaning…
Zhuang, Jie; Randall, Billi; Stamatakis, Emmanuel A.; Marslen-Wilson, William D.; Tyler, Lorraine K.
This study compared visual wordrecognition (speechreading) in video sequences showing either full face or lips plus mandible to 26 normal hearing college students and 4 adults with bilateral sensorineural hearing loss. Percent phoneme correct scores were similar in the two conditions and scores significantly improved for the repeated measure in…
In a tonal language, the identity of a word depends largely on the tonal identification of the contour of vocal fundamental frequency energy of which usually centers in a low frequency of less than 600 Hz. However, cochlear dead region (DR) is present mostly in the frequency range of 2000 Hz to 4000 Hz, and the effect of DR on a tonal language is worth investigating. Thirty-two native Mandarin speakers with moderate-to-severe degree of sensorineural hearing loss were included in this study. The pure-tone audiometry, speech recognition threshold (SRT) and wordrecognition score (WRS) were used to evaluate the degree of hearing loss and wordrecognition. The threshold equalizing noise (TEN) tests were used to identify the presence of DR. The results showed that most DRs were present in high frequencies. The hearing thresholds of the ears with a DR were not significantly different from those without DR. However, the WRS was significantly worse for the DR ears, especially for those whose DR included three or more audiometric frequencies. A DR caused a significantly worse wordrecognition for the tonal language speakers of Mandarin in Taiwan, although the DR frequency occurred in the high frequency of 2000 Hz to 4000 Hz. PMID:23656214
The purpose of this study was to examine the extent to which a preassessment of motor development and perceptual skills predicts achievement in wordrecognition for kindergarten children. The instruments used for evaluation were the Lincoln-Oseretsky Motor Development Scale, Thurstone's Identical Forms Test, Wepman Auditory Discrimination Test,…
The aim of the study presented in this paper was to investigate the relation between phonological awareness and orthographic knowledge in deaf children who read in the transparent Greek orthography. Preschool and school-aged deaf children (N = 24) and two comparison groups of hearing children (N = 30) were administered measures of phonological awareness, letter-sound knowledge and wordrecognition at
A normative study was conducted using the Deese/Roediger-McDermott paradigm (DRM) to obtain false recognition for 60 six-word lists in Spanish, designed with a completely new methodology. For the first time, lists included words (e.g., bridal, newlyweds, bond, commitment, couple, to marry) simultaneously associated with three critical words (e.g., love, wedding, marriage). Backward associative strength between lists and critical words was taken into account when creating the lists. The results showed that all lists produced false recognition. Moreover, some lists had a high false recognition rate (e.g., 65%; jail, inmate, prison: bars, prisoner, cell, offender, penitentiary, imprisonment). This is an aspect of special interest for those DRM experiments that, for example, record brain electrical activity. This type of list will enable researchers to raise the signal-to-noise ratio in false recognition event-related potential studies as they increase the number of critical trials per list, and it will be especially useful for the design of future research. PMID:21298572
|Several empirical lines of investigation support the idea that syllable-sized units may be involved in visual wordrecognition processes. In this perspective, the present study aimed at investigating further the nature of the process that causes syllabic effects in reading. To do so, the syllable frequency effect was investigated in French using…
|We investigated the behavioral and brain responses (ERPs) of bilingual wordrecognition to three fundamental psycholinguistic factors, frequency, morphology, and lexicality, in early bilinguals vs. monolinguals. Earlier behavioral studies have reported larger frequency effects in bilinguals' nondominant vs. dominant language and in some studies…
Previous functional magnetic resonance imaging (fMRI) studies have investigated the role of phonological processing by utilizing nonword rhyming decision tasks (e.g., Pugh et al., 1996). Although such tasks clearly engage phonological components of visual wordrecognition, it is clear that decision tasks are more cognitively involved than the simple overt naming tasks, which more closely map onto normal reading behavior. Our research aim for this study was to examine the advantages of overt naming tasks for fMRI studies of wordrecognition processes. Process models are presented to highlight the similarities and differences between two cognitive tasks that are used in the wordrecognition literature, pseudohomophone naming (e.g., pronounce BRANE) and rhyming decision (e.g., do LEAT and JEAT rhyme?). An fMRI study identified several differences in cortical activation associated with the differences observed in the process models. Specifically, the results show that the overt naming task involved the insular cortex and inferior frontal gyrus, whereas the rhyming decision task engaged the temporal-parietal regions. It is argued that future fMRI research examining the neuroanatomical components of basic visual wordrecognition utilize overt naming tasks. PMID:15172523
Previous functional magnetic resonance imaging (fMRI) studies have investigated the role of phonological processing by utilizing nonword rhyming decision tasks (e.g., Pugh et al., 1996). Although such tasks clearly engage phonological components of visual wordrecognition, it is clear that decision tasks are more cognitively involved than the simple overt naming tasks, which more closely map onto normal reading behavior.
|This study investigated knowledge of letter names and letter sounds, their learning, and their contributions to wordrecognition. Of 123 preschoolers examined on letter knowledge, 65 underwent training on both letter names and letter sounds in a counterbalanced order. Prior to training, children were more advanced in associating letters with…
The purpose of this study was to determine the relationship between wordrecognition and comprehension achieved by second and fifth grade students when reading material at various levels of readability. A random sample of twenty-five second and twenty-five fifth graders, taken from three middle class schools, was administered a…
The Third International Chinese Language Processing Bakeoff was held in Spring 2006 to assess the state of the art in two important tasks: word segmentation and named entity recognition. Twenty-nine groups submitted result sets in the two tasks across two tracks and a total of five corpora. We found strong results in both tasks as well as continuing challenges.
The present study investigates how semantic constraint of a sentence context modulates language-non-selective activation in bilingual visual wordrecognition. We recorded Dutch-English bilinguals' eye movements while they read cognates and controls in low and high semantically constraining sentences in their second language. Early and late…
Van Assche, Eva; Drieghe, Denis; Duyck, Wouter; Welvaert, Marijke; Hartsuiker, Robert J.
The vast majority of commercially available isolated word recognizers use a filter bank analysis as the front end processing for recognition. It is not well understood how the parameters of different filter banks (e.g., number of filters, types of filters, filter spacing, etc.) affect recognizer performance. In this paper we present results of performance evaluation of several types of filter
BRUCE A. DAUTRICH; LAWRENCE R. RABINER; THOMAS B. MARTIN
|Malay is a consistent alphabetic orthography with complex syllable structures. The focus of this research was to investigate wordrecognition performance in order to inform reading interventions for low-progress early readers. Forty-six Grade 1 students were sampled and 11 were identified as low-progress readers. The results indicated that both…
|Recent research on bilingualism has shown that lexical access in visual wordrecognition by bilinguals is not selective with respect to language. In the present study, the authors investigated language-independent lexical access in bilinguals reading sentences, which constitutes a strong unilingual linguistic context. In the first experiment,…
Duyck, Wouter; Van Assche, Eva; Drieghe, Denis; Hartsuiker, Robert J.
The split-fovea theory proposes that visual wordrecognition is mediated by the splitting of the foveal image, with letters to the left of fixation projected to the right hemisphere (RH) and letters to the right of fixation projected to the left hemisphere (LH). We applied repetitive transcranial magnetic stimulation (rTMS) over the left and right occipital cortex during a lexical
|R. Ratcliff, P. Gomez, and G. McKoon (2004) suggested much of what goes on in lexical decision is attributable to decision processes and may not be particularly informative about wordrecognition. They proposed that lexical decision should be characterized by a decision process, taking the form of a drift-diffusion model (R. Ratcliff, 1978), that…
An American Sign Language (ASL) recognition system is being developed using artificial neural networks (ANNs) to translate ASL words into English. The system uses a sensory glove called the Cyberglove™ and a Flock of Birds® 3-D motion tracker to extract the gesture features. The data regarding finger joint angles obtained from strain gauges in the sensory glove define the hand
|Children raised in the home as English or Welsh monolinguals or English-Welsh bilinguals were tested on untrained word form recognition using both behavioral and neurophysiological procedures. Behavioral measures confirmed the onset of a familiarity effect at 11 months in English but failed to identify it in monolingual Welsh infants between 9…
|Seven peer commentaries focus on an article that evaluated the BIA model of bilingual wordrecognition in the light of recent empirical evidence, pointed out problems with it, and proposed a new model, the BIA+. Raise several issues of concern. (Author/VWL)|
Brysbaert, Marc; van Wijnendaele, Ilse; Duyck, Wouter; Jacquet, Maud; French, Robert M.; Green, David W.; van Hell, Janet G.; Li, Ping; Roelofs, Ardi; Thomas, Michael S. C.
|Evaluates the BIA model of bilingual wordrecognition in the light of recent empirical evidence. Points out problems with the model and proposes a new model, the BIA+. The new model extends the old one by adding phonological and semantic lexical representations to the available orthographic ones, and assigns a different role to the so-called…
Artificial Intelligence (AI) plays the following two crucial roles in medical form analysis: recognition, as an input, of the New York State (NYS) Prehospital Care Report (PCR), and data inferences as an output. The PCR provides medical, legal, and quality assurance (QA) data (approximately 2-3 Years behind in storage and analysis) that needs to be efficiently centralized to aid health
|A visual semantic categorization task in English was performed by native English speakers (Experiment 1) and late bilinguals whose first language was Japanese (Experiment 2) or Spanish (Experiment 3). In the critical conditions, the targetword was a homophone of a correct category exemplar (e.g., A BODY OF WATER-SEE; cf. SEA) or a word that…
Ota, Mitsuhiko; Hartsuiker, Robert J.; Haywood, Sarah L.
Research has demonstrated that irrelevant suprathreshold motion stimuli that are aligned with attended targets in a separate task, fail to illicit inhibitory control in a subsequent motion direction discrimination task (Tsushima, Seitz, & Watanabe, 2008). We extended these findings to conditions involving higher exposure levels to a more salient stimulus (written words) in an inattentional blindness paradigm. Across three experiments, participants were required to respond to immediate picture repetitions in a stream of serially presented line drawings, while at the same time ignore a simultaneously presented stream of superimposed words. Immediately following, a surprise test was given that measured recognition for the unattended words. Words that had appeared simultaneously with a repeated picture in the repetition detection task were not inhibited, but instead recognized significantly more often than words that had appeared with nonrepeating pictures. These findings support the notion that when attention is taxed, recognition for target-aligned task-irrelevant semantic items can be enhanced in a subsequent recognition task. This indicates a learning effect for frequently exposed, high-level irrelevant-stimuli that were temporally aligned with a relevant item in a separate task. (PsycINFO Database Record (c) 2013 APA, all rights reserved). PMID:23276115
Dewald, Andrew D; Sinnett, Scott; Doumas, Leonidas A A
Emotional tone of voice (ETV) is essential for optimal verbal communication. Research has found that the impact of variation in nonlinguistic features of speech on spoken wordrecognition differs according to a time course. In the current study, we investigated whether intratalker variation in ETV follows the same time course in two long-term repetition priming experiments. We found that intratalker variability in ETVs affected reaction times to spoken words only when processing was relatively slow and difficult, not when processing was relatively fast and easy. These results provide evidence for the use of both abstract and episodic lexical representations for processing within-talker variability in ETV, depending on the time course of spoken wordrecognition. PMID:23405913
Synthetic aperture radar (SAR) imaging and automatic targetrecognition (ATR) of moving targets pose a significant challenge due to the inherent difficulty of focusing moving targets. As a result, ATR of moving targets has received increased interest. High range resolution (HRR) radar mode offers an approach for recognizing moving targets by forming focused HRR profiles with significantly enhanced target-to-(clutter+noise) (T\\/(C+N))
R. Williams; J. Westerkamp; D. Gross; A. Palomion; T. Fister
Segment-based speech recognition systems have been proposed in recent years to overcome some of the deficiencies of the current state-of-the-art HMM based systems. In this paper, we present a segmental speech recogniser, where the speech trajectory segments are modelled using their mean, variance and shape. The shape is chosen from a codebook of global vector quantised trajectories, obtained from uniformly
Ramalingam Hariharan; Juha Häkkinen; Kari Laurila; Janne Suontausta
In this paper, we describe efforts to improve the performance of FEATURE, the Carnegie-Mellon University speaker-independent speech recognition system that classifies isolated letters of the English alphabet by enabling the system to learn the acoustical characteristics of individual speakers. Even when features are designed to be speaker-independent, it is frequently observed that feature values may vary more from speaker to
Time series modeling is proposed for identification of targets whose images are not clearly seen. The model building takes into account air turbulence, precipitation, fog, smoke and other factors obscuring and distorting the image. The complex of library data (of images, etc.) serving as a basis for identification provides the deterministic part of the identification process, while the partial image features, distorted parts, irrelevant pieces and absence of particular features comprise the stochastic part of the target identification. The missing data approach is elaborated that helps the prediction process for the image creation or reconstruction. The results are provided.
Debate surrounds the precise cortical location and timing of access to phonological information during visual wordrecognition. Therefore, using whole head magnetoencephalography (MEG), we investigated the spatiotemporal pattern of brain responses induced by a masked pseudohomophone priming task. Twenty healthy adults read targetwords that were preceded by one of three kinds of nonword prime: pseudohomophones (e.g., brein-BRAIN), where 4 of 5 letters are shared between prime and target, and the pronunciation is the same; matched orthographic controls (e.g., broin-BRAIN), where the same 4 of 5 letters are shared between prime and target but pronunciation differs; and unrelated controls (e.g., lopus-BRAIN), where neither letters nor pronunciation are shared between prime and target. All three priming conditions induced activation in the pars opercularis of the left inferior frontal gyrus (IFGpo) and the left precentral gyrus (PCG) within 100ms of targetword onset. However, for the critical comparison which reveals a processing difference specific to phonology, we found that the induced pseudohomophone priming response was significantly stronger than the orthographic priming response in left IFG/PCG at ~100ms. This spatio-temporal concurrence demonstrates early phonological influences during visual wordrecognition and is consistent with phonological access being mediated by a speech production code.
Wheat, Katherine L; Cornelissen, Piers L; Frost, Stephen J; Hansen, Peter C
As a result of gene sequencing and proteomic efforts, thousands of new genes and proteins are now available as potential drug targets. The milieu of these proteins is complex and interactive; thousands of proteins activate, inhibit, and control each other's actions. The effect of blocking or activating a protein in a cell is far-reaching, and can affect whole, as well as adjacent pathways. This network of pathways is dynamic and a cellular response can change depending on the stimulus. In this section, the identification and role of individual proteins within the context of networked pathways, and the regulation of the activity of these proteins is discussed. Diverse chemical libraries, combinatorial libraries, natural products, as well as unnatural natural products that are derived from combinatorial biology (Chiu  Proc. Natl. Acad. Sci. USA. 98:8548-8553), provide the chemical diversity in the search for new drugs to block new targets. Identifying new compounds that can become drugs is a long, expensive, and arduous task and potential targets must be carefully defined so as not to waste valuable resources. Equally important is the selection of compounds to be future drug candidates. Target selectivity in no way guarantees clinical efficacy, as the compound must meet pharmaceutical requirements, such as solubility, absorption, tissue distribution, and lack of toxicity. Thus matching biological diversity with chemical diversity involves something more than tight interactions, it involves interactions of the compounds with a variety host factors that can modulate its activity. PMID:11842421
Previous studies have reported that semantic richness facilitates visual wordrecognition (see, e.g., Buchanan, Westbury,\\u000a & Burgess, 2001; Pexman, Holyk, & Monfils, 2003). We compared three semantic richness measures—number of semantic neighbors (NSN), the number of words appearing in similar lexical contexts; number of features (NF), the number of features listed for a word’s referent; and contextual dispersion (CD), the
Penny M. Pexman; Ian S. Hargreaves; Paul D. Siakaluk; Glen E. Bodner; Jamie Pope
Abstract Does native language phonology influence visual word processing in a second language? This question was investigated in two experiments with two groups of Russian-English bilinguals, differing in their English experience, and a monolingual English control group. Experiment 1 tested visual wordrecognition following semantic…
There is considerable evidence (e.g., Pexman et al., 2008) that semantically rich words, which are associated with relatively more semantic information, are recognized faster across different lexical processing tasks. The present study extends this earlier work by providing the most comprehensive evaluation to date of semantic richness effects on visual wordrecognition performance. Specifically, using mixed effects analyses to control for the influence of correlated lexical variables, we considered the impact of number of features, number of senses, semantic neighborhood density, imageability, and body–object interaction across five visual wordrecognition tasks: standard lexical decision, go/no-go lexical decision, speeded pronunciation, progressive demasking, and semantic classification. Semantic richness effects could be reliably detected in all tasks of lexical processing, indicating that semantic representations, particularly their imaginal and featural aspects, play a fundamental role in visual wordrecognition. However, there was also evidence that the strength of certain richness effects could be flexibly and adaptively modulated by task demands, consistent with an intriguing interplay between task-specific mechanisms and differentiated semantic processing.
Yap, Melvin J.; Pexman, Penny M.; Wellsby, Michele; Hargreaves, Ian S.; Huff, Mark J.
