Effect of continuous speech and non-speech signals on stuttering frequency in adults who stutter.

The inhibitory effects of continuously presented audio signals (/a/, /s/, 1,000 Hz pure-tone) on stuttering were examined. Eleven adults who stutter participated. Participants read four 300-syllable passages (i.e. in the presence and absence of the audio signals). All of the audio signals induced a significant reduction in stuttering frequency relative to the control condition (P = 0.005). A significantly greater reduction in stuttering occurred in the /a/ condition (P < 0.05), while there was no significant difference between the /s/ and 1,000 Hz pure-tone conditions (P > 0.05). These findings are consistent with the notion that the percept of a second signal as speech or non-speech can respectively augment or attenuate the potency for reducing stuttering frequency.

The effects of frequency altered feedback on the reading processes of adults with reading disorders.

Various factors have been shown to influence the reading comprehension of reading disordered individuals including altered auditory feedback. This study investigated the influence of frequency altered feedback (FAF) on the reading comprehension and decoding accuracy of reading disordered and normal reading adults. Participants consisted of 30 college students with normal and disordered reading abilities. Percentage accuracy data was collected for both comprehension and decoding. Results indicate that FAF has an enhancing effect on the oral reading comprehension of reading disordered adults whereas it has a detrimental effect on the reading comprehension of normal reading adults. FAF had no effect on decoding accuracy for either group.

The effects of frequency altered feedback on reading comprehension abilities of normal and reading disordered children.

The effects of frequency altered feedback (FAF) on the reading comprehension levels and error types of normal children and children with reading disorders were examined. Participants read aloud third, sixth, and ninth grade level material in non-altered auditory feedback (NAF) and FAF conditions. Comprehension improved significantly when the reading disordered children read aloud under the FAF listening condition, regardless of the reading level. Significant differences did not occur in reading comprehension for the normal readers under NAF versus FAF conditions. Reading disordered children produced significantly more reading errors as compared to the normal reading children under the NAF listening condition. No significant difference was found in reading errors between groups when reading under FAF regardless of the reading level, suggesting that the FAF signal produced a facilitory effect on reading errors in the reading disordered children. Theoretically, the FAF signal may have activated those cortical regions responsible for the relationship that has been shown to exist between lexical encoding and decoding of verbal and written material, respectively.

The effects of mild traumatic brain injury on confrontation naming in adults.

PRIMARY OBJECTIVE: To compare confrontation-naming in adults with MTBI to a group of normal adults under increased processing load conditions. RESEARCH DESIGN: A randomized block, repeated measures design was used to examine confrontation-naming response latency and accuracy using a computerized experimental program. METHODS AND PROCEDURES: Twenty-four adults having sustained a MTBI (aged 18-53) and 24 age-matched controls named pictures from three levels of vocabulary as quickly and accurately as possible. All MTBI participants were assessed with the Scales of Cognitive Ability for Traumatic Brain Injury (SCATBI) for later comparison. MAIN OUTCOMES AND RESULTS: The results revealed a main effect of group ( p < or = 0.001) for the latency data and a group by vocabulary level interaction ( p = 0.043) for the accuracy data. No significant correlations were found between response latency and accuracy with performance on the SCATBI. Reaction time measures may reveal inefficiencies not tapped by traditional measures.

Choral reading with filtered speech: effect on stuttering.

This study investigated use of choral reading with filtered components of speech and whispered speech on the frequency of stuttering. Three passages read by a normal adult male were lowpass filtered with kneepoint frequencies at 100 Hz (approximate glottal source), 500 Hz (source and first formant), and 1 kHz (source and the first two formants). Along with a whispered passage, a normal passage, and a control condition, these stimuli were used in a repeated-measures design with 12 adult stutterers as they read passages while listening to one of the stimuli. Frequencies of stuttering in each condition were analyzed. The choral speech, the 500-Hz, the 1-kHz, and the whispered speech conditions all decreased the frequency of stuttering while the 100-Hz stimuli did not. It is suggested that articulatory events, chiefly the encoded speech output from the vocal tract, create effective cues and may induce fluent speech in people who stutter.

Influence of duration and location of pauses on comprehension of a temporarily ambiguous utterance in adults.

Despite the important influence of prosody on comprehension, it remains unclear how the individual parameters of prosody contribute to the process. Therefore, this study examined the magnitude of one prosodic cue, duration of the pause, that precipitates comprehension when the pause is located either early or late in an ambiguous phrase. Adults between the ages of 20 and 40 years (men: M = 27.9, SD = 4.1, women: M = 26.2, SD = 3.7) listened to a series of phrases and made a decision regarding the meaning of each phrase. Analysis of variance for repeated measures yielded main effects of location and duration of pause with an interaction of location by duration. When the pause was located early in the phrase, a longer pause was needed before adults selected the correct meaning. However, when the pause was located later in the phrase, a pause of much shorter duration was sufficient for accurate selection of the intended meaning. A difference in pause duration of 175 msec. was found between the two locations studied.

