Neighborhood Of Frequency Research Articles

Phonological neighborhood and word frequency effects in the stuttered disfluencies of children who stutter.

The purpose of this study was to examine (a) the role of neighborhood density (number of words that are phonologically similar to a target word) and frequency variables on the stuttering-like disfluencies of preschool children who stutter, and (b) whether these variables have an effect on the type of stuttering-like disfluency produced. A 500+ word speech sample was obtained from each participant (N = 15). Each stuttered word was randomly paired with the firstly produced word that closely matched it in grammatical class, familiarity, and number of syllables/phonemes. Frequency, neighborhood density, and neighborhood frequency values were obtained for the stuttered and fluent words from an online database. Findings revealed that stuttered words were lower in frequency and neighborhood frequency than fluent words. Words containing part-word repetitions and sound prolongations were also lower in frequency and/or neighborhood frequency than fluent words, but these frequency variables did not have an effect on single-syllable word repetitions. Neighborhood density failed to influence the susceptibility of words to stuttering, as well as the type of stuttering-like disfluency produced. In general, findings suggest that neighborhood and frequency variables not only influence the fluency with which words are produced in speech, but also have an impact on the type of stuttering-like disfluency produced.

The Role of Selected Lexical Factors on Confrontation Naming Accuracy, Speed, and Fluency in Adults Who Do and Do Not Stutter

The purpose of this study was to investigate whether lexical access in adults who stutter (AWS) differs from that in people who do not stutter. Specifically, the authors examined the role of 3 lexical factors on naming speed, accuracy, and fluency: word frequency, neighborhood density, and neighborhood frequency. If stuttering results from an impairment in lexical access, these factors were hypothesized to differentially affect AWS performance on a confrontation naming task. Twenty-five AWS and 25 normally fluent comparison speakers, matched for age and education, participated in a confrontation naming task designed to explore within-speaker performance on naming accuracy, speed, and fluency based on stimulus word frequency and neighborhood characteristics. Accuracy, fluency, and reaction time (from acoustic waveform analysis) were computed. In general, AWS demonstrated the same effects of lexical factors on their naming as did adults who do not stutter. However, accuracy of naming was reduced for AWS. Stuttering rate was influenced by word frequency but not other factors. Results suggest that AWS could have a fundamental deficit in lexical retrieval, but this deficit is unlikely to be at the level of the word's abstract phonological representation. Implications for further research are discussed.

Orthographic neighborhood effects in reading Chinese two-character words

The present study investigates the effects of neighborhood size and neighborhood frequency in reading Chinese two-character words. The neighborhood size of a word is defined as the summation of neighbors sharing the first constituent (neighborhood size 1) and the second constituent (neighborhood size 2) characters. The first experiment found two opposite neighborhood size effects in lexical decision of high-frequency and low-frequency words. The regression analysis showed that neighborhood size 1 influenced word reading more than the neighborhood size 2. The second experiment confirmed this finding and showed that reading words with higher frequency neighbors took a longer time and elicited greater N400 and LPC than those without higher frequency neighbors. These findings indicate that, when reading Chinese two-character words, all words sharing the first constituent character are activated in the early stage of word recognition and the existence of high-frequency words among neighbors leads to greater competition in the stage of semantic integration and response selection.

The orthographic neighbourhood frequency effect in French: A letter-case manipulation study.

The neighbourhood frequency effect was investigated by a letter-case manipulation of French words presented in the go/no-go lexical decision task. Accented words were presented both in lower-case letters with written accents and upper-case letters with no written accents, two usual typographies in French. This procedure addressed the stimulus-matching problem by using intra-word comparisons as some words have different orthographic neighbourhoods in the two cases. Neighbourhood frequency was varied across case change for half of the words while it was held constant for the other half. The results showed an interaction between letter-case and neighbourhood constancy, so the inhibitory neighbourhood frequency effect could not be attributed to interstimulus comparisons or to typographical change. Implications are discussed in current models of visual word recognition.

