Predictive processing of music and language in autism: Evidence from Mandarin and English speakers.

Atypical predictive processing has been associated with autism across multiple domains, based mainly on artificial antecedents and consequents. As structured sequences where expectations derive from implicit learning of combinatorial principles, language and music provide naturalistic stimuli for investigating predictive processing. In this study, we matched melodic and sentence stimuli in cloze probabilities and examined musical and linguistic prediction in Mandarin- (Experiment 1) and English-speaking (Experiment 2) autistic and non-autistic individuals using both production and perception tasks. In the production tasks, participants listened to unfinished melodies/sentences and then produced the final notes/words to complete these items. In the perception tasks, participants provided expectedness ratings of the completed melodies/sentences based on the most frequent notes/words in the norms. While Experiment 1 showed intact musical prediction but atypical linguistic prediction in autism in the Mandarin sample that demonstrated imbalanced musical training experience and receptive vocabulary skills between groups, the group difference disappeared in a more closely matched sample of English speakers in Experiment 2. These findings suggest the importance of taking an individual differences approach when investigating predictive processing in music and language in autism, as the difficulty in prediction in autism may not be due to generalized problems with prediction in any type of complex sequence processing.

The Relationship Between Autism and Pitch Perception is Modulated by Cognitive Abilities.

Previous studies reported mixed findings on autistic individuals' pitch perception relative to neurotypical (NT) individuals. We investigated whether this may be partly due to individual differences in cognitive abilities by comparing their performance on various pitch perception tasks on a large sample (n = 164) of autistic and NT children and adults. Our findings revealed that: (i) autistic individuals either showed similar or worse performance than NT individuals on the pitch tasks; (ii) cognitive abilities were associated with some pitch task performance; and (iii) cognitive abilities modulated the relationship between autism diagnosis and pitch perception on some tasks. Our findings highlight the importance of taking an individual differences approach to understand the strengths and weaknesses of pitch processing in autism.

Frequent experience with face coverings for 10 months improves emotion perception among individuals with high autistic traits: A repeated cross-sectional study.

Face coverings pose difficulties for emotion recognition, but it is unclear whether improvement in recognising emotions from the eyes is possible with experience and whether this might be dependent on one's autistic traits, given the associations between high autistic traits and poorer emotion perception and reduced gaze to the eye region. In this preregistered study, participants completed a forced-choice emotion recognition task with photographs of eyes and demographic questionnaires that measure their autistic traits and their interaction frequency with others wearing face coverings at two time points: once at the start of the face covering mandate and again 10 months later. We found that after 10 months, individuals with high autistic traits as a cohort recognised emotions from just the eyes better as a function of their experience with others wearing face coverings, suggesting that emotion perception is malleable even for those who have difficulties with emotion perception.

Probabilistic Learning of Cue-Outcome Associations is not Influenced by Autistic Traits.

According to Bayesian/predictive coding models of autism, autistic individuals may have difficulties learning probabilistic cue-outcome associations, but empirical evidence has been mixed. The target cues used in previous studies were often straightforward and might not reflect real-life learning of such associations which requires learners to infer which cue(s) among many to track. Across two experiments, we compared adult learners with varying levels of autistic traits on their ability to infer the correct cue to learn probabilistic cue-outcome associations when explicitly instructed to do so or when exposed implicitly. We found no evidence for the effect of autistic traits on probabilistic learning accuracy, contrary to the predictions of Bayesian/predictive coding models. Implications for the current Bayesian/predictive coding models are discussed.

Mental representations of speech and musical pitch contours reveal a diversity of profiles in autism spectrum disorder.

LAY ABSTRACT: As a key auditory attribute of sounds, pitch is ubiquitous in our everyday listening experience involving language, music and environmental sounds. Given its critical role in auditory processing related to communication, numerous studies have investigated pitch processing in autism spectrum disorder. However, the findings have been mixed, reporting either enhanced, typical or impaired performance among autistic individuals. By investigating top-down comparisons of internal mental representations of pitch contours in speech and music, this study shows for the first time that, while autistic individuals exhibit diverse profiles of pitch processing compared to non-autistic individuals, their mental representations of pitch contours are typical across domains. These findings suggest that pitch-processing mechanisms are shared across domains in autism spectrum disorder and provide theoretical implications for using music to improve speech for those autistic individuals who have language problems.

Learning to Perceive Non-Native Tones via Distributional Training: Effects of Task and Acoustic Cue Weighting.

