Impairment of temporal organization of speech in basal ganglia diseases.

Absolute and relative speech timing were examined in patients suffering from Parkinson's, Huntington's, and Wilson's disease. The task was to speak a standard sentence 10 times, first slowly, and then successively faster up to maximum rate. All patient groups had low maximal speech rates and showed decreased variability of speech rate. The duration of pauses between words was the same as in normals and the relative time structure of the test sentence was basically preserved. For comparison, two cases with nonfluent aphasia had even slower speech rates, large increases in pause duration, and major changes in relative speech timing. The results show the same type of alterations of the temporal organization of speech as those characteristic for rapid alternating limb movements in such patients. They support the view that the speech and skeletomotor systems share common neural control modes despite fundamental biomechanical differences. The common denominator between the speech and the skeletomotor disturbances in basal ganglia diseases may be the undamping and slowing of a fast central oscillator.     

A technique for measuring processing load during speech production

A technique is presented for the measurement of fluctuations in processing demands during spontaneous speech. The technique consists of the analysis of errors on a secondary tracking task. Data are presented from illustrative samples of spontaneous speech; thus, evidence was found to suggest that one level of planning in speech is clauses that contain a single main verb. Evidence was also obtained that there is an increase in processing demands at the gap in subject relative and object relative clauses. It is concluded that the secondary tracking task is a useful technique that could be extended to studies of reading and speech comprehension.     

非言语声音影响汉语听者言语声音的知觉

采用启动范式, 以汉语听者为被试, 考察了非言语声音是否影响言语声音的知觉。实验1考察了纯音对辅音范畴连续体知觉的影响, 结果发现纯音影响到辅音范畴连续体的知觉, 表现出频谱对比效应。实验2考察了纯音和复合音对元音知觉的影响, 结果发现与元音共振峰频率一致的纯音或复合音加快了元音的识别, 表现出启动效应。两个实验一致发现非言语声音能够影响言语声音的知觉, 表明言语声音知觉也需要一个前言语的频谱特征分析阶段, 这与言语知觉听觉理论的观点一致。     

从脑机制角度看言语知觉的理论争论

言语知觉领域主要的理论争论是听觉理论和动觉理论的对立, 争论的焦点围绕言语知觉是否需要动作表征的中介。言语知觉脑机制的研究有助于澄清事实。脑机制的探讨表明言语知觉主要激活了后部听觉皮层区, 包括颞上皮层的背侧(颞横回和颞平面)和外侧区(颞上回和颞上沟); 而前部和言语产生相关的动作皮层并没有表现出一致的激活模式。言语产生相关的动作表征主要在一些特殊任务情形中以自上而下的反馈机制影响了言语知觉, 可能并非正常言语知觉所必须。     

The effects of simulated stuttering and prolonged speech on the neural activation patterns of stuttering and nonstuttering adults

Functional magnetic resonance imaging was used to investigate the neural correlates of passive listening, habitual speech and two modified speech patterns (simulated stuttering and prolonged speech) in stuttering and nonstuttering adults. Within-group comparisons revealed increased right hemisphere biased activation of speech-related regions during the simulated stuttered and prolonged speech tasks, relative to the habitual speech task, in the stuttering group. No significant activation differences were observed within the nonstuttering participants during these speech conditions. Between-group comparisons revealed less left superior temporal gyrus activation in stutterers during habitual speech and increased right inferior frontal gyrus activation during simulated stuttering relative to nonstutterers. Stutterers were also found to have increased activation in the left middle and superior temporal gyri and right insula, primary motor cortex and supplementary motor cortex during the passive listening condition relative to nonstutterers. The results provide further evidence for the presence of functional deficiencies underlying auditory processing, motor planning and execution in people who stutter, with these differences being affected by speech manner.     

Relative Difficulty of Understanding Foreign Accents as a Marker of Proficiency

Foreign‐accented speech is generally harder to understand than native‐accented speech. This difficulty is reduced for non‐native listeners who share their first language with the non‐native speaker. It is currently unclear, however, how non‐native listeners deal with foreign‐accented speech produced by speakers of a different language. We show that the process of (second) language acquisition is associated with an increase in the relative difficulty of processing foreign‐accented speech. Therefore, experiencing greater relative difficulty with foreign‐accented speech compared with native speech is a marker of language proficiency. These results contribute to our understanding of how phonological categories are acquired during second language learning.     