The language model design and implementation issue is researched in this paper. Different from previous research, we want to emphasize the importance of n-gram models based on words in the study of language model. We build up a word based language model using the toolkit of SRILM and implement it for contextual language processing on Chinese documents. A modified Absolute Discount smoothing algorithm is proposed to reduce the perplexity of the language model. The word based language model improves the performance of post-processing of online handwritten character recognition system compared with the character based language model, but it also increases computation and storage cost greatly. Besides quantizing the model data non-uniformly, we design a new tree storage structure to compress the model size, which leads to an increase in searching efficiency as well. We illustrate the set of approaches on a test corpus of recognition results of online handwritten Chinese characters, and propose a modified confidence measure for recognition candidate characters to get their accurate posterior probabilities while reducing the complexity. The weighted combination of linguistic knowledge and candidate confidence information proves successful in this paper and can be further developed to achieve improvements in recognition accuracy.
Laser active imaging is fit to conditions such as no difference in temperature between target and background, pitch-black night, bad visibility. Also it can be used to detect a faint target in long range or small target in deep space, which has advantage of high definition and good contrast. In one word, it is immune to environment. However, due to the affect of long distance, limited laser energy and atmospheric backscatter, it is impossible to illuminate the whole scene at the same time. It means that the target in every single frame is unevenly or partly illuminated, which make the recognition more difficult. At the same time the speckle noise which is common in laser active imaging blurs the images . In this paper we do some research on laser active imaging and propose a new targetrecognition method based on multi-frame images . Firstly, multi pulses of laser is used to obtain sub-images for different parts of scene. A denoising method combined homomorphic filter with wavelet domain SURE is used to suppress speckle noise. And blind deconvolution is introduced to obtain low-noise and clear sub-images. Then these sub-images are registered and stitched to combine a completely and uniformly illuminated scene image. After that, a new targetrecognition method based on contour moments is proposed. Firstly, canny operator is used to obtain contours. For each contour, seven invariant Hu moments are calculated to generate the feature vectors. At last the feature vectors are input into double hidden layers BP neural network for classification . Experiments results indicate that the proposed algorithm could achieve a high recognition rate and satisfactory real-time performance for laser active imaging.
Wang, Can-jin; Sun, Tao; Wang, Tin-feng; Chen, Juan
Two perception experiments are conducted to quantify the relationship between imager sampling artifacts and targetrecognition and identification performance using that imager. The results of these experiments show that in-band aliasing (aliasing that overlaps the base-band signal) does not degrade target identification performance, but out-of- band aliasing (such as visible display raster) degrades identification performance significantly. Aliasing had less impact
Richard H. Vollmerhausen; Ronald G. Driggers; Barbara L. O'Kane
We present a near-real-time visual-processing approach for automatic airborne target detection and classification. Detection is based on fast and robust background modeling and shape extraction, while recognition of target classes is based on shape and texture-fused querying on a-priori built real datasets. The presented approach can be used in defense and surveillance scenarios where passive detection capabilities are preferred (or required) over a secured area or protected zone.
Kovács, Levente; Kovács, Andrea; Utasi, Ákos; Szirányi, Tamás
In this paper, a fuzzy multiscale edge detection method is proposed, based on wavelet transform. The goal is to relate the results of this analysis to the structure of the IIR for ship targetrecognition. Experiments are carried out for the method with practical IIR added with white noise, and the corresponding results indicate that the advantage of the new
This paper explores the use of wavelets to improve the selection of discriminant features in the targetrecognition problem using High Range Resolution (HRR) radar signals in an air to air scenario. We show that there is statistically no difference between four different wavelet families in extracting discriminatory features. Since similar results can be obtained from any of the four
Dale E. Nelson; Janusz A. Starzyk; D. David Ensley
In automatic targetrecognition we often face a problem in having to train a large neural network upon a very limited data set. This paper presents methods designed to analyze trained networks. The methods allow us to investigate how the network makes its decisions as well as its generalization properties. The methods interact with each other and are intended to
Automated targetrecognition (ATR) software has been designed to perform image segmentation and scene analysis. Specifically, this software was developed as a package for the Army's Minefield and Reconnaissance and Detector (MIRADOR) program. MIRADOR is an on\\/off road, remote control, multisensor system designed to detect buried and surface- emplaced metallic and nonmetallic antitank mines. The basic requirements for this ATR
One of the unique features of the Arabic orthography that differentiates it from many other alphabetical ones is the fact that most letters connect obligatorily to each other. Hence, these letters change their forms according to the location in the word (i.e. beginning, middle, or end), leading to the suggestion that connectivity adds a visual load which negatively impacts reading in Arabic. In this study, we investigated the effects of the orthographic connectivity on the time course of early brain electric responses during the visual wordrecognition. For this purpose, we collected event-related potentials (ERPs) from adult skilled readers while performing a lexical decision task using fully connected (Cw), partially connected and non-connected words (NCw). Reaction times variance was higher and accuracy was lower in NCw compared to Cw words. ERPs analysis revealed significant amplitude and latency differences between Cw and NCw at posterior electrodes during the N170 component which implied the temporo-occipital areas. Our findings show that instead of slowing down reading, orthographic connectivity in Arabic skilled readers seems to impact positively the reading process already during the early stages of wordrecognition. These results are discussed in relation to previous observations in the literature. PMID:22864655
The main objective of this research is to automate WEFT (Wings, Engine, Fuselage, Tail) technique as input to aid VATR (Visual Automatic TargetRecognition) system. VATR systems are relatively mobile in nature and easy to use in field. Earlier aircrafts have been observed using traditional binocular techniques, which are still in use along with some early warning system. The prime
Algorithms for estimating the angular velocity, angular acceleration, orientation, length, and width of an ISAR target and for identifying the scattering points of ISAR targets are derived and demonstrated. A correspondence between the ISAR motion estimation operations and a rigid body dynamical model is illustrated. It will be shown that an ISAR image amounts to projecting scatterers into a plane perpendicular to the target axis of rotation and coplanar with the range axis. The proper Doppler scale factor of imagery and its variation is proportional to the rotation rate and acceleration. These result as a by-product of SAIC ISAR motion estimation techniques. Improved geometric estimates can then be found by incorporating modeling assumptions and a priori knowledge. A number of land and sea examples are provided to reinforce the above concepts.
The present disclosure relates to systems, methods, and computer-readable media for generating a lexicon for use with speech recognition. The method includes receiving symbolic input as labeled speech data, overgenerating potential pronunciations based on the symbolic input, identifying potential pronunciations in a speech recognition context, and storing the identified potential pronunciations in a lexicon. Overgenerating potential pronunciations can include establishing a set of conversion rules for short sequences of letters, converting portions of the symbolic input into a number of possible lexical pronunciation variants based on the set of conversion rules, modeling the possible lexical pronunciation variants in one of a weighted network and a list of phoneme lists, and iteratively retraining the set of conversion rules based on improved pronunciations. Symbolic input can include multiple examples of a same spoken word. Speech data can be labeled explicitly or implicitly and can include words as text and recorded audio.
Conkie; Alistair D. (Morristown, NJ); Gilbert; Mazin (Warren, NJ); Ljolje; Andrej (Morris Plains, NJ)
We present the design of an automatic targetrecognition (ATR) system that is part of a hybrid system incorporating some domain knowledge. This design obtains an adaptive trade-off between training performance and memorization capacity by decomposing the learning process with respect to a relevant hidden variable. The probability of correct classification over 10 target classes is 73.4%. The probability of correct classification between the target- class and the clutter-class (where clutters are the false alarms obtained from another ATR) is 95.1%. These performances can be improved by reducing the memorization capacity of this system because its estimation shows that it is too large.
The paper considers the following problem: given a 3D model of a reference target and a sequence of images of a 3D scene, identify the object in the scene most likely to be the reference target and determine its current pose. Finding the best match in each frame independently of previous decisions is not optimal, since past information is ignored. Our solution concept uses a novel Bayesian framework for multi target tracking and object recognition to define and sequentially update the probability that the reference target is any one of the tracked objects. The approach is applied to problems of automatic lock-on and missile guidance using a laser radar seeker. Field trials have resulted in high target hit probabilities despite low resolution imagery and temporarily highly occluded targets.
The mechanisms that give rise to familiarity memory have received intense research interest. One current topic of debate concerns the extent to which familiarity is driven by the same fluency sources that give rise to certain implicit memory phenomena. Familiarity may be tied to conceptual fluency, given that familiarity and conceptual implicit memory can exhibit similar neurocognitive properties. However, familiarity can also be driven by perceptual factors, and its neural basis under these circumstances has received less attention. Here we recorded brain potentials during recognition testing using a procedure that has previously been shown to encourage a reliance on letter information when assessing familiarity for words. Studied and unstudied words were derived either from two separate letter pools or a single letter pool ("letter-segregated" and "normal" conditions, respectively) in a within-subjects contrast. As predicted, recognition accuracy was higher in the letter-segregated relative to the normal condition. Electrophysiological analyses revealed parietal old-new effects from 500-700ms in both conditions. In addition, a topographically dissociable occipital old-new effect from 300-700ms was present in the letter-segregated condition only. In a second experiment, we found that similar occipital brain potentials were associated with confident false recognition of words that shared letters with studied words but were not themselves studied. These findings indicate that familiarity is a multiply determined phenomenon, and that the stimulus dimensions on which familiarity is based can moderate its neural correlates. Conceptual and perceptual contributions to familiarity vary across testing circumstances, and both must be accounted for in theories of recognition memory and its neural basis. PMID:23871869
Schizophrenia is a major mental disorder which is characterized by several cognitive deficits. Investigations of the neural\\u000a basis of memory dysfunctions using neuroimaging techniques suggest that the hippocampus plays an important role in declarative\\u000a memory impairment. The goal of this study was to investigate possible dysfunctions in cerebral activation in schizophrenic\\u000a patients during both word and face recognition memory tasks.
Giuseppina Rametti; Carme Junqué; Pere Vendrell; Rosa Catalán; Rafael Penadés; Nuria Bargalló; Miguel Bernardo
Bags-of-visual-Words (BoW) and Spatio-Temporal Shapes (STS) are two very popular approaches for action recognition from video. The former (BoW) is an un-structured global representation of videos which is built using a large set of local features. The latter (STS) uses a single feature located on a region of interest (where the actor is) in the video. Despite the popularity of
Teofilo de Campos; Mark Barnard; Krystian Mikolajczyk; Josef Kittler; Fei Yan; William Christmas; David Windridge
It has been known for some time that the recognition of a noun is affected by the gender marking, such as masculine or feminine,\\u000a that is carried by a preceding word. In this study, we used auditory naming to examine how early and late English-French bilinguals\\u000a react to gender marking when processing French. The early bilinguals showed clear facilitation and
Although wordrecognition is a skill commonly expected to rely more on ventral rather than dorsal stream processing, there\\u000a is some evidence for a magnocellular\\/dorsal impairment in dyslexia. The early rapid feedforward\\/feedback loop through the\\u000a dorsal stream seen in primate has been suggested to allow an initial global analysis, and in human early activation of parietal\\u000a attention mechanisms for detecting
Robin Laycock; David P. Crewther; Paul B. Fitzgerald; Sheila G. Crewther
\\u000a Issue of speech interface to computer has been capturing the global attention because of convenience put forth by it. Although\\u000a speech recognition is not a new phenomenon in existing developments of user-machine interface studies but the highlighted\\u000a facts only provide promising solutions for widely accepted language English. This paper presents development of an experimental,\\u000a speaker-dependent, real-time, isolated word recognizer for
In many domains of cognitive processing there is strong support for bottom-up priority and delayed top-down (contextual) integration. We ask whether this applies to supra-lexical context that could potentially constrain lexical access. Previous findings of early context integration in wordrecognition have typically used constraints that can be linked to pair-wise conceptual relations between words. Using an artificial lexicon, we found immediate integration of syntactic expectations based on pragmatic constraints linked to syntactic categories rather than words: phonologically similar “nouns” and “adjectives” did not compete when a combination of syntactic and visual information strongly predicted form class. These results suggest that predictive context is integrated continuously, and that previous findings supporting delayed context integration stem from weak contexts rather than delayed integration.
Magnuson, James S.; Tanenhaus, Michael K.; Aslin, Richard N.
We examined the influence of print exposure on the body-object interaction (BOI) effect in visual wordrecognition. High print exposure readers and low print exposure readers either made semantic categorizations (“Is the word easily imageable?”; Experiment 1) or phonological lexical decisions (“Does the item sound like a real English word?”; Experiment 2). The results from Experiment 1 showed that there was a larger BOI effect for the low print exposure readers than for the high print exposure readers in semantic categorization, though an effect was observed for both print exposure groups. However, the results from Experiment 2 showed that the BOI effect was observed only for the high print exposure readers in phonological lexical decision. The results of the present study suggest that print exposure does influence the BOI effect, and that this influence varies as a function of task demands.
This paper describes a novel evolutionary method for automatic induction of targetrecognition procedures from examples. The learning process starts with training data containing SAR images with labeled targets and consists in coevolving the population of feature extraction agents that cooperate to build an appropriate representation of the input image. Features extracted by a team of cooperating agents are used to induce a machine learning classifier that is responsible for making the final decision of recognizing a target in a SAR image. Each agent (individual) contains feature extraction procedure encoded according to the principles of linear genetic programming (LGP). Like ‘plain" genetic programming, in LGP an agent"s genome encodes a program that is executed and tested on the set of training images during the fitness calculation. The program is a sequence of calls to the library of parameterized operations, including, but not limited to, global and local image processing operations, elementary feature extraction, and logic and arithmetic operations. Particular calls operate on working variables that enable the program to store intermediate results, and therefore design complex features. This paper contains detailed description of the learning and recognition methodology outlined here. In experimental part, we report and analyze the results obtained when testing the proposed approach for SAR targetrecognition using MSTAR database.
Several studies have claimed that, when fixating a word, letters to the left and right of fixation project to different hemispheres and are consequently subjected to different processes. In support of this claim, Lavidor M, et al. (2001; hereafter LES&B) report that lexical decisions were affected by increasing the number of letters to the left of fixation but not to the right, and that this indicates divided hemispheric access at the point of fixation to length-sensitive processes in the right hemisphere (RH). We re-evaluated these claims in Experiment 1 using Lavidor et al.'s original stimuli and procedure of merely instructing participants where to fixate. In contrast to the earlier study, increases in the number of letters to the left and right of the designated fixation location produced near-identical effects on reaction time, and increases to the left actually improved response accuracy and increases to the right impaired it. When larger stimuli were used to improve stimulus perceptibility and an eye-tracker monitored fixation accuracy (Experiment 2), left and right increases in the number of letters again produced near-identical effects on reaction time (and accuracy), but frequent and substantial fixation errors were revealed. When an eye-tracker ensured accurate fixations (Experiment 3), left and right increases in the number of letters again produced near-identical effects on reaction time and accuracy. Thus, the findings of all three experiments provide no support for the findings of LES&B (2001) and no evidence of split-fovea processing. The findings also indicate the dangers of assuming fixation of precisely-specified locations within words, both in experiments designed to reveal split-foveal processing and hemispheric asymmetry and in more normal circumstances of word perception. PMID:19231478
Jordan, Timothy R; Paterson, Kevin B; Stachurski, Marcin
|Do older English as a second language (ESL) children have the same knowledge of word meanings as English as a first language (EL1) children? How important is vocabulary's role in predicting wordrecognition in these groups? This study sought to answer these questions by examining the profiles of ESL and EL1 upper elementary aged children, for a…
MicroRNAs (miRNAs) are endogenous ~23-nt RNAs that can play important gene-regulatory roles in animals and plants by pairing to the mRNAs of protein-coding genes to direct their posttranscriptional repression. This review outlines the current understanding of miRNA targetrecognition in animals and discusses the widespread impact of miRNAs on both the expression and evolution of protein-coding genes.
This thesis explores a new approach to the classification of tactical targets using a new biologically-based neural network. The targets of interest were generated from Doppler imagery and forward looking infrared imagery, and consisted of tanks, trucks, armored personnel carriers, jeeps and petroleum, oil, and lubricant tankers. Each target was described by feature vectors, such as normalized moment invariants. The features were generated from the imagery using a segmenting process. These feature vectors were used as the input to a neural network classifier for tactical targetrecognition. The neural network consisted of a multilayer perceptron architecture, employing a backward error propagation learning algorithm. The minimization technique used was an approximation to Newton's method. This second order algorithm is a generalized version of well known first order techniques, i.e., gradient of steepest descent and momentum methods. Classification using both first and second order techniques was performed, with comparisons drawn.
