Suppression of normal speech disfluencies through response cost

The speech disfluencies of five normal-speaking college students were modified in a series of 10 to 17 sessions by means of response cost. During Point-loss, each disfluency (repetition or interjection of a sound, syllable, word, etc.) resulted in the loss of a penny, as indicated on a screen in front of the subject. Disfluencies were suppressed and kept at very low levels for four of the subjects during the punishment procedures, and there was general resistance to extinction. Even though points were subtracted only during speech, there was a tendency for disfluencies to decrease, though not as markedly, during reading probes as well.     

Teaching speech sounds to young children using randomly ordered, variably complex task sequences

Three children, ages 4:8 to 5:11, were taught a speech sound using a randomly ordered variably complex task sequence (concurrent treatment), in which practice occurred in randomized easy-to-hard tasks. In an AB research design replicated across participants, the children quickly advanced to 60% accurate productions of the target speech sound and displayed generalization to untaught tasks.     

Using auditory feedback to improve striking for mixed martial artists

The purpose of this study was to evaluate auditory feedback to increase the effectiveness of throwing a “right cross.” Auditory feedback, implemented by the mixed martial arts coach, was evaluated in multiple baselines across participants design with four mixed martial arts students, two males and two females, 25–54 years old. The target behavior was the percentage of correct steps in the 20‐step task analysis of throwing a right cross. In the auditory feedback procedure, the coach used a handheld clicker and make the clicking sound as a reinforcer each time the participant performed a specific step in the task analysis correctly. This process continued until all steps were performed correctly. The percentage of correct steps of the right cross improved substantially during assessment sessions following the introduction of the auditory feedback and maintained at 90% or more for all participants during follow‐up. Improvements were also noted in the social validity assessment.     

Training Japanese listeners to identify English /r/ and /l/: long-term retention of learning in perception and production.

Previous work from our laboratories has shown that monolingual Japanese adults who were given intensive high-variability perceptual training improved in both perception and production of English /r/-/l/ minimal pairs. In this study, we extended those findings by investigating the long-term retention of learning in both perception and production of this difficult non-native contrast. Results showed that 3 months after completion of the perceptual training procedure, the Japanese trainees maintained their improved levels of performance of the perceptual identification task. Furthermore, perceptual evaluations by native American English listeners of the Japanese trainees' pretest, posttest, and 3-month follow-up speech productions showed that the trainees retained their long-term improvements in the general quality, identifiability, and overall intelligibility of their English/r/-/l/ word productions. Taken together, the results provide further support for the efficacy of high-variability laboratory speech sound training procedures, and suggest an optimistic outlook for the application of such procedures for a wide range of "special populations."     

Gestural overlap in consonant clusters: effects on the fluent speech of stuttering and non-stuttering subjects

This study was designed to investigate if persons who stutter differ from persons who do not stutter in the coproduction of different types of consonant clusters, as measured in the number of dysfluencies and incorrect speech productions, in speech reaction times and in word durations. Based on the Gestural Phonology Model of Browman and Goldstein, two types of consonant clusters were formed: homorganic and heterorganic clusters, both intra-syllabic (CVCC) and inter-syllabic (CVC#CVC). Overall, the results indicated that homorganic clusters elicited more incorrect speech productions and longer reaction times than the heterorganic clusters, but there was no difference between the homorganic and the heterorganic clusters in the word duration data. Persons who stutter showed a higher percentage dysfluencies and a higher percentage incorrect speech productions than PWNS but there were no main group effects in reaction times and word durations. However, there was a significant three-way interaction effect between group, cluster type and cluster place: homorganic clusters elicited longer reaction times than heterorganic clusters, but only in the inter-syllabic condition and only for persons who stutter. These results suggest that the production of two consonants with the same place of articulation across a syllable boundary puts higher demands on motor planning and/or initiation than producing the same cluster at the end of a syllable, in particular for PWS. The findings are discussed in light of current theories on speech motor control in stuttering. EDUCATIONAL OBJECTIVES: The reader will be able to describe: (1) the effect of gestural overlap between consonant clusters on speech reaction time and word duration of people who do and do not stutter and be able to (2) identify the literature in the field of gestural overlap between consonant clusters.     