Say it with me: stuttering inhibited.

This study examined fluency enhancement in people who stutter via the concomitant presentation of silently mouthed visual speech. Ten adults who stutter recited memorized text while watching another speaker silently mouth linguistically equivalent and linguistically different material. Relative to a control condition, in which no concomitant stimulus was provided, stuttering was reduced by 71% in the linguistically equivalent condition versus only 35% in the linguistically different condition. Despite being an 'incomplete' second speech signal, visual speech possesses the capacity to immediately and substantially enhance fluency when it is linguistically equivalent to the intended utterance. It is suggested that fluency enhancement via concomitantly presented external speech is achieved through the extraction of relevant speech gestures from the external speech signal that compliment the intended production, thereby compensating for possible internal inconsistencies in the matching of speech codes in people who stutter. As visual speech perception relies on fewer redundant cues to demarcate the intended gestures, when used as an external stuttering inhibitor, higher degrees of linguistic equivalence seem to be necessary for optimal stuttering inhibition.

Voluntary stuttering suppresses true stuttering: a window on the speech perception-production link.

In accord with a proposed innate link between speech perception and production (e.g., motor theory), this study provides compelling evidence for the inhibition of stuttering events in people who stutter prior to the initiation of the intended speech act, via both the perception and the production of speech gestures. Stuttering frequency during reading was reduced in 10 adults who stutter by approximately 40% in three of four experimental conditions: (1) following passive audiovisual presentation (i.e., viewing and hearing) of another person producing pseudostuttering (stutter-like syllabic repetitions) and following active shadowing of both (2) pseudostuttered and (3) fluent speech. Stuttering was not inhibited during reading following passive audiovisual presentation of fluent speech. Syllabic repetitions can inhibit stuttering both when produced and when perceived, and we suggest that these elementary stuttering forms may serve as compensatory speech gestures for releasing involuntary stuttering blocks by engaging mirror neuronal systems that are predisposed for fluent gestural imitation.

A temporal window for the central inhibition of stuttering via exogenous speech signals in adults.

We explored a possible temporal window for central stuttering inhibition via exogenously presented speech signals. Thirteen adults who stutter were asked to read while listening to a continuous vowel /a/, or a repeating 1 s vowel /a/ followed by 1, 3 and 5 s silences. In all conditions, stuttering was significantly reduced. However, the continuous and 1 s repeating conditions showed the greatest reduction in stuttering relative to all other conditions. Furthermore, these conditions did not differ significantly from each other, suggesting a temporal window of at least 1 s for stuttering inhibition induced by a 1 s stimulus. We propose that exogenous speech signals provide an additional speech source that engages mirror neurons for 'on-line' stuttering inhibition during continous speech. Employing dual speech sources results in 'on-line' stuttering inhibition and continuous speech flow. In contrast, endogenous (single source) inhibitory techniques require speech flow to be interrupted and go 'off-line' to derive the mirror neuronal.

The influence of vocabulary age and spatial dimension on rapid picture naming in children with reading disorders.

The present study measured naming reaction times of normal and reading disordered (RD) children to a series of centrally presented picture stimuli of varying vocabulary age and spatial dimension. Results of the ANOVA on reaction times indicated significant interactions of Group x Dimension and Group x Vocabulary. Post hoc tests on the former interaction suggested that the feature of dimension differentially affected naming reaction times for the two groups. The control group produced faster naming reaction times to the three-dimensional pictures, while the reading disordered group was faster in naming two-dimensional stimuli. In the later interaction, the normal readers produced faster reaction times to the lower-level vocabulary. Although the same pattern of response was obtained for the reading disordered children, they were found to evidence a generalized slowing in their responses with a greater temporal difference occurring between the two levels of vocabulary. These findings suggest that children with reading disorders exhibit deficits in rapid lexical access of later acquired and more complex vocabulary.(1). As a result of this activity, the participant will be able to identify critical stimulus features of pictorial stimuli that effect rapid retrieval abilities. (2). As a result of this activity, the participant will be able to explain the individual subsystems and interactions of processes (Cascade Model) that characterize picture naming. (3). As a result of this activity, the participant will be able to differentiate between patterns of lexical access as a function of critical stimulus features, for children with reading disorders and normal reading abilities.

Can within-category naming identify subtle cognitive deficits in the mild traumatic brain-injured patient?

BACKGROUND: This investigation examined the effect of a speeded, computer-controlled task on detecting differences in latency and accuracy of within-category name generation in adults having sustained a mild traumatic brain injury (MTBI). METHODS: Twenty-four adults in acute recovery and 24 age-matched controls were instructed to view 72 pictures on a computer monitor, and then name another item belonging to the same category as the visual stimulus as quickly as possible. RESULTS: The MTBI group demonstrated significantly longer latencies (p < 0.001) and lower accuracy (p < 0.001) than the control group. Both groups displayed similar patterns of response, although the MTBI group produced significantly more perseverative errors (p < 0.001). No significant correlations were found between performance on the Scales of Cognitive Ability for Traumatic Brain Injury and response latency or accuracy. CONCLUSION: The MTBI group performed the task significantly slower and less accurately than controls. Reaction time measures may prove more sensitive than traditional assessment measures in detecting subtle difficulties.