Rather than emitting pulses, passive radar systems rely on illuminators of opportunity, such as TV and FM radio, to illuminate potential targets. These systems are particularly attractive since they allow receivers to operate without emitting energy, rendering them covert. Many existing passive radar systems estimate the locations and velocities of targets. This paper focuses on adding an automatic targetrecognition (ATR) component to such systems. Our approach to ATR compares the Radar Cross Section (RCS) of targets detected by a passive radar system to the simulated RCS of known targets. To make the comparison as accurate as possible, the received signal model accounts for aircraft position and orientation, propagation losses, and antenna gain patterns. The estimated positions become inputs for an algorithm that uses a coordinated flight model to compute probable aircraft orientation angles. The Fast Illinois Solver Code (FISC) simulates the RCS of several potential target classes as they execute the estimated maneuvers. The RCS is then scaled by the Advanced Refractive Effects Prediction System (AREPS) code to account for propagation losses that occur as functions of altitude and range. The Numerical Electromagnetic Code (NEC2) computes the antenna gain pattern, so that the RCS can be further scaled. The Rician model compares the RCS of the illuminated aircraft with those of the potential targets. This comparison results in target identification.
|Discusses three experiments that used a visual version of the syllable monitoring technique to investigate the role of syllabic units in beginning and adult readers. Participants responded whenever a visually presented target syllable appeared at the beginning of a subsequently presented printed word. (Author/VWL)|
|Three eye-tracking experiments investigated how phonological reductions (e.g., "puter" for "computer") modulate phonological competition. Participants listened to sentences extracted from a spontaneous speech corpus and saw four printed words: a target (e.g., "computer"), a competitor similar to the canonical form (e.g., "companion"), one similar…
Three eye-tracking experiments investigated how phonological reductions (e.g., "puter" for "computer") modulate phonological competition. Participants listened to sentences extracted from a spontaneous speech corpus and saw four printed words: a target (e.g., "computer"), a competitor similar to the canonical form (e.g., "companion"), one similar…
Word frequency is one of the strongest determiners of reaction time (RT) in wordrecognition tasks; it is an important theoretical\\u000a and methodological variable. The Ku?era and Francis (1967) word frequency count (derived from the 1-million-word Brown corpus)\\u000a is used by most investigators concerned with the issue of word frequency. Word frequency estimates from the Brown corpus were\\u000a compared with
Participants performed a 2-choice categorization task on visible wordtargets that were preceded by novel (unpracticed) prime words. The prime words were presented for 33 ms and followed either immediately (Experiments 1-3) or after a variable delay (Experiments 1 and 4) by a pattern mask. Both subjective and objective measures of prime visibility…
Ortells, Juan J.; Mari-Beffa, Paloma; Plaza-Ayllon, Vanesa
This paper on adaptive image segmentation and classification describes research activities on statistical pattern recognition in combination with methods of object recognition by geometric matching of model and image structures. In addition, aspects of sensor fusion for airborne application systems like terminal missile guidance were considered using image sequences of multispectral data from real sensor systems and from computer simulations. The main aspect of the adaptive classification is the support of model-based structural image analysis by detection of image segments representing specific objects, e.g. forests, rivers and urban areas. The classifier, based on textural features, is automatically adapted to the changes of textural signatures during target approach by interpretation of the segmentation results of each actual frame of the image sequence.
Automated targetrecognition (ATR) software has been designed to perform image segmentation and scene analysis. Specifically, this software was developed as a package for the Army's Minefield and Reconnaissance and Detector (MIRADOR) program. MIRADOR is an on/off road, remote control, multisensor system designed to detect buried and surface- emplaced metallic and nonmetallic antitank mines. The basic requirements for this ATR software were the following: (1) an ability to separate target objects from the background in low signal-noise conditions; (2) an ability to handle a relatively high dynamic range in imaging light levels; (3) the ability to compensate for or remove light source effects such as shadows; and (4) the ability to identify target objects as mines. The image segmentation and target evaluation was performed using an integrated and parallel processing approach. Three basic techniques (texture analysis, edge enhancement, and contrast enhancement) were used collectively to extract all potential mine target shapes from the basic image. Target evaluation was then performed using a combination of size, geometrical, and fractal characteristics, which resulted in a calculated probability for each target shape. Overall results with this algorithm were quite good, though there is a tradeoff between detection confidence and the number of false alarms. This technology also has applications in the areas of hazardous waste site remediation, archaeology, and law enforcement.
Previous studies have reported facilitatory effects of semantic richness on wordrecognition (e.g., Yap et al., 2012). These effects suggest that word meaning is an important contributor to lexical decision task (LDT) performance, but what are the effects of repeated LDT practice on these semantic contributions? The current study utilized data from the British Lexicon Project (BLP) in which 78 participants made lexical decision judgments for 28,730 words over 16 h. We used linear mixed effects to detect practice-driven changes in the explanatory variance accounted for by a set of lexical predictors that included numerous indices of relative semantic richness, including imageability, the number of senses and average radius of co-occurrence (ARC). Results showed that practice was associated with decreasing effects of predictors such as word frequency and imageability. In contrast, ARC effects were only slightly diminished with repeated practice, and effects of the number of senses and the age of acquisition were unaffected by practice. We interpret our results within a framework in which variables may dynamically influence lexical processing and the post-lexical decision making mechanisms that also contribute to LDT performance.
Background In the current era of scientific research, efficient communication of information is paramount. As such, the nature of scholarly and scientific communication is changing; cyberinfrastructure is now absolutely necessary and new media are allowing information and knowledge to be more interactive and immediate. One approach to making knowledge more accessible is the addition of machine-readable semantic data to scholarly articles. Results The Word add-in presented here will assist authors in this effort by automatically recognizing and highlighting words or phrases that are likely information-rich, allowing authors to associate semantic data with those words or phrases, and to embed that data in the document as XML. The add-in and source code are publicly available at http://www.codeplex.com/UCSDBioLit. Conclusions The Word add-in for ontology term recognition makes it possible for an author to add semantic data to a document as it is being written and it encodes these data using XML tags that are effectively a standard in life sciences literature. Allowing authors to mark-up their own work will help increase the amount and quality of machine-readable literature metadata.
We offer a computational model of gaze planning during reading that consists of two main components: a lexical representation network, acquiring lexical representations from input texts (a subset of the Italian CHILDES database), and a gaze planner, designed to recognize written words by mapping strings of characters onto lexical representations. The model implements an active sensing strategy that selects which characters of the input string are to be fixated, depending on the predictions dynamically made by the lexical representation network. We analyze the developmental trajectory of the system in performing the wordrecognition task as a function of both increasing lexical competence, and correspondingly increasing lexical prediction ability. We conclude by discussing how our approach can be scaled up in the context of an active sensing strategy applied to a robotic setting.
WE OFFER A COMPUTATIONAL MODEL OF GAZE PLANNING DURING READING THAT CONSISTS OF TWO MAIN COMPONENTS: a lexical representation network, acquiring lexical representations from input texts (a subset of the Italian CHILDES database), and a gaze planner, designed to recognize written words by mapping strings of characters onto lexical representations. The model implements an active sensing strategy that selects which characters of the input string are to be fixated, depending on the predictions dynamically made by the lexical representation network. We analyze the developmental trajectory of the system in performing the wordrecognition task as a function of both increasing lexical competence, and correspondingly increasing lexical prediction ability. We conclude by discussing how our approach can be scaled up in the context of an active sensing strategy applied to a robotic setting. PMID:20577589
Much evidence indicates that emotion enhances memory, but the precise effects of the two primary factors of arousal and valence remain at issue. Moreover, the current knowledge of emotional memory enhancement is based mostly on small samples of extremely emotive stimuli presented in unnaturally high proportions without adequate affective, lexical, and semantic controls. To investigate how emotion affects memory under conditions of natural variation, we tested whether arousal and valence predicted recognition memory for over 2500 words that were not sampled for their emotionality, and we controlled a large variety of lexical and semantic factors. Both negative and positive stimuli were remembered better than neutral stimuli, whether arousing or calming. Arousal failed to predict recognition memory, either independently or interactively with valence. Results support models that posit a facilitative role of valence in memory. This study also highlights the importance of stimulus controls and experimental designs in research on emotional memory. PMID:24041838
Market surveys consistently show that only 22% of those with hearing loss own hearing aids. This is often ascribed to cosmetics, but is it possible that patients apply a different auditory criterion than do audiologists and manufacturers? We tabulated hearing aid ownership in a survey of 1000 consecutive patients. We separated hearing loss cases, with one cohort in which wordrecognition in quiet could improve with gain (vs. 40 dB HL) and another without such improvement but nonetheless with audiometric thresholds within the manufacturer's fitting ranges. Overall, we found that exactly 22% of hearing loss patients in this sample owned hearing aids; the same finding has been reported in many previous, well-accepted surveys. However, while all patients in the two cohorts experienced difficulty in noise, patients in the cohort without wordrecognition improvement were found to own hearing aids at a rate of 0.3%, while those patients whose wordrecognition could increase with level were found to own hearing aids at a rate of 50%. Results also coherently fit a logistic model where shift of the wordrecognition performance curve by level corresponded to the likelihood of ownership. In addition to the common attribution of low hearing aid usage to patient denial, cosmetic issues, price, or social stigma, these results provide one alternative explanation based on measurable improvement in wordrecognition performance. PMID:22104328
We propose a novel SAR(Synthetic Aperture Radar) automatic targetrecognition framework that is capable of processing images extremely rapidly while achieving high recognition rates. This SAR ATR system is used for classification of three types of ground vehicles in the moving and stationary target acquisition and recognition (MSTAR) public release database. The MSTAR data is a standard dataset in the
Background Previous studies have claimed that a precise split at the vertical midline of each fovea causes all words to the left and right of fixation to project to the opposite, contralateral hemisphere, and this division in hemispheric processing has considerable consequences for foveal wordrecognition. However, research in this area is dominated by the use of stimuli from Latinate languages, which may induce specific effects on performance. Consequently, we report two experiments using stimuli from a fundamentally different, non-Latinate language (Arabic) that offers an alternative way of revealing effects of split-foveal processing, if they exist. Methods and Findings Words (and pseudowords) were presented to the left or right of fixation, either close to fixation and entirely within foveal vision, or further from fixation and entirely within extrafoveal vision. Fixation location and stimulus presentations were carefully controlled using an eye-tracker linked to a fixation-contingent display. To assess wordrecognition, Experiment 1 used the Reicher-Wheeler task and Experiment 2 used the lexical decision task. Results Performance in both experiments indicated a functional division in hemispheric processing for words in extrafoveal locations (in recognition accuracy in Experiment 1 and in reaction times and error rates in Experiment 2) but no such division for words in foveal locations. Conclusions These findings from a non-Latinate language provide new evidence that although a functional division in hemispheric processing exists for wordrecognition outside the fovea, this division does not extend up to the point of fixation. Some implications for wordrecognition and reading are discussed.
Almabruk, Abubaker A. A.; Paterson, Kevin B.; McGowan, Victoria; Jordan, Timothy R.
This paper presents a novel feature vector to be used with a robust automatic targetrecognition (ATR) classifier designed for a ground surveillance radar. A three element feature vector has been used where features are based on radar audio signal of 100 milliseconds duration. The short feature length allows fast real-time implementation of the classifier. Classification is done using a
S. Liaqat; S. A. Khan; M. B. Ihsan; S. Z. Asghar; A. Ejaz; A. I. Bhatti
Speech recognition test reliability is optimized with 450 test items, and the Computer Assisted Speech Recognition Assessment (CASRA) test is a practical approach for achieving this goal by combining 50 presentations of 3 consonant-vowel nucleus-consonant (CNC) words each with phonemic scoring (S. A. Gelfand, 1998). However, optimized reliability might not be essential if reliability is as high as possible in light of practical constraints and what the clinician is trying to do with the results. The CASRA paradigm addresses these compromise goals with a reduced number of 3-word sets: 25 sets yield 25 (groups) x 3 (words) x 3 (phonemes) = 225 test items, 20 sets give 20 x 3 x 3 = 180 items, and 10 sets provide 10 x 3 x 3 = 90 items. This study addressed the empirical reliability of such an approach, and the extent to which results on shortened versions predict full-test scores. Test and retest scores were obtained for 10-, 20-, and 25-set versions of the CASRA for 144 participants with a wide range of hearing ability. For group data, first and second scores were highly correlated and not significantly different from each other for all 3 test sizes. Performance based on 20 and 25 sets accounted for roughly 97% of the variance of full (50-set) test scores, and scores based on 10 sets accounted for about 88% of the full-test variance. Individual test-retest reliability agreed with theoretical expectations based on 95% binomial confidence intervals. Cases outside the 95% confidence limits were 7.6% for 10 sets, and 3.5% for 20 and 25 sets with phoneme scoring, and 4.9% for 10 and 20 sets and 3.5% for 25 sets with word scoring. The shortened CASRA is a practical way to achieve improvements in reliability over traditional word tests. The 20-set version may approximate the strongest compromise when trying to shorten test size without appreciably reducing reliability for clinical purposes. However, the 10-set version is probably a more practical approach for routine use because it accounts for 88% of full-test variance, is more reliable than a traditional 75-word test, and does not appear to be subject to significant short-term learning effects. PMID:14700381
In the picture-word interference task the naming of a picture is hampered by the presence of a distractor word that is to be ignored. Two main components of this interference effect can be distinguished: an interference effect induced by an unrelated distractor word in comparison with a nonword control, and an additional interference effect that is due to a semantic
The traditional method to extract target contour from aerial target image is changing the aerial image into a gray level image with multiple thresholds or binary image with single threshold. From the edge of target, contour can be extracted according to the changed value. The traditional method is useful only when contrast between target and background is in the proper degree. Snakes are curves defined within an image domain that can move under the influence of internal force coming from within the curve itself and external forces are defined so that the snake will conform to an object boundary or other desired features within an image. Snakes have been proved an effective method and widely used in image processing and computer vision. Snakes synthesize parametric curves within an image domain and allow them to move toward desired edges. Particular advantages of the GVF(Gradient Vector Flow) snakes over a traditional snakes are its insensitivity to initialization and its ability to move into boundary concavities. Its initializations can be inside, outside, or across the object"s boundary. The GVF snake does not need prior knowledge about whether to shrink or expand toward the boundary. This increased capture range is achieved through a diffusion process that does not blur the edges of themselves. Affected by the light from different incident angle, the brightness of aerial target surface changed greatly in a complicate mode. So the GVF snakes is not fast, accurate and effective all the time for this kind of images. A new contour extracting method, GVF Snakes Combined with wavelet multi-resolution Analysis is proposed in this paper. In this algorithm, bubble wavelet is used iteratively to do the multi resolution analysis in the order of degressive scale before GVF Snakes is used every time to extract accurate contour of target. After accurate contour is extracted, polygon approximation is used to extract characteristics to realize the recognition of aerial target. The process is in the following: Step 1: use bubble wavelet filter to cut big part of the noises, weakening false edges. Step 2: initialize active contour and control the contour"s move according to GVF to get a new contour. Step 3: decrease the scale of filter, and use the new contour as the initial contour and control the contour"s move to get new contour again. Step 4: repeat step 3 till the set scale is reached. The last new contour is the final contour. Step 5: find the center determine an axis by calculate distance between every point on the final contour to the center. Step 6: adjust the distance threshold and combine the points until the contour is changed into a polygon with fixed angle number which is best fit the targetrecognition demand. Step 7: use the polygon to match the target plate to recognize target. Applied the new algorithm to aerial target images of a helicopter and a F22 battleplan, the contour extraction and polygon approximation results show that targets can be matched and recognized successfully. This paper mainly focuses on contour extraction and polygon approximation in the recognition area.
While classification techniques can be applied for automatic unknown wordrecognition in a language without word boundary, it faces with the problem of unbalanced datasets where the number of positive unknown word candidates is dominantly smaller than that of negative candidates. To solve this problem, this paper presents a corpus-based approach that introduces a so-called group-based ranking evaluation technique into ensemble learning in order to generate a sequence of classification models that later collaborate to select the most probable unknown word from multiple candidates. Given a classification model, the group-based ranking evaluation (GRE) is applied to construct a training dataset for learning the succeeding model, by weighing each of its candidates according to their ranks and correctness when the candidates of an unknown word are considered as one group. A number of experiments have been conducted on a large Thai medical text to evaluate performance of the proposed group-based ranking evaluation approach, namely V-GRE, compared to the conventional naïve Bayes classifier and our vanilla version without ensemble learning. As the result, the proposed method achieves an accuracy of 90.93±0.50% when the first rank is selected while it gains 97.26±0.26% when the top-ten candidates are considered, that is 8.45% and 6.79% improvement over the conventional record-based naïve Bayes classifier and the vanilla version. Another result on applying only best features show 93.93±0.22% and up to 98.85±0.15% accuracy for top-1 and top-10, respectively. They are 3.97% and 9.78% improvement over naive Bayes and the vanilla version. Finally, an error analysis is given.
People tracking in crowded scene have been a popular, and at the same time a very difficult topic in computer vision. It is mainly because of the difficulty for the acquisition of intrinsic signatures of targets from a single view of the scene. Many factors, such as variable illumination conditions and viewing angles, will induce illusive modification of intrinsic signatures of targets. The objective of this paper is to verify if colour constancy (CC) approach really helps people tracking in CCTV network system. We have testified a number of CC algorithms together with various colour descriptors, to assess the efficiencies of people recognitions from multi-camera i-LIDS data set via receiver operation characteristics (ROC). It is found that when CC is applied together with some form of colour restoration mechanisms such as colour transfer, it does improve people recognition by at least a factor of 2. An elementary luminance based CC coupled with a pixel based colour transfer algorithm have been developed and it is reported in this paper.
