Bad maps may not always get you lost: Lexically driven perceptual recalibration for substituted phonemes.

The speech perception system adjusts its phoneme categories based on the current speech input and lexical context. This is known as lexically driven perceptual recalibration, and it is often assumed to underlie accommodation to non-native accented speech. However, recalibration studies have focused on maximally ambiguous sounds (e.g., a sound ambiguous between "sh" and "s" in a word like "superpower"), a scenario that does not represent the full range of variation present in accented speech. Indeed, non-native speakers sometimes completely substitute a phoneme for another, rather than produce an ambiguous segment (e.g., saying "shuperpower"). This has been called a "bad map" in the literature. In this study, we scale up the lexically driven recalibration paradigm to such cases. Because previous research suggests that the position of the critically accented phoneme modulates the success of recalibration, we include such a manipulation in our study. And to ensure that participants treat all critical items as words (an important point for successful recalibration), we use a new exposure task that incentivizes them to do so. Our findings suggest that while recalibration is most robust after exposure to ambiguous sounds, it also occurs after exposure to bad maps. But interestingly, positional effects may be reversed: recalibration was more likely for ambiguous sounds late in words, but more likely for bad maps occurring early in words. Finally, a comparison of an online versus in-lab version of these conditions shows that experimental setting may have a non-trivial effect on the results of recalibration studies.

Reconciling the contradictory effects of production on word learning: Production may help at first, but it hurts later.

Does saying a novel word help to recognize it later? Previous research on the effect of production on this aspect of word learning is inconclusive, as both facilitatory and detrimental effects of production are reported. In a set of three experiments, we sought to reconcile the seemingly contrasting findings by disentangling the production from other effects. In Experiment 1, participants learned eight new words and their visual referents. On each trial, participants heard a novel word twice: either (a) by hearing the same speaker produce it twice (Perception-Only condition) or (b) by first hearing the speaker once and then producing it themselves (Production condition). At test, participants saw two pictures while hearing a novel word and were asked to choose its correct referent. Experiment 2 was identical to Experiment 1, except that in the Perception-Only condition each word was spoken by 2 different speakers (equalizing talker variability between conditions). Experiment 3 was identical to Experiment 2, but at test words were spoken by a novel speaker to assess generalizability of the effect. Accuracy, reaction time, and eye-movements to the target image were collected. Production had a facilitatory effect during early stages of learning (after short training), but its effect became detrimental after additional training. The results help to reconcile conflicting findings regarding the role of production on word learning. This work is relevant to a wide range of research on human learning in showing that the same factor may play a different role at different stages of learning. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Just give it time: Differential effects of disruption and delay on perceptual learning.

Speech perception and production are critical skills when acquiring a new language. However, the nature of the relationship between these two processes is unclear, particularly for non-native speech sound contrasts. Although it has been assumed that perception and production are supportive, recent evidence has demonstrated that, under some circumstances, production can disrupt perceptual learning. Specifically, producing the to-be-learned contrast on each trial can disrupt perceptual learning of that contrast. Here, we treat speech perception and speech production as separate tasks. From this perspective, perceptual learning studies that include a production component on each trial create a task switch. We report two experiments that test how task switching can disrupt perceptual learning. One experiment demonstrates that the disruption caused by switching to production is sensitive to time delays: Increasing the delay between perception and production on a trial can reduce and even eliminate disruption of perceptual learning. The second experiment shows that if a task other than producing the to-be-learned contrast is imposed, the task-switching component of disruption is not influenced by a delay. These experiments provide a new understanding of the relationship between speech perception and speech production, and clarify conditions under which the two cooperate or compete.

Intermodality differences in statistical learning: phylogenetic and ontogenetic influences.

In Basque-Spanish bilinguals, statistical learning (SL) in the visual modality was more efficient on nonlinguistic than linguistic input; in the auditory modality, we found the reverse pattern of results. We hypothesize that SL was shaped for processing nonlinguistic environmental stimuli and only later, as the language faculty emerged, recycled for speech processing. This led to further adaptive changes in the neurocognitive mechanisms underlying speech processing, including SL. By contrast, as a recent cultural innovation, written language has not yet led to adaptations. The current study investigated whether such phylogenetic influences on SL can be modulated by ontogenetic influences on a shorter timescale, over the course of individual development. We explored how SL is modulated by the ambient linguistic environment. We found that SL in the auditory modality can be further modulated by exposure to a bilingual environment, in which speakers need to process a wider range of diverse speech cues. This effect was observed only on linguistic, not nonlinguistic, material. We conclude that ontogenetic factors modulate the efficiency of already existing SL ability, honing it for specific types of input, by providing new targets for selection via exposure to different cues in the sensory input.