Determinants of Active Travel to School

BACKGROUND: The proportion of students walking and bicycling to/from school has declined substantially over the past 30 years. Distance and parents' fear of crime and traffic danger are often cited as barriers. Counter measures to reduce these barriers and increase active travel (AT) to school are needed. In order to create effective interventions targeting AT, a better understanding of the determinants of AT are needed. PURPOSE: To compare the characteristics of students who use AT and their parents to those who do not (NAT). METHODS: Schools (13) representing 5 geographic regions of the US were randomly chosen from a convenience sample of respondents to a Walk to School (WTS) survey. WTS coordinators provided school level information and parents of 4th and 5th grade students completed a brief survey. School level data (size, % free or reduced lunch, walkability assessments, WTS Day participation, etc.) and parent level data (child gender and age, distance between home and school, perceived barriers of AT, perceived norms, etc.) were compared based on parent-reported AT status. After assessing differences between AT & NAT, we used a Generalized Estimating Equation (GEE) procedure to identify significant predictors of AT. To build the model, we used a split-sample validation approach. RESULTS: Five significant covariates for AT were included in the final model: gender, distance, perceived barriers around personal safety, and two norm-related variables-the perceived use of walking or bicycling for school travel by other children in the neighborhood and the reported frequency with which neighbors walked or bicycled with kids to school. Boys were twice as likely to use AT compared to girls (OR =2.1, CI: 1.29, 3.42). The odds of AT increased by a factor of 2.73 (CI: 1.95, 3.86) for every 1/2 mile closer the child lived to school. Those who identified fewer personal safety barriers were significantly more likely to use AT (OR = 1.18, CI: 1.05, 1.32). The odds of using AT increased three-fold when parents noted the presence of other children walking or bicycling in the neighborhood (OR = 2.88, CI: 2.12, 3.91). Finally, those who reported higher frequency of neighbors walking or bicycling with children to school had higher odds of AT (OR 1.34, CI: 1.14, 1.58). CONCLUSION: In addition to the association of gender and the previously described barriers of distance and safety, perceived norms about walking/bicycling to school are important predictors of AT. These findings suggest that efforts to increase AT may need to address personal as well as community factors. Funded by the Centers for Disease Control and Prevention, SIP 9

Is there a neighborhood frequency effect in English? Evidence from reading and lexical decision.

What is the effect of a word's higher frequency neighbors on its identification time? According to activation-based models of word identification (J. Grainger & A. M. Jacobs, 1996; J. L. McClelland & D. E. Rumelhart, 1981), words with higher frequency neighbors will be processed more slowly than words without higher frequency neighbors because of the lexical competition mechanism embodied in these models. Although a critical prediction of these models, this inhibitory neighborhood frequency effect has been elusive in studies that have used English stimuli. In the present experiments, the effect of higher frequency neighbors was examined in the lexical decision task and when participants were reading sentences while their eye movements were monitored. Results suggest that higher frequency neighbors have little, if any, effect on the identification of English words. The implications for activation-based models of word identification are discussed.

SEMANTIC ACTIVATION IN VISUAL RECOGNITION OF JAPANESE TWO-KANJI COMPOUND WORDS: INTERFERENCE AND FACILITATORY EFFECTS OF NEIGHBORS

Japanese two-kanji compound words (Jukugo: e.g., 病院 “hospital”) have two sets of neighbors: Rear-neighbors that share the same front-kanji and vary in the rear-kanji, and Front-neighbors that share the same rear-kanji and vary in the front-kanji of the Jukugo. We investigated the role of semantic activation of word neighbors in Japanese kanji word recognition. The effects of neighborhood frequency for Rear-neighbors and Front-neighbors (Experiment 1) and semantic similarity between a Jukugo and its Rear-neighbor (Experiment 2) were examined using the lexical decision task. In Experiment 1, when a Jukugo and its neighbors were semantically similar, Rear-neighbors of higher frequency produced longer reaction times, whereas Front-neighbors of higher frequency produced shorter reaction times. In Experiment 2, semantic similarity between a Jukugo and its neighbor of higher frequency produced longer reaction times, although no delay was observed for semantically dissimilar Jukugo and neighbors. The results are interpreted within the companion-activation model.