As many distributional learning (DL) studies have shown, adult listeners can achieve discrimination of a difficult non-native contrast after a short repetitive exposure to tokens falling at the extremes of that contrast. Such studies have shown using behavioural methods that a short distributional training can induce perceptual learning of vowel and consonant contrasts. However, much less is known about the neurological correlates of DL, and few studies have examined non-native lexical tone contrasts. Here, Australian-English speakers underwent DL training on a Mandarin tone contrast using behavioural (discrimination, identification) and neural (oddball-EEG) tasks, with listeners hearing either a bimodal or a unimodal distribution. Behavioural results show that listeners learned to discriminate tones after both unimodal and bimodal training; while EEG responses revealed more learning for listeners exposed to the bimodal distribution. Thus, perceptual learning through exposure to brief sound distributions (a) extends to non-native tonal contrasts, and (b) is sensitive to task, phonetic distance, and acoustic cue-weighting. Our findings have implications for models of how auditory and phonetic constraints influence speech learning.

Musicians show enhanced perception, but not production, of native lexical tones.

Many studies have reported a musical advantage in perceiving lexical tones among non-native listeners, but it is unclear whether this advantage also applies to native listeners, who are likely to show ceiling-like performance and thus mask any potential musical advantage. The ongoing tone merging phenomenon in Hong Kong Cantonese provides a unique opportunity to investigate this as merging tone pairs are reported to be difficult to differentiate even among native listeners. In the present study, native Cantonese musicians and non-musicians were compared based on discrimination and identification of merging Cantonese tone pairs to determine whether a musical advantage in perception will be observed, and if so, whether this is seen on the phonetic and/or phonological level. The tonal space of the subjects' lexical tone production was also compared. Results indicated that the musicians outperformed the non-musicians on the two perceptual tasks, as indexed by a higher accuracy and faster reaction time, particularly on the most difficult tone pair. In the production task, however, there was no group difference in various indices of tonal space. Taken together, musical experience appears to facilitate native listeners' perception, but not production, of lexical tones, which partially supports a music-to-language transfer effect.

The influence of referent type and familiarity on word-referent mapping.

Is our memory for pairs of items dependent on item characteristics? The present study explores this question using a word learning paradigm; specifically, we examined whether referent characteristics, such as referent type (face/object) and familiarity (known/unknown), may influence word-referent mapping. Moreover, we examined this effect across two test sessions to determine if the influence of referent characteristics might be more pronounced over time, and across two age groups (young vs. older adults) to determine if there might be age-related differences. Participants were presented with pseudoword-referent mappings in four referent conditions (face/object × known/unknown) and then were tested with a recognition task immediately after learning, and again after a short delay. Our findings indicated that names for faces were not learned better than names for objects, despite previous literature suggesting that faces are processed differently. We also found that known referents (defined as having a pre-existing label for a referent) were learned better than unknown items but this familiarity advantage was only observed for faces and not for objects. While there were several age-related findings, these might be due to the longer delay between the immediate and delayed tests among the older adults relative to young adults. Taken together, our results suggest that certain referent characteristics do interact and influence our learning of and memory for such pairings.

One Way or Another: Evidence for Perceptual Asymmetry in Pre-attentive Learning of Non-native Contrasts.

Research investigating listeners' neural sensitivity to speech sounds has largely focused on segmental features. We examined Australian English listeners' perception and learning of a supra-segmental feature, pitch direction in a non-native tonal contrast, using a passive oddball paradigm and electroencephalography. The stimuli were two contours generated from naturally produced high-level and high-falling tones in Mandarin Chinese, differing only in pitch direction (Liu and Kager, 2014). While both contours had similar pitch onsets, the pitch offset of the falling contour was lower than that of the level one. The contrast was presented in two orientations (standard and deviant reversed) and tested in two blocks with the order of block presentation counterbalanced. Mismatch negativity (MMN) responses showed that listeners discriminated the non-native tonal contrast only in the second block, reflecting indications of learning through exposure during the first block. In addition, listeners showed a later MMN peak for their second block of test relative to listeners who did the same block first, suggesting linguistic (as opposed to acoustic) processing or a misapplication of perceptual strategies from the first to the second block. The results also showed a perceptual asymmetry for change in pitch direction: listeners who encountered a falling tone deviant in the first block had larger frontal MMN amplitudes than listeners who encountered a level tone deviant in the first block. The implications of our findings for second language speech and the developmental trajectory for tone perception are discussed.

Effect of Linguistic and Musical Experience on Distributional Learning of Nonnative Lexical Tones.

Purpose: Evidence suggests that extensive experience with lexical tones or musical training provides an advantage in perceiving nonnative lexical tones. This investigation concerns whether such an advantage is evident in learning nonnative lexical tones based on the distributional structure of the input. Method: Using an established protocol, distributional learning of lexical tones was investigated with tone language (Mandarin) listeners with no musical training (Experiment 1) and nontone language (Australian English) listeners with musical training (Experiment 2). Within each experiment, participants were trained on a bimodal (2-peak) or a unimodal (single peak) distribution along a continuum spanning a Thai lexical tone minimal pair. Discrimination performance on the target minimal pair was assessed before and after training. Results: Mandarin nonmusicians exhibited clear distributional learning (listeners in the bimodal, but not those in the unimodal condition, improved significantly as a function of training), whereas Australian English musicians did not (listeners in both the bimodal and unimodal conditions improved as a function of training). Conclusions: Our findings suggest that veridical perception of lexical tones is not sufficient for distributional learning of nonnative lexical tones to occur. Rather, distributional learning appears to be modulated by domain-specific pitch experience and is constrained possibly by top-down interference.