Lexico-semantic access and audiovisual integration in the aging brain: Insights from mixed-effects regression analyses of event-related potentials.

We investigated how aging modulates lexico-semantic processes in the visual (seeing written items), auditory (hearing spoken items) and audiovisual (seeing written items while hearing congruent spoken items) modalities. Participants were young and older adults who performed a delayed lexical decision task (LDT) presented in blocks of visual, auditory, and audiovisual stimuli. Event-related potentials (ERPs) revealed differences between young and older adults despite older adults' ability to identify words and pseudowords as accurately as young adults. The observed differences included more focalized lexico-semantic access in the N400 time window in older relative to young adults, stronger re-instantiation and/or more widespread activity of the lexicality effect at the time of responding, and stronger multimodal integration for older relative to young adults. Our results offer new insights into how functional neural differences in older adults can result in efficient access to lexico-semantic representations across the lifespan.

Selective adaptation in speech: Measuring the effects of visual and lexical contexts.

Speech selective adaptation is a phenomenon in which repeated presentation of a speech stimulus alters subsequent phonetic categorization. Prior work has reported that lexical, but not multisensory, context influences selective adaptation. This dissociation suggests that lexical and multisensory contexts influence speech perception through separate and independent processes (see Samuel & Lieblich, 2014). However, this dissociation is based on results reported by different studies using different stimuli. This leaves open the possibility that the divergent effects of multisensory and lexical contexts on selective adaptation may be the result of idiosyncratic differences in the stimuli rather than separate perceptual processes. The present investigation used a single stimulus set to compare the selective adaptation produced by lexical and multisensory contexts. In contrast to the apparent dissociation in the literature, we find that multisensory information can in fact support selective adaptation. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Auditory selective adaptation moment by moment, at multiple timescales.

Over the course of a lifetime, adults develop perceptual categories for the vowels and consonants in their native language, based on the distribution of those sounds in their environment. However, in any given listening situation, the short-term distribution of sounds can cause changes in this long-term categorization. For example, if the same sound (the "adaptor") is heard many times in a short period of time, listeners adapt and become less prone to hearing that sound. Although hundreds of speech selective adaptation experiments have been published, there is almost no information about how long this adaptation lasts. Using stimuli chosen to produce very large initial adaptation, we test adaptation effects with essentially no delay, and with delays of 25 min, 90 min, and 5.5 hr; these tests probe the duration of adaptation both in the (single) ear to which the adaptor was presented, and in the opposite ear. Reliable adaptation remains 5.5 hr after exposure in the same-ear condition, whereas it is undetectable at 90 min in the opposite ear. Surprisingly, the amount of residual adaptation is largely unaffected by whether the listener is exposed to speech between adaptation and test, unless the speech shares critical acoustic properties with the adapting sounds. Analyses of the shifts on three time scales (seconds, minutes, and hours) provide information about the multiple levels of analysis that the speech signal undergoes. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Second-language word recognition in noise: Interdependent neuromodulatory effects of semantic context and crosslinguistic interactions driven by word form similarity.

Spoken language comprehension is a fundamental component of our cognitive skills. We are quite proficient at deciphering words from the auditory input despite the fact that the speech we hear is often masked by noise such as background babble originating from talkers other than the one we are attending to. To perceive spoken language as intended, we rely on prior linguistic knowledge and context. Prior knowledge includes all sounds and words that are familiar to a listener and depends on linguistic experience. For bilinguals, the phonetic and lexical repertoire encompasses two languages, and the degree of overlap between word forms across languages affects the degree to which they influence one another during auditory word recognition. To support spoken word recognition, listeners often rely on semantic information (i.e., the words we hear are usually related in a meaningful way). Although the number of multilinguals across the globe is increasing, little is known about how crosslinguistic effects (i.e., word overlap) interact with semantic context and affect the flexible neural systems that support accurate word recognition. The current multi-echo functional magnetic resonance imaging (fMRI) study addresses this question by examining how prime-target word pair semantic relationships interact with the target word's form similarity (cognate status) to the translation equivalent in the dominant language (L1) during accurate word recognition of a non-dominant (L2) language. We tested 26 early-proficient Spanish-Basque (L1-L2) bilinguals. When L2 targets matching L1 translation-equivalent phonological word forms were preceded by unrelated semantic contexts that drive lexical competition, a flexible language control (fronto-parietal-subcortical) network was upregulated, whereas when they were preceded by related semantic contexts that reduce lexical competition, it was downregulated. We conclude that an interplay between semantic and crosslinguistic effects regulates flexible control mechanisms of speech processing to facilitate L2 word recognition, in noise.