关于普通话声调知觉中心的初步研究

通常将普通话单音节的声调F0曲线划分成“弯头段”、“调型段”和“降尾段”。考察“调型段”的具体位置和相对长度,对普通话语音教学,对开发语音识别和语音合成系统,都是很有意义的。本文使用两大类合成刺激连续体,通过辨认试验,初步确定了“调型段”在音节F0曲线上的位置,即一个单音节,不论是清声母音节,还是浊声母音节,也不论是何种声调和调域,其声调知觉中心(P-CT)的位置位于韵母段中部,而且,只要“调型段”的长度为浊音段的一半左右,就可能被感知成相应的调类。     

THE APPLICATION OF NATURALISTIC CONVERSATION TRAINING TO SPEECH PRODUCTION IN CHILDREN WITH SPEECH DISABILITIES

The purpose of this experiment was to test the effectiveness of including speech production into naturalistic conversation training for 2 children with speech production disabilities. A multiple baseline design across behaviors (target phonemes) and across subjects (for the same phoneme) indicated that naturalistic conversation training resulted in improved spontaneous speech production. The implications of these findings are discussed relative to existing models of speech production training and other aspects of communication disorders.     

Visuospatial competency, handedness, and cerebral dominance

The present study addressed the question of Levy's (1974, Psychobiological implications of bilateral assymetry. In S. Dimond &; J. G. Beaumont, Hemispheric function in the human brain, NY: Halstead. Pp. 121–183.) proposal that left handers would have lowered spatial skills relative to verbal skills. In the first part of the study, performance on the PMA (visuospatial subtest) and WAIS Block Design subtest were compared between right and left handed high school and college samples. No support could be found for deficient visuo-spatial performance in the left handers. In the second part of the experiment, no relative impairment of visuospatial skills was found when subjects were classified into predicted speech dominance groups on the basis of a dichotic listening task and/or a visual half-field task. An extreme groups comparison of the most left dominant and most right dominant groups again yielded no significant differences in visuo-spatial performance. Finally, the relationship between degree of speech lateralization and visuo-spatial skills was examined. Only partial support for differences in cerebral organization for speech in left handers was found in the college sample.     

Individuals with congenital amusia imitate pitches more accurately in singing than in speaking: Implications for music and language processing

In this study, we investigated the impact of congenital amusia, a disorder of musical processing, on speech and song imitation in speakers of a tone language, Mandarin. A group of 13 Mandarin-speaking individuals with congenital amusia and 13 matched controls were recorded while imitating a set of speech and two sets of song stimuli with varying pitch and rhythm patterns. The results indicated that individuals with congenital amusia were worse than controls in both speech and song imitation, in terms of both pitch matching (absolute and relative) and rhythm matching (relative time and number of time errors). Like the controls, individuals with congenital amusia achieved better absolute and relative pitch matching and made fewer pitch interval and contour errors in song than in speech imitation. These findings point toward domain-general pitch (and time) production deficits in congenital amusia, suggesting the presence of shared pitch production mechanisms but distinct requirements for pitch-matching accuracy in language and music processing.     

Vocal Expression and Perception of Emotion

Speech is an acoustically rich signal that provides considerable personal information about talkers. The expression of emotions in speech sounds and corresponding abilities to perceive such emotions are both fundamental aspects of human communication. Findings from studies seeking to characterize the acoustic properties of emotional speech indicate that speech acoustics provide an external cue to the level of nonspecific arousal associated with emotionalprocesses and to a lesser extent, the relative pleasantness of experienced emotions. Outcomes from perceptual tests show that listeners are able to accurately judge emotions from speech at rates far greater than expected by chance. More detailed characterizations of these production and perception aspects of vocal communication will necessarily involve knowledge aboutdifferences among talkers, such as those components of speech that provide comparatively stable cues to individual talkers identities.     

Audiovisual speech from emotionally expressive and lateralized faces

Emotional expression and how it is lateralized across the two sides of the face may influence how we detect audiovisual speech. To investigate how these components interact we conducted experiments comparing the perception of sentences expressed with happy, sad, and neutral emotions. In addition we isolated the facial asymmetries for affective and speech processing by independently testing the two sides of a talker's face. These asymmetrical differences were exaggerated using dynamic facial chimeras in which left- or right-face halves were paired with their mirror image during speech production. Results suggest that there are facial asymmetries in audiovisual speech such that the right side of the face and right-facial chimeras supported better speech perception than their left-face counterparts. Affective information was also found to be critical in that happy expressions tended to improve speech performance on both sides of the face relative to all other emotions, whereas sad emotions generally inhibited visual speech information, particularly from the left side of the face. The results suggest that approach information may facilitate visual and auditory speech detection.     

The effects of presenting a click in syllable-initial position on the speech of stutterers: Comparison with a metronome click

The speech of ten stutterers, recorded while they were listening to a concurrent metronome click and with a click which was triggered so that it occurred at the beginning of every syllable, was assessed. Speech rate and number of disfluencies were measured in each speaking condition. The results indicated that fewer disfluencies occurred (relative to normal reading performance) when a metronome or syllable-initial click was presented.In a perceptual experiment, a group of normal listeners was presented with samples of each of the stutterers' speech from all three speaking conditions. The listeners were asked to choose that which sounded most natural. The speech recorded from the condition where a click occurred at syllable onset was judged more natural than normal speech or speech recorded while the stutterers heard a metronome click.     