CMUT array modeling through free acoustic CMUT modes and analysis of the fluid CMUT interface through Fourier transform methods

A method for analyzing capacitive micromachined ultrasonic transducer (CMUT) arrays and arrays of elements composed of several CMUTs is proposed. It is based on a combination of a free acoustic mode description of an isolated CMUT, and the coupling of these modes to the fluid in which waves should be excited or detected through an impedance matrix that will depend on frequency. The parameters of the model describing the isolated CMUT is independent of frequency and excitation of neighbor CMUTs, whereas the acoustic impedance matrix describing the coupling to the fluid will depend on both the excitation of neighbor CMUTs and frequency. Hence, this splitting of the calculations has a potential for saving computer time. The analysis gives transfer functions from excitations that vary harmonically with time and space along the array surface to CMUT parameters as current, mode excitations, or output acoustic pressure. Based on this, the response of essentially arbitrary excitations of the CMUTs may be obtained. The method is used to analyze an infinitely large array of circular CMUTs on a rectangular grid. The CMUTs are assumed to be operating in collapsed mode. Sharp resonances are shown to occur that could be significantly damped by adding series resistors to the CMUTs or increasing the water viscosity.

End reflections in a layered piezoelectric circular cylinder

End reflection phenomenon in a semi-infinitely long layered piezoelectric circular cylinder is constructed with modal data from a spectral decomposition of the differential operator governing its natural vibrations. These modal data consist of all propagating modes and edge vibrations and they constitute the basis for a wave function expansion of the reflection of waves arriving at the traction-free end of the cylinder. Without any other external stimulus, a passive reflection event occurs. This traction-free end condition is enforced at the Gaussian integration points over the end cross-section on the combination of incoming and reflected wave fields. Reflections due to monochromatic incoming axisymmetric ( m = 0) and flexural ( m = 1) waves are studied and two numerical examples are presented. For an incoming axisymmetric wave, there is a particular frequency that induces an end resonance, which is characterized by high (but finite) amplitudes of end displacements vis-a-vis those of neighboring (i.e., slightly different) frequencies. This phenomenon is illustrated in the two cylinder examples. It is possible to modify the passive reflection event by imposing some voltage distribution over the free end. For an oscillating end voltage that is out-of-phase with the incoming wave, it is possible to extract electrical energy from it, i.e., energy harvesting. Examples of such an oscillating voltage with a particular radial distribution are given, that illustrate the amount of extracted energy as a function of the frequency of the incident monochromatic wave.

Do postonset segments define a lexical neighborhood?

Previous research has demonstrated that the number and frequency of lexical neighbors affects the perception of individual sounds within a nonword in a phoneme identification task. In the present research, the issue of what items should be considered part of a word's neighborhood was explored. These experiments, in which both lexical decision and phoneme identification tasks were used, demonstrate that lexical neighborhood effects are not limited to words that match the target item syllable initially (the cohort). Words that differ from a target only in their first phoneme influence the process of lexical access. This argues against the notion that word onsets serve a unique or special purpose in word recognition.

Incidental effects of emotional valence in single word processing: An fMRI study

The present study aimed at identifying the neural responses associated with the incidental processing of the emotional valence of single words using event-related functional magnetic resonance imaging (fMRI). Twenty right-handed participants performed a visual lexical decision task, discriminating between nouns and orthographically and phonologically legal nonwords. Positive, neutral and negative word categories were matched for frequency, number and frequency of orthographic neighbors, number of letters and imageability. Response times and accuracy data differed significantly between positive and neutral, and positive and negative words respectively, thus, replicating the findings of a pilot study. Words showed distributed, mainly left hemisphere activations, indicating involvement of a neural network responsible for semantic word knowledge. The neuroimaging data further revealed areas in left orbitofrontal gyrus and bilateral inferior frontal gyrus with greater activation to emotional than to neutral words. These brain regions are known to be involved in processing semantic and emotional information. Furthermore, distinct activations associated with positive words were observed in bilateral middle temporal and superior frontal gyrus, known to support semantic retrieval, and a distributed network, namely anterior and posterior cingulate gyrus, lingual gyrus and hippocampus when comparing positive and negative words. The latter areas were previously associated with explicit and not incidental processing of the emotional meaning of words and emotional memory retrieval. Thus, the results are discussed in relation to models of processing semantic and episodic emotional information.