An evolutionary account of intermodality differences in statistical learning.

The cognitive mechanisms underlying statistical learning are engaged for the purposes of speech processing and language acquisition. However, these mechanisms are shared by a wide variety of species that do not possess the language faculty. Moreover, statistical learning operates across domains, including nonlinguistic material. Ancient mechanisms for segmenting continuous sensory input into discrete constituents have evolved for general-purpose segmentation of the environment and been readopted for processing linguistic input. Linguistic input provides a rich set of cues for the boundaries between sequential constituents. Such input engages a wider variety of more specialized mechanisms operating on these language-specific cues, thus potentially reducing the role of conditional statistics in tokenizing a continuous linguistic stream. We provide an explicit within-subject comparison of the utility of statistical learning in language versus nonlanguage domains across the visual and auditory modalities. The results showed that in the auditory modality statistical learning is more efficient with speech-like input, while in the visual modality efficiency is higher with nonlanguage input. We suggest that the speech faculty has been important for individual fitness for an extended period, leading to the adaptation of statistical learning mechanisms for speech processing. This is not the case in the visual modality, in which linguistic material presents a less ecological type of sensory input.

Phonemic contrasts under construction? Evidence from Basque.

Attunement theories of speech perception development suggest that native-language exposure is one of the main factors shaping infants' phonemic discrimination capacity within the second half of their first year. Here, we focus on the role of acoustic-perceptual salience and language-specific experience by assessing the discrimination of acoustically subtle Basque sibilant contrasts. We used the infant-controlled version of the habituation procedure to assess discrimination in 6- to 7-month and 11- to 12-month-old infants who varied in their amount of exposure to Basque and Spanish. We observed no significant variation in the infants' discrimination behavior as a function of their linguistic experience. Infants in both age-groups exhibited poor discrimination, consistent with Basque adults finding these contrasts more difficult than some others. Our findings are in agreement with previous research showing that perceptual discrimination of subtle speech sound contrasts may follow a different developmental trajectory, where increased native-language exposure seems to be a requisite.

Examining bilingual language switching across the lifespan in cued and voluntary switching contexts.

How bilinguals control their languages and switch between them may change across the life span. Furthermore, bilingual language control may depend on the demands imposed by the context. Across 2 experiments, we examined how Spanish-Basque children, teenagers, younger, and older adults switch between languages in voluntary and cued picture-naming tasks. In the voluntary task, bilinguals could freely choose a language while the cued task required them to use a prespecified language. In the cued task, youths and older adults showed larger language mixing costs than young adults, suggesting that using 2 languages in response to cues was more effortful. Cued switching costs, especially when the switching sequence was predictable, were also greater for youths and older adults. The voluntary switching task showed limited age effects. Older adults, but not youths, showed larger switching costs than younger adults. A voluntary mixing benefit was found in all ages, implying that voluntarily using 2 languages was less effortful than using one language across the life span. Thus, while youths and older adults experience greater difficulties using multiple languages in response to external cues, they are affected less when they can freely use their languages. This shows that age effects on bilingual language control are context-dependent. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Lexical access versus lexical decision processes for auditory, visual, and audiovisual items: Insights from behavioral and neural measures.

In two experiments, we investigated the relationship between lexical access processes, and processes that are specifically related to making lexical decisions. In Experiment 1, participants performed a standard lexical decision task in which they had to respond as quickly and as accurately as possible to visual (written), auditory (spoken) and audiovisual (written + spoken) items. In Experiment 2, a different group of participants performed the same task but were required to make responses after a delay. Linear mixed effect models on reaction times and single trial Event-Related Potentials (ERPs) revealed that ERP lexicality effects started earlier in the visual than auditory modality, and that effects were driven by the written input in the audiovisual modality. More negative ERP amplitudes predicted slower reaction times in all modalities in both experiments. However, these predictive amplitudes were mainly observed within the window of the lexicality effect in Experiment 1 (the speeded task), and shifted to post-response-probe time windows in Experiment 2 (the delayed task). The lexicality effects lasted longer in Experiment 1 than in Experiment 2, and in the delayed task, we additionally observed a "re-instantiation" of the lexicality effect related to the delayed response. Delaying the response in an otherwise identical lexical decision task thus allowed us to separate lexical access processes from processes specific to lexical decision.

The relationship between phonemic category boundary changes and perceptual adjustments to natural accents.

