Speech Production Errors Research Articles

Taboo: A Novel Paradigm to Elicit Aphasia-Like Trouble-Indicating Behaviour in Normally Speaking Individuals

Two important research lines in neuro- and psycholinguistics are studying natural or experimentally induced slips of the tongue and investigating the symptom patterns of aphasic individuals. Only few studies have focused on explaining aphasic symptoms by provoking aphasic symptoms in healthy speakers. While all experimental techniques have so far dealt with the single word or the sentence level, the current study intended to provoke aphasia-like trouble-indicating behaviour (i.e. prepairs and repairs) in the spontaneous language production of unimpaired speakers. In their descriptions of complex pictures, the participants were requested to avoid particular words terming central elements of the pictures. The results show that the error pattern provoked by the novel "taboo" paradigm resembled substantially the pattern of aphasic individuals. Consequently, the paradigm is applicable for further studies, e.g. for bringing forward the understanding of spontaneous language production or for comparing the neurofunctional basis of errors in healthy and aphasic speakers.

The Sensory Consequences of Speaking: Parametric Neural Cancellation during Speech in Auditory Cortex

When we speak, we provide ourselves with auditory speech input. Efficient monitoring of speech is often hypothesized to depend on matching the predicted sensory consequences from internal motor commands (forward model) with actual sensory feedback. In this paper we tested the forward model hypothesis using functional Magnetic Resonance Imaging. We administered an overt picture naming task in which we parametrically reduced the quality of verbal feedback by noise masking. Presentation of the same auditory input in the absence of overt speech served as listening control condition. Our results suggest that a match between predicted and actual sensory feedback results in inhibition of cancellation of auditory activity because speaking with normal unmasked feedback reduced activity in the auditory cortex compared to listening control conditions. Moreover, during self-generated speech, activation in auditory cortex increased as the feedback quality of the self-generated speech decreased. We conclude that during speaking early auditory cortex is involved in matching external signals with an internally generated model or prediction of sensory consequences, the locus of which may reside in auditory or higher order brain areas. Matching at early auditory cortex may provide a very sensitive monitoring mechanism that highlights speech production errors at very early levels of processing and may efficiently determine the self-agency of speech input.

MORPHOLOGICAL ERRORS IN SPANISH SECOND LANGUAGE LEARNERS AND HERITAGE SPEAKERS

Morphological variability and the source of these errors have been intensely debated in SLA. A recurrent finding is that postpuberty second language (L2) learners often omit or use the wrong affix for nominal and verbal inflections in oral production but less so in written tasks. According to the missing surface inflection hypothesis, L2 learners have intact functional projections, but errors stem from problems during production only (a mapping or processing deficit). This article shows that morphological variability is also characteristic of heritage speakers (early bilinguals of ethnic minority languages) who were exposed to the family language naturalistically in early childhood but failed to acquire age-appropriate linguistic competence in the language. However, because errors in heritage speakers are more frequent in written than in oral tasks, the missing surface inflection hypothesis does not apply to them. The discussion considers how morphological errors in the two populations seem to be related to the type of experience.

