Real Word Stimuli Research Articles

The effect of real word stimuli versus non-word stimuli on oral diadochokinetic rates across the life span: An item discrimination analysis.

Diadochokinetic (DDK) rate tasks are extensively used in the evaluation of speech disorders; however, it is unclear how the different types of speech stimuli affect DDK rate performance. To investigate the effect of age, gender and type of stimuli (non-words versus real words) on the DDK rates in individuals across the lifespan and to provide normative data for Greek. Also to examine the discrimination ability of the speech DDK stimuli administered (non-words and real words) based on a dual DDK assessment protocol using a polytomous item response theory (IRT) model. The participants were 1747 monolingual Greek speakers (376 children, aged 4-17 years; and 1371 adults, aged 18-90+ years). All participants had normal hearing acuity which allowed them to understand and follow instructions. Participants with a medical condition or a language disorder which would affect DDK rate performance were excluded from the study. The time-by-count method was used, and all participants had to repeat as accurately and fast as possible: (1) four disyllabic non-words (/'gaba/, /'taka/, /'kata/, /'baga/), (2) four disyllabic real words (/'kapa/, /'tapa/, /ka'la/, /'paka/) and (3) two trisyllabic non-words (/'pataka/, /'badaga/). All responses were recorded and the speech samples that did not include at least 5 s of correct repetitions were excluded from the analysis. Age affected significantly DDK rates with performance increasing gradually until approximately the age of 40 and then gradually decreasing. Gender had no effect. Overall, there was a significant advantage of disyllabic real word stimuli over disyllabic non-word stimuli and of trisyllabic non-word stimuli over disyllabic non-word stimuli on DDK rates performance. IRT analysis suggested that the data fit the polytomous model reasonably well and all DDK stimuli (real words and non-words) showed a strong relationship (loadings > 0.50) with the latent trait. The current study complements prior research which supports that age and type of stimuli significantly affect DDK rates performance. It is the first study, that testifies to the benefit of real-word stimuli over non-word stimuli on DDK rates across the lifespan in a large representative sample. The implementation of IRT analysis provides empirical evidence about the discrimination ability of the DDK stimuli administered and confirms the reliability of this dual DDK assessment protocol. These findings are valuable for clinicians who work with motor speech disorders. What is already known on this subject Age, type of stimuli (real words versus non-words) and language significantly affect DDK rates performance. Current research strongly suggests the administration of language-specific norms since language-dependent features seem to have a noteworthy effect on the DDK rates, but scarce evidence exists about the discriminatory ability of the DDK speech stimuli commonly administered. What this study adds to the existing knowledge Conflicting findings have been reported about the effect of different types of DDK speech stimuli (real words and non-words) but no study to date has evaluated their discriminatory abilities. The current study is the first to implement a polytomous IRT model to examine this issue. This is also the first study to attempt an investigation of the effect of types of stimuli (real words versus non-words) on a large representative sample across the lifespan (4-90+ years) and to provide normative data for Greek. What are the practical and clinical implications of this work? The present study offers concrete evidence about the advantage of real-word stimuli over non-word stimuli in Greek, as well as normative data for the Greek-speaking populations. Moreover, the IRT analysis testifies to the discriminatory ability of real-word and non-word stimuli affirming the reliability of the present dual DDK assessment protocol as a psychometrically sound measure of DDK ability. The above has significant value for clinicians who work with individuals with motor speech disorders as the protocol can help them with the diagnosis and differential diagnosis of motor speech disorders.

Diadochokinetic rates in healthy young and elderly Greek-speaking adults: The effect of types of stimuli.