People often experience difficulties when they first hear a novel accent. Prior research has shown that relatively fast natural accent accommodation can occur. However, there has been little investigation of the underlying perceptual mechanism that drives the learning. The current study examines whether phonemic boundary changes play a central role in natural accent accommodation. Two well-established boundary shifting phenomena were used here-recalibration and selective adaptation-to index the flexibility of phonemic category boundaries. Natural accent accommodation was measured with a task in which listeners heard accented words and nonwords before and after listening to English sentences produced by one of two native Mandarin Chinese speakers with moderate accents. In two experiments, participants completed recalibration, selective adaptation, and natural accent accommodation tasks focusing on a consonant contrast that is difficult for native Chinese speakers to produce. We found that: (a) On the accent accommodation task, participants showed an increased endorsement of accented/mispronounced words after exposure to a speaker's accented speech, indicating a potential relaxation of criteria in the word recognition process; (b) There was no strong link between recalibrating phonemic boundaries and natural accent accommodation; (c) There was no significant correlation between recalibration and selective adaptation. These results suggest that recalibration of phonemic boundaries does not play a central role in natural accent accommodation. Instead, there is some evidence suggesting that natural accent accommodation involves a relaxation of phonemic categorization criteria. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

The effect of orthography on the recognition of pronunciation variants.

In conversational speech, it is very common for words' segments to be reduced or deleted. However, previous research has consistently shown that during spoken word recognition, listeners prefer words' canonical pronunciation over their reduced pronunciations (e.g., pretty pronounced [prɪti] vs. [prɪɾi]), even when the latter are far more frequent. This surprising effect violates most current accounts of spoken word recognition. The current study tests the possibility that words' orthography may be 1 factor driving the advantage for canonical pronunciations during spoken word recognition. Participants learned new words presented in their reduced pronunciation (e.g., [trɒti]), paired with 1 of 3 spelling possibilities: (a) no accompanying spelling, (b) a spelling consistent with the reduced pronunciation (a reduced spelling, e.g., "troddy"), or (c) a spelling consistent with the canonical pronunciation (a canonical spelling, e.g., "trotty"). When listeners were presented with the new words' canonical forms for the first time, they erroneously accepted them at a higher rate if the words had been learned with a canonical spelling. These results remained robust after a delay period of 48 hr, and after additional learning trials. Our findings suggest that orthography plays an important role in the recognition of spoken words and that it is a significant factor driving the canonical pronunciation advantage observed previously. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Speech Rhythm Convergence as a Social Coalition Signal.

Patterns of nonverbal and verbal behavior of interlocutors become more similar as communication progresses. Rhythm entrainment promotes prosocial behavior and signals social bonding and cooperation. Yet, it is unknown if the convergence of rhythm in human speech is perceived and is used to make pragmatic inferences regarding the cooperative urge of the interactors. We conducted two experiments to answer this question. For analytical purposes, we separate pulse (recurring acoustic events) and meter (hierarchical structuring of pulses based on their relative salience). We asked the listeners to make judgments on the hostile or collaborative attitude of interacting agents who exhibit different or similar pulse (Experiment 1) or meter (Experiment 2). The results suggest that rhythm convergence can be a marker of social cooperation at the level of pulse, but not at the level of meter. The mapping of rhythmic convergence onto social affiliation or opposition is important at the early stages of language acquisition. The evolutionary origin of this faculty is possibly the need to transmit and perceive coalition information in social groups of human ancestors. We suggest that this faculty could promote the emergence of the speech faculty in humans.

Regularity in speech rhythm as a social coalition signal.

Regular rhythm facilitates audiomotor entrainment and synchronization in motor behavior and vocalizations between individuals. As rhythm entrainment between interacting agents is correlated with higher levels of cooperation and prosocial affiliative behavior, humans can potentially map regular speech rhythm onto higher cooperation and friendliness between interacting individuals. We tested this hypothesis at two rhythmic levels: pulse (recurrent acoustic events) and meter (hierarchical structuring of pulses based on their relative salience). We asked the listeners to make judgments of the hostile or collaborative attitude of two interacting agents who exhibit either regular or irregular pulse (Experiment 1) or meter (Experiment 2). The results confirmed a link between the perception of social affiliation and rhythmicity: evenly distributed pulses (vowel onsets) and consistent grouping of pulses into recurrent hierarchical patterns are more likely to be perceived as cooperation signals. People are more sensitive to regularity at the level of pulse than at the level of meter, and they are more confident when they associate cooperation with isochrony in pulse. The evolutionary origin of this faculty is possibly the need to transmit and perceive coalition information in social groups of human ancestors. We discuss the implications of these findings for the emergence of speech in humans.

The Role of Native Language and the Fundamental Design of the Auditory System in Detecting Rhythm Changes.