Investigation of self-monitoring in fluent aphasia with jargon

Background: Some individuals with fluent aphasia produce jargon errors in speech production. Jargon likely results from derailed encoding operations required for language production, although the exact mechanism remains debated. It is also unclear if persons who produce jargon are able to self-monitor; that is, detect the non-word status of their imminent utterance and self-correct the error. Aims: This study investigated the characteristics of speech monitoring in individuals with fluent aphasia who produce jargon. The association of speech monitoring with amount of jargon produced and success in auditory comprehension was examined. Further, the role of post-articulatory auditory feedback on speech-monitoring success was examined by introducing an auditory masker (white noise). Finally, the influence of task demands on amount of jargon and speech monitoring was examined. Methods & Procedures: Five individuals with fluent aphasia with jargon participated in the study. Speech monitoring was tested using three production tasks (picture naming, non-word repetition, and word repetition) under two listening conditions (normal listening and masking noise). Speech-monitoring score was derived from self-judgements of production accuracy. Auditory processing was examined in speech discrimination, lexical decision, and single-word identification tasks. Outcomes & Results: Results indicated that severity of self-monitoring impairment is: (1) strongly correlated with severity of jargon production, (2) poorly correlated with auditory processing abilities, (3) worse under masking noise, and (4) worse for naming compared to repetition. Conclusions: Overall, all five participants with jargon demonstrated severely impaired speech monitoring under both listening conditions across all three production tasks, suggesting that the role of speech-monitoring impairment in jargon cannot be disregarded. The increase in amount of jargon and severity of speech-monitoring failure with increased linguistic demands of the production task (as in picture naming and non-word repetition) raises the possibility of a post-semantic deficit in accessing phonological codes. This possible locus of deficit, and implications for understanding production of jargon, are discussed.

Speech errors in progressive non-fluent aphasia

The nature and frequency of speech production errors in neurodegenerative disease have not previously been precisely quantified. In the present study, 16 patients with a progressive form of non-fluent aphasia (PNFA) were asked to tell a story from a wordless children’s picture book. Errors in production were classified as either phonemic, involving language-based deformations that nevertheless result in possible sequences of English speech segments; or phonetic, involving a motor planning deficit and resulting in non-English speech segments. The distribution of cortical atrophy as revealed by structural MRI scans was examined quantitatively in a subset of PNFA patients ( N = 7). The few errors made by healthy seniors were only phonemic in type. PNFA patients made more than four times as many errors as controls. This included both phonemic and phonetic errors, with a preponderance of errors (82%) classified as phonemic. The majority of phonemic errors were substitutions that shared most distinctive features with the target phoneme. The systematic nature of these substitutions is not consistent with a motor planning deficit. Cortical atrophy was found in prefrontal regions bilaterally and peri-Sylvian regions of the left hemisphere. We conclude that the speech errors produced by PNFA patients are mainly errors at the phonemic level of language processing and are not caused by a motor planning impairment.

Which words are hard to recognize? Prosodic, lexical, and disfluency factors that increase speech recognition error rates

Despite years of speech recognition research, little is known about which words tend to be misrecognized and why. Previous work has shown that errors increase for infrequent words, short words, and very loud or fast speech, but many other presumed causes of error (e.g., nearby disfluencies, turn-initial words, phonetic neighborhood density) have never been carefully tested. The reasons for the huge differences found in error rates between speakers also remain largely mysterious. Using a mixed-effects regression model, we investigate these and other factors by analyzing the errors of two state-of-the-art recognizers on conversational speech. Words with higher error rates include those with extreme prosodic characteristics, those occurring turn-initially or as discourse markers, and doubly confusable pairs: acoustically similar words that also have similar language model probabilities. Words preceding disfluent interruption points (first repetition tokens and words before fragments) also have higher error rates. Finally, even after accounting for other factors, speaker differences cause enormous variance in error rates, suggesting that speaker error rate variance is not fully explained by differences in word choice, fluency, or prosodic characteristics. We also propose that doubly confusable pairs, rather than high neighborhood density, may better explain phonetic neighborhood errors in human speech processing.

“L” is for tiger: Effects of phonological (mis)cueing on picture naming in semantic aphasia

Semantic aphasia (SA) refers to a subset of aphasic patients who exhibit multimodal semantic deficits (Jefferies, E., & Lambon Ralph, M. (2006). Semantic impairment in stroke aphasia vs semantic dementia: a case-series comparison. Brain, 129(8), 2132–2147). Consistent with their underlying semantic control deficit, SA picture naming accuracy can be improved considerably with a correct phonological cue. The performance of normal individuals in the tempo picture naming paradigm reveals an increased impact of both correct and incorrect phonological cueing, and it has been suggested that this technique reduces resources available for semantic control in neurologically-intact participants (Hodgson, C., & Lambon Ralph, M. (2008). Mimicking aphasic semantic naming errors in normal speech production: Evidence from a novel experimental paradigm. Brain and Language, 104(1), 89–101.). We tested this hypothesis by considering the impact of both correct and incorrect phonological cues on picture naming in a case series of SA patients, using exactly the same items as those presented to normal participants for tempo naming. The results confirmed the positive effect of correct cues and revealed for the first time the negative effects of category co-ordinate miscues amongst these patients in both overall accuracy and semantic error rates. The implications of our results for current speech production models are considered.