Diadochokinetic rates tasks are frequently used for the assessment of diadochokinesia (DKK) in young and elderly adults. However, there is scarce research on healthy elderly adults over 65 years old, and little is known about the effect of different types of stimuli (non-words/real words) in this specific population. Furthermore, the current research supports significant language variations, highlighting the need for language-specific norms. To investigate the effect of age, gender and type of stimuli (non-words versus real words) in DDK rates in healthy elderly adults of over 65 years of age, and to provide normative data for the Greek language. The participants were 791 healthy monolingual Greek-speaking adults (531 adults, aged 20-39 years; 157 participants aged 65-74 years; and 103 participants aged over 75 years). All participants were monolingual speakers of Greek and had normal hearing acuity, which allowed them to understand and follow instructions. Participants with a medical condition, which would affect DDK rates' performance, were excluded from the study. The time-by-count method was used, and all participants had to repeat as accurately and fast as possible: (1) four disyllabic non-words (/'gaba/, /'taka/, /'kata/, /'baga/); (2) four disyllabic real words (/'kapa/, /'tapa/, /ka'la/, /'paka/); and (3) two trisyllabic non-words (/'pataka/, /'badaga/). All responses were recorded and the speech samples that did not include at least 5 s of correct repetitions were excluded from the analysis. Age affected DDK rates significantly, with older adults achieving slower DDK rates for all speech stimuli (non-words/real words). Gender did not have an effect on the performance of DDK rates. The type of speech stimuli affected DDK rates significantly for all age groups. Analytically, trisyllabic non-word stimuli were articulated more slowly than disyllabic non-word stimuli, and real words were produced faster than non-words. A linear regression analysis revealed that only the repetition of non-words predicted 68.4% of the performance on the repetition of trisyllabic non-words. The above results complement prior research, which supports that real word stimuli yield faster performance than non-word stimuli. Clinicians should keep in mind that age, language and type of stimuli (non-words/real words) affect significantly the performance of DDK rates, as well as the fact that different types of stimuli tap distinct underlying levels of speech. The current research highlights the need for language-specific norms for different populations. What is already known on the subject DDK rates are significantly affected by the types of stimuli and language used. Moreover, the normal ageing process decreases performance in terms of DDK rates, but scarce evidence exists for healthy elderly adults over 65 years old. What this paper adds to existing knowledge Most studies have examined DDK rates in healthy elderly people with restricted samples and using non-word stimuli. The current study administered different types of stimuli (non-words/words) in a large sample of healthy elderly participants. This is also the first study to attempt to provide DDK normative data for this population in the Greek language. What are the potential or actual clinical implications of this work? The results of this study strongly suggest that clinicians should bear in mind the significant impact age and language have on performance in terms of DDK rates, especially when normative data are not available for a certain language or age group. Furthermore, non-word and real-word stimuli cannot be used interchangeably since they tap into distinct underlying levels of speech, thus providing clinicians with useful information about the level of breakdown and the proper treatment plan.

Oral diadochokinetic rates for real words and non-words in Greek-speaking children

Abstract This study examined the performance of Greek monolingual typically developing (TD) children on diadochokinetic (DDK) rates in real words and non-words and attempted to establish normative data for Greek. The effects of age, type of stimuli and gender were investigated. A total of 380 children aged 4.0–15.0 years as well as a control group of 313 adults participated in the study. Age significantly affected DDK performance, yet normative data differ from other studies. DDK rates for bisyllabic stimuli were faster than DDK rates for trisyllabic stimuli and real words were articulated faster than non-words. Adolescents aged 13.0–15.0 years were slower than adults both in real word and in non-word /ˈpataka/ repetition. Additionally, overall boys were significantly faster than girls. These findings show the need to: (a) implement real word stimuli in DDK tasks in order to better depict an individual’s oral-motor abilities and (b) establish language-specific normative data for TD children.

Transferring perceptual cue-weighting from second language into first language: Cues to voicing in Russian speakers of English

Does second language experience affect first language perception? The present paper addresses this question in a study of bilingual cue weighting with a focus on perceptual cues that are of markedly different importance for the corresponding monolingual groups. The study investigates the use of vowel duration and glottal pulsing duration as cues to stop voicing by adult Russian speakers of English, long-term residents of the USA, (n = 37, average age 38.8 years), as well as a control group of monolingual Russians, recruited and tested in Russia, (n = 34, average age 26.1 years) and a control group of monolingual English speakers, recruited and tested in the USA, (n = 34, average age 21.7 years). Participants took part in a binary-choice voicing identification experiment using resynthesized real-word stimuli recorded by native speakers of each language. The stimuli varied orthogonally in terms of preceding vowel duration and duration of glottal pulsing during stop closure. Results demonstrate that monolingual English participants assigned a greater perceptual weight to vowel duration and a lesser perceptual weight to glottal pulsing than monolingual Russian participants. Bilinguals also used different cue weighting depending on the language mode. Bilinguals’ cue weighting in English mode was not statistically different from that of monolingual English participants. Bilinguals’ cue weighting in Russian mode showed an increased reliance on vowel duration and a decreased reliance on glottal pulsing, compared to monolingual Russians, indicating the influence of English. These findings demonstrate that second language experience affects cue weighting patterns in bilinguals’ first language.