Soori, Umair; Yuen, P. W. T.; Ibrahim, I.; Han, J.; Tsitiridis, A.; Hong, K.; Chen, T.; Jackman, J.; James, D.; Richardson, M.
Mandarin Chinese has a logographic script in which graphemes map onto syllables and morphemes. It is not clear whether Chinese readers activate phonological information during lexical access, although phonological information is not explicitly represented in Chinese orthography. In the present study, we examined the activation of phonological information, including segmental and tonal information in Chinese visual wordrecognition, using the Stroop paradigm. Native Mandarin speakers named the presentation color of Chinese characters in Mandarin. The visual stimuli were divided into five types: color characters (e.g., , hong2, "red"), homophones of the color characters (S+T+; e.g., , hong2, "flood"), different-tone homophones (S+T-; e.g., , hong1, "boom"), characters that shared the same tone but differed in segments with the color characters (S-T+; e.g., , ping2, "bottle"), and neutral characters (S-T-; e.g., , qian1, "leading through"). Classic Stroop facilitation was shown in all color-congruent trials, and interference was shown in the incongruent trials. Furthermore, the Stroop effect was stronger for S+T- than for S-T+ trials, and was similar between S+T+ and S+T- trials. These findings suggested that both tonal and segmental forms of information play roles in lexical constraints; however, segmental information has more weight than tonal information. We proposed a revised visual wordrecognition model in which the functions of both segmental and suprasegmental types of information and their relative weights are taken into account. PMID:23400856
Explored the contribution of two working memory systems, the articulatory loop and the central executive, and short-term memory to the wordrecognition and comprehension deficits of children with learning disabilities. Results of 2 experiments with 150 children support the idea that poor wordrecognition and comprehension reflect deficits in a…
Passive radar systems exploit illuminators of opportunity, such as TV and FM radio, to illuminate potential targets. Doing so allows them to operate covertly and inexpensively. Our research seeks to enhance passive radar systems by adding automatic targetrecognition (ATR) capabilities. In previous papers we proposed conducting ATR by comparing the radar cross section (RCS) of aircraft detected by a passive radar system to the precomputed RCS of aircraft in the target class. To effectively model the low-frequency setting, the comparison is made via a Rician likelihood model. Monte Carlo simulations indicate that the approach is viable. This paper builds on that work by developing a method for quickly assessing the potential performance of the ATR algorithm without using exhaustive Monte Carlo trials. This method exploits the relation between the probability of error in a binary hypothesis test under the Bayesian framework to the Chernoff information. Since the data are well-modeled as Rician, we begin by deriving a closed-form approximation for the Chernoff information between two Rician densities. This leads to an approximation for the probability of error in the classification algorithm that is a function of the number of available measurements. We conclude with an application that would be particularly cumbersome to accomplish via Monte Carlo trials, but that can be quickly addressed using the Chernoff information approach. This application evaluates the length of time that an aircraft must be tracked before the probability of error in the ATR algorithm drops below a desired threshold.
Recent studies report that the occipito-temporal N170 component of the ERP is enhanced by letter strings, relative to non-linguistic strings of similar visual complexity, with a left-lateralized distribution. This finding is consistent with underlying mechanisms that serve visual wordrecognition. Conclusions about the level of analysis reflected within the N170 effects, and therefore the timecourse of wordrecognition, have been mixed. Here, we investigated the timing and nature of brain responses to putatively low- and high-level processing difficulty. Low-level processing difficulty was modulated by manipulating letter-rotation parametrically at 0°, 22.5°, 45°, 67.5°, and 90°. Higher-level processing difficulty was modulated by manipulating lexical status (words vs. word-like pseudowords). Increasing letter-rotation enhanced the N170 led to monotonic increases in P1 and N170 amplitude up to 67.5° but then decreased amplitude at 90°. Pseudowords enhanced the N170 over left occipital-temporal sites, relative to words. These combined findings are compatible with a cascaded, interactive architecture in which lower-level analysis (e.g., word-form feature extraction) leads higher-level analysis (e.g., lexical access) in time, but that by approximately 170 ms, the brain's response to a visual word includes parallel, interactive processing at both low-level feature extraction and higher-order lexical access levels of analysis. PMID:22784511
Sign language (SL), which is a highly visual–spatial, linguistically complete, and natural language, is the main mode of communication among deaf people. Described in this paper are two different American Sign Language (ASL) wordrecognition systems developed using artificial neural networks (ANN) to translate the ASL words into English. Feature vectors of signing words taken at five time instants were
Purpose: This study examined differences in voiced consonant-vowel (CV) perception in older listeners with normal hearing and in 2 groups of older listeners with matched hearing losses: those with good and those with poor wordrecognition scores. Method: Thirty-six participants identified CVs from an 8-item display from the natural voiced initial…
Phillips, Susan L.; Richter, Scott J.; McPherson, David
|Recent research has demonstrated that slight increases of inter-letter spacing have a positive impact on skilled readers' recognition of visually presented words. In the present study, we examined whether this effect generalises to young normal readers and readers with developmental dyslexia, and whether increased inter-letter spacing affects the…
Perea, Manuel; Panadero, Victoria; Moret-Tatay, Carmen; Gomez, Pablo
Comparisons across languages have long been a means to investigate universal properties of the cognitive system. Although differences between languages may be salient, it is the underlying similarities that have advanced our understanding of language processing. Frost is not unique in emphasizing that the interaction among linguistic codes reinforces the inadequacy of constructing a model of wordrecognition where orthographic processes operate in isolation.
Feldman, Laurie Beth; Martin, Fermin Moscoso del Prado
|Research using online comprehension measures with monolingual children shows that speed and accuracy of spoken wordrecognition are correlated with lexical development. Here we examined speech processing efficiency in relation to vocabulary development in bilingual children learning both Spanish and English (n=26 ; 2 ; 6). Between-language…
Marchman, Virginia A.; Fernald, Anne; Hurtado, Nereyda
|Through study of clinical cases with brain lesions as well as neuroimaging studies of cognitive processing of words and pictures, it has been established that material-specific hemispheric specialization exists. It remains however unclear whether such specialization holds true for all processes involved in complex tasks, such as recognition…
|This article describes the usage of linguistic units and instructional strategies that facilitate wordrecognition for Latino kindergarten students who are beginning to read in Spanish. This case study was based on coding videotaped reading and language arts instruction of two bilingual kindergarten teachers at the beginning, middle, and end of…
Pollard-Durodola, Sharolyn D.; Cedillo, Gabriela Delagarza; Denton, Carolyn A.
Recent research has demonstrated that slight increases of inter-letter spacing have a positive impact on skilled readers' recognition of visually presented words. In the present study, we examined whether this effect generalises to young normal readers and readers with developmental dyslexia, and whether increased inter-letter spacing affects the…
Perea, Manuel; Panadero, Victoria; Moret-Tatay, Carmen; Gomez, Pablo
The Fourth International Chinese Language Processing Bakeoff was held in 2007 to as- sess the state of the art in three important tasks: Chinese word segmentation, named entity recognition and Chinese POS tagging. Twenty-eight groups submitted result sets in the three tasks across two tracks and a total of seven corpora. Strong results have been found in all the tasks
|Examines the relationships among phonological awareness, phonological memory, and development of reading skills in a longitudinal study, by following 222 Finnish preschoolers through grade 2. Focuses on the role of phonological memory in wordrecognition and comprehension. Underlines the stability of development of phonological memory,…
Many studies have suggested that a word’s orthographic form must be processed before its meaning becomes available. Some interpret the (null) finding of equal facilitation after semantically transparent and opaque morphologically related primes in early stages of morphological processing as consistent with this view. Recent literature suggests that morphological facilitation tends to be greater after transparent than after opaque primes, however. To determine whether the degree of semantic transparency influences parsing into a stem and a suffix (morphological decomposition) in the forward masked priming variant of the lexical decision paradigm, we compared patterns of facilitation between semantically transparent (e.g., coolant–cool) and opaque (e.g., rampant–ramp) prime–target pairs. Form properties of the stem (frequency, neighborhood size, and prime–target letter overlap), as well as related–unrelated and transparent–opaque affixes, were matched. Morphological facilitation was significantly greater for semantically transparent pairs than for opaque pairs. Ratings of prime–target relatedness predicted the magnitude of facilitation. The results limit the scope of form-then-meaning models of wordrecognition and demonstrate that semantic similarity can influence even early stages of morphological processing.
Feldman, Laurie Beth; O'Connor, Patrick A.; del Prado Martin, Fermin Moscoso
Several empirical lines of investigation support the idea that syllable-sized units may be involved in visual wordrecognition processes. In this perspective, the present study aimed at investigating further the nature of the process that causes syllabic effects in reading. To do so, the syllable frequency effect was investigated in French using event related potentials while participants performed a lexical decision task (experiment 1). Consistent with previous studies, manipulating the frequency of the first syllable in words and pseudowords yielded two temporally distinct effects. Compared to items with a first syllable of low frequency, items with a syllable of high frequency elicited a weaker P200 component, reflecting early sub-lexical facilitation, and a larger N400 component, supposed to ensue from competition between syllabic neighbours. To examine which factors determine the strength of interference during lexical access, regression analyses were conducted on the late temporal window potentials. The inhibitory syllable frequency effect was best predicted by leader strength, that is, the frequency ratio between the most frequent syllabic neighbour and the others. When this variable was directly manipulated while controlling for syllable frequency and number of higher frequency syllabic neighbours (experiment 2), electrophysiological data confirmed the impact of leader strength. The results are discussed in the context of interactive activation-based models augmented with syllabic representations. PMID:23044275
Research on language and aging typically shows that language comprehension is preserved across the life span. Recent neuroimaging results suggest that this good performance is underpinned by age-related neural reorganization [e.g., Tyler, L. K., Shafto, M. A., Randall, B., Wright, P., Marslen-Wilson, W. D., & Stamatakis, E. A. Preserving syntactic processing across the adult life span: The modulation of the frontotemporal language system in the context of age-related atrophy. Cerebral Cortex, 20, 352–364, 2010]. The current study examines how age-related reorganization affects the balance between component linguistic processes by manipulating semantic and phonological factors during spoken wordrecognition in younger and older adults. Participants in an fMRI study performed an auditory lexical decision task where words varied in their phonological and semantic properties as measured by degree of phonological competition and imageability. Older adults had a preserved lexicality effect, but compared with younger people, their behavioral sensitivity to phonological competition was reduced, as was competition-related activity in left inferior frontal gyrus. This was accompanied by increases in behavioral sensitivity to imageability and imageability-related activity in left middle temporal gyrus. These results support previous findings that neural compensation underpins preserved comprehension in aging and demonstrate that neural reorganization can affect the balance between semantic and phonological processing.
Shafto, Meredith; Randall, Billi; Stamatakis, Emmanuel A.; Wright, Paul; Tyler, L. K.
Purpose The authors assessed whether (a) a full-insertion cochlear implant would provide a higher level of speech understanding than bilateral low-frequency acoustic hearing, (b) contralateral acoustic hearing would add to the speech understanding provided by the implant, and (c) the level of performance achieved with electric stimulation plus contralateral acoustic hearing would be similar to performance reported in the literature for patients with a partial insertion cochlear implant. Method Monosyllabic wordrecognition as well as sentence recognition in quiet and at +10 and +5 dB was assessed. Before implantation, scores were obtained in monaural and binaural conditions. Following implantation, scores were obtained in electric-only and electric-plus-contralateral acoustic conditions. Results Postoperatively, all individuals achieved higher scores in the electric-only test conditions than they did in the best pre-implant test conditions. All individuals benefited from the addition of low-frequency information to the electric hearing. Conclusion A full-insertion cochlear implant provides better speech understanding than bilateral, low-frequency residual hearing. The combination of an implant and contralateral acoustic hearing yields comparable performance to that of patients with a partially inserted implant and bilateral, low-frequency acoustic hearing. These data suggest that a full-insertion cochlear implant is a viable treatment option for patients with low-frequency residual hearing.
Gifford, Rene H.; Dorman, Michael F.; McKarns, Sharon A.; Spahr, Anthony J.
Speech Recognition systems, historically, have proven to be cumbersome and insufficiently accurate for a range of applications. The ultimate goal of our proposed technology is to fundamentally change the way current Speech Recognition (SR) systems interact with humans and develop an application that is extremely hardware efficient. Accurate SR and reasonable hardware requirements will afford the average first responder officer, e.g., police officer, a true break-through technology that will change the way an officer performs his duties. The presented technology provides a cutting-edge solution for human-machine interaction through the utilization of a properly solved Wake-Up-Word (WUW) SR problem. This paradigm-shift provides the basis for development of SR systems with truly "Voice Activated" capabilities, impacting all SR based technologies and the way in which humans interact with computers. This shift is a radical departure from the current "push-to-talk" paradigm currently applied to all speech-to-text or speech-recognition applications. To be able to achieve this goal, a significantly more accurate pattern classification and scoring technique is required, which in turn provides SR systems enhanced performance for correct recognition (i.e., minimization of false rejection) as well as correct rejection (i.e., minimization of false acceptance). A revolutionary and innovative classification and scoring technique is used that is a significant enhancement over an earlier method presented in reference . The solution in reference  has been demonstrated to meet the stringent requirements of the WUW-SR task. Advanced solution of  is a novel technique that is model and algorithm independent. Therefore, it could be used to significantly improve performance of existing recognition algorithms and systems. Reduction of error rates of over 40% are commonly observed for both false rejections and false acceptance. In this paper the architecture of the WUW-SR based system as interface to current SR applications is presented. In this system WUW-SR is used as a gateway for truly Voice Activated applications utilizing the current solution without "push-to-talk" paradigm. The technique has been developed with hardware optimization in mind and therefore has the ability to run as a "background" application on a standard Windows-based PC platform.
Two findings serve as the hallmark for hemispheric specialization during lateralized lexical decision. First is an overall word advantage, with words being recognized more quickly and accurately than non-words (the effect being stronger in response latency). Second, a right visual field advantage is observed for words, with little or no hemispheric differences in the ability to identify non-words. Several theories
Steinernemacarpocapsae is a nematode pathogenic in a wide variety of insect species. The great pathogenicity of this nematode has been ascribed to its ability to overcome the host immune response; however, little is known about the mechanisms involved in this process. The analysis of an expressed sequence tags (EST) library in the nematode during the infective phase was performed and a highly abundant contig homologous to serine protease inhibitors was identified. In this work, we show that this contig is part of a 641-bp cDNA that encodes a BPTI-Kunitz family inhibitor (Sc-KU-4), which is up-regulated in the parasite during invasion and installation. Recombinant Sc-KU-4 protein was produced in Escherichia coli and shown to inhibit chymotrypsin and elastase activities in a dose-dependent manner by a competitive mechanism with Ki values of 1.8 nM and 2.6 nM, respectively. Sc-KU-4 also inhibited trypsin and thrombin activities to a lesser extent. Studies of the mode of action of Sc-KU-4 and its effects on insect defenses suggest that although Sc-KU-4 did not inhibit the activation of hemocytes or the formation of clotting fibers, it did inhibit hemocyte aggregation and the entrapment of foreign particles by fibers. Moreover, Sc-KU-4 avoided encapsulation and the deposition of clotting materials, which usually occurs in response to foreign particles. We show by protein-protein interaction that Sc-KU-4 targetsrecognition proteins of insect immune system such as masquerade-like and serine protease-like homologs. The interaction of Sc-KU-4 with these proteins explains the ability of the nematode to overcome host reactions and its large pathogenic spectrum, once these immune proteins are well conserved in insects. The discovery of this inhibitor targeting insect recognition proteins opens new avenues for the development of S. carpocapsae as a biological control agent and provides a new tool to study host-pathogen interactions. PMID:24098715
Toubarro, Duarte; Avila, Mónica Martinez; Montiel, Rafael; Simões, Nelson
Steinernemacarpocapsae is a nematode pathogenic in a wide variety of insect species. The great pathogenicity of this nematode has been ascribed to its ability to overcome the host immune response; however, little is known about the mechanisms involved in this process. The analysis of an expressed sequence tags (EST) library in the nematode during the infective phase was performed and a highly abundant contig homologous to serine protease inhibitors was identified. In this work, we show that this contig is part of a 641-bp cDNA that encodes a BPTI-Kunitz family inhibitor (Sc-KU-4), which is up-regulated in the parasite during invasion and installation. Recombinant Sc-KU-4 protein was produced in Escherichia coli and shown to inhibit chymotrypsin and elastase activities in a dose-dependent manner by a competitive mechanism with Ki values of 1.8 nM and 2.6 nM, respectively. Sc-KU-4 also inhibited trypsin and thrombin activities to a lesser extent. Studies of the mode of action of Sc-KU-4 and its effects on insect defenses suggest that although Sc-KU-4 did not inhibit the activation of hemocytes or the formation of clotting fibers, it did inhibit hemocyte aggregation and the entrapment of foreign particles by fibers. Moreover, Sc-KU-4 avoided encapsulation and the deposition of clotting materials, which usually occurs in response to foreign particles. We show by protein-protein interaction that Sc-KU-4 targetsrecognition proteins of insect immune system such as masquerade-like and serine protease-like homologs. The interaction of Sc-KU-4 with these proteins explains the ability of the nematode to overcome host reactions and its large pathogenic spectrum, once these immune proteins are well conserved in insects. The discovery of this inhibitor targeting insect recognition proteins opens new avenues for the development of S. carpocapsae as a biological control agent and provides a new tool to study host-pathogen interactions.