I: Effect of delayed auditory feedback on speech and keytapping

The effects of delayed auditory feedback (DAF) on the performance of simple speech and keytapping tasks were compared. In the first experiment, each of the fourteen young adult subjects was asked to repeat the speech sound “b” in groups of three sounds. The subject heard his undelayed speech sounds through earphones. Under the delay condition, the speech sounds were delayed 244 millisec. before being returned to the subject's earphones. In the second experiment, each of the same subjects was asked to tap on a key in groups of three taps. The subjects heard an undelayed click through earphones each time they tapped on the key. Under the delay condition, the clicks were delayed 244 millisec. before being returned to the earphones. Graphic recordings were made of the time and intensity characteristics of tapping under both conditions.

The changes which occurred in speech and keytapping under DAF were qualitatively the same and consisted of increases in intensity and unit-to-unit time of both taps and speech sounds. When performing under DAF, the subjects also exhibited a tendency to repeat more sounds or to tap more times than had been requested. The percentage of change in intensity and time characteristics for speech and keytapping performances which occurred under DAF were not significantly different for the two motor systems. The amount of change in speech performance under DAF did not correlate significantly with the amount of change in keytapping performance.     

A unified account of categorical effects in phonetic perception

Categorical effects are found across speech sound categories, with the degree of these effects ranging from extremely strong categorical perception in consonants to nearly continuous perception in vowels. We show that both strong and weak categorical effects can be captured by a unified model. We treat speech perception as a statistical inference problem, assuming that listeners use their knowledge of categories as well as the acoustics of the signal to infer the intended productions of the speaker. Simulations show that the model provides close fits to empirical data, unifying past findings of categorical effects in consonants and vowels and capturing differences in the degree of categorical effects through a single parameter.     

Test Review: Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV)

Objective: Evaluate neuropsychological functioning in children with non-syndromic cleft of the lip and/or palate (NSCL/P) through profile variance within type of cleft and comparisons to controls.

Methods: Children ages 7 to 17 years participated; 66 had a diagnosis of NSCL/P and 87 were healthy controls. Neuropsychological tests of language, visual-perceptual, executive functioning, and memory skills were administered. Between- and within-group differences were assessed.

Results: Within cleft types, children with NSCLP had an even profile with equal Verbal and Performance IQ (VIQ and PIQ, respectively). Children with non-syndromic cleft palate only (NSCP) had significantly lower VIQ than PIQ, while children with non-syndromic cleft lip only (NSCL) showed a nonsignificant trend for higher VIQ than PIQ. Overall, subjects with NSCL/P performed lower on measures of expressive language and verbal memory than controls.

Conclusions: While deficits in verbal and memory skills for children with NSCL/P remain apparent, there is still uncertainty around the possible influence of cleft type on the pattern of deficits.     

Effect of exteroceptive feedback in controlling electrodermal activity in pre-conditioned fears.

Ss with a strong fear of snakes were taught to increase and decrease their skin resistance during practice sessions with a continuous visual display. Ss were not aware that they were increasing or decreasing their levels of skin resistance and attempted only to influence the magnitude of the multimeter display, the polarity of which was controlled by the experimenter. The study used a within-subjects reversal design to investigate whether bidirectional control could be acquired over skin resistance level. To investigate whether this acquired control could affect the magnitude of elicited pre-conditioned autonomic responses, a pre- and post-training comparison was made between the GSRs elicited during test sessions in which Ss viewed slides of snakes while attempting to influence their electrodermal activity with the assistance of the visual display. The results suggest that Ss are able to acquire voluntarily bidirectional control of their level of skin resistance with continuous visual feedback and that this control can either depress or facilitate the magnitude of pre-conditioned emotional responses as a function of visual feedback.     

NMDA receptor blockade in the basolateral amygdala disrupts consolidation of stimulus-reward memory and extinction learning during reinstatement of cocaine-seeking in an animal model of relapse