Speed and accuracy of dyslexic versus typical word recognition: an eye-movement investigation.

Developmental dyslexia is often characterized by a dual deficit in both word recognition accuracy and general processing speed. While previous research into dyslexic word recognition may have suffered from speed-accuracy trade-off, the present study employed a novel eye-tracking task that is less prone to such confounds. Participants (10 dyslexics and 12 controls) were asked to look at real word stimuli, and to ignore simultaneously presented non-word stimuli, while their eye-movements were recorded. Improvements in word recognition accuracy over time were modeled in terms of a continuous non-linear function. The words' rhyme consistency and the non-words' lexicality (unpronounceable, pronounceable, pseudohomophone) were manipulated within-subjects. Speed-related measures derived from the model fits confirmed generally slower processing in dyslexics, and showed a rhyme consistency effect in both dyslexics and controls. In terms of overall error rate, dyslexics (but not controls) performed less accurately on rhyme-inconsistent words, suggesting a representational deficit for such words in dyslexics. Interestingly, neither group showed a pseudohomophone effect in speed or accuracy, which might call the task-independent pervasiveness of this effect into question. The present results illustrate the importance of distinguishing between speed- vs. accuracy-related effects for our understanding of dyslexic word recognition.

The Filtered Words Test and the Influence of Lexicality

In the present study, the authors aimed to investigate the language confounds of filtered words tests by examining the repetition of real words versus nonsense words as a function of level of filtering. Fifty-five young, native-English-speaking women with normal hearing were required to repeat 80 real-word and 80 nonsense-word monosyllables that were matched for phonemic content and low-pass filtered. Thirty participants were tested using a harsher filter range of 2000 to 500 Hz, and 25 participants were tested using a milder filter range of 3000 to 1500 Hz. Paired-sample t tests compared accuracy (percentage of phonemes correct) for word and nonsense-word stimuli at each filter level. At filter levels between 3000 and 1750 Hz, performance for word stimuli was significantly better than for nonsense-word stimuli. Conversely, at filter levels between 500 and 1250 Hz, performance was significantly better for nonsense words. The linguistic content of real-word stimuli benefits performance on low-pass filtered speech tests at filter levels above 1500 Hz. Caution must be taken when using real-word stimuli in low-pass filtered speech tests as part of an auditory processing diagnostic test battery, because language ability will impact on performance.

Phonological learning and lexicality of treated stimuli

The purpose was to evaluate the lexicality of treated stimuli relative to phonological learning by preschool children with functional phonological disorders. Four children were paired in a single-subject alternating treatments design that was overlaid on a multiple baseline across subjects design. Within each pair, one child was taught one sound in real words and a second sound in non-words; for the other child of the pair, lexicality was reversed and counterbalanced. The dependent variable was production accuracy of the treated sounds as measured during the session-by-session course of instruction. Results indicated that production accuracy of the treated sound was as good as or better using non-word as opposed to real word stimuli. The clinical implications are considered, along with potential accounts of the patterns of learning.