Purpose We investigated whether rhythm discrimination is mainly driven by the native language of the listener or by the fundamental design of the human auditory system and universal cognitive mechanisms shared by all people irrespective of rhythmic patterns in their native language. Method In multiple experiments, we asked participants to listen to 2 continuous acoustic sequences and to determine whether their rhythms were the same or different (AX discrimination). Participants were native speakers of 4 languages with different rhythmic properties (Spanish, French, English, and German) to understand whether the predominant rhythmic patterns of a native language affect sensitivity, bias, and reaction time in detecting rhythmic changes in linguistic (Experiment 2) and in nonlinguistic (Experiments 1 and 2) acoustic sequences. We examined sensitivity and bias measures, as well as reaction times. We also computed Bayes factors in order to assess the effect of native language. Results All listeners performed better (i.e., responded faster and manifested higher sensitivity and accuracy) when detecting the presence or absence of a rhythm change when the 1st stimulus in an AX test pair exhibited regular rhythm (i.e., a syllable-timed rhythmic pattern) than when the 1st stimulus exhibited irregular rhythm (i.e., stress-timed rhythmic pattern). This result pattern was observed both on linguistic and nonlinguistic stimuli and was not modulated by the native language of the participant. Conclusion We conclude that rhythm change detection is a fundamental function of a processing system that relies on general auditory mechanisms and is not modulated by linguistic experience.

Better than native: Tone language experience enhances English lexical stress discrimination in Cantonese-English bilingual listeners.

While many second language (L2) listeners are known to struggle when discriminating non-native features absent in their first language (L1), no study has reported that L2 listeners perform better than native listeners in this regard. The present study tested whether Cantonese-English bilinguals were better in discriminating English lexical stress in individual words or pseudowords than native English listeners, even though lexical stress is absent in Cantonese. In experiments manipulating acoustic, phonotactic, and lexical cues, Cantonese-English bilingual adults exhibited superior performance in discriminating English lexical stress than native English listeners across all phonotactic/lexical conditions when the fundamental frequency (f0) cue to lexical stress was present. The findings underscore the facilitative effect of Cantonese tone language experience on English lexical stress discrimination.

Sound changes that lead to seeing longer-lasting shapes.

To survive, people must construct an accurate representation of the world around them. There is a body of research on visual scene analysis, and a largely separate literature on auditory scene analysis. The current study follows up research from the smaller literature on audiovisual scene analysis. Prior work demonstrated that when there is an abrupt size change to a moving object, observers tend to see two objects rather than one-the abrupt visual change enhances visible persistence of the briefly presented different-sized object. Moreover, if a sequence of tones accompanies the moving object, visible persistence is enhanced if the tone frequency suddenly changes at the same time that the object's size changes. Here, we show that although a sound change must occur at roughly the same time as a visual change to enhance visible persistence, there is a fairly wide time frame during which the sound change can occur. In addition, the impact of a sound change on visible persistence is not simply matter of the physical pattern: The same pattern of sound can enhance visible persistence or not, depending on how the pattern is itself perceived. Specifically, a change in a tone's frequency can enhance visible persistence when it accompanies a visual size change, but the same frequency change will not do so if the shift is embedded in a larger pattern that makes the change merely a continuation of alternating frequencies. The current study supports a scene analysis process that is both multimodal and actively constructive.

The effects of ethnicity, musicianship, and tone language experience on pitch perception.

Language and music are intertwined: music training can facilitate language abilities, and language experiences can also help with some music tasks. Possible language-music transfer effects are explored in two experiments in this study. In Experiment 1, we tested native Mandarin, Korean, and English speakers on a pitch discrimination task with two types of sounds: speech sounds and fundamental frequency (F0) patterns derived from speech sounds. To control for factors that might influence participants' performance, we included cognitive ability tasks testing memory and intelligence. In addition, two music skill tasks were used to examine general transfer effects from language to music. Prior studies showing that tone language speakers have an advantage on pitch tasks have been taken as support for three alternative hypotheses: specific transfer effects, general transfer effects, and an ethnicity effect. In Experiment 1, musicians outperformed non-musicians on both speech and F0 sounds, suggesting a music-to-language transfer effect. Korean and Mandarin speakers performed similarly, and they both outperformed English speakers, providing some evidence for an ethnicity effect. Alternatively, this could be due to population selection bias. In Experiment 2, we recruited Chinese Americans approximating the native English speakers' language background to further test the ethnicity effect. Chinese Americans, regardless of their tone language experiences, performed similarly to their non-Asian American counterparts in all tasks. Therefore, although this study provides additional evidence of transfer effects across music and language, it casts doubt on the contribution of ethnicity to differences observed in pitch perception and general music abilities.