节律在听觉言语理解中的作用

言语理解是听者接受外部语音输入并且获得意义的心理过程。日常交流中,听觉言语理解受多尺度节律信息的影响,常见有韵律结构节律、语境节律、和说话者身体语言节律三方面外部节律。它们改变听者在言语理解中的音素判别、词汇感知以及言语可懂度等过程。内部节律表现为大脑内神经振荡,其能够表征外部言语输入在不同时间尺度下的层级特征。外部节律性刺激与内部神经活动的神经夹带能够优化大脑对言语刺激的处理,并受到听者自上而下的认知过程的调节进一步增强目标言语的内在表征。我们认为它可能是实现内外节律相互联系并共同影响言语理解的关键机制。对内外节律及其联系机制的揭示能够为理解言语这种在多层级时间尺度上具有结构规律的复杂序列提供了一个研究窗口。     

The role of speech rhythm in language discrimination: further tests with a non-human primate

Human newborns discriminate languages from different rhythmic classes, fail to discriminate languages from the same rhythmic class, and fail to discriminate languages when the utterances are played backwards. Recent evidence showing that cotton-top tamarins discriminate Dutch from Japanese, but not when utterances are played backwards, is compatible with the hypothesis that rhythm discrimination is based on a general perceptual mechanism inherited from a primate ancestor. The present study further explores the rhythm hypothesis for language discrimination by testing languages from the same and different rhythmic class. We find that tamarins discriminate Polish from Japanese (different rhythmic classes), fail to discriminate English and Dutch (same rhythmic class), and fail to discriminate backwards utterances from different and same rhythmic classes. These results provide further evidence that language discrimination in tamarins is facilitated by rhythmic differences between languages, and suggest that, in humans, this mechanism is unlikely to have evolved specifically for language.     

Evidence against a predictive role for rhythm in speech perception

Some languages create the impression of being stress timed. Claims have been made that this timing of stressed syllables enables the listener to predict the future locations of informative parts later in a sentence. The fact that phoneme monitoring is delayed when targets in a spoken sentence are displaced has been taken as supporting this claim (Meltzer, Martin, Bergfeld Mills, Imhoff and Zohar, 1976). In the present study temporal displacement was induced without introducing phonetic discontinuities. In Dutch sentences a word just in advance of a target-bearing word was replaced by another one differing in length. Results show that the temporal displacement per se did not have any effect on phoneme-monitoring reaction times. Implications for a theory of fpeech processing are discussed.     

The role of effort in perceiving distance

Berkeley proposed that space is perceived in terms of effort. Consistent with his proposal, the present studies show that perceived egocentric distance increases when people are encumbered by wearing a heavy backpack or have completed a visual-motor adaptation that reduces the anticipated optic flow coinciding with walking effort. In accord with Berkeley's proposal and Gibson's theory of affordances, these studies show that the perception of spatial layout is influenced by locomotor effort.     

The role of surface attraction in perceiving volumetric shape

Rock [1973, Orientation and Form (New York: Academic Press)] showed that form perception generally depends more on the orientation of a stimulus in world coordinates than on its orientation in retinal coordinates. He suggested that the assignment of an object's 'environmental orientation' depends on gravity, visual frame of reference, and the observer's ability to impose orientation along one axis or another. This paper shows that the assignment of environmental orientation and perceived 3-D form also depends on the relationship between an object and retinally adjacent surfaces in the scene to which it might be attached. Whereas previous examples have demonstrated effects of orientation on 2-D form, we show that orientation can affect the perceived intrinsic 3-D shape of a volume.     

Ability in perceiving nonnative contrasts: Performance on natural and synthetic speech stimuli

The perception of the distinction between /r/ and /l/ by native speakers of American English and of Japanese was studied using natural and synthetic speech. The American subjects were all nearly perfect at recognizing the natural speech sounds, whereas there was substantial variation among the Japanese subjects in their accuracy of recognizing /r/ and /l/ except in syllable-final position. A logit model, which additively combined the acoustic information conveyed byF1-transition duration and byF3-onset frequency, provided a good fit to the perception of synthetic /r/ and /l/ by the American subjects. There was substantial variation among the Japanese subjects in whether theF1 andF3 cues had a significant effect on their classifications of the synthetic speech. This variation was related to variation in accuracy of recognizing natural /r/ and /l/, such that greater use of both theF1 cue and theF3 cue in classifying the synthetic speech sounds was positively related to accuracy in recognizing the natural sounds. However, multiple regression showed that use of theF1 cue did not account for significant variance in natural speech performance beyond that accounted for by theF3 cue, indicating that theF3 cue is more important than theF1 cue for Japanese speakers learning English. The relation between performance on natural and synthetic speech also provides external validation of the logit model by showing that it predicts performance outside of the domain of data to which it was fit.     