영어 모음사이 자음의 인지와 발화에서 철자의 영향: 파일럿 연구

한국어에서는 모음사이에서 겹자음이 나타날 수 있으나 영어에서는 이것이 불가능하므로 영어를 배우는 한국 학생들이 <TEX>$su\underline{mm}er$</TEX>와 같이 겹자음 철자를 포함하는 단어들을 발음할 때 철자의 겹자음을 모두 발음하는 오류를 흔히 범한다. 따라서 본 파일럿 연구에서는 한국 학생들이 영어 겹자음 철자를 어떻게 발음하고 인지하는지 살펴보기 위해서 영어 겹자음과 단자음의 (유사) 최소변별쌍으로 구성된 36개의 실제어를 20명의 대학생이 듣고 발음하는 인지와 발화 실험을 실행하였다. 실험 결과 한국 학생들은 철자의 영향으로 영어 단자음 철자 단어를 발음할 때보다 겹자음 철자 단어를 발음할 때 이중으로 길게 발음하는 오류를 더 흔히 범해서 겹자음 철자 단어의 정확율보다 단자음의 정확율이 크게 높았으며, 인지의 경우에도 마찬가지로 단자음 철자 단어의 인지 정확율이 겹자음 철자보다 확연하게 높았다. 덧붙여, 한국 학생들의 영어 유성 파열음의 발화 오류율이 낮은 이유를 한국어 음운 체계의 전이로 설명하였다. 끝으로, 한국학생들의 발화를 스펙트로그램을 통해서 분석함으로써 영어 단자음 철자보다는 겹자음 철자에서 더 많은 발화오류를 일으키는 것도 보여주었고 또한 교육적인 함축점도 제안하였다. While Korean allows the same consonants at the coda of the preceding syllable and at the onset of the following syllable, English does not allow the geminate consonants in the same intervocalic position. Due to this difference between Korean and English, Korean learners of English tend to incorrectly produce geminate consonants for English geminate graphemes as in <TEX>$su\underline{mm}er$</TEX>. Based on this observation, a pilot study was designed to investigate how Korean learners of English perceive and produce English doubleton graphemes and singleton graphemes. Twenty Korean college students were asked to perform a forced-choice perception test as well as a production test for the 36 real word stimuli which consist of (near) minimal pairs of singleton and doubleton graphemes. The result showed that the accuracy rates for the words with singleton graphemes were higher than those for the words with doubleton graphemes both in perception and production because the subjects misperceived and misproduced the doubleton graphemes as geminates due to orthographic influence. In addition, the low error rates of the word with voiced stops were accounted for by Korean language transfer. Further, spectrographic analyses were provided where more production errors were witnessed in doubleton grapheme words than singleton grapheme words. Finally, pedagogical implications are provided.

Phonotactics, density, and entropy in spoken word recognition

Previous research has demonstrated that increases in phonotactic probability facilitate spoken word processing, whereas increased competition among lexical representations is often associated with slower and less accurate recognition. We examined the combined effects of probabilistic phonotactics and lexical competition by generating words and nonwords that varied orthogonally on phonotactics and similarity neighbourhood density. The results from a speeded same-different task revealed simultaneous facilitative effects of phonotactics and inhibitory effects of lexical competition for real word stimuli. However, the nonword stimuli produced an apparently anomalous pattern of results. In a subsequent experiment, we identified the source of this anomaly by estimating behaviourally the specific lexical competitors activated by our nonwords. Our results suggest that, under specific circumstances, neighbourhood density and probabilistic phonotactics may combine to produce non-additive or synergistic effects of lexical competition on processing times.

Differences in auditory processing of words and pseudowords: an fMRI study.

Although there has been great interest in the neuroanatomical basis of reading, little attention has been focused on auditory language processing. The purpose of this study was to examine the differential neuroanatomical response to the auditory processing of real words and pseudowords. Eight healthy right-handed participants performed two phoneme monitoring tasks (one with real word stimuli and one with pseudowords) during a functional magnetic resonance imaging (fMRI) scan with a 4.1 T system. Both tasks activated the inferior frontal gyrus (IFG), the posterior superior temporal gyrus (pSTG) and the inferior parietal lobe (IPL). Pseudoword processing elicited significantly more activation within the posterior cortical regions compared with real word processing. Previous reading studies have suggested that this increase is due to an increased demand on the lexical access system. The left inferior frontal gyrus, on the other hand, did not reveal a significant difference in the amount of activation as a function of stimulus type. The lack of a differential response in IFG for auditory processing supports its hypothesized involvement in grapheme to phoneme conversion processes. These results are consistent with those from previous neuroimaging reading studies and emphasize the utility of examining both input modalities (e.g., visual or auditory) to compose a more complete picture of the language network.