Self-perceptions of speech language pathologists-in-training before and after pseudostuttering experiences on the telephone.

PURPOSE: This survey investigated the effect of 'pseudostuttering' experiences on self-perceptions of 29 female, graduate students enrolled in a graduate seminar in stuttering while in a programme of study to become professional speech language pathologists. METHOD: Perceptions of self prior to, and immediately after, participation in five scripted telephone calls that contained pseudostuttering were measured via a 25-item semantic differential scale. RESULTS: Participants perceived themselves as significantly more (p < 0.002) withdrawn, tense, avoiding, afraid, introverted, nervous, self-conscious, anxious, quiet, inflexible, fearful, shy, careless, hesitant, uncooperative, dull, passive, unpleasant, insecure, unfriendly, guarded, and reticent after their pseudostuttering telephone call experiences. CONCLUSIONS: Findings suggests that the pseudostuttering experiences have an impact on self-perceptions and that the experience of 'adopting the disability of a person who stutters' may provide insight as to the social and emotional impact of communicative failure. It is suggested that pseudostuttering exercises may be a valuable teaching tool for the graduate students, especially for those who do not stutter.

Self-contained in-the-ear device to deliver altered auditory feedback: applications for stuttering.

The design and operating characteristics of the first self-contained in-the-ear device to deliver altered auditory feedback is described for applications with those who stutter. The device incorporates a microdigital signal processor core that reproduces the high fidelity of unaided listening and auditory self-monitoring while at the same time delivering altered auditory feedback. Delayed auditory feedback and frequency-altered feedback signals in combination or isolation can be generated to the user in a cosmetically appealing custom in-the-canal and completely-in-the-canal design. Programming of the device is achieved through a personal computer, interface, and fitting software. Researchers and clinicians interested in evaluating persons who stutter outside laboratory settings in a natural environment and persons who stutter looking for an alternative or adjunct to traditional therapy options are ideal candidates for this technology. In both instances an inconspicuous ear level alternative to traditional body worn devices with external microphones and earphones is offered.

Stuttering frequency on content and function words in adults who stutter: a concept revisited.

This study investigated stuttering frequency as a function of grammatical word type (i.e., content and function). Ten adults who stutter participated. Participants recited aloud a list of 126 words consisting of an equal number of content and function words, which were presented individually and visually via a laptop computer. Each word belonged to a single grammatical category. Further, words were matched for initial sound and approximate number of syllables. The results indicated that adults who stutter exhibited significantly greater stuttering frequency on content words when presented in isolation (p = 0.018). It was conjectured that the responsible factor contributing to differences in stuttering frequency in adults who stutter resides in word frequency disparities between the two classes of words categories. That is, because the function words are limited in number and are used frequently, repeated use on the part of adults who stutter may lead to a generalized adaptation effect for function words and hence reduced stuttering frequency (as compared with content words).

Effect of delayed auditory feedback on normal speakers at two speech rates.

This study investigated the effect of short and long auditory feedback delays at two speech rates with normal speakers. Seventeen participants spoke under delayed auditory feedback (DAF) at 0, 25, 50, and 200 ms at normal and fast rates of speech. Significantly two to three times more dysfluencies were displayed at 200 ms (p<0.05) relative to no delay or the shorter delays. There were significantly more dysfluencies observed at the fast rate of speech (p = 0.028). These findings implicate the peripheral feedback system(s) of fluent speakers for the disruptive effects of DAF on normal speech production at long auditory feedback delays. Considering the contrast in fluency/dysfluency exhibited between normal speakers and those who stutter at short and long delays, it appears that speech disruption of normal speakers under DAF is a poor analog of stuttering.

The effect of dimension and vocabulary age on rapid picture naming in children.

UNLABELLED: This investigation involved measures of the reaction times of normally developing children who were asked to name a series of centrally presented picture stimuli of varying vocabulary age and dimension. Results of the ANOVA on reaction times indicated a significant main effect of vocabulary level and an interaction of Dimension x Vocabulary level for the normally developing children. Post-hoc tests showed significant differences between two- and three-dimensional pictures for higher-level vocabulary items, but not for lower-level vocabulary items. This finding indicates that central operations involved in picture naming are influenced differentially by the physical characteristics of the stimulus items. The finding that two-dimensional higher-level vocabulary items were associated with significantly longer reaction times than the three-dimensional higher-level vocabulary suggests that dimensionality may be a critical feature for rapid lexical access for higher-level picture vocabulary. Clinically, the employment of three-dimensional forms may facilitate access to stored visual object memory for advanced levels of picture vocabulary. LEARNING OUTCOMES: As a result of this activity, participants will be able to (1) identify the various visual and verbal processes involved in the naming of pictures; and (2) understand the influence of physical characteristics of pictures on reaction time in rapid naming tasks.