Planning time effects of phonological competition: Articulatory and acoustic data.

One major cause for speech production variability and errors is competition between phonologically similar sequences in an utterance. Since one recent model of speech production planning [Nam (2004)] also posits a systematic relation between planning time and kinematic variability, we decided to directly investigate whether competition increases planning time, i.e., whether it takes longer to initiate a sequence such as “tape cape” compared with “tape tape.” Effects of competition in the onset were compared to competition in the coda (e.g., “tape take”). Results from two studies are reported: articulatory latencies from a delayed naming task recorded using EMA (four speakers), and acoustic latencies from a delayed naming task, a simple naming task, and a picture naming task (ten speakers). Latencies were significantly affected by competition, i.e., latencies were longer for items like “tape cape” and “tape take” than for “tape tape.” However, no significant differences were found in competition effects between onset and coda positions. Apart from latency, overall duration increased and clusters formed across words showed less overlap. Observed effects on latency were largest for picture naming, followed by simple naming and least for delayed naming. [Work supported by NIH DC008780.]

A comparison of native speaker and American adult learner Vietnamese lexical tones

This study introduces a modification of the traditional carrier sentence elicitation task, provides new native speaker data regarding aspects of pitch and voice quality in Vietnamese lexical tones, and provides an empirical description of non-native speaker errors in tone production. Participants produce a series of three-word utterances in response to target words that appear individually on a computer screen in one of four colors. In this way, participants actively describe a changing event, while critical components remain constant: the identity of the word preceding the target, the target position (utterance medial), and the target's focus structure. Native speaker results are consistent with existing descriptions of fundamental frequency contours and creakiness. In addition, they provide evidence supporting claims that breathiness can occur in two different tones: the falling tone (huyen) and curve tone (hoi). Non-native speaker results suggest that adult learners struggle with voice quality distinctions and pitch shape.

Children with Comorbid Speech Sound Disorder and Specific Language Impairment are at Increased Risk for Attention-Deficit/Hyperactivity Disorder

This study focuses on the comorbidity between attention-deficit/hyperactivity disorder (ADHD) symptoms and speech sound disorder (SSD). SSD is a developmental disorder characterized by speech production errors that impact intelligibility. Previous research addressing this comorbidity has typically used heterogeneous groups of speech-language disordered children. This study employed more precise speech-language diagnostic criteria and examined ADHD symptomatology in 108 SSD children between the ages of 4 and 7 years old with specific language impairment (SLI) (n = 23, 14 males, 9 females) and without SLI (n = 85, 49 males, 36 females). We also examined whether a subcategory of SSD, persistent (n = 39, 25 males, 14 females) versus normalized SSD (n = 67, 38 males, 29 females), was associated with ADHD and/or interacted with SLI to predict ADHD symptomatology. Results indicated that participants in the SSD + SLI group had higher rates of inattentive ADHD symptoms than those in the SSD-only and control groups. In addition, an unexpected interaction emerged such that children with SLI and normalized-SSD had significantly higher ADHD inattentive ratings than the other subgroups. A proposed explanation for this interaction is discussed.

Tongue Kinematics during Utterances Elicited with the SLIP Technique

In the past years, there have been an increasing number of instrumental investigations as to the nature of speech production errors, prompted by the concern that decades of transcription-based speech error data may be tainted by perceptual biases. While all of these instrumental studies suggest that errors are not, as previously thought, necessarily a matter of all-or-none, it is unclear what implications these studies have for phonological encoding as a cognitive process. Due to their repetition-based design, the ill-formed errors obtained in these studies may be articulation errors rather than cognitive planning errors. The present study reports for the first time tongue movement data collected during an error elicitation study based on the SLIP technique, which has traditionally been hypothesized to elicit errors at the phonological planning level. Results indicate that tongue kinematics during errors in the present task are comparable to those found in errorful utterances in repetition tasks. The findings are interpreted within a dynamic model of speech production as errors in phasing between the interacting consonant gestures.