Toubarro, Duarte; Avila, Monica Martinez; Montiel, Rafael; Simoes, Nelson
Dallas and Merikle (1976a, 1976b) demonstrated that when participants were presented with a pair of words for over 1 s and subsequently cued to pronounce one of the words aloud (postcue task) semantic priming effects occurred. Humphreys, Lloyd-Jones, and Fias (1995) failed to replicate this postcue semantic priming effect using word pairs that were semantic category co-ordinates. The aim of Experiment 1 was to determine if the disparate postcue task results reported by these researchers could be accounted for by the prime-target contexts or cue types engaging different attentional processes or a combination of these factors. A postcue pronunciation task was used and word pairs presented were taken from an associate-semantic context and a semantic category context. In the Dallas and Merikle condition the line cue flanked the location in which the targetword was previously shown. In the Humphreys et al. condition the cue word UPPER or lower was centrally presented and indicated the location in which the targetword previously appeared. Results demonstrated that the occurrence of semantic and associate-semantic priming effects under postcue task conditions varied for the two cue types. Experiment 2 investigated if these results were attributable to a between subject manipulation of cue type. Using a fully repeated measures design priming effects were evident for top located targets in both the associate-semantic and semantic prime-target contexts. Experiment 3 used a between subjects design to rule out the possibility that carry over effects between cue and context conditions contributed to the postcue task priming effects. Priming was evident for top located targets in an associate-semantic and semantic context for the line cue. For the word cue there was priming for top located targets from an associate-semantic context and a reverse priming effect for top located targets from the semantic context. Possible explanations for the occurrence of priming effects under postcue task conditions are discussed.
Dallas and Merikle (1976a, 1976b) demonstrated that when participants were presented with a pair of words for over 1 s and subsequently cued to pronounce one of the words aloud (postcue task) semantic priming effects occurred. Humphreys, Lloyd-Jones, and Fias (1995) failed to replicate this postcue semantic priming effect using word pairs that were semantic category co-ordinates. The aim of Experiment 1 was to determine if the disparate postcue task results reported by these researchers could be accounted for by the prime-target contexts or cue types engaging different attentional processes or a combination of these factors. A postcue pronunciation task was used and word pairs presented were taken from an associate-semantic context and a semantic category context. In the Dallas and Merikle condition the line cue flanked the location in which the targetword was previously shown. In the Humphreys et al. condition the cue word UPPER or lower was centrally presented and indicated the location in which the targetword previously appeared. Results demonstrated that the occurrence of semantic and associate-semantic priming effects under postcue task conditions varied for the two cue types. Experiment 2 investigated if these results were attributable to a between subject manipulation of cue type. Using a fully repeated measures design priming effects were evident for top located targets in both the associate-semantic and semantic prime-target contexts. Experiment 3 used a between subjects design to rule out the possibility that carry over effects between cue and context conditions contributed to the postcue task priming effects. Priming was evident for top located targets in an associate-semantic and semantic context for the line cue. For the word cue there was priming for top located targets from an associate-semantic context and a reverse priming effect for top located targets from the semantic context. Possible explanations for the occurrence of priming effects under postcue task conditions are discussed. PMID:22007264
The present research aimed to investigate whether, as previously observed with pictures, background auditory rhythm would also influence visual wordrecognition. In a lexical decision task, participants were presented with bisyllabic visual words, segmented into two successive groups of letters, while an irrelevant strongly metric auditory sequence was played in a loop. The first group of letters could either be congruent with the syllabic division of the word (e.g. val in val/se) or not (e.g. va in va/lse). In agreement with the Dynamic Attending Theory (DAT), our results confirmed that the presentation of the correct first syllable on-beat (i.e. in synchrony with a peak of covert attention) facilitated visual wordrecognition compared to when it was presented off-beat. However, when an incongruent first syllable was displayed on-beat, this led to an aggravation of impaired recognition. Thus, our results suggest that oscillatory attention tapped into cognitive processes rather than perceptual or decisional and motor stages. We like to think of our paradigm, which combines background auditory rhythm with segmented visual stimuli, as a sort of temporal magnifying glass which allows for the enlargement of the reaction time differences between beneficial and detrimental processing conditions in human cognition. PMID:23454794
A precise recognition method of missile warhead and decoy in multi-target scene is presented in this paper. In multi-target scene, the echoes received by radar are the mixture of backscattered signals from all targets within radar beam. In order to separate backscattered signal of each target by Independent Components Analysis (ICA) method, a radar system of multiple antennas with different
I have argued that orthographic processing cannot be understood and modeled without considering the manner in which orthographic structure represents phonological, semantic and morphological information in a given writing system. A reading theory, therefore, must be a theory of the interaction of the reader with his/her linguistic environment. This outlines a novel approach to studying and modeling visual wordrecognition, an approach that focuses on the common cognitive principles involved in processing printed words across different writing systems. These claims were challenged by several commentaries that contested the merits of my general theoretical agenda, the relevance of the evolution of writing systems, and the plausibility of finding commonalities in reading across orthographies. Other commentaries extended the scope of the debate by bringing into the discussion additional perspectives. My response addresses all these issues. By considering the constraints of neurobiology on modeling reading, developmental data, and a large scope of cross-linguistic evidence, I argue that front-end implementations of orthographic processing that do not stem from a comprehensive theory of the complex information conveyed by writing systems do not present a viable approach for understanding reading. The common principles by which writing systems have evolved to represent orthographic, phonological and semantic information in a language reveal the critical distributional characteristics of orthographic structure that govern reading behavior. Models of reading should thus be learning models, primarily constrained by cross-linguistic developmental evidence that describes how the statistical properties of writing systems shape the characteristics of orthographic processing. When this approach is adopted a universal model of reading is possible.
A laboratory simulation experiment was performed to determine the effect of the TV camera lens field of view upon air-to-ground targetrecognition by closed-circuit television. Measures of performance were probability of correct targetrecognition, range ...
This paper on adaptive image segmentation and classification describes research activities on statistical pattern recognition in combination with methods of object recognition by geometric matching of model and image structures. In addition, aspects of sensor fusion for airborne application systems like terminal missile guidance were considered using image sequences of multispectral data from real sensor systems and from computer simulations.
Bernhard Bargel; Karl-Heinz Bers; Klaus Jaeger; Gabriele Schwan
In the first of 3 experiments, university undergraduates were presented a list of 300 words and 100 nonwords in two sessions. Their confidence that an item was a word was indicated for each item on a 6-point scale. This experiment demonstrated the feasibi...
J. Zimmerman P. K. Broder J. J. Shaughnessy B. J. Underwood
Groups of 7, 8, and 9-year-old children who were learning to read in English and German were given three different continuous reading tasks: a numeral reading task, a number word reading task, and a nonsense word reading task. The nonsense words could be read by analogy to the number words. Whereas reading time and error rates in numeral and number
Dividing attention across multiple words occasionally results in misidentifications whereby letters apparently migrate between words. Previous studies have found that letter migrations preserve within-word letter position, which has been interpreted as support for position-specific letter coding. To investigate this issue, the authors used word…
Studies of word production in patients with Alzheimer's disease have identified the age of acquisition of words as an important predictor of retention or loss, with early acquired words remaining accessible for longer than later acquired words. If, as proposed by current theories, effects of age of acquisition reflect the involvement of semantic representations in task performance, then some aspects
|Three ERP experiments examined the effect of word presentation rate (i.e., stimulus onset asynchrony, SOA) on the time course of word frequency and predictability effects in sentence reading. In Experiments 1 and 2, sentences were presented word-by-word in the screen center at an SOA of 700 and 490ms, respectively. While these rates are typical…
Dambacher, Michael; Dimigen, Olaf; Braun, Mario; Wille, Kristin; Jacobs, Arthur M.; Kliegl, Reinhold
|Two findings serve as the hallmark for hemispheric specialization during lateralized lexical decision. First is an overall word advantage, with words being recognized more quickly and accurately than non-words (the effect being stronger in response latency). Second, a right visual field advantage is observed for words, with little or no…
|Studies of word production in patients with Alzheimer's disease have identified the age of acquisition of words as an important predictor of retention or loss, with early acquired words remaining accessible for longer than later acquired words. If, as proposed by current theories, effects of age of acquisition reflect the involvement of semantic…
Cuetos, Fernando; Herrera, Elena; Ellis, Andrew W.
The hypothesis that word context reduces visual rather than acoustic confusion between possible targets was tested in a series of experiments. All involved tachistoscopic presentation of letter strings followed by a pattern mask. Data from eight college students showed that target letters that are confusable only visually and acoustically ("b" and…
To gain insight into memory disturbances in Complex Posttraumatic Stress Disorder (Complex PTSD), we investigated declarative memory function and medial temporal lobe activity in patients and healthy non-traumatized controls. A case-control study was performed in nine patients with Complex PTSD and nine controls. All respondents performed a declarative memory task with neutral and emotional, negative words during functional magnetic resonance imaging. Memory performance of neutral words was impaired in Complex PTSD with a relative conservation of recall of negative words. Deep encoding of later remembered negative words, as well as correct recognition of negative words and false alarms, was associated with an enhanced Blood Oxygenation Level Dependent (BOLD) response in the left hippocampus extending into the parahippocampal gyrus of Complex PTSD patients compared with controls. Post-hoc volumetric comparisons did not reveal significant anatomical differences in the medial temporal lobe between Complex PTSD patients and controls. We conclude that in Complex PTSD preferential recall of negative words is associated with increased activation in the left hippocampus and parahippocampal gyrus during both successful and false recall. These findings support a model of an abnormally functioning hippocampus in Complex PTSD. PMID:19081708
Thomaes, Kathleen; Dorrepaal, Ethy; Draijer, Nel P J; de Ruiter, Michiel B; Elzinga, Bernet M; van Balkom, Anton J; Smoor, Paulien L M; Smit, Johannes; Veltman, Dick J
Memory disturbances found in obsessive–compulsive disorder (OCD) may partially be related to dysfunction of cortico–subcortical circuits. However, it is still unknown how OCD symptomatology is related to memory processing. To explore this question, event-related potentials (ERPs) were recorded in a continuous word-recognition paradigm in OCD patients with either severe or moderate scores on the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) (group S
Yuanyuan Zhang; Sebastian Feutl; Ute Hauser; Claudia Richter-Witte; Philip Schmorl; Hinderk M. Emrich; Detlef E. Dietrich
Low-income, inner-city children were involved in a two-year intervention delivered in the regular classroom by regular classroom teachers to develop phonological awareness and wordrecognition skills. For the treatment children, an 11-week phoneme awareness program in kindergarten was followed by a first grade reading program (extended to grade 2 for some children) that emphasized explicit, systematic instruction in the alphabetic
Benita A. Blachman; Darlene M. Tangel; Eileen Wynne Ball; Rochella Black; Collen K. McGraw
Two experiments tested language switching effects with bilingual participants in a priming paradigm with masked primes (duration of 50ms in Experiment 1 and 100ms in Experiment 2). Participants had to monitor targetwords for animal names, and ERPs were recorded to critical (non-animal) words in L1 and L2 primed by unrelated words from the same or the other language. Both experiments revealed language priming (switching) effects that depended on target language. For targetwords in L1, most of the language switch effect appeared in the N400 ERP component, with L2 primes generating a more negative going wave than L1 primes. For L2 targetwords, on the other hand, the effects of a language switch appeared mainly in an earlier ERP component (N250) peaking at approximately 250ms post-target onset, and showing greater negativity following an L1 prime than an L2 prime. This is the first evidence for fast-acting language-switching effects occurring in the absence of overt task switching. PMID:18191445
A common complaint of the hearing impaired is the inability to understand speech in noisy environments even with their hearing assistive devices. Only a few single-channel algorithms have significantly improved speech intelligibility in noise for hearing-impaired listeners. The current study introduces a cochlear noise reduction algorithm. It is based on a cochlear representation of acoustic signals and real-time derivation of a binary speech mask. The contribution of the algorithm for enhancing wordrecognition in noise was evaluated on a group of 42 normal-hearing subjects, 35 hearing-aid users, 8 cochlear implant recipients, and 14 participants with bimodal devices. Recognition scores of Hebrew monosyllabic words embedded in Gaussian noise at several signal-to-noise ratios (SNRs) were obtained with processed and unprocessed signals. The algorithm was not effective among the normal-hearing participants. However, it yielded a significant improvement in some of the hearing-impaired subjects under different listening conditions. Its most impressive benefit appeared among cochlear implant recipients. More than 20% improvement in recognition score of noisy words was obtained by 12, 16, and 26 hearing-impaired at SNR of 30, 24, and 18 dB, respectively. The algorithm has a potential to improve speech intelligibility in background noise, yet further research is required to improve its performances. PMID:22978899
Normal hearing listeners whose first language was Spanish were tested with English phonemes, words and sentences. Listeners were divided into four categories according to experience with the second language. Speech was presented in a sound treated booth at a level of 70 dBA. Listening conditions included noise (SNR of 15 dB, 10 dB, 5 dB, 0 dB, and 5 dB) and reduced spectral information (2, 4, 6, 8 and 16 frequency bands). Plomp's Model [J. Speech Hear. Res. 29, 146-154 (1986)] was applied to the data. The distortion factor ``D'' defined by Plomp was found to increase with an increased loss of spectral resolution. It was also found to increase with age of learning of the second language. An additional ``distortion'' seems to be introduced when a second language is learned at a later age. Non-native listeners had more difficulty understanding vowels, words and sentences. Surprisingly, English experience had less effect on word and sentence recognition than on vowel recognition. Significantly lower performance on vowel recognition was seen even for fully bilingual listeners with reduced spectral resolution which could probably be related to the conflicting vowel spaces of the two languages. [Work funded by NIDCD.
Adults with sensory impairment, such as reduced hearing acuity, have impaired ability to recall identifiable words, even when their memory is otherwise normal. We hypothesize that poorer stimulus quality causes weaker activity in neurons responsive to the stimulus and more time to elapse between stimulus onset and identification. The weaker activity and increased delay to stimulus identification reduce the necessary strengthening of connections between neurons active before stimulus presentation and neurons active at the time of stimulus identification. We test our hypothesis through a biologically motivated computational model, which performs item recognition, memory formation and memory retrieval. In our simulations, spiking neurons are distributed into pools representing either items or context, in two separate, but connected winner-takes-all (WTA) networks. We include associative, Hebbian learning, by comparing multiple forms of spike-timing-dependent plasticity (STDP), which strengthen synapses between coactive neurons during stimulus identification. Synaptic strengthening by STDP can be sufficient to reactivate neurons during recall if their activity during a prior stimulus rose strongly and rapidly. We find that a single poor quality stimulus impairs recall of neighboring stimuli as well as the weak stimulus itself. We demonstrate that within the WTA paradigm of wordrecognition, reactivation of separate, connected sets of non-word, context cells permits reverse recall. Also, only with such coactive context cells, does slowing the rate of stimulus presentation increase recall probability. We conclude that significant temporal overlap of neural activity patterns, absent from individual WTA networks, is necessary to match behavioral data for word recall.
Do task demands change the way we extract information from a stimulus, or only how we use this information for decision making? In order to answer this question for visual wordrecognition, we used EEG/MEG as well as fMRI to determine the latency ranges and spatial areas in which brain activation to words is modulated by task demands. We presented letter strings in three tasks (lexical decision, semantic decision, silent reading), and measured combined EEG/MEG as well as fMRI responses in two separate experiments. EEG/MEG sensor statistics revealed the earliest reliable task effects at around 150 ms, which were localized, using minimum norm estimates (MNE), to left inferior temporal, right anterior temporal and left precentral gyri. Later task effects (250 and 480 ms) occurred in left middle and inferior temporal gyri. Our fMRI data showed task effects in left inferior frontal, posterior superior temporal and precentral cortices. Although there was some correspondence between fMRI and EEG/MEG localizations, discrepancies predominated. We suggest that fMRI may be less sensitive to the early short-lived processes revealed in our EEG/MEG data. Our results indicate that task-specific processes start to penetrate wordrecognition already at 150 ms, suggesting that early word processing is flexible and intertwined with decision making.
Chen, Y.; Davis, M. H.; Pulvermuller, F.; Hauk, O.
