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This research explores the potential of machine learning (ML) in identifying vocal markers for schizophrenia. While previous research showed that voice-based ML models can accurately predict schizophrenia diagnosis and symptoms, it is unclear to what extent such ML markers generalize to different clinical subpopulations and languages: the assessment of generalization performance is however crucial for testing their clinical applicability.We systematically examined voice-based ML model performance on a large cross-linguistic dataset (3 languages: Danish, German, Chinese). Employing a rigorous pipeline to minimize overfitting, including cross-validated training sets and multilingual models, we assessed generalization on participants with schizophrenia and controls speaking the same or different languages. Model performance was comparable to state-of-the art findings (F1-score ~ 0.75) within the same language; however, models did not generalize well - showing a substantial decrease - when tested on new languages, and the performance of multilingual models was also generally low (F1-score ~ 0.50).

Capacities for abstract thinking and problem-solving are central to human cognition. Processes of abstraction allow the transfer of experiences and knowledge between contexts helping us make informed decisions in new or changing contexts. While we are often inclined to relate such reasoning capacities to individual minds and brains, they may in fact be contingent on human-specific modes of collaboration, dialogue, and shared attention. In an experimental study, we test the hypothesis that social interaction enhances cognitive processes of rule-induction, which in turn improves problem-solving performance. Through three sessions of increasing complexity, individuals and groups were presented with a problem-solving task requiring them to categorize a set of visual stimuli. To assess the character of participants' problem representations, after each training session, they were presented with a transfer task involving stimuli that differed in appearance, but shared relations among features with the training set. Besides, we compared participants' categorization behaviors to simulated agents relying on exemplar learning. We found that groups performed superior to individuals and agents in the training sessions and were more likely to correctly generalize their observations in the transfer phase, especially in the high complexity session, suggesting that groups more effectively induced underlying categorization rules from the stimuli than individuals and agents. Crucially, variation in performance among groups was predicted by semantic diversity in members' dialogical contributions, suggesting a link between social interaction, cognitive diversity, and abstraction.

When speaking to infants, adults often produce speech that differs systematically from that directed to other adults. To quantify the acoustic properties of this speech style across a wide variety of languages and cultures, we extracted results from empirical studies on the acoustic features of infant-directed speech. We analysed data from 88 unique studies (734 effect sizes) on the following five acoustic parameters that have been systematically examined in the literature: fundamental frequency (f0), f0 variability, vowel space area, articulation rate and vowel duration. Moderator analyses were conducted in hierarchical Bayesian robust regression models to examine how these features change with infant age and differ across languages, experimental tasks and recording environments. The moderator analyses indicated that f0, articulation rate and vowel duration became more similar to adult-directed speech over time, whereas f0 variability and vowel space area exhibited stability throughout development. These results point the way for future research to disentangle different accounts of the functions and learnability of infant-directed speech by conducting theory-driven comparisons among different languages and using computational models to formulate testable predictions.

Engraved ochres and ostrich eggshells from the South African Blombos Cave and Diepkloof Rock Shelter are among the earliest expressions of human symbolic behavior. Furthermore, they appear to document a continuous practice of abstract mark-making across ~40.000 years. During this time, the engraved patterns change from simpler unstructured patterns to complex, ordered and symmetric cross-hatchings. To inform discussions of the possible function of the engravings, we conducted a two-part experimental study. Based on the assumption that the pragmatic use of an artifact will motivate incremental adaptive refinements, we used transmission chain experiments to reconstruct the original trajectory of changes. We then conducted five experiments to assess the cognitive implications of changes to the patterns and compared these to the original engravings. Although we observe interesting similarities, our findings suggest the Blombos and Diepkloof engravings are not only a product of human cognitive biases and constraints on working memory.