Previous research from our laboratory has implicated the basolateral amygdala (BLA) complex in the acquisition and consolidation of cue-cocaine associations, as well as extinction learning, which may regulate the long-lasting control of conditioned stimuli (CS) over drug-seeking behavior. Given the well established role of NMDA glutamate receptor activation in other forms of amygdalar-based learning, we predicted that BLA-mediated drug-cue associative learning would be NMDA receptor dependent. To test this hypothesis, male Sprague-Dawley rats self-administered i.v. cocaine (0.6 mg/kg/infusion) in the absence of explicit CS pairings (2-h sessions, 5 days), followed by a single 1-h classical conditioning (CC) session, during which they received passive infusions of cocaine discretely paired with a light+tone stimulus complex. Following additional cocaine self-administration sessions in the absence of the CS (2-h sessions, 5 days) and extinction training sessions (no cocaine or CS presentation, 2-h sessions, 7 days), the ability of the CS to reinstate cocaine-seeking on three test days was assessed. Rats received bilateral intra-BLA infusions (0.5 microl/hemisphere) of vehicle or the selective NMDA receptor antagonist, 2-amino-5-phosphonovalerate (AP-5), immediately prior to the CC session (acquisition), immediately following the CC session (consolidation), or immediately following reinstatement testing (consolidation of conditioned-cued extinction learning). AP-5 administered before or after CC attenuated subsequent CS-induced reinstatement, whereas AP-5 administered immediately following the first two reinstatement tests impaired the extinction of cocaine-seeking behavior. These results suggest that NMDA receptor-mediated mechanisms within the BLA play a crucial role in the consolidation of drug-CS associations into long-term memories that, in turn, drive cocaine-seeking during relapse.     

Faded Versus Increasing Feedback,Task Variability Trajectories,and Transfer of Training

We assessed the merit of the advice given in the literature to fade feedback over the course of training because it was not based on solid research evidence. In a transfer experiment, we compared the effects of faded versus increasing feedback-provided guidance over the course of training on performers' task variability patterns and the subsequent transfer of effective responses to different task conditions. We found that faded feedback led to a rapid change in the percentage of favorable (vs. unfavorable) task conditions experienced over the course of training, which facilitated the transfer of effective responses to favorable task conditions. Alternatively, increasing feedback-provided guidance resulted in a gradual increase in the percentage of favorable (vs. unfavorable) task conditions experienced over the course of training and more balanced exposure to different task conditions. This facilitated the transfer of effective responses to unfavorable task conditions and more equal transfer of effective responses to favorable and unfavorable task conditions. The results indicated that recommendations to fade feedback over training need to be qualified and have implications for the design of feedback interventions used in training and other developmental activities.     

Effect of reading with reversed speech on frequency of stuttering in adults

This study explored the effect of reading with reversed speech on the frequency of stuttering. Eight adults who stutter served as participants and read four 300-syllable passages while listening to three types of speech stimuli: normal speech (choral reading), reversed speech at normal speed, reversed speech at half speed, and a control condition of no auditory feedback. A repeated-measures analysis of variance showed a significant decrease in stuttering frequency in the choral reading condition but not in reversed speech at normal and half speed. However, the reversed speech at half-speed condition showed a large effect size (omega2 = 0.32). Data suggest that a forward moving speech feedback is not essential to decrease the frequency of stuttering in adults who stutter.     

Reinforcing effects of prerecorded words and delayed speech feedback on the verbal behavior of a neologistic schizophrenic

The possibility of using prerecorded words and 2-sec. delayed speech feedback as reinforcement in the reconditioning of intelligible verbal responses in a chronic, neologistic schizophrenic patient was investigated. A test situation was devised which involved daily presentation of 100 stimulus word-picture cards to elicit verbal responses. The results indicated that both singly presented prerecorded words and delayed speech feedback apparently strengthened correct and intelligible verbal responding.     

Speech clarity/intelligibility: test-retest reliability of magnitude-estimation scaling

The reliability of magnitude-estimation scaling as a measure of overall clarity of speech was investigated. 40 subjects (M age = 19 yr.) provided magnitude-estimation responses for nine audiotaped versions of a nonsense sentence varying systematically in number of correct consonant phonemes. There was no significant difference in the magnitude-estimation responses of the subjects during two test sessions separated by one week. Analysis suggested that magnitude-estimation scaling is a reliable measure of speech clarity/intelligibility. This finding is discussed in relation to speech samples varying in aspects other than number of consonant phonemes correct and possible further clinical research applications.     

Learning foreign sounds in an alien world: videogame training improves non-native speech categorization

Although speech categories are defined by multiple acoustic dimensions, some are perceptually weighted more than others and there are residual effects of native-language weightings in non-native speech perception. Recent research on nonlinguistic sound category learning suggests that the distribution characteristics of experienced sounds influence perceptual cue weights: Increasing variability across a dimension leads listeners to rely upon it less in subsequent category learning (Holt & Lotto, 2006). The present experiment investigated the implications of this among native Japanese learning English /r/-/l/ categories. Training was accomplished using a videogame paradigm that emphasizes associations among sound categories, visual information, and players' responses to videogame characters rather than overt categorization or explicit feedback. Subjects who played the game for 2.5h across 5 days exhibited improvements in /r/-/l/ perception on par with 2-4 weeks of explicit categorization training in previous research and exhibited a shift toward more native-like perceptual cue weights.     