Event-Related Brain Potentials Elicited during Phonological Processing Differentiate Subgroups of Reading Disabled Adolescents

Visual and auditory rhyme judgment tasks were administered to adolescent dyslexics and normal readers while event-related brain potentials were recorded. Reading disabled subjects were split into two groups based on a median split of scores on a visual non-word decoding test. The better decoders were called Phonetics and the poorer decoders were referred to as Dysphonetics. Single syllable, real word stimuli were used, and both rhyming and non-rhyming targets had a 50% chance for matching orthography. In the visual paradigm the normal readers exhibited a left frontal CNV before targets, a large reduction in frontal N400 for matching orthography (orthographic priming), and a large reduction in parietal N400 for rhyming targets (phonological priming). Dysphonetics had an intact CNV and orthographic priming, but the group's phonological priming was very reduced. Phonetics showed both orthographic and phonological priming but had a marked reduction in their CNV. In the auditory task, controls showed a left parietal N400 priming effect for rhyming targets. Dysphonetics showed a similar bilateral effect. The Phonetics did not show a normal priming effect, but produced evidence for priming at a longer latency. Additionally, the Phonetic group responded more slowly than either of the other two groups, who responded with similar latencies. These results support the separation of the reading disabled into a group that has difficulty translating orthography into phonology, and a group that is slower functioning and has reduced capacity in preparing for a response.

Lexical decisions in patients with Alzheimer's disease: Some notes on automatic versus controlled processing

This study examined the lexical decisions of age, gender and education matched groups of Alzheimer's disease (AD) and normally aging (NA) subjects. The subjects were asked to make lexical decisions on real word, pseudoword and nonword orthographic stimuli. Analysis of the data revealed that the accuracy of the lexical decisions of the AD group was comparable to those of their NA peers for real word stimuli, but significantly different for the pseudo-word and non-word stimuli. The findings appeared to support the notion that AD patients' single word decoding may be disrupted in a way that is not readily apparent during the mild stages of the disease course.

Audiovisual integration in perception of real words.

Three experiments follow up on Easton and Basala's (1982) report that the "McGurk effect" (an influence of a visibly mouthed utterance on a dubbed acoustic one) does not occur when utterances are real words rather than nonsense syllables. In contrast, with real-word stimuli, Easton and Basala report a strong reverse effect whereby a dubbed soundtrack strongly affects identification of lipread words. In Experiment 1, we showed that a strong McGurk effect does obtain when dubbed real words are discrepant with observed words in consonantal place of articulation. A second experiment obtained only a weak reverse effect of dubbed words on judgments of lipread words. A final experiment was designed to provide a sensitive test of effects of lipread words on judgments of heard words and of heard words on judgments of lipread words. The findings reinforced those of the first two experiments that both effects occur, but, with place-of-articulation information discrepant across the modalities, the McGurk effect is strong and the reverse effect weak.

The use of novel and real-word stimuli in the assessment of english morphology in adults with aphasia

Abstract Fifteen aphasic subjects were administered two 10-item production tasks of English morphology based on the novel words like those from the Berko Test and equivalent real words selected from the Grammatic Closure subtest of the Illinois Test of Psycholinguistic Abilities (ITPA). Aphasia severity was estimated with the Porch Index of Communicative Ability (PICA). Analysis of the results revealed that significantly more correct responses were obtained from meaningful words than novel words, and there was a positive and significant correlation between severity of aphasia and an aphasic subject's production of certain bound English morphemes. There was a similar hierarchy of morphological forms produced by aphasic subjects on both test forms. Further, the hierarchy of forms assessed through these novel-word stimuli did not parallel closely the order of acquisition of these same morphological structures found previously in children.

Linguistic processing and reaction time differences in stutterers and nonstutterers.

Linguistic processing by the left and right cerebral hemispheres was investigated in 10 adult male stutters and 10 matched nonstutterers. Subjects performed a lexical decision task in which nonword and real-word stimuli were presented tachistoscopically to the right and left visual hemifields. Vocal and manual reaction times to real words were measured to assess hemispheric participation in processing linguistic information and to determine differences between response modes. The stuttering group exhibited a left visual field efficiency or right hemisphere preference for this task and were slower in both vocal and manual reaction times. Ramifications for hemispheric processing theories and laryngeal dysfunction hypotheses are discussed.