We present two stochastic filters for an FM-band passive air surveillance radar. The first system uses an extended Kalman filter and delay-Doppler measurements to track targets. The second system uses a particle filter to simultaneously track and classify targets. Automatic targetrecognition is made possible by the inclusion of radar cross section (RCS) in the measurement vector. The extended Kalman
With the release of the Moving and Stationary Target Acquisition and Recognition (MSTAR) public data set, high quality Synthetic Aperture Radar (SAR) imagery of military ground vehicles has been made accessible to the entire research community. Furthermor...
|Magnetoencephalography (MEG) has shown pseudohomophone priming effects at Broca's area (specifically pars opercularis of left inferior frontal gyrus and precentral gyrus; LIFGpo/PCG) within [approximately]100 ms of viewing a word. This is consistent with Broca's area involvement in fast phonological access during visual wordrecognition. Here we…
Wheat, Katherine L.; Cornelissen, Piers L.; Sack, Alexander T.; Schuhmann, Teresa; Goebel, Rainer; Blomert, Leo
This research examined phonological awareness (PA) and single word reading in 14 school-age children with autism and 10 age-matched, typically developing (TD) children between 5-7 years. Two measures of PA, an elision task (ELI) and a sound blending task (BLW), were given along with two measures of single word reading, word identification for real…
|This research examined phonological awareness (PA) and single word reading in 14 school-age children with autism and 10 age-matched, typically developing (TD) children between 5-7 years. Two measures of PA, an elision task (ELI) and a sound blending task (BLW), were given along with two measures of single word reading, word identification for…
Purpose: To examine the possibility that early signal-to-word form mapping capabilities are robust enough to handle substantial indexical variation in the realization of words. Method: Two groups of 7.5-month-olds were tested with the Headturn Preference Procedure. Half of the infants were exposed to words embedded in passages spoken by their…
This book lets readers see how children and youth learn words in the oral and written languages--and how teachers can best assist learners in the understanding, reading, and writing of words for successful literacy development. In the book teachers learn the differing rationales for using sound/symbol or phonics approaches in word learning, for…
Regardless of the script, in the process of learning to read words, readers develop awareness of the structural and functional properties of words with increased exposure to the script. However, as sub-word units that are critical for phonological or morphological processing or both are not uniform, the types of the awareness may vary from script…
|This article discusses using sign language to help students with learning disabilities remember sight words. It describes the rationale for using sign language, gives directions for playing a game called Sign-o (similar to the game Bingo), provides extension activities, and includes a game board ready for duplication. (Contains references.)…
We present an evaluation of the impact of a recently developed point-enhanced high range-resolution (HRR) radar profile reconstruction method on automatic targetrecognition (ATR) performance. We use several pattern recognition techniques to compare the performance of point-enhanced HRR profiles with conventional Fourier transform-based profiles. We use measured radar data of civilian ships and produce range profiles from such data. We use two types of classifiers to quantify recognition performance. The first type of classifier is based on the nearest neighbor technique. We demonstrate the performance of this classifier using a variety of extracted features, and a number of different distance metrics. The second classifier we use for targetrecognition involves position specific matrices, which have previously been used in gene sequencing. We compare the classification performance of point-enhanced HRR profiles with conventional profiles, and observe that point enhancement results in higher recognition rates in general.
In this paper, a Synthetic Aperture Radar Automatic TargetRecognition approach based on Gaussian process (GP) classification is proposed. It adopts kernel principal component analysis to extract sample features and implements targetrecognition by using GP classification with automatic relevance determination (ARD) function. Compared with k-Nearest Neighbor, NaÃ¯ve Bayes classifier and Support Vector Machine, GP with ARD has the advantage of automatic model selection and hyper-parameter optimization. The experiments on UCI datasets and MSTAR database show that our algorithm is self-tuning and has better recognition accuracy as well.
NCI-ACS Childhood Cancer Workshop May 5-6, 2005 Summary Report - 1 - June 2006 Summary of the Childhood Cancer Targeted Therapeutics Workshop Sponsored by the American Cancer Society and the National Cancer Institute List of workshop participants
We examined associative priming of words (e.g., toad) and pseudohomophones of those words (e.g., tode) in lexical decision.\\u000a In addition to word frequency effects, reliable base-word frequency effects were observed for pseudohomophones: Those based\\u000a on high-frequency words elicited faster and more accurate correct rejections. Associative priming had disparate effects on\\u000a high- and low-frequency items. Whereas priming improved performance to high-frequency
D. Vaughn Becker; Stephen D. Goldinger; Gregory O. Stone
We investigated the influences of phonological similarity on the time course of spoken word processing in Mandarin Chinese. Event related potentials were recorded while adult native speakers of Mandarin (N=19) judged whether auditory words matched or mismatched visually presented pictures. Mismatching words were of the following nature: segmental (e.g., picture: hua1 'flower'; sound: hua4 'painting'); cohort (e.g., picture: hua1 'flower'; sound: hui1 'gray'); rhyme (e.g., picture: hua1 'flower'; sound: gua1 'melon'); tonal (e.g., picture: hua1 'flower'; sound: jing1 'whale'); unrelated (e.g., picture: hua1 'flower'; sound: lang2 'wolf'). Expectancy violations in the segmental condition showed an early-going modulation of components (starting at 250 ms post-stimulus onset), suggesting that listeners used tonal information to constrain wordrecognition as soon as it became available, just like they did with phonemic information in the cohort condition. However, effects were less persistent and more left-lateralized in the segmental than cohort condition, suggesting dissociable cognitive processes underlie access to tonal versus phonemic information. Cohort versus rhyme mismatches showed distinct patterns of modulation which were very similar to what has been observed in English, suggesting onsets and rimes are weighted similarly across the two languages. Last, we did not observe effects for whole-syllable mismatches above and beyond those for mismatches in individual components, suggesting the syllable does not merit a special status in Mandarin spoken wordrecognition. These results are discussed with respect to modifications needed for existing models to accommodate the tonal languages spoken by a large proportion of the world's speakers. PMID:22595659
Most speech recognition systems, especially LVCSR, use context dependent phones as the basic acoustic unit for recognition. The primary motive for this is the relative ease with which phone based systems can be trained robustly with small amounts of data. However as recent research indicates, significant improvements in recognition accuracy can be gained by using acoustic units of longer duration
|Word substitution errors from a corpus of 2,400 French slips of the tongue were grouped into several categories: contaminational, semantic, formal, and mixed cases; substitutions of syntagmatic codependents also occurred. Semantic and formal substitutions involved a resemblance between target and error. All substitutions exhibited a strong degree…
In this paper we propose a new automatic targetrecognition algorithm to recognize and distinguish of three classes of targets: personnel, wheeled vehicles and animals, using a low-resolution ground surveillance pulse Doppler radar. Using the chirplet transformation, a time-frequency signal processing technique, the parameterized radar signal is then used by the Zernike moments (ZM) for the pertinent features of the
This paper presents a novel methodology for targetrecognition and reconstruction of rigid body moving targets. Traditional methods such as Synthetic Aperture Radar (SAR) rely on information gathered from multiple sensor locations and complex processing algorithms. Additional processing is often required to mitigate the effects of motion and improve the image resolution. Many of these techniques rely on information external
A study was conducted to investigate the effect of binocular rivalry on a simple target detection/recognition task. Six observers were required to detect and identify a target numeral (6, 7, or 8) that was embedded in a matrix of letters (Bs, Gs or Zs). B...
SAR(synthetic aperture radar) image understanding and interpretation is essential for remote sensing of earth environment and target detection. In development of aided targetrecognition and identification system, SAR image database with rich information content plays important role is essential. This paper presents a RCS computation for simulation of orbital SAR image. After demodulation, the received SAR signal is given as
Ladar range images have attracted considerable attention in automatic targetrecognition fields. In this paper, Zernike moments (ZMs) are applied to classify the target of the range image from an arbitrary azimuth angle. However, ZMs suffer from high computational costs. To improve the performance of targetrecognition based on small samples, even-order ZMs with serial-parallel backpropagation neural networks (BPNNs) are applied to recognize the target of the range image. It is found that the rotation invariance and classified performance of the even-order ZMs are both better than for odd-order moments and for moments compressed by principal component analysis. The experimental results demonstrate that combining the even-order ZMs with serial-parallel BPNNs can significantly improve the recognition rate for small samples. PMID:23128699
The importance of networked automatic targetrecognition systems for surveillance applications is continuously increasing. Because of the requirement of a low cost and limited payload, these networks are traditionally equipped with lightweight, low-cost sensors such as electro-optical (EO) or infrared sensors. The quality of imagery acquired by these sensors critically depends on the environmental conditions, type and characteristics of sensors, and absence of occluding or concealing objects. In the past, a large number of efficient detection, tracking, and recognition algorithms have been designed to operate on imagery of good quality. However, detection and recognition limits under nonideal environmental and/or sensor-based distortions have not been carefully evaluated. We introduce a fully automatic targetrecognition system that involves a Haar-based detector to select potential regions of interest within images, performs adjustment of detected regions, segments potential targets using a region-based approach, identifies targets using Bessel K form-based encoding, and performs clutter rejection. We investigate the effects of environmental and camera conditions on target detection and recognition performance. Two databases are involved. One is a simulated database generated using a 3-D tool. The other database is formed by imaging 10 die-cast models of military vehicles from different elevation and orientation angles. The database contains imagery acquired both indoors and outdoors. The indoors data set is composed of clear and distorted images. The distortions include defocus blur, sided illumination, low contrast, shadows, and occlusions. All images in this database, however, have a uniform (blue) background. The indoors database is applied to evaluate the degradations of recognition performance due to camera and illumination effects. The database collected outdoors includes a real background and is much more complex to process. The numerical results demonstrate that the complexity of the background and the presence of occlusions present a serious challenge for automatic target detection and recognition.
With advantages of flexibility, high bandwidth, high spatial resolution and high-speed parallel operation, the opto-electronic hybrid targetrecognition system can be applied in many civil and military areas, such as video surveillance, intelligent navigation and robot vision. A miniature opto-electronic hybrid targetrecognition system based on FPGA+DSP is designed, which only employs single Fourier lens and with a focal length. With the precise timing control of the FPGA and images pretreatment of the DSP, the system performs both Fourier transform and inverse Fourier transform with all optical process, which can improve recognition speed and reduce the system volume remarkably. We analyzed the system performance, and a method to achieve scale invariant pattern recognition was proposed on the basis of lots of experiments.
The paper considers the following problem: given a 3D model of a reference target and a sequence of images of a 3D scene, identify the object in the scene most likely to be the reference target and determine its current pose. Finding the best match in each frame independently of previous decisions is not optimal, since past information is ignored.
People tracking in crowded scenes from closed-circuit television (CCTV) footage has been a popular and challenging task in computer vision. Due to the limited spatial resolution in the CCTV footage, the color of people's dress may offer an alternative feature for their recognition and tracking. However, there are many factors, such as variable illumination conditions, viewing angles, and camera calibration, that may induce illusive modification of intrinsic color signatures of the target. Our objective is to recognize and track targets in multiple camera views using color as the detection feature, and to understand if a color constancy (CC) approach may help to reduce these color illusions due to illumination and camera artifacts and thereby improve targetrecognition performance. We have tested a number of CC algorithms using various color descriptors to assess the efficiency of targetrecognition from a real multicamera Imagery Library for Intelligent Detection Systems (i-LIDS) data set. Various classifiers have been used for target detection, and the figure of merit to assess the efficiency of targetrecognition is achieved through the area under the receiver operating characteristics (AUROC). We have proposed two modifications of luminance-based CC algorithms: one with a color transfer mechanism and the other using a pixel-wise sigmoid function for an adaptive dynamic range compression, a method termed enhanced luminance reflectance CC (ELRCC). We found that both algorithms improve the efficiency of targetrecognitions substantially better than that of the raw data without CC treatment, and in some cases the ELRCC improves target tracking by over 100% within the AUROC assessment metric. The performance of the ELRCC has been assessed over 10 selected targets from three different camera views of the i-LIDS footage, and the averaged targetrecognition efficiency over all these targets is found to be improved by about 54% in AUROC after the data are processed by the proposed ELRCC algorithm. This amount of improvement represents a reduction of probability of false alarm by about a factor of 5 at the probability of detection of 0.5. Our study concerns mainly the detection of colored targets; and issues for the recognition of white or gray targets will be addressed in a forthcoming study.
Soori, Umair; Yuen, Peter; Han, Ji Wen; Ibrahim, Izzati; Chen, Wentao; Hong, Kan; Merfort, Christian; James, David; Richardson, Mark
|Words are processed as units. This is not as evident as it seems, given the division of the human cerebral cortex in two hemispheres and the partial decussation of the optic tract. In two experiments, we investigated what underlies the unity of foveally presented words: A bilateral projection of visual input in foveal vision, or interhemispheric…
|Serial attention models of eye-movement control during reading were evaluated in an eye-tracking experiment that examined how lexical activation combines with visual information in the parafovea to affect word skipping (where a word is not fixated during first-pass reading). Lexical activation was manipulated by repetition priming created through…
|Words presented to the right visual field (RVF) are recognized more readily than those presented to the left visual field (LVF). Whereas the attentional bias theory proposes an explanation in terms of attentional imbalance between visual fields, the attentional advantage theory assumes that words presented to the RVF are processed automatically…
|To test the hypothesis that native language (L1) phonology can affect the lexical representations of nonnative words, a visual semantic-relatedness decision task in English was given to native speakers and nonnative speakers whose L1 was Japanese or Arabic. In the critical conditions, the word pair contained a homophone or near-homophone of a…
Ota, Mitsuhiko; Hartsuiker, Robert J.; Haywood, Sarah L.
|Attempts to replicate the release-from-competition effect (a difficult concurrent memory task speeds pronunciation of low-frequency irregular words but slows pronunciation of other word types) with mature normal readers of Norwegian (undergraduate education students) and thus tested the generalizability of dual-route models to a considerably more…
|The present study examined how contextual learning and in particular emotionality conditioning impacts the neural processing of words, as possible key factors for the acquisition of words' emotional connotation. 21 participants learned on five consecutive days associations between meaningless pseudowords and unpleasant or neutral pictures using…
|Toward the end of their first year of life, infants' overly specified word representations are thought to give way to more abstract ones, which helps them to better cope with variation not relevant to word identity (e.g., voice and affect). This developmental change may help infants process the ambient language more efficiently, thus enabling…
Schmale, Rachel; Cristia, Alejandrina; Seidl, Amanda; Johnson, Elizabeth K.
According to a simple anatomical and functional model of word reading, letters displayed in one hemifield are first analysed through a cascade of contralateral retinotopic areas, which compute increas- ingly abstract representations. Eventually, an invariant representa- tion of letter identities is created in the visual word form area (VWFA), reproducibly located within the left occipito-temporal sulcus. The VWFA then projects
L. Cohen; O. Martinaud; C. Lemer; S. Lehéricy; Y. Samson; M. Obadia; A. Slachevsky; S. Dehaene
|Previous research indicates that pairing pictures with associated words when teaching sight-word reading may hinder acquisition (e.g., Didden, Prinsen, & Sigafoos, 2000; Singh & Solman, 1990; Solman & Singh, 1992). The purpose of the current study was to determine whether this phenomenon was due to a previously learned association between the…
We present an evaluation of the impact of a recently developed point-enhanced high range-resolution (HRR) radar profile reconstruction method on automatic targetrecognition (ATR) performance. We use several pattern recognition techniques to compare the performance of point-enhanced HRR profiles with conventional Fourier transform-based profiles. We use measured radar data of civilian ships and produce range profiles from such data. We
In this paper, we propose photon counting three-dimensional (3D) passive sensing and object recognition using integral imaging. The application of this approach to 3D automatic targetrecognition (ATR) is investigated using both linear and nonlinear matched filters. We find there is significant potential of the proposed system for 3D sensing and recognition with a low number of photons. The discrimination capability of the proposed system is quantified in terms of discrimination ratio, Fisher ratio, and receiver operating characteristic (ROC) curves. To the best of our knowledge, this is the first report on photon counting 3D passive sensing and ATR with integral imaging.
In this paper, focused on three targets with simple structure, such as cone, sphere and cone, cylinder and cone, dynamic RCS echo signals is predicted with the improved Greco software. The Dynamic RCS echo signals of targets with micro-movement are preprocessed by using short time Fourier transform, and high-resolution time-frequency distribution images are obtained. A new radar targetrecognition method
Weixing Sheng; Kang Pan; Fang Wang; Xiaofeng Ma; Hao Wang
One of the most formidable intelligence challenges existing in the non-proliferation community is the detection of buried targets. The physical parameter that all buried targets share, whether the target is buried armaments, a tunnel or a bunker, is mass. In the case of buried armaments, there is an excess mass (higher density) compared to the surrounding area; for a tunnel or bunker, the mass is missing. In either case, this difference in mass generates a distinct gravitational signature. The Superconducting Gravity Gradiometer project at Sandia worked toward developing an airborne device for the detection of these underground structures.
