Integration of acoustical information in the perception of impacted sound sources: The role of information accuracy and exploitability.

Sound sources are perceived by integrating information from multiple acoustical features. The factors influencing the integration of information are largely unknown. We measured how the perceptual weighting of different features varies with the accuracy of information and with a listener’s ability to exploit it. Participants judged the hardness of two objects whose interaction generates an impact sound: a hammer and a sounding object. In a first discrimination experiment, trained listeners focused on the most accurate information, although with greater difficulty when perceiving the hammer. We inferred a limited exploitability for the most accurate hammer-hardness information. In a second rating experiment, listeners focused on the most accurate information only when estimating sounding-object hardness. In a third rating experiment, we synthesized sounds by independently manipulating source properties that covaried in Experiments 1 and 2: sounding-object hardness and impact properties. Sounding-object hardness perception relied on the most accurate acoustical information, whereas impact-properties influenced more strongly hammer hardness perception. Overall, perceptual weight increased with the accuracy of acoustical information, although information that was not easily exploited was perceptually secondary, even if accurate. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of perception in the sound change of velar palatalization

Voiceless velar stops may become palatoalveolar affricates before front vowels. This sound change is not only one of the most common types of palatalization, but is a very common sound change in the world's languages. Nevertheless, we do not have an adequate understanding of how this sound change takes place. Three experiments reported here test the hypothesis that velar palatalization is the result of listeners' on-line perceptual reanalysis of fast rate speech. It is shown that velars before front vowels are both acoustically and perceptually similar to palatoalveolars. This supports the proposal that velar palatalization is perceptually conditioned.     

Coordinating information from perception and working memory.

Individuals must often coordinate information in working memory with information from perception. The demands of coordination have been analyzed in terms of the cost to switch attention. Coordination is considered in terms of the organization of control processes. Ss in 4 experiments performed list-processing tasks that sometimes required alternation between sets of items that were held in working memory or were currently displayed. Exp 1 demonstrated that performance was slower and more error-prone when alternating between sets than when reporting a single set. On alternation tasks, latency varied with serial position, indicating that Ss paused between pairs of responses. In Exp 2, this serial position function was observed for tasks requiring alternation between sets of information in the same modality (memory or perception). Exps 3 and 4 demonstrate that this effect depends on the requirement to generate a new sequence of responses. A model of control processes for coordination is developed and tested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sources of information in word perception.

Disyllabic words were presented tachistoscopically to a total of 16 undergraduates in 2 experiments, and report of the words was required. In Exp I, word frequency was varied but the frequencies of the constituent syllables were held constant. In Exp II, syllable frequency varied while word frequency remained constant. The prime determinant of perceptual accuracy was word frequency, but an analysis of partial errors showed that some discriminability effects at both the word and the syllable level were present. There was a slight advantage for the 1st syllable over the 2nd within a word. There was no overall improvement with practice, but errors on high frequency words became fewer and on low frequency words correspondingly more frequent. Results suggest that word perception involves extraction and resynthesis of information about components of several different sizes within a word. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Configural information in facial expression perception.

Composite facial expressions were prepared by aligning the top half of one expression (e.g., anger) with the bottom half of another (e.g., happiness). Experiment 1 shows that participants are slower to identify the expression in either half of these composite images relative to a "noncomposite" control condition in which the 2 halves are misaligned. This parallels the composite effect for facial identity (A. W. Young, D. Hellawell, & D. C. Hay, 1987), and like its identity counterpart, the effect is disrupted by inverting the stimuli (Experiment 2). Experiment 3 shows that no composite effect is found when the top and bottom sections contain different models' faces posing the same expression; this serves to exclude many nonconfigural interpretations of the composite effect (e.g., that composites are more "attention-grabbing" than noncomposites). Finally, Experiment 4 demonstrates that the composite effects for identity and expression operate independently of one another. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Embodied auditory perception: The emotional impact of approaching and receding sound sources.