Mimicking aphasic semantic errors in normal speech production: Evidence from a novel experimental paradigm

Semantic errors are commonly found in semantic dementia (SD) and some forms of stroke aphasia and provide insights into semantic processing and speech production. Low error rates are found in standard picture naming tasks in normal controls. In order to increase error rates and thus provide an experimental model of aphasic performance, this study utilised a novel method- tempo picture naming. Experiment 1 showed that, compared to standard deadline naming tasks, participants made more errors on the tempo picture naming tasks. Further, RTs were longer and more errors were produced to living items than non-living items a pattern seen in both semantic dementia and semantically-impaired stroke aphasic patients. Experiment 2 showed that providing the initial phoneme as a cue enhanced performance whereas providing an incorrect phonemic cue further reduced performance. These results support the contention that the tempo picture naming paradigm reduces the time allowed for controlled semantic processing causing increased error rates. This experimental procedure would, therefore, appear to mimic the performance of aphasic patients with multi-modal semantic impairment that results from poor semantic control rather than the degradation of semantic representations observed in semantic dementia [Jefferies, E. A., & Lambon Ralph, M. A. (2006). Semantic impairment in stoke aphasia vs. semantic dementia: A case-series comparison. Brain, 129, 2132–2147]. Further implications for theories of semantic cognition and models of speech processing are discussed.

Speech errors and the phonological similarity effect in short-term memory: Evidence suggesting a common locus

In three experiments, we tested the hypothesis that those errors in immediate serial recall (ISR) that are attributable to phonological confusability share a locus with segmental errors in normal speech production. In the first two experiments, speech errors were elicited in the repeated paced reading of six-letter lists. The errors mirrored the phonological confusions seen in ISR. In a third experiment, participants performed ISR for four-word lists. Some of the lists were designed to encourage the exchange of onset consonants between adjacent words. ISR was shown to be sensitive to this manipulation, further supporting the common-locus hypothesis. The results are discussed in the context of theories of serial recall and of speech production, and are further related to neuropsychological data.

Multistage speaker diarization of broadcast news

This paper describes recent advances in speaker diarization with a multistage segmentation and clustering system, which incorporates a speaker identification step. This system builds upon the baseline audio partitioner used in the LIMSI broadcast news transcription system. The baseline partitioner provides a high cluster purity, but has a tendency to split data from speakers with a large quantity of data into several segment clusters. Several improvements to the baseline system have been made. First, the iterative Gaussian mixture model (GMM) clustering has been replaced by a Bayesian information criterion (BIC) agglomerative clustering. Second, an additional clustering stage has been added, using a GMM-based speaker identification method. Finally, a post-processing stage refines the segment boundaries using the output of a transcription system. On the National Institute of Standards and Technology (NIST) RT-04F and ESTER evaluation data, the multistage system reduces the speaker error by over 70% relative to the baseline system, and gives between 40% and 50% reduction relative to a single-stage BIC clustering system

Dynamic action units slip in speech production errors

In the past, the nature of the compositional units proposed for spoken language has largely diverged from the types of control units pursued in the domains of other skilled motor tasks. A classic source of evidence as to the units structuring speech has been patterns observed in speech errors – “slips of the tongue”. The present study reports, for the first time, on kinematic data from tongue and lip movements during speech errors elicited in the laboratory using a repetition task. Our data are consistent with the hypothesis that speech production results from the assembly of dynamically defined action units – gestures – in a linguistically structured environment. The experimental results support both the presence of gestural units and the dynamical properties of these units and their coordination. This study of speech articulation shows that it is possible to develop a principled account of spoken language within a more general theory of action.