It is known that manipulation of the encoding strategy affects behavioral and activation data during later retrieval. In the present fMRI study, we examined brain activity during the recognition of words encoded using three different strategies formed by the combination of two factors of relational and self-performed processes. The first encoding strategy involved subjects learning words using both relational and self-performed processes (R+S+). In the second, subjects learned words using only a relational process (R+S-). In the third, subjects learned words without using either process (R-S-). During fMRI after encoding, subjects were randomly presented with words encoded previously and with new words (New) and were required to judge whether or not the word presented had been previously encoded. The fMRI experiment was performed with the event-related design. Compared to New, activation of the left medial temporal lobe (MTL) occurred during the recognition of words encoded using R+S+ and R+S-, whereas right MTL activations only occurred with the R+S+ strategy. ROI analysis for the bilateral hippocampus and parahippocampal gyrus showed a linear increase in left MTL activity (hippocampus and parahippocampal gyrus) during the recognition of words encoded with the R-S-, R+S-, to R+S+, whereas right MTL activity (parahippocampal gyrus) was only increased with the R+S+ strategy. The findings suggest that the left and right MTL structures may contribute differentially to the processes involved in the recognition of stimuli and that these differential activities may depend on the encoding strategies formed by the two factors of relational and self-performed processes. PMID:15784424
This study examined the effect of presumed mismatches between speech input and the phonological representations of English words by native speakers of English (NE) and Spanish (NS). The English test words, which were produced by a NE speaker and a NS speaker, varied orthogonally in lexical frequency and neighborhood density and were presented to NE listeners and to NS listeners who differed in English pronunciation proficiency. It was hypothesized that mismatches between phonological representations and speech input would impair wordrecognition, especially for items from dense lexical neighborhoods which are phonologically similar to many other words and require finer sound discrimination. Further, it was assumed that L2 phonological representations would change with L2 proficiency. The results showed the expected mismatch effect only for words from dense neighborhoods. For Spanish-accented stimuli, the NS groups recognized more words from dense neighborhoods than the NE group did. For native-produced stimuli, the low-proficiency NS group recognized fewer words than the other two groups. The-high proficiency NS participants' performance was as good as the NE group's for words from sparse neighborhoods, but not for words from dense neighborhoods. These results are discussed in relation to the development of phonological representations of L2 words. (200 words). .
The study of multiple classifier systems has become an area of intensive research in pattern recognition. Also in handwriting, recognition, systems combining several classifiers have been investigated. In the paper new methods for the creation of classifier ensembles based on feature selection algorithms are introduced. These new methods are evaluated and compared to existing approaches in the context of handwritten
|Purpose: This study sought to compare dichotic right-ear advantages (REAs) of young adults to older adult data (C. M. Roup, T. L. Wiley, & R. H. Wilson, 2006) after matching for overall levels of recognition performance. Specifically, speech-spectrum noise was introduced in order to reduce dichotic recognition performance of young adults to a…
Speech Recognition systems, historically, have proven to be cumbersome and insufficiently accurate for a range of applications. The ultimate goal of our proposed technology is to fundamentally change the way current Speech Recognition (SR) systems interact with humans and develop an application that is extremely hardware efficient. Accurate SR and reasonable hardware requirements will afford the average first responder officer,
Traditionally, speech recognition systems use only the acoustic speech signal (speech). However, the source of the signal and the way speech is produced and whether this information can aid in speech recognition needs to be investigated. The objective of this study was to assess the contribution of using the electroglottograph (EGG) as an additional source of information along with speech
We present an effective quadratic time-frequency S-method based approach in conjunction with the Viterbi algorithm to extract m-D features. The effectiveness of the S-method in extracting m-D features is demonstrated through the application to indoor and outdoor experimental data sets such as rotating fan and human gait. The Viterbi algorithm for the instantaneous frequency estimation is used to enhance the weak human micro-Doppler features in relatively high noise environments. As such, this paper contributes additional experimental micro-Doppler data and analysis, which should help in developing a better picture of the human gait micro-Doppler research and its applications to indoor and outdoor imaging and automatic gait recognition systems.
IS10 inserts preferentially into particular hotspots. We describe here mutations of IS10 transposase, called 'ATS' that confer Altered Target Specificity. These mutations yield a general relaxation in target specificity but do not affect other aspects of transposition. Thus, the preference for specific nucleotide sequences at the target site can be cleanly separated from other steps of the transposition reaction. Eleven ATS mutations identified in a genetic screen occur at only two codons in transposase, one in each of two regions of the protein previously implicated in target site interactions (Patch I and Patch II). Genetic analysis suggests that mutations at the two ATS codons affect the same specific function of transposase, thus raising the possibility that Patch I and Patch II interact. For wild-type IS10, insertion specificity is determined in part by a specific 6 bp consensus sequence and in part by the immediately adjacent sequence context of the target DNA. The ATS mutations do not qualitatively alter the hierarchy with which base pairs are recognized in the consensus sequence; instead, sites selected by ATS transposase exhibit a reduction in the degree to which certain base pairs are preferred over others. Models for the basis of this phenotype are discussed. Images
Time-differencing process, with the help of image registration techniques, is useful for image-domain moving target detection under heavy clutter conditions. Time-differencing between two well-registered image frames can significantly suppress the heavy static background clutter, and thus improve moving target detection. However, we may still lose detection of a moving target from time to time under heavy clutter conditions (Pd < 100%), and also we may lose detection of a moving target when this target stops moving. For example, a moving vehicle will temporarily stop moving in front of a red light or a stop sign. In general, the performance of a conventional tracking process depends on the performance of the detection process. In this paper, we present our newly developed image-domain moving target tracking and process using an adaptive local target correlation tracker. Once we started to track a target, the correlation tracker can continue to track this target, no matter whether we can still detect this target in the future image frames or not. Both single and multiple target tracking capabilities using the correlation tracker have been developed. Furthermore, while continuing to track a moving vehicle, we apply a super-resolution image enhancement (SRIE) process developed at SAIC  to improve the vehicle resolution and signal-to-noise ratio (SNR) for better automatic targetrecognition (ATR) or human/pilot-monitored recognition performance.
The aims were to: (1) provide wordrecognition thresholds (WRTs) at 31, 43, and 61 months of age; (2) investigate developmental changes over time; (3) investigate the relationship between OME and WRT, and (4) investigate the relationship between WRT and hearing thresholds. Around 1000 children were tested longitudinally as part of the ALSPAC study, using an adaptive measure of wordrecognition in quiet. Mean WRTs were 28, 23, and 23 dB (A) at 31, 43, and 61 months, respectively. Normal auditory development is associated with a mean improvement in WRT of 5 dB between age 31 and 61 months. There was a mean increase in WRT of 5 dB and 15 dB when OME was present in one and two ears, respectively. Thus, both unilateral and bilateral OME results in a detrimental effect on hearing ability for speech. Additionally, early and ‘persistent’ OME is associated with greater disability. However by 61 months, previous OME status was not significant. To our knowledge, this is the largest longitudinal study reporting WRT in preschool children with different middle ear status.
We formulate a Bayesian approach to the joint tracking and recognition of airborne targets via reflected commercial television and FM radio signals measured by an array of sensors. Such passive system may remain covert, whereas traditional active systems must reveal their presence and location by their transmissions. Since the number of aircraft in the scene is not known a priori, and targets may enter and leave the scene at unknown times, the parameters space is a union of subspaces of varying dimensions as well as varying target classes. Targets tracks are parameterized via both positions and orientations, with the orientations naturally represented as elements of the special orthogonal group. A prior on target tracks is constructed from Newtonian equations of motion. This prior results in a coupling between the position and orientation estimates, yielding a coupling between the tracking and recognition problems.
A novel automatic targetrecognition algorithm based on statistical dispersion of infrared multispectral images(SDOIMI) is proposed. Firstly, infrared multispectral characteristic matrix of the scenario is constructed based on infrared multispectral characteristic information (such as radiation intensity and spectral distribution etc.) of targets, background and decoys. Then the infrared multispectral characteristic matrix of targets is reconstructed after segmenting image by maximum distance method and fusing spatial and spectral information. Finally, an statistical dispersion of infrared multispectral images(SDOIMI) recognition criteria is formulated in terms of spectral radiation difference of interesting targets. In simulation, nine sub-bands multispectral images of real ship target and shipborne aerosol infrared decoy modulated by laser simulating ship geometry appearance are obtained via using spectral radiation curves. Digital simulation experiment result verifies that the algorithm is effective and feasible.
Models of affect assume a two-dimensional framework, composed of emotional valence and arousal. Although neuroimaging evidence supports a neuro-functional distinction of their effects during single word processing, electrophysiological studies have not yet compared the effects of arousal within the same category of valence (positive and negative). Here we investigate effects of arousal and valence on written lexical decision. Amplitude differences between emotion and neutral words were seen in the early posterior negativity (EPN), the late positive complex and in a sustained slow positivity. In addition, trends towards interactive effects of valence and arousal were observed in the EPN, showing larger amplitude for positive, high-arousal and negative, low-arousal words. The results provide initial evidence for interactions between arousal and valence during processing of positive words and highlight the importance of both variables in studies of emotional stimulus processing. PMID:23142715
Citron, Francesca M M; Weekes, Brendan S; Ferstl, Evelyn C
The importance of Networked Automatic TargetRecognition systems for surveillance applications is continuously increasing. Because of the requirement of a low cost and limited payload these networks are traditionally equipped with lightweight, low-cost sensors such as Electro Optical or Infrared sensors. The quality of imagery acquired by these sensors critically depends on the environmental conditions, type and characteristics of sensors, and absence of occluding or concealing objects. In the past a large number of efficient detection, tracking, and recognition algorithms have been designed to operate on imagery of good quality. However, detection and recognition limits under non-ideal environmental and/or sensor based distortions have not been carefully evaluated. This work describes a real image dataset formed by imaging 10 die cast models of military vehicles at different elevation and orientation angles. The dataset contains imagery acquired both indoors and outdoors. The indoors dataset is composed of clear and distorted images. The distortions include defocus blur, sided illumination, low contrast, shadows and occlusions. All images in this dataset, however, have a uniform blue background. The indoors dataset is applied to evaluate the degradations of recognition performance due to camera and illumination effects. The recognition method is based on Bessel K forms. The dataset collected outdoors includes real background and is much more complex to process. This dataset is used to evaluate performance of a fully automatic targetrecognition system that involves a Haar-based detector to select potential regions of interest within images; performs adjustment and fusion of detected regions; segments potential targets using a region based approach; identifies targets using Bessel K form-based encoding; and performs clutter rejection. The numerical results demonstrate that the complexity of the background and the presence of occlusions lead to substantial detection and recognition performance degradations.
The relative importance of internal and external letter features of words in children's developing reading was investigated to clarify further the nature of early featural analysis. In Experiment 1, 72 6-, 8-, and 10-year-olds read aloud words displayed as wholes, external features only (central features missing, thereby preserving word shape information), or internal features only (central features preserved). There was an improvement in the processing of external features compared with internal features as reading experience increased. Experiment 2 examined the processing of the internal and external features of words employing a forward priming paradigm with 60 8-, 10-, and 12-year-olds. Reaction times to internal feature primes were equivalent to a nonprime blank condition, whereas responses to external feature primes were faster than those to the other two prime types. This advantage for the external features of words is discussed in terms of an early and enduring role for processing the external visual features in words during reading development. PMID:16530781
Webb, Tessa M; Beech, John R; Mayall, Kate M; Andrews, Antony S
Diversity-generating retroelements (DGRs) are in vivo sequence diversification machines that are widely distributed in bacterial, phage, and plasmid genomes. They function to introduce vast amounts of targeted diversity into protein-encoding DNA sequences via mutagenic homing. Adenine residues are converted to random nucleotides in a retrotransposition process from a donor template repeat (TR) to a recipient variable repeat (VR). Using the Bordetella bacteriophage BPP-1 element as a prototype, we have characterized requirements for DGR target site function. Although sequences upstream of VR are dispensable, a 24 bp sequence immediately downstream of VR, which contains short inverted repeats, is required for efficient retrohoming. The inverted repeats form a hairpin or cruciform structure and mutational analysis demonstrated that, while the structure of the stem is important, its sequence can vary. In contrast, the loop has a sequence-dependent function. Structure-specific nuclease digestion confirmed the existence of a DNA hairpin/cruciform, and marker coconversion assays demonstrated that it influences the efficiency, but not the site of cDNA integration. Comparisons with other phage DGRs suggested that similar structures are a conserved feature of target sequences. Using a kanamycin resistance determinant as a reporter, we found that transplantation of the IMH and hairpin/cruciform-forming region was sufficient to target the DGR diversification machinery to a heterologous gene. In addition to furthering our understanding of DGR retrohoming, our results suggest that DGRs may provide unique tools for directed protein evolution via in vivo DNA diversification.
Guo, Huatao; Tse, Longping V.; Nieh, Angela W.; Czornyj, Elizabeth; Williams, Steven; Oukil, Sabrina; Liu, Vincent B.; Miller, Jeff F.
In this paper we present a fuzzy system based hyperspectral classifier for automatic target identification. The system is based on partitioning the spectral band space into clusters using a modified fuzzy C-Means clustering algorithm. Classification of each pixel is then carried out by calculating its fuzzy membership in each cluster. The results showed that the fuzzy hyperspectral classifier is successful
Two brain regions with established roles in reading are the posterior middle temporal gyrus and the posterior fusiform gyrus (FG). Lesion studies have also suggested that the region located between them, the posterior inferior temporal gyrus (pITG), plays a central role in wordrecognition. However, these lesion results could reflect disconnection effects since neuroimaging studies have not reported consistent lexicality effects in pITG. Here we tested whether these reported pITG lesion effects are due to disconnection effects or not using parallel Event-related Potentials (ERP)/functional magnetic resonance imaging (fMRI) studies. We predicted that the Recognition Potential (RP), a left-lateralized ERP negativity that peaks at about 200-250 msec, might be the electrophysiological correlate of pITG activity and that conditions that evoke the RP (perceptual degradation) might therefore also evoke pITG activity. In Experiment 1, twenty-three participants performed a lexical decision task (temporally flanked by supraliminal masks) while having high-density 129-channel ERP data collected. In Experiment 2, a separate group of fifteen participants underwent the same task while having fMRI data collected in a 3T scanner. Examination of the ERP data suggested that a canonical RP effect was produced. The strongest corresponding effect in the fMRI data was in the vicinity of the pITG. In addition, results indicated stimulus-dependent functional connectivity between pITG and a region of the posterior FG near the Visual Word Form Area (VWFA) during word compared to nonword processing. These results provide convergent spatiotemporal evidence that the pITG contributes to early lexical access through interaction with the VWFA. PMID:23701693
Dien, Joseph; Brian, Eric S; Molfese, Dennis L; Gold, Brian T
Pattern recognition myoelectric control shows great promise as an alternative to conventional amplitude based control to control multiple degree of freedom prosthetic limbs. Many studies have reported pattern recognition classification error performances of less than 10% during offline tests; however, it remains unclear how this translates to real-time control performance. In this contribution, we compare the real-time control performances between pattern recognition and direct myoelectric control (a popular form of conventional amplitude control) for participants who had received targeted muscle reinnervation. The real-time performance was evaluated during three tasks; 1) a box and blocks task, 2) a clothespin relocation task, and 3) a block stacking task. Our results found that pattern recognition significantly outperformed direct control for all three performance tasks. Furthermore, it was found that pattern recognition was configured much quicker. The classification error of the pattern recognition systems used by the patients was found to be 16% ±(1.6%) suggesting that systems with this error rate may still provide excellent control. Finally, patients qualitatively preferred using pattern recognition control and reported the resulting control to be smoother and more consistent. PMID:24110008
Recently, Besner, Stolz, and Boutilier (1997) showed that by coloring a single letter instead of the whole word, Stroop interference\\u000a is reduced or even eliminated, a result that is at odds with the widely accepted assumption that wordrecognition is automatic.\\u000a In a replication of the Besner et al. study, we computed priming effects in addition to the standard Stroop
Adaptive driving controls such as mechanical hand controls or electromechanical contact switches are now available which allow even the most severely impaired to drive. The residual functions, however, are all directed toward primary controls such as steering, braking, and accelerating, limiting the ability to operate secondary controls such as the horn, turn signals, ignition, and headlights, etc. In this paper, we discuss the application of speech recognition technology when operating these secondary controls. The performance of a speech recognition system inside a vehicle is studied, and the types of noise that degrade the recognition accuracy are also identified. Results are presented on the degradation in recognition performance caused by engine noise, fan noise, and interfering speech. PMID:1831857
The authors present results obtained by applying the connectionist approach of multilayer perceptrons (MLPs) to three tasks of practical interest: classification of speech in terms of broad phonetic classes, speaker-independent recognition of yes\\/no answers through the dialed-up telephone line, and speaker-independent recognition of isolated digits through the telephone line. The first task assesses the capability of a simple MLP to
P. Demichelis; L. Fissore; P. Laface; G. Micca; E. Piccolo
Fluorescent sensors capable of recognizing cancer-associated glycans, such as sialyl Lewis X (sLex) tetrasaccharide, have great potential for cancer diagnosis and therapy. Studies on water-soluble and biocompatible sensors for in situ recognition of cancer-associated glycans in live cells and targeted imaging of cancer cells are very limited at present. Here we report boronic acid-functionalized peptide-based fluorescent sensors (BPFSs) for in situ recognition and differentiation of cancer-associated glycans, as well as targeted imaging of cancer cells. By screening BPFSs with different structures, it was demonstrated that BPFS1 with a FRGDF peptide could recognize cell-surface glycan of sLex with high specificity and thereafter fluorescently label and discriminate cancer cells through the cooperation with the specific recognition between RGD and integrins. The newly developed peptide-based sensor will find great potential as a fluorescent probe for cancer diagnosis.