Research has shown the existence of perceptual and neural bias toward sounds perceived as sources approaching versus receding a listener. It has been suggested that a greater biological salience of approaching auditory sources may account for these effects. In addition, these effects may hold only for those sources critical for our survival. In the present study, we bring support to these hypotheses by quantifying the emotional responses to different sounds with changing intensity patterns. In 2 experiments, participants were exposed to artificial and natural sounds simulating approaching or receding sources. The auditory-induced emotional effect was reflected in the performance of participants in an emotion-related behavioral task, their self-reported emotional experience, and their physiology (electrodermal activity and facial electromyography). The results of this study suggest that approaching unpleasant sound sources evoke more intense emotional responses in listeners than receding ones, whereas such an effect of perceived sound motion does not exist for pleasant or neutral sound sources. The emotional significance attributed to the sound source itself, the loudness of the sound, and loudness change duration seem to be relevant factors in this disparity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The perception of concurrent sound objects in harmonic complexes impairs gap detection.

Since the introduction of the concept of auditory scene analysis, there has been a paucity of work focusing on the theoretical explanation of how attention is allocated within a complex auditory scene. Here we examined signal detection in situations that promote either the fusion of tonal elements into a single sound object or the segregation of a mistuned element (i.e., harmonic) that “popped out” as a separate individuated auditory object and yielded the perception of concurrent sound objects. On each trial, participants indicated whether the incoming complex sound contained a brief gap or not. The gap (i.e., signal) was always inserted in the middle of one of the tonal elements. Our findings were consistent with an object-based account in which perception of two simultaneous auditory objects interfered with signal detection. This effect was observed for a wide range of gap durations and was greater when the mistuned harmonic was perceived as a separate object. These results suggest that attention may be initially shared among concurrent sound objects thereby reducing listeners' ability to process acoustic details belonging to a particular sound object. These findings provide new theoretical insight for our understanding of auditory attention and auditory scene analysis. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Independence of lexical context and phonological information in speech perception.

M. A. Pitt (see record 1995-42750-001) studied the joint influence of phonological information and lexical context in W. F. Ganong's (1980) task. Pitt improved on earlier studies by collecting enough observations to make possible the quantitative analyses of an individual's data. The present article shows that the results of such analyses demonstrate that the integration of phonological information and lexical context is very well accounted for by the fuzzy logical model of perception (FLMP). Although Pitt concluded that the results of his research argued against the FLMP in favor of an interactive feedback system, his conclusion was based on an analysis of transformed results. It is argued that this use of a response transformation led to incorrect conclusions and that ultimately, models must be tested directly against observed behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interactive use of lexical information in speech perception.

[Correction Notice: An erratum for this article was reported in Vol 13(3) of Journal of Experimental Psychology: Human Perception and Performance (see record 2008-10755-001). In the aforementioned article, Figures 1 and 2 were inadvertently transposed. The figure on p. 294 is actually Figure 2, and the figure on p. 296 is actually Figure 1. The captions are correct as they stand.] Two experiments are reported that demonstrate contextual effects on identification of speech voicing continua. Experiment 1 demonstrated the infuence of lexical knowledge on identification of ambiguous tokens from word–nonword and nonword–word continua. Reaction times for word and nonword responses showed a word advantage only for ambiguous stimulus tokens (at the category boundary); no word advantage was found for clear stimuli (at the continua endpoints). Experiment 2 demonstrated an effect of a postperceptual variable, monetary payoff, on nonword–nonword continua. Identification responses were influenced by monetary payoff, but reaction times for bias-consistent and bias-inconsistent responses did not differ at the category boundary. An advantage for bias-consistent responses was evident at the continua endpoints. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional limits on the perception and memory of visual information.

