Language experience influences audiovisual speech integration in unimodal and bimodal bilingual infants

Infants as young as 2 months can integrate audio and visual aspects of speech articulation. A shift of attention from the eyes towards the mouth of talking faces occurs around 6 months of age in monolingual infants. However, it is unknown whether this pattern of attention during audiovisual speech processing is influenced by speech and language experience in infancy. The present study investigated this question by analysing audiovisual speech processing in three groups of 4‐ to 8‐month‐old infants who differed in their language experience: monolinguals, unimodal bilinguals (infants exposed to two or more spoken languages) and bimodal bilinguals (hearing infants with Deaf mothers). Eye‐tracking was used to study patterns of face scanning while infants were viewing faces articulating syllables with congruent, incongruent and silent auditory tracks. Monolinguals and unimodal bilinguals increased their attention to the mouth of talking faces between 4 and 8 months, while bimodal bilinguals did not show any age difference in their scanning patterns. Moreover, older (6.6 to 8 months), but not younger, monolinguals (4 to 6.5 months) showed increased visual attention to the mouth of faces articulating audiovisually incongruent rather than congruent faces, indicating surprise or novelty. In contrast, no audiovisual congruency effect was found in unimodal or bimodal bilinguals. Results suggest that speech and language experience influences audiovisual integration in infancy. Specifically, reduced or more variable experience of audiovisual speech from the primary caregiver may lead to less sensitivity to the integration of audio and visual cues of speech articulation.     

Bimodal and trimodal multisensory enhancement: effects of stimulus onset and intensity on reaction time

Manual reaction times to visual, auditory, and tactile stimuli presented simultaneously, or with a delay, were measured to test for multisensory interaction effects in a simple detection task with redundant signals. Responses to trimodal stimulus combinations were faster than those to bimodal combinations, which in turn were faster than reactions to unimodal stimuli. Response enhancement increased with decreasing auditory and tactile stimulus intensity and was a U-shaped function of stimulus onset asynchrony. Distribution inequality tests indicated that the multisensory interaction effects were larger than predicted by separate activation models, including the difference between bimodal and trimodal response facilitation. The results are discussed with respect to previous findings in a focused attention task and are compared with multisensory integration rules observed in bimodal and trimodal superior colliculus neurons in the cat and monkey.     

Colavita dominance effect revisited: the effect of semantic congruity

To investigate the effect of semantic congruity on audiovisual target responses, participants detected a semantic concept that was embedded in a series of rapidly presented stimuli. The target concept appeared as a picture, an environmental sound, or both; and in bimodal trials, the audiovisual events were either consistent or inconsistent in their representation of a semantic concept. The results showed faster detection latencies to bimodal than to unimodal targets and a higher rate of missed targets when visual distractors were presented together with auditory targets, in comparison to auditory targets presented alone. The findings of Experiment 2 showed a cross-modal asymmetry, such that visual distractors were found to interfere with the accuracy of auditory target detection, but auditory distractors had no effect on either the speed or the accuracy of visual target detection. The biased-competition theory of attention (Desimone & Duncan Annual Review of Neuroscience 18: 1995; Duncan, Humphreys, & Ward Current Opinion in Neurobiology 7: 255–261 1997) was used to explain the findings because, when the saliency of the visual stimuli was reduced by the addition of a noise filter in Experiment 4, visual interference on auditory target detection was diminished. Additionally, the results showed faster and more accurate target detection when semantic concepts were represented in a visual rather than an auditory format.     

Multisensory cues capture spatial attention regardless of perceptual load

We compared the ability of auditory, visual, and audiovisual (bimodal) exogenous cues to capture visuo-spatial attention under conditions of no load versus high perceptual load. Participants had to discriminate the elevation (up vs. down) of visual targets preceded by either unimodal or bimodal cues under conditions of high perceptual load (in which they had to monitor a rapidly presented central stream of visual letters for occasionally presented target digits) or no perceptual load (in which the central stream was replaced by a fixation point). The results of 3 experiments showed that all 3 cues captured visuo-spatial attention in the no-load condition. By contrast, only the bimodal cues captured visuo-spatial attention in the high-load condition, indicating for the first time that multisensory integration can play a key role in disengaging spatial attention from a concurrent perceptually demanding stimulus.     