The use of rhythm in attending to speech

Three experiments examined attentional allocation during speech processing to determine whether listeners capitalize on the rhythmic nature of speech and attend more closely to stressed than to unstressed syllables. Ss performed a phoneme monitoring task in which the target phoneme occurred on a syllable that was either predicted to be stressed or unstressed by the context preceding the target word. Stimuli were digitally edited to eliminate the local acoustic correlates of stress. A sentential context and a context composed of word lists, in which all the words had the same stress pattern, were used. In both cases, the results suggest that attention may be preferentially allocated to stressed syllables during speech processing. However, a normal sentence context may not provide strong predictive cues to lexical stress, limiting the use of the attentional focus.     

The role of melodic and temporal cues in perceiving musical meter

A number of different cues allow listeners to perceive musical meter. Three experiments examined effects of melodic and temporal accents on perceived meter in excerpts from folk songs scored in 6/8 or 3/4 meter. Participants matched excerpts with 1 of 2 metrical drum accompaniments. Melodic accents included contour change, melodic leaps, registral extreme, melodic repetition, and harmonic rhythm. Two experiments with isochronous melodies showed that contour change and melodic repetition predicted judgments. For longer melodies in the 2nd experiment, variables predicted judgments best at the beginning of excerpts. The final experiment, with rhythmically varied melodies, showed that temporal accents, tempo, and contour change were the strongest predictors of meter. The authors' findings suggest that listeners combine multiple melodic and temporal features to perceive musical meter.     

The role of eye height in perceiving affordances and object dimensions

In four experiments on perceived object height and width, the effects of shifting participants’ effective eye height (EEH) on affordance (intrinsic) and apparent size (extrinsic) judgments were con-trasted. In Experiment 1, EEH shifts produced comparable overestimations ofheight in intrinsic and extrinsic tasks. A similar result was found with a more abstract extrinsic height task (Experiment 2). However, Experiment 3 revealed a dissociation between intrinsic and extrinsic tasks of perceivedwidth. Affordance judgments were affected by EEH shifts, whereas apparent size judgments were not. Experiment 4 compared participants’ performance on comparable extrinsic tasks of height and width. Height judgments were affected by EEH shifts, but width judgments were again unaffected. It is concluded that eye height may be a more natural metric for object height than for width. Moreover, this difference reflects a basic flexibility within the human visual system for selectively attuning to the most accessible sources of size information.     

Audiovisual perception of noise vocoded speech in dyslexic and non-dyslexic adults: The role of low-frequency visual modulations

Visual speech inputs can enhance auditory speech information, particularly in noisy or degraded conditions. The natural statistics of audiovisual speech highlight the temporal correspondence between visual and auditory prosody, with lip, jaw, cheek and head movements conveying information about the speech envelope. Low-frequency spatial and temporal modulations in the 2–7 Hz range are of particular importance. Dyslexic individuals have specific problems in perceiving speech envelope cues. In the current study, we used an audiovisual noise-vocoded speech task to investigate the contribution of low-frequency visual information to intelligibility of 4-channel and 16-channel noise vocoded speech in participants with and without dyslexia. For the 4-channel speech, noise vocoding preserves amplitude information that is entirely congruent with dynamic visual information. All participants were significantly more accurate with 4-channel speech when visual information was present, even when this information was purely spatio-temporal (pixelated stimuli changing in luminance). Possible underlying mechanisms are discussed.     

The role of diagnosticity in stereotype formation: perceiving group means and variances.

Three experiments tested the hypotheses that while forming stereotypes of social groups, people abstract the central tendency and variability of different attribute dimensions to determine which ones best differentiate the groups and that more differentiating dimensions are more likely to become stereotypical in the sense of becoming strongly associated with the groups in memory. Supporting these hypotheses. Experiment 1 found that, after viewing behaviors performed by members of 2 groups, Ss characterized the groups more in terms of attribute dimensions indicating larger differences between the central tendencies of the groups, and Experiment 2 showed that this effect did not occur when Ss formed impressions of only 1 group. Experiment 3 found that Ss also characterized groups more in terms of attribute dimensions indicating lower within-group variability.     

Ability in perceiving nonnative contrasts: performance on natural and synthetic speech stimuli.

The perception of the distinction between /r/ and /l/ by native speakers of American English and of Japanese was studied using natural and synthetic speech. The American subjects were all nearly perfect at recognizing the natural speech sounds, whereas there was substantial variation among the Japanese subjects in their accuracy of recognizing /r/ and /l/ except in syllable-final position. A logit model, which additively combined the acoustic information conveyed by F1-transition duration and by F3-onset frequency, provided a good fit to the perception of synthetic /r/ and /l/ by the American subjects. There was substantial variation among the Japanese subjects in whether the F1 and F3 cues had a significant effect on their classifications of the synthetic speech. This variation was related to variation in accuracy of recognizing natural /r/ and /l/, such that greater use of both the F1 cue and the F3 cue in classifying the synthetic speech sounds was positively related to accuracy in recognizing the natural sounds. However, multiple regression showed that use of the F1 cue did not account for significant variance in natural speech performance beyond that accounted for by the F3 cue, indicating that the F3 cue is more important than the F1 cue for Japanese speakers learning English. The relation between performance on natural and synthetic speech also provides external validation of the logit model by showing that it predicts performance outside of the domain of data to which it was fit.     