Attentional limits on perception and memory were measured by the decline in performance with increasing numbers of objects in a display. Multiple objects were presented to Ss who discriminated visual attributes. In a representative condition, 4 lines were briefly presented followed by a single line in 1 of the same locations. Ss were required to judge if the single line in the 2nd display was longer or shorter than the line in the corresponding location of the 1st display. The length difference threshold was calculated as a function of the number of objects. The difference thresholds doubled when the number of objects was increased from 1 to 4. This effect was generalized in several ways, and nonattentional explanations were ruled out. Further analyses showed that the attentional processes must share information from at least 4 objects and can be described by a simple model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A dual mechanism for sound pitch perception: new evidence from brain electrophysiology

The N1 component of the auditory brain evoked potential was used as a direct electrophysiological index, to study how the perception of pitch for complex periodic tones can be influenced by the phase of the harmonics that make up a sound, according to their ranks. Results showed that in the low pitch and/or high spectra region, N1 latency was modified by phase, whereas it was not in the high pitch and low spectra region. These data help bring evidence towards a dual mechanism for pitch perception, and demonstrate that these processes take place within 110 ms following stimulus onset. Results are compatible with a model based on the resolvability of components and on the bandwidth of auditory filters.     

Depth perception as a function of motion parallax and absolute-distance information.

Conducted 3 experiments with 12 observers from a university community to determine whether the visual system calibrates motion parallax according to absolute-distance information in processing depth and to map the range of depth perception as a function of distance and motion parallax. The parallax was created by yoking the relative movement of random dots displayed on a CRT to the movements of the head. In Exp I, at viewing distances of 40 and 80 cm, Ss reported the apparent depth produced by motion parallax equivalent to a binocular disparity of 0.47°. The mean apparent depth at 80 cm was 2.6 times larger than at 40 cm. In Exp II, again at viewing distances of 40 and 80 cm, Ss adjusted the extent of parallax so that the apparent depth was 7.0 cm. The mean extent of parallax at 80 cm was 31% of that at 40 cm. These findings show that the visual system does calibrate motion parallax according to absolute-distance information in processing depth. In Exp III, distances ranged from 40 to 320 cm, and a wide range of parallax was used. As distance and parallax increased, the perception of a rigid 3-dimensional surface was accompanied by rocking motion; perception of depth was replaced by perception of motion in some trials at 320 cm. Moreover, the mean apparent depths were proportional to the viewing distance at 40 and 80 cm but not at 160 and 320 cm. (25 ref) (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Annoyance and behavioral aftereffects following interfering and noninterfering aircraft noise.

In Exp I, 120 college Ss aged 17–57 yrs performed 1 of 2 tasks (a listening or a cancellation task) within 1 of 3 auditory environments (continuous noise, intermittent noise, quiet). Aftereffects of noise on performance similar to those found by D. C. Glass and J. E. Singer (1972) were not obtained. Ss reported greater annoyance with noise when they worked on the listening task (with which the noise interfered) than when they worked on a routine cancellation task (with which the noise did not interfere). Exp II (48 Ss) was designed to replicate more closely Glass and Singer's procedures but produced essentially the same results as Exp I. Possible explanations for the absence of aftereffects are discussed. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

交通地图图像中道路识别与道路信息提取

提出了一种基于道路中心线的闭环反馈改善交通地图图像中道路识别与提取的方法,以达到识别与提取完整道路网络的目的.依据于微观识别与宏观排除的逼近思想,实现了道路图层的初始聚类与输出反馈控制下的道路图层完全提取.针对标准城市交通地图,确定了道路与区域阈值条件.通过对噪声的再聚类过程实现道路与区域的二值完全聚类.利用交通道路中心线特征构成道路图层反馈再聚类策略.反馈再聚类策略能够保证道路图层优化过程的收敛性质.试验结果表明了该方法具有较高的准确性、全自动化和通用性.     

Infants' perception of expressive behaviors: Differentiation of multimodal information.