Adaptive Subcarrier Block Modulation with Differentially Modulated Pilot Symbol Assistance for Downlink OFDM Using Uplink Delay Spread

In AMS/OFDM systems, base station is in control of the modulation level of each subcarrier, and then, adaptive modulated packet is transmitted from the base station to the mobile station. In this case, the mobile station is required the modulation level information (MLI) to demodulate the received packet. The MLI is generally transmitted as a data symbol, therefore, the throughput is degraded. In an OFDM, the channel response at a particular subcarrier frequency is not supposed to be totally different from its neighboring frequencies, and hence, they must have correlation which depends on the coherence bandwidth of the channel Bc. If we could assign the same modulation level for coherently faded subcarrier block, MLI is required only one time for each subcarrier block. Moreover, we can assign the data on the empty space of pilot signals for increasing the total transmission. In this paper, we propose an adaptive subcarrier block modulation with differentially modulated pilot symbol assistance for downlink OFDM using uplink delay spread.

Blind source separation of acoustic signals in realistic environments based on ICA in the time‐frequency domain

We present an approach for blind separation of acoustic sources produced from multiple speakers mixed in realistic room environments. We first transform recorded signals into the time‐frequency domain to make mixing become instantaneous. We then separate the sources in each frequency bin based on an independent component analysis (ICA) algorithm. For the present paper, we choose the complex version of fixedpoint iteration (CFPI), i.e. the complex version of FastICA, as the algorithm. From the separated signals in the time‐frequency domain, we reconstruct output‐separated signals in the time domain. To solve the so‐called permutation problem due to the indeterminacy of permutation in the standard ICA, we propose a method that applies a special property of the CFPI cost function. Generally, the cost function has several optimal points that correspond to the different permutations of the outputs. These optimal points are isolated by some non‐optimal regions of the cost function. In different but neighboring bins, optimal points with the same permutation are at almost the same position in the space of separation parameters. Based on this property, if an initial separation matrix for a learning process in a frequency bin is chosen equal to the final separation matrix of the learning process in the neighboring frequency bin, the learning process automatically leads us to separated signals with the same permutation as that of the neighbor frequency bin. In each bin, but except the starting one, by chosen the initial separation matrix in such a way, the permutation problem in the time domain reconstruction can be avoided. We present the results of some simulations and experiments on both artificially synthesized speech data and real‐world speech data, which show the effectiveness of our approach.

Solution of the Skyrme–Hartree–Fock–Bogolyubov equations in the Cartesian deformed harmonic-oscillator basis. (V) HFODD(v2.08k)

Solution of the Skyrme–Hartree–Fock–Bogolyubov equations in the Cartesian deformed harmonic-oscillator basis. (V) HFODD(v2.08k)

Neighborhood density effects in spoken word recognition in Spanish

The present work examined the relationships among familiarity ratings, frequency of occurrence, neighborhood density, and word length in a corpus of Spanish words. The observed relationships were similar to the relationships found among the same variables in English. An auditory lexical decision task was then performed to examine the influence of word frequency, neighborhood density, and neighborhood frequency on spoken word recognition in Spanish. In contrast to the competitive effect of phonological neighborhoods typically observed in English, a facilitative effect of neighborhood density and neighborhood frequency was found in Spanish. Implications for models of spoken word recognition and language disorders are discussed.

The impact of lexical factors on children's word-finding errors.

This retrospective, exploratory investigation examined the types of target words that 30 children with word-finding difficulties (aged 8 to 12 years) had difficulty naming and the types of errors they made on these words. Words were studied with reference to lexical factors that might influence naming performance: word frequency, age of acquisition, familiarity, and lexical neighborhood. Findings indicated that neighborhood density predicted word-finding success, and target word substitutions and error patterns manifested were affected by the lexical factors under study. Students tended to produce substitutions that were higher in frequency, learned earlier, and that resided in neighborhoods of greater density and higher frequency than the target word. Lexical factors also influenced children's error patterns. Neighborhood density predicted form-related errors: Children produced more blocked errors on words from sparse neighborhoods. Word frequency and neighborhood frequency predicted form-segment-related errors as phonologic errors occurred on rare words and words whose neighbors contained lower frequency, uncommon phonological patterns. This important first step in the examination of how lexical factors have an impact on word-finding errors in children suggests that different types of words are more likely to result in failures of lexical access at different stages of processing. Theoretical and practical implications of these preliminary findings are discussed.