Transitivity in Japanese sentence production: Speech errors of the dative NI and the accusative O

Abstract This study examines native Japanese speakers’ speech errors of the case particles, the dative ni and the accusative o, occurring in object NPs of two-place predicates. The speech error data demonstrate that the semantic basis of ni and o errors in native Japanese speakers’ utterances is closely related to transitivity (as discussed by Hopper and Thompson 1980). Japanese speakers tend to use the accusative o for the object NPs (even when the dative ni is required by the verb) if the meanings of the events and actions that the speakers wish to talk about are relatively high in transitivity and ni if the events are relatively low in transitivity and if they involve some kind of directionality. The findings suggest that Japanese speakers utilize dynamic online semantic mapping when selecting case particles in speech and that such mapping may facilitate online sentence production when the verb selection (the retrieval of the target verb) is not finalized.

Agrammatism: A Cross-Linguistic Clinical Perspective

Agrammatism: A Cross-Linguistic Clinical Perspective

Jargon dyslexia in an individual with semantic dementia: Further evidence for task-specificity in phonological output

We report a patient with semantic dementia who demonstrated a very unusual dyslexia. He had a global loss of conceptual knowledge in the context of a fluent dysphasia and intact syntax. However, he did not have the surface dyslexia which is typical of semantic dementia; rather his reading impairment was characterized by speech production errors resulting in multiple neologisms. In a series of experiments it was established that input phonological and input orthographical processing were intact as was output phonology for naming and propositional speech. We demonstrate that our patient has a task-specific phonological deficit and we argue that reading and propositional speech rely upon dissociable phonological output systems. Thus we corroborate our earlier evidence of task-specific phonological output stores (Crutch and Warrington, 2001). We also document a greater difficulty with comprehending the written than the spoken word. We account for this pattern of performance in terms of our patient’s attempting to read by the indirect phonological route, as with other semantic dementia patients, but suggest that this process is overridden by the task-specific speech production deficit.

Linkage of speech sound disorder to reading disability loci

Speech sound disorder (SSD) is a common childhood disorder characterized by developmentally inappropriate errors in speech production that greatly reduce intelligibility. SSD has been found to be associated with later reading disability (RD), and there is also evidence for both a cognitive and etiological overlap between the two disorders. The present study tested whether SSD is linked to replicated risk loci for RD. One hundred and eleven probands with SSD and their 76 siblings were tested with measures of speech, phonological memory (Nonword Repetition-NWR), and phonological awareness and genotyped for linkage markers on chromosomes 1p36, 6p22, and 15q21. Both single point and multipoint linkage were tested with multiple methods. The speech and NWR phenotypes were linked to the RD loci on chromosomes 6 and 15, with suggestive results for the RD locus on chromosome 1. It now appears that several RD loci are pleiotropic for SSD, extending the findings of Stein et al. (2004) for the RD locus on Chromosome 3.

Reliablity of measurements from ultrasound images

As ultrasound imaging gains popularity in phonetic and speech science research, examining the reliability of measures taken from ultrasound images becomes important. This study assesses the reliability of hand measures of ultrasound data collected by graduate student researchers at the University of South Florida ultrasound imaging lab. Speech production data from two different experiments, ‘‘Ultrasound analysis of velar fronting’’ (Wodzinski, 2004) and ‘‘Ultrasound study of errors in speech production’’ [Frisch, (2003)] were analyzed by two different researchers to obtain inter-rater reliability measures. In addition, one data set was measured twice by the same researcher, once when inexperienced with ultrasound analysis and 7 months later after considerable experience had been gained. The study compared researcher’s choice of image to analyze, the measures of the location of articulatory landmarks, and the measures used to quantify articulatory postures. Overall, hand measures of ultrasound images were found to be reliable. There were some differences in the absolute measures obtained, however, different researcher’s measures of the same data led to the same conclusions about articulation. In addition, it was found that the measurements of different researchers became more similar to one another with experience.