Pause and utterance durations and fundamental frequency characteristics of repeated oral readings by stutterers and nonstutterers

Effects of repeated oral readings on durational and fundamental frequency characteristics and number and kinds of reading errors were investigated in 11 stutterers and 11 sex- +and age-matched nonstutterers. Computer analysis of durational and fundamental frequency characteristics of the first and sixth readings demonstrated statistically significant differences in mean pause duration, speaking-time ratio, and total speaking time between the stutterers and the nonstutterers. In addition, there were significant differences in mean utterance duration and number of utterances (and pauses) between the first and sixth readings. Finally, correlational analyses indicated variable performance in the stutterers whereas the nonstutterers demonstrated highly consistent performance between the first and sixth readings. Results of reading error analysis showed more and different types of reading errors by the stutterers in comparison to the nonstutterers although both groups demonstrated a reduction in reading errors from the first to the sixth readings.     

Timing and stiffness in speech motor control of stuttering and nonstuttering adults

Twelve stutterers and 12 nonstutterers were investigated in order to measure speech movements of the jaw. They spoke the nonsense word /papapas/ with stress on either the first or second syllable and with three speech rates (fast, moderate, and slow). During these trials, jaw movements were analyzed with a selspot-like optical tracking system. It was shown that stutters and nonstutterers applied the same strategies for realizing jaw movements of accented and unaccented syllables. The first strategy (stiffness variation) was used to achieve fast jaw movements while the second strategy (timing) was used in order to realize jaw movements for accented syllables. These results were taken as evidence for the assumption that, in general, stutterers and nonstutterers used the same control strategies when speaking fluently. However, it was also evident that stutterers produced lengthened jaw opening and closing durations as well as reduced peak velocities and maximal opening and closing displacements. This deviating movement pattern was supposed to reflect motor compensations necessary to achieve fluent speech rather than anomalies of the speech neuromotor system.     

词频与阅读方式对词跨行呈现效应的影响

通过使用眼动追踪技术,采用2（呈现条件：同行呈现、跨行呈现）×2（词频：高频、低频）×2（阅读方式：朗读、默读）的被试内实验设计,探讨了词频和阅读方式对词跨行呈现效应的影响。结果发现,呈现条件、词频和阅读方式的主效应显著,跨行呈现、低频和朗读的凝视时间和总注视时间更长、总注视次数更多;呈现条件之间在凝视时间上的差异,高频词大于低频词;呈现条件之间在凝视时间和总注视次数上的差异,朗读大于默读。结果表明,词跨行呈现干扰了阅读,且这种干扰作用受词频和阅读方式的影响。     

Attention and stuttering: Do stutterers think too much about speech?

In this investigation the ability of stutterers and nonstutterers to simultaneously perform speech and nonspeech tasks was compared. Subjects were 10 stutterers and 10 nonstutterers. Two experiments were conducted. In the first, subjects performed a non-attention-demanding gross-motor task while they read aloud. In the second, subjects performed an attention-demanding task (reading comprehension) during speech. Results indicated that there was no significant change in the disfluency values of stutterers during the motor activity or as a result of the reading comprehension task. However, stutterers were found to perform significantly poorer than nonstutterers on the reading comprehension task. This finding was taken as evidence that stutterers devote more attention to speech than do nonstutterers.     

fMRI of developmental stuttering: a pilot study

The purpose of this investigation was to explore the feasibility of fMRI in the study of developmental stuttering. Speech contrasts (loud versus silent reading) and language contrasts (reading of semantically meaningful text versus nonsense words) of six developmental stutterers and six nonstutterers were compared using a commercial 1 Tesla MR-Scanner (Siemens Expert). Results indicate that mapping cortical function in persons who stutter is indeed feasible, even with a 1TMR-system. Compared to normals the stutterers seemed to employ different and particularly less differentiated auditory and motor feedback strategies in speech. They apparently rely on auditory processing and on cerebellar contribution as much during silent reading as during reading aloud. Moreover, they showed a greater involvement of the right hemisphere in language processing, activating not only the typical language areas on the left but also and with equal magnitude the right side homologues of these areas. In spite of the promising results, at present several practical problems such as possible movement artifacts and possible masking through scanner noise still hamper a more straightforward use of fMRI in the study of developmental stuttering.     