Adaptation to delayed auditory feedback

Delayed auditory feedback disrupts the production of speech, causing an increase in speech duration as well as many articulatory errors. To determine whether prolonged exposure to delayed auditory feedback IDAFI leads to adaptive compensations in speech production, 10 subjects were exposed in separate experimental sessions to both incremental and constantdelay exposure conditions. Significant adaptation occurred for syntactically structured stimuli in the form of increased speaking rates. After DAF was removed, aftereffects were apparent for all stimulus types in terms of increased speech rates. A carry-over effect from the first to the second experimental session was evident as long as 29 days after the first session. The use of strategies to overcome DAF and the differences between adaptation to DAF and adaptation to visual rearrangement are discussed.     

Inappropriate speech in a severely retarded child: a case study in language conditioning and generalization

The modification of inappropriate speech, a class of behaviors rather than a limited number of specific examples, is little known in the severely retarded. In this study, operant techniques were used to modify the strikingly bizarre and inappropriate speech of a severely retarded boy. The boy's appropriate verbal responses to questions about magazine pictures were reinforced with candy. When he responded inappropriately, the magazine was withdrawn, and social interaction was discontinued for a 10-sec timeout period. Negative responses were ignored, the next picture displayed, and the next question asked immediately. In 10 sessions, appropriate responses increased from 26% to 86% of all responses. A reversal of reinforcement was then introduced, in which inappropriate responses were reinforced, appropriate responses resulted in timeout, and negative responses were treated as before. This reduced the percentage of appropriate responses to 24%. Subsequent sessions of reinforcement for appropriate responses increased appropriate responses to 96% of all responses. At significant stages in the experiment, a measure of possible generalization was attempted. Although some generalization was recorded, it was minimal: some explanations are discussed.     

A phonetic approach to consonant repetition in early words

The goal of this study was to evaluate movement-based principles for understanding early speech output patterns. Consonant repetition patterns within children's actual productions of word forms were analyzed using spontaneous speech data from 10 typically developing American-English learning children between 12 and 36 months of age. Place of articulation, word level patterns, and developmental trends in CVC and CVCV repeated word forms were evaluated. Labial and coronal place repetitions dominated. Regressive repetition (e.g., [gag] for “dog”) occurred frequently in CVC but not in CVCV word forms. Consonant repetition decreased over time. However, the children produced sound types available reported as being within young children's production system capabilities in consonant repetitions in all time periods. Findings suggest that a movement-based approach can provide a framework for comprehensively characterizing consonant place repetition patterns in early speech development.     

Systematic studies of modified vocalization: speech production changes during a variation of metronomic speech in persons who do and do not stutter

The most common way to induce fluency using rhythm requires persons who stutter to speak one syllable or one word to each beat of a metronome, but stuttering can also be eliminated when the stimulus is of a particular duration (e.g., 1 second [s]). The present study examined stuttering frequency, speech production changes, and speech naturalness during rhythmic speech that alternated 1 s of reading with 1 s of silence. A repeated-measures design was used to compare data obtained during a control reading condition and during rhythmic reading in 10 persons who stutter (PWS) and 10 normally fluent controls. Ratings for speech naturalness were also gathered from naïve listeners. Results showed that mean vowel duration increased significantly, and the percentage of short phonated intervals decreased significantly, for both groups from the control to the experimental condition. Mean phonated interval length increased significantly for the fluent controls. Mean speech naturalness ratings during the experimental condition were approximately “7” on a 1–9 scale (1 = highly natural; 9 = highly unnatural), and these ratings were significantly correlated with vowel duration and phonated intervals for PWS. The findings indicate that PWS may be altering vocal fold vibration duration to obtain fluency during this rhythmic speech style, and that vocal fold vibration duration may have an impact on speech naturalness during rhythmic speech. Future investigations should examine speech production changes and speech naturalness during variations of this rhythmic condition.Educational objectives: The reader will be able to: (1) describe changes (from a control reading condition) in speech production variables when alternating between 1 s of reading and 1 s of silence, (2) describe which rhythmic conditions have been found to sound and feel the most natural, (3) describe methodological issues for studies about alterations in speech production variables during fluency-inducing conditions, and (4) describe which fluency-inducing conditions have been shown to involve a reduction in short phonated intervals.