The role of eye height in perceiving affordances and object dimensions.

In four experiments on perceived object height and width, the effects of shifting participants' effective eye height (EEH) on affordance (intrinsic) and apparent size (extrinsic) judgments were contrasted. In Experiment 1, EEH shifts produced comparable overestimations of height in intrinsic and extrinsic tasks. A similar result was found with a more abstract extrinsic height task (Experiment 2). However, Experiment 3 revealed a dissociation between intrinsic and extrinsic tasks of perceived width. Affordance judgments were affected by EEH shifts, whereas apparent size judgments were not. Experiment 4 compared participants' performance on comparable extrinsic tasks of height and width. Height judgments were affected by EEH shifts, but width judgments were again unaffected. It is concluded that eye height may be a more natural metric for object height than for width. Moreover, this difference reflects a basic flexibility within the human visual system for selectively attuning to the most accessible sources of size information.     

Selective attention and cerebral dominance in perceiving and responding to speech messages

The effect of attention on cerebral dominance and the asymmetry between left and right ears was investigated using a selective listening task. Right handed subjects were presented with simultaneous dichotic speech messages; they shadowed one message in either the right or left ear and at the same time tapped with either the right or the left hand when they heard a specified target word in either message. The ear asymmetry was shown only when subjects' attention was focused on some other aspect of the task: they tapped to more targets in the right ear, but only when these came in the non-shadowed message; they made more shadowing errors with the left ear message, but chiefly for non-target words. The verbal response of shadowing showed the right ear dominance more clearly than the manual response of tapping. Tapping with the left hand interfered more with shadowing than tapping with the right hand, but there was little correlation between the degree of hand and of ear asymmetry over individual subjects. The results support the idea that the right ear dominance is primarily a quantitative difference in the distribution of attention to left and right ear inputs reaching the left hemisphere speech areas. This affects both the efficiency of speech perception and the degree of response competition between simultaneous verbal and manual responses.     

The role of orthographic and phonotactic rules in perceiving letter patterns.

Three experiments examined the role of orthographic and phonotactic rules in the tachistoscopic recognition of letter strings. Experiment 1 showed that the presence of a vowel or multiletter spelling patterns facilitates perceptual accuracy. To account for these results a model was proposed in which an input string is first parsed into syllablelike units, which are then recorded into speech. It was demonstrated that the perceptual accuracy for a string is correlated with the number of recoding steps needed to convert that string into speech. Experiment 2 further demonstrated that this recoding process can predict perceptibility differences among strings with varying numbers of phonotactic violations, and Experiment 3 assessed some of the specific assumptions of the recoding process.     

The role of central and peripheral vision in perceiving the direction of self-motion

Three experiments were performed to examine the role that central and peripheral vision play in the perception of the direction of translational self-motion, or heading, from optical flow. When the focus of radial outflow was in central vision, heading accuracy was slightly higher with central circular displays (10°–25° diameter) than with peripheral annular displays (40° diameter), indicating that central vision is somewhat more sensitive to this information. Performance dropped rapidly as the eccentricity of the focus of outflow increased, indicating that the periphery does not accurately extract radial flow patterns. Together with recent research on vection and postural adjustments, these results contradict theperipheral dominance hypothesis that peripheral vision is specialized for perception of self-motion. We propose afunctional sensitivity hypothesis—that. self-motion is perceived on the basis of optical information rather than the retinal locus of stimulation, but that central and peripheral vision are differentially sensitive to the information characteristic of each retinal region.     

The role of intentionality in perceiving terrorism as a more important problem than traffic accidents

Current Psychology - We hypothesized that perceived intentionality is one of the factors explaining why terrorism is perceived to be a more important problem than traffic accidents. In Study 1, we...     

Hearing speech in noise: seeing a loud talker is better

Seeing the talker improves the intelligibility of speech degraded by noise (a visual speech benefit). Given that talkers exaggerate spoken articulation in noise, this set of two experiments examined whether the visual speech benefit was greater for speech produced in noise than in quiet. We first examined the extent to which spoken articulation was exaggerated in noise by measuring the motion of face markers as four people uttered 10 sentences either in quiet or in babble-speech noise (these renditions were also filmed). The tracking results showed that articulated motion in speech produced in noise was greater than that produced in quiet and was more highly correlated with speech acoustics. Speech intelligibility was tested in a second experiment using a speech-perception-in-noise task under auditory-visual and auditory-only conditions. The results showed that the visual speech benefit was greater for speech recorded in noise than for speech recorded in quiet. Furthermore, the amount of articulatory movement was related to performance on the perception task, indicating that the enhanced gestures made when speaking in noise function to make speech more intelligible.