Variability in the initiation of articulatory movements in the speech of stutterers and normal speakers

This study was designed to investigate the differences between stutterers and normal speakers in phonatory and articulatory timing during the initiation of fluent utterances of monosyllabic words. Electromyographic recordings of four articulatory muscles and recordings of glottal vibrations were made of repetitive utterances of a series of monosyllabic words by 15 stutterers and 17 nonstutterers. These data were analyzed in terms of average interval times between voice onset and onset of EMG activity and between onset of EMG activity in each articulator and in terms of the intrasubject variability of these durational measures. Results showed that there were no significant differences between stutterers and nonstutterers in average interval times and that stutterers, in general, were significantly more variable in their speech onset timing. Findings are discussed in terms of recent hypotheses concerning the role of timing disturbances as the main source of speech disruption in stutterers.     

Effect of threat of shock for being disfluent of fluency of normal speakers.

Each of 20 adult nonstutterers read a 330-word passage six times with a one minute pause between readings. Between the third and fourth reading or the fifth and sixth reading (determined by a table of random numbers) Ss were informed that at the conclusion of the next reading an electric shock would be administered for each instance of disfluency detected by E during that reading. Ss did not become less fluent as a consequence of the experimental condition. Their mean disfluency frequency during the threat-of-shock reading was lower than during the preceding one. Thus, threat of shock for being disfluent may be a condition which differentiates stutterers from nonstutterers since stutterers have been reported to become less fluent under this condition.     

Stuttering and syllable stress

Eighteen adult stutterers read two lists each of 16 bisyllabic words. In one list, stress appeared on the first syllable; in the second, the “same” words carried second syllable stress. There proved to be no significant difference in proportion between stressed and unstressed syllables associated with stuttering. This investigation appears to dispute the proposition that stressed syllables provide the focal points of stuttering (Wingate, 1976).     

Syllabic tone articulation influences the identification and use of words during Chinese sentence reading: Evidence from ERP and eye movement recordings

In two experiments, we examined the contribution of articulation-specific features to visual word recognition during the reading of Chinese. In spoken Standard Chinese, a syllable with a full tone can be tone-neutralized through sound weakening and pitch contour change, and there are two types of two-character compound words with respect to their articulation variation. One type requires articulation of a full tone for each constituent character, and the other requires a full- and a neutral-tone articulation for the first and second characters, respectively. Words of these two types with identical first characters were selected and embedded in sentences. Native speakers of Standard Chinese were recruited to read the sentences. In Experiment 1, the individual words of a sentence were presented serially at a fixed pace while event-related potentials were recorded. This resulted in less-negative N100 and anterior N250 amplitudes and in more-negative N400 amplitudes when targets contained a neutral tone. Complete sentences were visible in Experiment 2, and eye movements were recorded while participants read. Analyses of oculomotor activity revealed shorter viewing durations and fewer refixations on—and fewer regressive saccades to—target words when their second syllable was articulated with a neutral rather than a full tone. Together, the results indicate that readers represent articulation-specific word properties, that these representations are routinely activated early during the silent reading of Chinese sentences, and that the representations are also used during later stages of word processing.     

Prosodic phonological representations early in visual word recognition

Two experiments examined the nature of the phonological representations used during visual word recognition. We tested whether a minimality constraint (R. Frost, 1998) limits the complexity of early representations to a simple string of phonemes. Alternatively, readers might activate elaborated representations that include prosodic syllable information before lexical access. In a modified lexical decision task (Experiment 1), words were preceded by parafoveal previews that were congruent with a target's initial syllable as well as previews that contained 1 letter more or less than the initial syllable. Lexical decision times were faster in the syllable congruent conditions than in the incongruent conditions. In Experiment 2, we recorded brain electrical potentials (electroencephalograms) during single word reading in a masked priming paradigm. The event-related potential waveform elicited in the syllable congruent condition was more positive 250-350 ms posttarget compared with the waveform elicited in the syllable incongruent condition. In combination, these experiments demonstrate that readers process prosodic syllable information early in visual word recognition in English. They offer further evidence that skilled readers routinely activate elaborated, speechlike phonological representations during silent reading.     