Learning novel musical pitch via distributional learning.

Because different musical scales use different sets of intervals and, hence, different musical pitches, how do music listeners learn those that are in their native musical system? One possibility is that musical pitches are acquired in the same way as phonemes, that is, via distributional learning, in which learners infer knowledge from the distributional structure of their input. In this study, we investigate whether novel musical pitch can be acquired distributionally. Nonmusician adults were trained on a continuum spanning a novel musical chord minimal pair (i.e., a novel chord and a mistuned version of that chord) in which the continuum was presented either in a bimodal distribution, with a modal peak at each end of the continuum, or in a unimodal distribution, with a single central modal peak. Discrimination of target minimal pairs was assessed before and after exposure to the distribution. Distributional learning would be said to occur if learners in the bimodal condition, but not those in the unimodal condition, showed evidence of learning, as indexed by improvement in discriminating the minimal pair from pretest to posttest. This indeed was the outcome, suggesting that the building blocks of musical melody-musical pitch-can be acquired using distributional learning. (PsycINFO Database Record

Naïve Learners Show Cross-Domain Transfer after Distributional Learning: The Case of Lexical and Musical Pitch.

Experienced listeners of a particular acoustic cue in either speech or music appear to have an advantage when perceiving a similar cue in the other domain (i.e., they exhibit cross-domain transfer). One explanation for cross-domain transfer relates to the acquisition of the foundations of speech and music: if acquiring pitch-based elements in speech or music results in heightened attention to pitch in general, then cross-domain transfer of pitch may be observed, which may explain the cross-domain phenomenon seen among listeners of a tone language and listeners with musical training. Here, we investigate this possibility in naïve adult learners, who were trained to acquire pitch-based elements using a distributional learning paradigm, to provide a proof-of-concept for the explanation. Learners were exposed to a stimulus distribution spanning either a Thai lexical tone minimal pair or a novel musical chord minimal pair. Within each domain, the distribution highlights pitch to facilitate learning of two different sounds (Bimodal distribution) or the distribution minimizes pitch so that the input is inferred to be from a single sound (Unimodal distribution). Learning was assessed before and after exposure to the distribution using discrimination tasks with both Thai tone and musical chord minimal pairs. We hypothesize: (i) distributional learning for learners in both the tone and the chord distributions, that is, pre-to-post improvement in discrimination after exposure to the Bimodal but not the Unimodal distribution; and (ii) for both the tone and chord conditions, learners in the Bimodal conditions but not those in the Unimodal conditions will show cross-domain transfer, as indexed by improvement in discrimination of test items in the domain other than what they were trained on. The results support both hypotheses, suggesting that distributional learning is not only used to acquire the foundations of speech and music, but may also play a role in cross-domain transfer: as a result of learning primitives based on a particular cue, learners show heightened attention to that cue in any auditory signal.

Distributional Learning of Lexical Tones: A Comparison of Attended vs. Unattended Listening.

This study examines whether non-tone language listeners can acquire lexical tone categories distributionally and whether attention in the training phase modulates the effect of distributional learning. Native Australian English listeners were trained on a Thai lexical tone minimal pair and their performance was assessed using a discrimination task before and after training. During Training, participants either heard a Unimodal distribution that would induce a single central category, which should hinder their discrimination of that minimal pair, or a Bimodal distribution that would induce two separate categories that should facilitate their discrimination. The participants either heard the distribution passively (Experiments 1A and 1B) or performed a cover task during training designed to encourage auditory attention to the entire distribution (Experiment 2). In passive listening (Experiments 1A and 1B), results indicated no effect of distributional learning: the Bimodal group did not outperform the Unimodal group in discriminating the Thai tone minimal pairs. Moreover, both Unimodal and Bimodal groups improved above chance on most test aspects from Pretest to Posttest. However, when participants' auditory attention was encouraged using the cover task (Experiment 2), distributional learning was found: the Bimodal group outperformed the Unimodal group on a novel test syllable minimal pair at Posttest relative to at Pretest. Furthermore, the Bimodal group showed above-chance improvement from Pretest to Posttest on three test aspects, while the Unimodal group only showed above-chance improvement on one test aspect. These results suggest that non-tone language listeners are able to learn lexical tones distributionally but only when auditory attention is encouraged in the acquisition phase. This implies that distributional learning of lexical tones is more readily induced when participants attend carefully during training, presumably because they are better able to compute the relevant statistics of the distribution.