Fluorescent sensors capable of recognizing cancer-associated glycans, such as sialyl Lewis X (sLe(x)) tetrasaccharide, have great potential for cancer diagnosis and therapy. Studies on water-soluble and biocompatible sensors for in situ recognition of cancer-associated glycans in live cells and targeted imaging of cancer cells are very limited at present. Here we report boronic acid-functionalized peptide-based fluorescent sensors (BPFSs) for in situ recognition and differentiation of cancer-associated glycans, as well as targeted imaging of cancer cells. By screening BPFSs with different structures, it was demonstrated that BPFS1 with a FRGDF peptide could recognize cell-surface glycan of sLe(x) with high specificity and thereafter fluorescently label and discriminate cancer cells through the cooperation with the specific recognition between RGD and integrins. The newly developed peptide-based sensor will find great potential as a fluorescent probe for cancer diagnosis. PMID:24042097
The goal of the study was to investigate the neural circuit recruited by adult readers during performance of a lexical decision task by assessing the relative timing of neurophysiological activity in the brain regions that comprise this circuit. The time course of regional activation associated with lexical decision was studied in 17 adult volunteers using magnetoencephalography. Following activity in mesial occipital cortices, activation progressed to lateral and ventral occipito-temporal regions (often encompassing the posterior portion of the middle temporal gyrus), followed by activity in the superior temporal gyri (STGp), motor/premotor cortices, and the inferior frontal gyrus. The latency of STGp activation relative to the latency of the motor response to the word stimuli did not support critical involvement of this area in lexical decision. Timing, word length, and word frequency effects found for activity in each area are discussed in relation to the purported roles of each region into the brain circuit for reading.
Simos, Panagiotis G.; Pugh, Kenneth; Mencl, Einar; Frost, Stephen; Fletcher, Jack M.; Sarkari, Shirin; Papanicolaou, Andrew C.
One-off aerial imaging system could work in rugged environments too hazardous for piloted or autonomous aircraft to cruise through, thus it has abroad potential utility in disaster assistance, exploration and some other fields. In this paper we develop a method for targetrecognition and tracking in image sequences from this kind of system. Targetrecognition is performed with local features of salient points, which could cope with partially obscured situation. We choose SIFT descriptor that is able to perform effective recognition with incoherent frames of one-off imaging system. Matching vector in high dimension is accelerated by our categorization scheme with a decision tree. In our method, no target detection operation is needed as targets are recognized directly by matching salient points. When initialization for tracking is finished, fast tracking methods start to record their position in following frames. The recognition algorithm is performed periodically to cope with entering and leaving problem and provide context for tracking method. Test with simulated image sequence demonstrates that our method can recognize and track predefined objects effectively in image sequences from one-off imaging system.
The location information of prominent points backscattering, extracted from the high resolution radar echoes by the Relax algorithm, is used as the feature for radar targetrecognition. The sensitivity of high range resolution (HRR) profiles to the LOS of radar yields an idea that the multiaspect radar echoes can be modeled by a hidden Markov model (HMM); it gives the
This paper explores the use of wavelets to improve the selection of discriminant features in the targetrecognition problem using High Range Resolution (HRR) radar signals in an air to air scenario. We show that there is statistically no difference among four different wavelet families in extracting discriminatory features. Since similar results can be obtained from any of the four
Dale E. Nelson; Janusz A. Starzyk; D. David Ensley
The report investigates the use of radar polarimetry for improving ground targetrecognition with a mm-wave seeker radar at 94 GHz. Modeling and simulation are used for the investigation, in addition to an experiment of demonstrative character. The scenar...
In this paper, adaptive CFAR tests are described which allow one to classify radar clutter into one of several major categories, including bird, weather, and target classes. These tests do not require the arbitrary selection of priors as in the Bayesian classifier. The decision rule of the recognition techniques is in the form of associating the p-dimensional vector of observations
N. A. Nechval; K. N. Nechval; G. Berzinsh; M. Purgailis
This paper reports how objects in street scenes, such as pedestrians and cars, can be spotted, recognised and then subsequently tracked in cluttered background using a cortex like vision approach. Unlike the conventional pixel based machine vision, tracking is achieved by recognition of the target implemented in neuromorphic ways. In this preliminary study the region of interest (ROI) of the
Aristeidis Tsitiridis; Peter Yuen; Kan Hong; Tong Chen; Firmin Kam; James Jackman; David James; Mark Richardson
The Modified Eigenvalue problem arises in many applications such as Array Processing, Automatic TargetRecognition (ATR), etc. These applications usually involve the Eigenvalue Decomposition (EVD) of matrices that are time varying. It is desirable to have methods that eliminate the need to perform an EVD every time the matrix changes but instead update the EVD adaptively, starting from the initial
P. Ragothaman; W. B. Mikhael; R. Muise; A. Mahalanobis; T. Yang
Automatic targetrecognition in agricultural harvesting robots is characterized by low detection rates and high false alarm rates due to the unstructured nature of both the environment and the objects. To improve detection human-robot collaboration levels were defined and implemented. The collaboration level is defined as the level of system autonomy or the level at which the human operator (HO)
Feature-aided target verification is a challenging field of research, with the potential to yield significant increases in the confidence of re-established target tracks after kinematic confusion events. Using appropriate control algorithms airborne multi-mode radars can acquire a library of HRR (High Range Resolution) profiles for targets as they are tracked. When a kinematic confusion event occurs, such as a vehicle dropping below MDV (Minimum Detectable Velocity) for some period of time, or two target tracks crossing, it is necessary to utilize feature-aided tracking methods to correctly associate post-confusion tracks with pre-confusion tracks. Many current HRR profile targetrecognition methods focus on statistical characteristics of either individual profiles or sets of profiles taken over limited viewing angles. These methods have not proven to be very effective when the pre- and post- confusion libraries do not overlap in azimuth angle. To address this issue we propose a new approach to targetrecognition from HRR profiles. We present an algorithm that generates 2-D imagery of targets from the pre- and post-confusion libraries. These images are subsequently used as the input to a targetrecognition/classifier process. Since, center-aligned HRR Profiles, while ideal for processing, are not easily computed in field systems, as they require the airborne platform's center of rotation to line up with the geometric center of the moving target (this is impossible when multiple targets are being tracked), our algorithm is designed to work with HRR profiles that are aligned to the leading edge (the first detection above a threshold, commonly referred to as Edge-Aligned HRR profiles). Our simulated results demonstrate the effectiveness of this method for classifying target vehicles based on simulations using both overlapping and non-overlapping HRR profile sets. The algorithm was tested on several test cases using an input set of .28 m resolution XPATCH generated HRR profiles of 20 test vehicles (civilian and military) at various elevation angles.
O'Donoughue, Nicholas A.; Kuklinski, Walter S.; Arabadjis, Constantine
Background When a second target (T2) is presented in close succession of a first target (T1) within a stream of non-targets, people often fail to detect T2–a deficit known as the attentional blink (AB). Two types of theories can be distinguished that have tried to account for this phenomenon. Whereas attentional-control theories suggest that protection of consolidation processes induces the AB, limited-resource theories claim that the AB is caused by a lack of resources. According to the latter type of theories, increasing difficulty of one or both targets should increase the magnitude of the AB. Similarly, attentional-control theories predict that a difficult T1 increases the AB due to prolonged processing. However, the prediction for T2 is not as straightforward. Prolonged processing of T2 could cause conflicts and increase the AB. However, if consolidation of T2 is postponed without loss of identity, the AB might be attenuated. Methodology/Principal Findings Participants performed an AB task that consisted of a stream of distractor non-words and two targetwords. Difficulty of T1 and T2 was manipulated by varying word-frequency. Overall performance for high-frequency words was better than for low-frequency words. When T1 was highly frequent, the AB was reduced. The opposite effect was found for T2. When T2 was highly frequent, performance during the AB period was relatively worse than for a low-frequency T2. A threaded-cognition model of the AB was presented that simulated the observed pattern of behavior by taking changes in the time-course of retrieval and consolidation processes into account. Our results were replicated in a subsequent ERP study. Conclusions/Significance The finding that a difficult low-frequency T2 reduces the magnitude of the AB is at odds with limited-resource accounts of the AB. However, it was successfully accounted for by the threaded-cognition model, thus providing an explanation in terms of attentional control.
Wierda, Stefan M.; Taatgen, Niels A.; van Rijn, Hedderik; Martens, Sander
A laser-based research system for gated viewing is currently being developed at FOI. One of its possible applications is long-range automatic targetrecognition. This report treats an implementation if a viable targetrecognition algorithm based on one-, ...
|Purpose: This study investigated an account of limited short-term memory capacity for children's speech perception in noise using a dual-task paradigm. Method: Sixty-four normal-hearing children (7-14 years of age) participated in this study. Dual tasks were repeating monosyllabic words presented in noise at 8 dB signal-to-noise ratio and…
|This book, one of four in the Teaching Reading Collection, presents the "best of the best" classroom-tested ideas, approaches, and practical applications for helping students learn about words. The articles have been drawn from the journal "The Reading Teacher" from 1993-1999. The ideas and strategies are intended to provide possible building…
Rasinski, Timothy V., Ed.; Padak, Nancy D., Ed.; Church, Brenda Weible, Ed.; Fawcett, Gay, Ed.; Hendershot, Judith, Ed.; Henry, Justina M., Ed.; Moss, Barbara G., Ed.; Peck, Jacqueline K., Ed.; Pryor, Elizabeth, Ed.; Roskos, Kathleen A., Ed.
Many studies have claimed that hemispheric processing is split precisely at the foveal midline and so place great emphasis on the precise location at which words are fixated. These claims are based on experiments in which a variety of fixation procedures were used to ensure fixation accuracy but the effectiveness of these procedures is unclear. We…
Jordan, Timothy R.; Paterson, Kevin B.; Kurtev, Stoyan; Xu, Mengyun
|The way in which letters are assigned their position when recognizing a visually presented word was examined in three experiments using nonwords created by transposing the two medial consonants of a bisyllabic baseword (e.g., "nakpin," "semron"). The difficulty in responding to such "TL" nonwords in a lexical decision task was shown to be lower…
Third-, sixth-, and college-grade students were presented with entire sentences for silent reading and were asked to monitor these sentences either for the presence of nonwords or for meaningfulness. The sentence forms were of three types: semantically coherent, syntactically intact (but nonmeaningful), and incoherent (nonmeaningful, nongrammatical). Three developmental differences were obtained in the speed of analyzing these sentences for words\\/nonwords
This paper describes a complete system for reading type- written lexicon words in noisy images - in this case mu- seum index cards. The system is conceptually simple, and straightforward to implement. It involves three stages of processing. The first stage extracts row-regions from the im- age, where each row is a hypothesized line of text. The next stage scans
We have investigated the time-dependent strand displacement activity of several targets with double-stranded DNA probes (dsProbes) of varying affinity. Here, the relative affinity of various dsProbes is altered through choices in hybridization length (11–15 bases) and the selective inclusion of center mismatches in the duplexes. While the dsProbes are immobilized on microspheres, the soluble, 15 base-long complementary sequence is presented either alone as a short target strand or as a recognition segment embedded within a longer target strand. Compared to the short target, strand displacement activity of the longer targets is slower, but still successful. Additionally, the longer targets exhibit modest differences in the observed displacement rates, depending on the location of recognition segment within the long target. Overall, our study demonstrates that the kinetics of strand displacement activity can be tuned through dsProbe sequence design parameters and is only modestly affected by the location of the complementary segment within a longer target strand.
Research using online comprehension measures with monolingual children shows that speed and accuracy of spoken wordrecognition are correlated with lexical development. Here we examined speech processing efficiency in relation to vocabulary development in bilingual children learning both Spanish and English (n=26; 2;6 yrs). Between-language associations were weak: vocabulary size in Spanish was uncorrelated with vocabulary in English, and children’s facility in online comprehension in Spanish was unrelated to their facility in English. Instead, efficiency of online processing in one language was significantly related to vocabulary size in that language, after controlling for processing speed and vocabulary size in the other language. These links between efficiency of lexical access and vocabulary knowledge in bilinguals parallel those previously reported for Spanish and English monolinguals, suggesting that children’s ability to abstract information from the input in building a working lexicon relates fundamentally to mechanisms underlying the construction of language.
Marchman, Virginia A.; Fernald, Anne; Hurtado, Nereyda
The nature of predictive relations between early language and later cognitive function is a fundamental question in research on human cognition. In a longitudinal study assessing speed of language processing in infancy, Fernald, Perfors and Marchman (2006) found that reaction time at 25 months was strongly related to lexical and grammatical development over the second year. In this follow-up study, children originally tested as infants were assessed at 8 years on standardized tests of language, cognition, and working memory. Speed of spoken wordrecognition and vocabulary size at 25 months each accounted for unique variance in linguistic and cognitive skills at 8 years, effects that were attributable to strong relations between both infancy measures and working memory. These findings suggest that processing speed and early language skills are fundamental to intellectual functioning, and that language development is guided by learning and representational principles shared across cognitive and linguistic domains.
Graphene related materials have been widely employed as highly efficient transducers for biorecognition. Here we show a conceptually new approach of using graphene oxide nanoplatelets (50 × 50 nm) as voltammetric inherently active labels for specific protein-target molecule recognition. This proof-of-principle is demonstrated by biotin-avidin recognition, which displays that graphene oxide nanoplatelet labels show excellent selectivity. Therefore, it is expected that inherently electroactive graphene oxide nanoplatelet labels will play a similar role as electroactive gold nanoparticle labels which were developed more than a decade ago.
Loo, Adeline Huiling; Bonanni, Alessandra; Pumera, Martin
This study examines how cognitive processes interrelate as well as predict learning-disabled (LD) readers’ wordrecognition and reading comprehension performance. Correlations between phonological, orthographic, semantic, metacognitive, and working memory measures with reading performance were examined in LD and skilled readers ages 8 to 12 years. Important results were (a) LD readers were deficient on all cognitive processes compared with skilled
|This article focuses on use of Microsoft[R] PowerPoint[TM] paired with direct instruction (DI) to teach wordrecognition to young children at risk. DI has been a widely used teaching method for over 40 years, and is often used to teach emergent literacy skills. Recent DI research with preschoolers at risk has suggested the potential for using…
Parette, Howard P.; Blum, Craig; Boeckmann, Nichole M.; Watts, Emily H.
The purpose of this small-scale exploratory study was to examine the effects of using a game-based instructional approach to teach wordrecognition and spelling to Grade 6 students with reading disabilities (RD) and attention deficit disorders. Treatment and comparison groups were formed. The students were placed in either a traditional spelling group or an alternate game group. Different measures of
In this special issue of Brain and Language, we examine what implications the division between the left and the right brain half has for the recognition of words presented in the center of the visual field. The different articles are a first indication that taking into account the split between the left and the right cerebral hemisphere need not be
Twelve healthy volunteers were tested in a double-blind crossover study to assess the effects of oxazepam and an extract of kava roots (Piper methysticum) on behavior and event-related potentials (ERPs) in a recognition memory task. The subjects’ task was to identify within a list of visually presented words those that were shown for the first time and those that were
A study examined the effectiveness of an integrated language arts instructional format for teaching reading compared with the effectiveness of the typical traditional reading program. The study investigated the effectiveness of approaches that are representative of both viewpoints of the reading process (i.e., wordrecognition and the construction…
Parmer, Lavada Jacumin; Thames, Dana G.; Kazelskis, Richard
Many models of spoken wordrecognition posit that the acoustic stream is parsed into phoneme level units, which in turn activate larger representations [McClelland, J. L., & Elman, J. L. The TRACE model of speech perception. Cognitive Psychology, 18, 1–86, 1986], whereas others suggest that larger units of analysis are activated without the need for segmental mediation [Greenberg, S. A
This article focuses on use of Microsoft[R] PowerPoint[TM] paired with direct instruction (DI) to teach wordrecognition to young children at risk. DI has been a widely used teaching method for over 40 years, and is often used to teach emergent literacy skills. Recent DI research with preschoolers at risk has suggested the potential for using…
Parette, Howard P.; Blum, Craig; Boeckmann, Nichole M.; Watts, Emily H.
Recent neurobiological studies revealed evidence for lexical representations that are not specified for the coronal place of articulation (PLACE; Friedrich, Eulitz, & Lahiri, 2006; Friedrich, Lahiri, & Eulitz, 2008). Here we tested when these types of underspecified representations influence neuronal speech recognition. In a unimodal…
Schild, Ulrike; Roder, Brigitte; Friedrich, Claudia K.
The repetition paradigm offers a useful technique for assessing recognition memory by evaluating how an individual responds to new versus old stimuli. While this paradigm has been extensively used in adults with and without clinical conditions, it has not, to our knowledge, been studied in a clinical pediatric population. Children with congenital hypothyroidism (CH) identified by newborn screening and treated
Sandra L. Hepworth; Elizabeth W. Pang; Joanne F. Rovet