Adaptation effect in nonfluent speech behavior of controlled stutterers and nonstutterers

The adaptation effect in stuttering behavior has received considerable attention. Adaptation effect is defined as the reduction in the frequency of nonfluencies in the speech of subjects during successive readings of the same passage. The objective of this investigation was to assess the adaptation effect of nonfluent speech behavior of controlled stutterers and nonstutterers. The subjects included 35 controlled stutterers and 35 nonstutterers matched for factors of sex, grade level, and age. Results suggest a significant mean difference between the number of nonfluencies between trials of controlled stutterers with evidence of adaptation in the speech of nonstutterers. Nonstutterers demonstrate significant mean differences in nonfluencies among replicated testing occasions. Findings of this investigation suggest that both controlled stutterers and nonstutterers demonstrate similar adaptation regarding their nonfluent speech behavior. Issues and import for future research are offered.     

Sequential effects of phonological priming in visual word recognition

Two masked priming experiments were conducted to examine phonological priming of bisyllabic words in French, and in particular, whether it operates sequentially or in parallel. Bisyllabic target words were primed by pseudowords that shared either the first or the second phonological syllable of the target. Overlap of the first syllable only-not the second-produced facilitation in both the lexical decision and the naming tasks. These findings suggest that, for polysyllabic words, phonological codes are computed sequentially during silent reading and reading aloud.     

Speech and bimanual hand organization in adult stutterers and nonstutterers

A multivariate approach was used to investigate the relationship between speech fluency and bimanual handwriting in right-handed male stutterers and nonstutterers. Handedness was determined by the Harris Test of Lateral Dominance. Subjects were required to write the numbers 1 through 12 simultaneously, as quickly as possible. Speech measures were derived from the Stuttering Severity Instrument and from a reading passage. Stutterers performed more poorly than nonstutterers on all speech measures. There were no differences in bimanual handwriting performance for the dominant hand. However, stutterers performed more poorly than nonstutterers in nondominant handwriting. There were no relationships between speech measures and bimanual handwriting for stutterers or nonstutterers. Some stutterers performed better on the handwriting task than did some nonstutterers. It is suggested that disorganization in interhemispheric integration functions may be a more fundamental problem in stuttering than is incomplete cerebral dominance.     

The effect of metronome pacing on selected aerodynamic patterns of stuttered speech: Some preliminary observations and interpretations

The purpose of this investigation was to provide some preliminary data regarding the effects of metronome pacing on physiological aspects of speech during stuttering. Five aerodynamic measures were chosen as dependent variables: (a) peak intraoral air pressure, (2) intraoral air pressure onset duration, (3) intraoral air pressure offset duration, (4) total intraoral air pressure duration, and (5) peak air flow rate. Five adult stutterers and five adult nonstutterers read a prose passage containing 12 English consonants, each in three syllable-initial stressed positions, during a control condition and experimental condition. In the experimental condition the subjects read the passage while synchronizing one word per beat at 60 beats per minute. The results demonstrated that both stutterers and normals evidenced lower peak pressures and greater pressure durations during metronome pacing. Air flow rates increased for normal subjects and decreased for stutterers in the experimental condition. Dysfluencies recorded during the control condition were observed to have much more rapid intraoral air pressure onsets when compared with fluent counterparts in the experimental reading. These results were interpreted with reference to Wingate's (1969) modified vocalization hypothesis and Van Riper's (1971) altered timing concept.     

A dual-task investigation of young stutterers and nonstutterers

Twenty right-handed grade-school stutterers and nonstutterers matched for sex, handedness, and age were the subjects of this neuromotor investigation. They were required to tap a button as rapidly as possible in a single-task control condition, in three increasingly demanding dual-task conditions in which finger-tapping and speech occured concurrently, and in a dual-task condition in which the subjects finger-tapped and vocalized the sound of a siren. The conditions were randomized, and hand order was counterbalanced. The overall tapping rate of the nonstutterers was statistically faster than that of the stutterers for both the right and left hand. Relative to the single-task silent control condition, the tapping rates of both groups decreased as the dual-task speech conditions became more demanding. However, the tapping rate of the nonstutterers was significantly faster across the speech conditions. Neither the group by hand, group by condition, or group by hand by condition interaction was statistically significant. The stutterers responded like the nonstutterers, though more slowly, providing support for the current contentions that the neuromotor system of stutterers is less robust than that of nonstutterers and more affected by the demands of speech production.     