Coding and non-coding DNA thermal stability differences in eukaryotes studied by melting simulation, base shuffling and DNA nearest neighbor frequency analysis

The melting of the coding and non-coding classes of natural DNA sequences was investigated using a program, MELTSIM, which simulates DNA melting based upon an empirically parameterized nearest neighbor thermodynamic model. We calculated T m results of 8144 natural sequences from 28 eukaryotic organisms of varying F GC (mole fraction of G and C) and of 3775 coding and 3297 non-coding sequences derived from those natural sequences. These data demonstrated that the T m vs. F GC relationships in coding and non-coding DNAs are both linear but have a statistically significant difference (6.6%) in their slopes. These relationships are significantly different from the T m vs. F GC relationship embodied in the classical Marmur–Schildkraut–Doty (MSD) equation for the intact long natural sequences. By analyzing the simulation results from various base shufflings of the original DNAs and the average nearest neighbor frequencies of those natural sequences across the F GC range, we showed that these differences in the T m vs. F GC relationships are largely a direct result of systematic F GC-dependent biases in nearest neighbor frequencies for those two different DNA classes. Those differences in the T m vs. F GC relationships and biases in nearest neighbor frequencies also appear between the sequences from multicellular and unicellular organisms in the same coding or non-coding classes, albeit of smaller but significant magnitudes.

Solution of the Skyrme–Hartree–Fock–Bogolyubov equations in the Cartesian deformed harmonic-oscillator basis. (IV) HFODD (v2.08i): a new version of the program

We describe the new version (v2.07f) of the code HFODD which solves the nuclear Skyrme-Hartree-Fock or Skyrme-Hartree-Fock-Bogolyubov problem by using the Cartesian deformed harmonic-oscillator basis. In the new version, all symmetries can be broken, which allows for calculations with angular frequency and angular momentum tilted with respect to the mass distribution. The new version contains an interface to the LAPACK subroutine ZHPEVX.

Neighborhood effects on nonword visual processing in a language with shallow orthography.

Neighborhood size and neighborhood frequency were orthogonally varied in two experiments on Italian nonwords. In Experiment 1, an inhibitory effect of neighborhood frequency on visual lexical decision was found: The presence of one high-frequency neighbor increased response latencies and error rates to nonwords. By contrast, no effect of neighborhood size and no neighborhood size x neighborhood frequency interaction were found. In Experiment 2, a facilitatory effect of neighborhood size on nonword naming was shown: Naming latencies were faster when nonwords had a large neighborhood. In the naming experiment, there was no effect of neighbors' frequency and no neighborhood size x neighborhood frequency interaction. An additional role for bigram frequency was found whereas syllable frequency did not give any independent contribution. These results further corroborate the view that, in a language with transparent orthography like Italian, despite a substantial contribution of sublexical print-to-sound mapping due to the language's high regularity/consistency, reading aloud of nonlexical material may benefit from the contribution of the lexical component.

Effets de la fréquence du voisinage orthographique interlangue lors de la reconnaissance visuelle de mots chez les bilingues

Résumé Nous avons manipulé la fréquence du voisinage orthographique interlangue dans une tâche de décision lexicale monolingue et de décision de langue. Dans la décision lexicale, les bilingues français/espagnol traitent plus lentement des mots qui possèdent un voisin orthographique plus fréquent dans l'autre langue (voisins orthographiques interlangues) que des mots spécifiques à une seule langue, à la fois dans les listes françaises et espagnoles. Pour les deux langues, nous obtenons des ralentissements similaires pour les voisins orthographiques interlangues dans la tâche de décision de langue. Les résultats sont interprétés dans le cadre du modèle d'Activation Interactive Bilingue (BIA). Mots clés : bilinguisme, reconnaissance visuelle de mots, voisins orthographiques interlangues, mots spécifiques.