内外源性空间注意对多感觉整合的影响

本文采用内-外源性空间线索靶子范式, 操控内源性线索有效性(有效线索、无效线索)、外源性线索有效性(有效线索、无效线索)、目标刺激类型(视觉刺激、听觉刺激、视听觉刺激)三个自变量。通过两个不同任务难度的实验(实验1: 简单定位任务; 实验2: 复杂辨别任务)来考察内外源性空间注意对多感觉整合的影响。两个实验结果均发现外源性空间注意显著减弱了多感觉整合效应, 内源性空间注意没有显著增强多感觉整合效应; 实验2中还发现了内源性空间注意会对外源性空间注意减弱多感觉整合效应产生影响。结果表明, 与内源性空间注意不同, 外源性空间注意对多感觉整合的影响不易受任务难度的调控; 当任务较难时内源性空间注意会影响外源性空间注意减弱多感觉整合效应的过程。由此推测, 内外源性空间注意对多感觉整合的调节并非彼此独立、而是相互影响的。     

选择性注意和分配性注意对多感觉整合的不同影响*

以简单图形为视觉刺激,以短纯音作为听觉刺激,通过指导被试注意不同通道（注意视觉、注意听觉、注意视听）以形成不同注意状态（选择性注意和分配性注意）,考察了注意对多感觉整合的影响,发现只有在分配性注意时被试对双通道目标的反应最快最准确。通过竞争模型分析发现,这种对双通道目标的加工优势源自于视听双通道刺激的整合。上述结果表明,只有在分配性注意状态下才会产生多感觉整合。     

视听跨通道信息的整合与冲突控制

多通道信息交互是指来自某个感觉通道的信息与另一感觉通道的信息相互作用、相互影响的一系列加工过程。主要包括两个方面：一是不同感觉通道的输入如何整合;二是跨通道信息的冲突控制。本文综述了视听跨通道信息整合与冲突控制的行为心理机制和神经机制,探讨了注意对视听信息整合与冲突控制的影响。未来需探究视听跨通道信息加工的脑网络机制,考察特殊群体的跨通道整合和冲突控制以帮助揭示其认知和社会功能障碍的机制。     

Audiovisual integration facilitates monkeys’ short-term memory

Many human behaviors are known to benefit from audiovisual integration, including language and communication, recognizing individuals, social decision making, and memory. Exceptionally little is known about the contributions of audiovisual integration to behavior in other primates. The current experiment investigated whether short-term memory in nonhuman primates is facilitated by the audiovisual presentation format. Three macaque monkeys that had previously learned an auditory delayed matching-to-sample (DMS) task were trained to perform a similar visual task, after which they were tested with a concurrent audiovisual DMS task with equal proportions of auditory, visual, and audiovisual trials. Parallel to outcomes in human studies, accuracy was higher and response times were faster on audiovisual trials than either unisensory trial type. Unexpectedly, two subjects exhibited superior unimodal performance on auditory trials, a finding that contrasts with previous studies, but likely reflects their training history. Our results provide the first demonstration of a bimodal memory advantage in nonhuman primates, lending further validation to their use as a model for understanding audiovisual integration and memory processing in humans.     

不同SOA下视觉返回抑制对视听觉整合的调节作用

基于外源性线索-靶子范式, 采用2(线索-靶子间隔时间, stimulus onset asynchronies, SOA：400~600 ms、1000~1200 ms) × 3(目标刺激类型：视觉、听觉、视听觉) × 2(线索有效性：有效线索、无效线索)的被试内实验设计, 要求被试对目标刺激完成检测任务, 以考察视觉线索诱发的返回抑制(inhibition of return, IOR)对视听觉整合的调节作用, 从而为感知觉敏感度、空间不确定性及感觉通道间信号强度差异假说提供实验证据。结果发现：(1) 随SOA增长, 视觉IOR效应显著降低, 视听觉整合效应显著增强; (2) 短SOA (400~600 ms)时, 有效线索位置上的视听觉整合效应显著小于无效线索位置, 但长SOA (1000~1200 ms)时, 有效与无效线索位置上的视听觉整合效应并无显著差异。结果表明, 在不同SOA条件下, 视觉IOR对视听觉整合的调节作用产生变化, 当前结果支持感觉通道间信号强度差异假说。     

The role of intersensory redundancy in the emergence of social referencing in 5½-month-old infants

Early evidence of social referencing was examined in 5?-month-old infants. Infants were habituated to 2 films of moving toys, one toy eliciting a woman's positive emotional expression and the other eliciting a negative expression under conditions of bimodal (audiovisual) or unimodal visual (silent) speech. It was predicted that intersensory redundancy provided by audiovisual (but not available in unimodal visual) events would enhance detection of the relation between emotional expressions and the corresponding toy. Consistent with predictions, only infants who received bimodal, audiovisual events detected a change in the affect-object relations, showing increased looking during a switch test in which the toy-affect pairing was reversed. Moreover, in a subsequent live preference test, they preferentially touched the 3-dimensional toy previously paired with the positive expression. These findings suggest social referencing emerges by 5? months in the context of intersensory redundancy provided by dynamic multimodal stimulation and that even 5?-month-old infants demonstrate preferences for 3-dimensional objects on the basis of affective information depicted in videotaped events.     