Audiovisual speech from emotionally expressive and lateralized faces

Emotional expression and how it is lateralized across the two sides of the face may influence how we detect audiovisual speech. To investigate how these components interact we conducted experiments comparing the perception of sentences expressed with happy, sad, and neutral emotions. In addition we isolated the facial asymmetries for affective and speech processing by independently testing the two sides of a talker's face. These asymmetrical differences were exaggerated using dynamic facial chimeras in which left- or right-face halves were paired with their mirror image during speech production. Results suggest that there are facial asymmetries in audiovisual speech such that the right side of the face and right-facial chimeras supported better speech perception than their left-face counterparts. Affective information was also found to be critical in that happy expressions tended to improve speech performance on both sides of the face relative to all other emotions, whereas sad emotions generally inhibited visual speech information, particularly from the left side of the face. The results suggest that approach information may facilitate visual and auditory speech detection.     

Tasks and timing in the perception of linguistic anomaly

Three experiments were conducted to investigate the relative timing of syntactic and pragmatic anomaly detection during sentence processing. Experiment 1 was an eye movement study. Experiment 2 employed a dual-task paradigm with compressed speech input, to put the processing routines under time pressure. Experiment 3 used compressed speech input in an anomaly monitoring task. The outcomes of these experiments suggest that there is little or no delay in pragmatic processing relative to syntactic processing in the comprehension of unambiguous sentences. This narrows the possible explanations for any delays that are observed in the use of pragmatic information for ambiguity resolution.The research reported in this paper was supported by Program Project Grant HD-01994 to Haskins Laboratories from the National Institutes of Child and Human Development, and in part by a grant to Stephen Crain and Donald Shankweiler from the University of Connecticut Research Foundation. We thank Jacques Mehler and Gerry Altmann for helpful information about speech compression algorithms. We are especially grateful to Ignatius Mattingly for his generous expert advice on speech compression and design of the experimental materials, and also for recording all the speech stimuli. Julie Boland, Brian McElree, Janet Nicol, and Martin Pickering provided very helpful advice on an earlier draft.     

Effects of talker variability on speechreading

The effects of talker variability on visual speech perception were tested by having subjects speechread sentences from either single-talker or mixed-talker sentence lists. Results revealed that changes in talker from trial to trial decreased speechreading performance. To help determine whether this decrement was due to talker change--and not a change in superficial characteristics of the stimuli--Experiment 2 tested speechreading from visual stimuli whose images were tinted by a single color, or mixed colors. Results revealed that the mixed-color lists did not inhibit speechreading performance relative to the single-color lists. These results are analogous to findings in the auditory speech literature and suggest that, like auditory speech, visual speech operations include a resource-demanding component that is influenced by talker variability.     

A Defining Presidential Moment: 9/11 and the Rally Effect

Public approval ratings of George W. Bush surged after the 11 September 2001 terrorist attacks. This study used a quasi–experimental, within–respondents design to investigate the relative contribution of five factors to this classic rally effect: the stimulus event itself, Bush's speech that evening, media exposure, partisan support, and gender effects. Respondents were pretested on the morning of the attacks; one group was posttested immediately after the speech, another group 41 hours later. Stability of effects was examined through an additional study of Bush's 20 September 2001 speech to a joint session of Congress. The findings indicate that Bush's 11 September speech was the critical factor in this rally effect; none of the other factors contributed significantly.     

Some problems of interarticulator phasing as an index of temporal regularity in speech

Tuller, Kelso, and Harris (1982) offered evidence that the relative timing of articulators in speech remains constant over changes in stress and speech rate. Their evidence is discussed in the light of the methods used, and alternative approaches are suggested. Further, the statements are compared with those of an earlier study within the same theoretical frame, and the implications for a model of speech production are briefly discussed.     

GESTURE, SPEECH, AND LEXICAL ACCESS:

Abstract— In a within-subjects design that varied whether speakers were allowed to gesture and the difficulty of lexical access, speakers were videotaped as they described animated action cartoons to a listener. When speakers were permitted to gesture, they gestured more often during phrases with spatial content than during phrases with other content. Speech with spatial content was less fluent when speakers could not gesture than when they could gesture, speech with nonspatial content was not affected by gesture condition. Preventing gesturing increased the relative frequency of nonjuncture filled pauses in speech with spatial content, but not in speech with other content. Overall, the effects of preventing speakers from gesturing resembled those of increasing the difficulty of lexical access by other means, except that the effects of gesture restriction were specific to speech with spatial content. The findings support the hypothesis that gestural accompaniments to spontaneous speech can facilitate access to the mental lexicon     

Auditory versus audio-visual intelligibility measurements of alaryngeal speech: a preliminary report.

This investigation supports the notion that audio-visual presentations of esophageal speech to 32 university student judges yield a relative increase in rated intelligibility in contrast with esophageal speech presented auditorily. Implications suggest that to construct realistic therapeutic goals of an esophageal speaker more effectively, the audio-visual component should be included in the clinical assessment.