The literature on infants' perception of facial and vocal expressions, combined with data from studies on infant-directed speech, mother-infant interaction, and social referencing, supports the view that infants come to recognize the affective expressions of others through a perceptual differentiation process. Recognition of affective expressions changes from a reliance on multimodally presented information to the recognition of vocal expressions and then of facial expressions alone. Face or voice properties become differentiated and discriminated from the whole, standing for the entire emotional expression. Initially, infants detect information that potentially carries the meaning of emotional expressions; only later do infants discriminate and then recognize those expressions. The author reviews data supporting this view and draws parallels between the perceptions of affective expressions and of speech. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Picture perception: Effects of luminance on available information and information-extraction rate.

Three experiments with 255 undergraduates and a 4th in which the author and 2 colleagues served as Ss showed that complex visual stimuli—pictures and digit arrays—were remembered better when shown at high luminance (LM) than at low LM. Evidence was found for the possibilities that lowering LM reduced the amount of available information in the stimulus and that lowering LM reduced the rate at which the information was extracted from the stimulus. When stimuli were presented at durations short enough to permit only a single eye fixation, LM affected only the rate at which information was extracted. Decreasing LM by a factor of 100 caused information to be extracted more slowly by a factor that ranged, over experiments, from 1.4 to 2.0. When pictures were presented at durations long enough to permit multiple fixations, however, LM affected the total amount of extractable information. In a 5th experiment, with 4 undergraduates, converging evidence was sought for the proposition that within the 1st eye fixation on a picture, LM affects the rate of information extraction. If this proposition is correct and the 1st eye fixation lasts until some criterion amount of information is extracted, then fixation duration should increase with decreasing LM. This prediction was confirmed. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hemispheric contributions to the integration of visual and auditory information in speech perception

Differential hemispheric contributions to the perceptual phenomenon known as the McGurk effect were examined in normal subjects, 1 callosotomy patient, and 4 patients with intractable epilepsy. Twenty-five right-handed subjects were more likely to demonstrate an influence of a mouthed word on identification of a dubbed acoustic word when the speaker's face was lateralized to the LVF as compared with the RVF. In contrast, display of printed response alternatives in the RVF elicited a greater percentage of McGurk responses than display in the LVF. Visual field differences were absent in a group of 15 left-handed subjects. These results suggest that in right-handers, the two hemispheres may make distinct contributions to the McGurk effect. The callosotomy patient demonstrated reliable McGurk effects, but at a lower rate than the normal subjects and the epileptic control subjects. These data support the view that both the right and left hemisphere can make significant contributions to the McGurk effect.     

The utility of motion parallax information for the perception and control of heading.

Two experiments in which participants were given control over the direction of computer-simulated self-motion were conducted. Environments were designed to evaluate the functionality of simple and multiple motion parallax as well as a separation ratio (?; indexing the separation of 2 objects in depth) for the perception and control of heading. Results provide a 1st indication of optimizing performance in the top end of the global optical flow velocity range available during human bipedal self-motion. The introduction of ?, developed to explain performance improvements with decreasing distance to the target, was able to account for most of the performance differences among all simulated environments. The rate of change in horizontal optical separation between at least 2 discontinuities was identified as a likely candidate for the optical foundation of the perception and control of heading during target approach. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Irrelevant sound disrupts order information in free recall as in serial recall

The claim that the sensitivity of free recall to disruption by irrelevant sound is a function of the extent to which rote rehearsal is employed as a mnemonic strategy was investigated in two experiments. The degree of disruption by irrelevant sound in terms of both item and order information was contrasted under serial and free recall instructions. Irrelevant sound was found to disrupt order and item information equally in serial and free recall tasks (Experiment 1). Contrary to previous reports, an effect of irrelevant sound was also demonstrated on free recall of particularly long lists, and the interaction between list length and retention interval in the irrelevant sound effect was examined (Experiment 2). Generally, the results support the view that irrelevant sound disrupts the use of order cues.