内源性空间线索有效性对视听觉整合的影响

采用内源性线索-靶子范式, 操纵线索类型(有效线索、无效线索)和靶刺激通道类型(视觉刺激、听觉刺激、视听觉刺激)两个自变量, 通过两个实验, 分别设置50%和80%两种内源性空间线索有效性来考察不同空间线索有效性条件下内源性空间注意对视听觉整合的影响。结果发现, 当线索有效性为50%时(实验1), 有效线索位置和无效线索位置的视听觉整合效应没有显著差异; 当线索有效性为80%时(实验2), 有效线索位置的视听觉整合效应显著大于无效线索位置的视听觉整合效应。结果表明, 线索有效性不同时, 内源性空间注意对视听觉整合产生了不同的影响, 高线索有效性条件下内源性空间注意能够促进视听觉整合效应。     

The development of infant discrimination of affect in multimodal and unimodal stimulation: The role of intersensory redundancy

This research examined the developmental course of infants' ability to perceive affect in bimodal (audiovisual) and unimodal (auditory and visual) displays of a woman speaking. According to the intersensory redundancy hypothesis (L. E. Bahrick, R. Lickliter, & R. Flom, 2004), detection of amodal properties is facilitated in multimodal stimulation and attenuated in unimodal stimulation. Later in development, however, attention becomes more flexible, and amodal properties can be perceived in both multimodal and unimodal stimulation. The authors tested these predictions by assessing 3-, 4-, 5-, and 7-month-olds' discrimination of affect. Results demonstrated that in bimodal stimulation, discrimination of affect emerged by 4 months and remained stable across age. However, in unimodal stimulation, detection of affect emerged gradually, with sensitivity to auditory stimulation emerging at 5 months and visual stimulation at 7 months. Further temporal synchrony between faces and voices was necessary for younger infants' discrimination of affect. Across development, infants first perceive affect in multimodal stimulation through detecting amodal properties, and later their perception of affect is extended to unimodal auditory and visual stimulation. Implications for social development, including joint attention and social referencing, are considered.     

How the bimodal format of presentation affects working memory: an overview

The best format in which information that has to be recalled is presented has been investigated in several studies, which focused on the impact of bimodal stimulation on working memory performance. An enhancement of participant’s performance in terms of correct recall has been repeatedly found, when bimodal formats of presentation (i.e., audiovisual) were compared to unimodal formats (i.e, either visual or auditory), in providing implications for multimedial learning. Several theoretical frameworks have been suggested in order to account for the bimodal advantage, ranging from those emphasizing early stages of processing (such as automatic alerting effects or multisensory integration processes) to those centred on late stages of processing (as postulated by the dual coding theory). The aim of this paper is to review previous contributions to this topic, providing a comprehensive theoretical framework, which is updated by the latest empirical studies.     

Assessing automaticity in audiovisual speech integration: evidence from the speeded classification task

The McGurk effect is usually presented as an example of fast, automatic, multisensory integration. We report a series of experiments designed to directly assess these claims. We used a syllabic version of the speeded classification paradigm, whereby response latencies to the first (target) syllable of spoken word-like stimuli are slowed down when the second (irrelevant) syllable varies from trial to trial. This interference effect is interpreted as a failure of selective attention to filter out the irrelevant syllable. In Experiment 1 we reproduced the syllabic interference effect with bimodal stimuli containing auditory as well as visual lip movement information, thus confirming the generalizability of the phenomenon. In subsequent experiments we were able to produce (Experiment 2) and to eliminate (Experiment 3) syllabic interference by introducing 'illusory' (McGurk) audiovisual stimuli in the irrelevant syllable, suggesting that audiovisual integration occurs prior to attentional selection in this paradigm.     

Attenuated audiovisual integration in middle-aged adults in a discrimination task

Numerous studies have focused on the diversity of audiovisual integration between younger and older adults. However, consecutive trends in audiovisual integration throughout life are still unclear. In the present study, to clarify audiovisual integration characteristics in middle-aged adults, we instructed younger and middle-aged adults to conduct an auditory/visual stimuli discrimination experiment. Randomized streams of unimodal auditory (A), unimodal visual (V) or audiovisual stimuli were presented on the left or right hemispace of the central fixation point, and subjects were instructed to respond to the target stimuli rapidly and accurately. Our results demonstrated that the responses of middle-aged adults to all unimodal and bimodal stimuli were significantly slower than those of younger adults (p < 0.05). Audiovisual integration was markedly delayed (onset time 360 ms) and weaker (peak 3.97%) in middle-aged adults than in younger adults (onset time 260 ms, peak 11.86%). The results suggested that audiovisual integration was attenuated in middle-aged adults and further confirmed age-related decline in information processing.     