Dichotic speech perception: A comparison between stuttering and nonstuttering children

A stop consonant-vowel dichotic listening task was administered to 90 right- handed boys, 30 in each age group of 5, 7, and 9 yr. Half in each group were stutterers, half nonstutterers. Two and a half times as many stutterers as nonstutterers were found to display either a left-ear advantage (LEA) or no ear advantage (NEA). This finding suggested a greater tendency on the part of stutterers, as opposed to nonstutterers, for reversed or bilateral representation of the auditory speech areas of the brain. In addition, both stutterers and nonstutterers displayed significant developmental increases in the number of times they were able to identify both dichotic speech stimuli, thereby supporting the hypothesis of an age-related increase in children's total information processing capacity. The results are discussed in terms of the differences between stutterers and nonstutterers with respect to the issues of motor representation, cognitive modes, and higher-order linguistic processes.     

EFFECTS OF RESPONSE AND TRIAL REPETITION ON SIGHT-WORD TRAINING FOR STUDENTS WITH LEARNING DISABILITIES

Alternating treatments designs were used to compare the effects of trial repetition (one response within five trials per word) versus response repetition (five response repetitions within one trial per word) on sight-word acquisition for 3 elementary students diagnosed with specific learning disabilities in reading. Although both interventions occasioned the same number of accurate responses per word during training, the trial-repetition condition, which involved complete antecedent-response-feedback sequences, resulted in more words mastered for all 3 students.     

Voice reaction time of stuttering and nonstuttering children and adults

The voice reaction time (VRT) of 5-yr old, 9-yr old, and adult stutterers and nonstutterers was investigated. Subjects initiated the sound / Λ / in response to fifty-five 1000-Hz tones of 1 sec duration. The tones were presented in five equal sets of 11 tones each with the silent intervals between the tones randomly selected to be 3, 4, 5, or 6 sec. Data analysis was based on responses 2–11 for each set. The VRTs for both the stutterers and the nonstutterers decreased significantly as an inverse function of age, with the largest decrease in reaction time occuring between 5 and 9 yr. The VRTs for the stutterers, however, were significantly slower than those of the nonstutterers at each of the three age levels. The results suggest that observed disruption in the laryngeal behavior for at least some stutterers may not result from the development of stuttering with age, but may contribute to early difficulty in the child's ability to produce fluent speech. Consideration of central factors are discussed.     

Reading strategies in orthographies of intermediate depth are flexible: Modulation of length effects in Portuguese

This paper examines the role of grapheme–phoneme conversion for skilled reading in an orthography of intermediate depth, Portuguese. The effects of word length in number of letters were determined in two studies. Mixed lists of five- and six-letter words and nonwords were presented to young adults in lexical decision and reading aloud tasks in the first study; in the second one, the length range was increased from four to six letters and an extra condition was added where words and nonwords were presented in separate, or blocked, lists. Reaction times were larger for longer words and nonwords in lexical decision, and in reading aloud mixed lists, but no effect of length was observed when reading words in blocked lists. The effect of word length is thus modulated by list composition. This is evidence that grapheme–phoneme conversion is not as predominant for phonological recoding in intermediate orthographies as it is in shallow ones, and suggests that skilled reading in those orthographies is highly responsive to tasks conditions because readers may switch from smaller segment-by-segment decoding to larger unit or lexicon-related processing.     

Effects of phonological similarity and concurrent irrelevant articulation on short-term-memory recall of repeated and novel word lists

The extent to which phonological similarity of list words impairs short-term-memory recall was investigated in two experiments. Experiment 1 showed that the phonological-similarity effect occurred both when list words were repeatedly sampled from a small set and when they were new on every trial, both when word-order information was required and when it was not. Furthermore, the adverse effect of phonological similarity on recall was apparent on the initial lists recalled, did not change over trials, and cannot be attributed to increasing levels of proactive inhibition across lists. In Experiment 2, subjects were required to count repeatedly to six during list presentation. Concurrent irrelevant articulation lowered recall and abolished the phonological similarity effect for both repeated and novel word lists.