Integration of audio‐visual information for spatial decisions in children and adults

In adults, decisions based on multisensory information can be faster and/or more accurate than those relying on a single sense. However, this finding varies significantly across development. Here we studied speeded responding to audio‐visual targets, a key multisensory function whose development remains unclear. We found that when judging the locations of targets, children aged 4 to 12 years and adults had faster and less variable response times given auditory and visual information together compared with either alone. Comparison of response time distributions with model predictions indicated that children at all ages were integrating (pooling) sensory information to make decisions but that both the overall speed and the efficiency of sensory integration improved with age. The evidence for pooling comes from comparison with the predictions of Miller's seminal ‘race model’, as well as with a major recent extension of this model and a comparable ‘pooling’ (coactivation) model. The findings and analyses can reconcile results from previous audio‐visual studies, in which infants showed speed gains exceeding race model predictions in a spatial orienting task (Neil et al., 2006) but children below 7 years did not in speeded reaction time tasks (e.g. Barutchu et al., 2009). Our results provide new evidence for early and sustained abilities to integrate visual and auditory signals for spatial localization from a young age.     

Constrained motor-perceptual task in infancy: effects of sensory modality

The authors examined the relative success of varying sensory stimulation modalities that they presented via a mobile reinforcement procedure for promoting left-knee extensions in 3-month-old infants. They separated 53 infants into 5 groups. Four groups received contingent unimodal auditory, enhanced auditory, or visual reinforcement or contingent bimodal auditory plus visual (aud + vis) reinforcement. One group (controls) received aud + vis noncontingent reinforcement. The group that received aud + vis contingent reinforcement was most successful in learning the motor task and maintained the highest attention levels. The authors observed few differences in learning and attention within the unimodal groups. The present findings confirm the effectiveness of contingent multisensory stimulation for promoting perception-action coupling in infancy.     

Auditory cueing facilitates temporospatial accuracy of sequential movements

Effectively executing goal-directed behaviours requires both temporal and spatial accuracy. Previous work has shown that providing auditory cues enhances the timing of upper-limb movements. Interestingly, alternate work has shown beneficial effects of multisensory cueing (i.e., combined audiovisual) on temporospatial motor control. As a result, it is not clear whether adding visual to auditory cues can enhance the temporospatial control of sequential upper-limb movements specifically. The present study utilized a sequential pointing task to investigate the effects of auditory, visual, and audiovisual cueing on temporospatial errors. Eighteen participants performed pointing movements to five targets representing short, intermediate, and large movement amplitudes. Five isochronous auditory, visual, or audiovisual priming cues were provided to specify an equal movement duration for all amplitudes prior to movement onset. Movement time errors were then computed as the difference between actual and predicted movement times specified by the sensory cues, yielding delta movement time errors (ΔMTE). It was hypothesized that auditory-based (i.e., auditory and audiovisual) cueing would yield lower movement time errors compared to visual cueing. The results showed that providing auditory relative to visual priming cues alone reduced ΔMTE particularly for intermediate amplitude movements. The results further highlighted the beneficial impact of unimodal auditory cueing for improving visuomotor control in the absence of significant effects for the multisensory audiovisual condition.     

双通道分配性注意对视听觉返回抑制的影响

本研究基于线索-靶子范式, 操纵目标刺激类型(视觉、听觉、视听觉)与线索有效性(有效线索、中性条件、无效线索)两个自变量, 通过3个实验来考察双通道分配性注意对视听觉返回抑制(inhibition of return, IOR)的影响。实验1 (听觉刺激呈现在左/右侧)结果发现, 在双通道分配性注意条件下, 视觉目标产生显著IOR效应, 而视听觉目标没有产生IOR效应; 实验2 (听觉刺激呈现在左/右侧)与实验3 (听觉刺激呈现在中央)结果发现, 在视觉通道选择性注意条件下, 视觉与视听觉目标均产生显著IOR效应但二者无显著差异。结果表明：双通道分配性注意减弱视听觉IOR效应。     

The relationship between multisensory integration and IQ in children

It is well accepted that multisensory integration has a facilitative effect on perceptual and motor processes, evolutionarily enhancing the chance of survival of many species, including humans. Yet, there is limited understanding of the relationship between multisensory processes, environmental noise, and children's cognitive abilities. Thus, this study investigated the relationship between multisensory integration, auditory background noise, and the general intellectual abilities of school-age children (N = 88, mean age = 9 years, 7 months) using a simple audiovisual detection paradigm. We provide evidence that children with enhanced multisensory integration in quiet and noisy conditions are likely to score above average on the Full-Scale IQ of the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV). Conversely, approximately 45% of tested children, with relatively low verbal and nonverbal intellectual abilities, showed reduced multisensory integration in either quiet or noise. Interestingly, approximately 20% of children showed improved multisensory integration abilities in the presence of auditory background noise. The findings of the present study suggest that stable and consistent multisensory integration in quiet and noisy environments is associated with the development of optimal general intellectual abilities. Further theoretical implications are discussed.