This study compared the acoustic properties of 26 (100% female, 100% monolingual) Danish caregivers' spontaneous speech addressed to their 11- to 24-month-old infants (infant-directed speech, IDS) and an adult experimenter (adult-directed speech, ADS). The data were collected between 2016 and 2018 in Aarhus, Denmark. Prosodic properties of Danish IDS conformed to cross-linguistic patterns, with a higher pitch, greater pitch variability, and slower articulation rate than ADS. However, an acoustic analysis of vocalic properties revealed that Danish IDS had a reduced or similar vowel space, higher within-vowel variability, raised formants, and lower degree of vowel discriminability compared to ADS. None of the measures, except articulation rate, showed age-related differences. These results push for future research to conduct theory-driven comparisons across languages with distinct phonological systems.

Linguistic repetitions in children are conceptualized as negative in children with autism -- echolalia, without communicative purpose -- and positive in typically developing (TD) children -- linguistic alignment involved in shared engagement, common ground and language acquisition. To investigate this apparent contradiction we analyzed spontaneous speech in 67 parent-child dyads from a longitudinal corpus (30 minutes of play activities at 6 visits over 2 years). We included 32 children with autism and 35 linguistically matched TD children (mean age at recruitment 32.76 and 20.27 months). We found a small number of exact repetitions in both groups (roughly 1% of utterances across visits), which increased over time in children with autism and decreased in the TD group. Partial repetitions were much more frequent: children reused caregivers' words at high rates regardless of diagnostic group (24% of utterances at first visit), and this increased in frequency (but not level) over time, faster for TD children (at final visit: 33% for autism, 40% for TD). The same happened for partial repetition of syntax and semantic alignment. However, chance alignment (as measured by surrogate pairs) also increased and findings for developmental changes were reliable only for syntactic and semantic alignment. Children with richer linguistic abilities also displayed a higher tendency to partially re-use their caregivers' language (alignment rates and semantic alignment). This highlights that all children commonly re-used the words, syntax, and topics of their caregivers, albeit with some quantitative differences, and that most repetition was at least potentially productive, with repeated language being re-contextualized and integrated with non-repeated language. The salience of echolalia in ASD might be partially explained by slight differences in frequency, amplified by lower semantic alignment, persistence over time, and expectations of echolalia. More in-depth qualitative and quantitative analyses of how repetitions are used and received in context are needed.

Voice atypicalities are a characteristic feature of schizophrenia, often associated with core negative symptoms. A recent meta-analysis identified atypicalities in pitch, speech rate, and pauses. However, heterogeneity across studies was large and replications almost nonexistent. Further, it is not clear whether vocal patterns are directly related to the mechanisms underlying the disorder and could therefore be found across languages, or not.In this study we implemented a more rigorously cumulative scientific approach by collecting and analyzing a large cross-linguistic corpus of voice recordings. We critically employed meta-analytic priors to systematically assess the replicability of previous findings, and modeled between-participants variability and cross-linguistic differences.We replicate previous meta-analytic findings across all languages for reduced pitch variability, while increased pause duration and lower speech rate results were replicated only in some languages. Most atypical voice patterns, thus, seem not to be distinctive of schizophrenia in general, but more specifically situated in linguistic/cultural differences.

Fluent conversation requires temporal organization between conversational exchanges. By performing a systematic review and Bayesian multi-level meta-analysis, we map the trajectory of infants' turn-taking abilities over the course of early development (0 to 70 months). We synthesize the evidence from 26 studies (78 estimates from 429 unique infants, of which at least 152 are female) reporting response latencies in infant-adult dyadic interactions. The data were collected between 1975 and 2019, exclusively in North America and Europe. Infants took on average circa 1 s to respond, and the evidence of changes in response over time was inconclusive. Infants' response latencies are related to those of their adult conversational partners: an increase of 1 s in adult response latency (e.g., 400 to 1400 ms) would be related to an increase of over 1 s in infant response latency (from 600 to 1857 ms). These results highlight the dynamic reciprocity involved in the temporal organization of turn-taking. Based on these results, we provide recommendations for future avenues of enquiry: studies should analyze how turn-by-turn exchanges develop on a longitudinal timescale, with rich assessment of infants' linguistic and social development.

Theories of vocal signalling in humans typically only consider communication within the interactive group and ignore intergroup dynamics. Recent work has found that colaughter generated between pairs of people in conversation can afford accurate judgements of affiliation across widely disparate cultures, and the acoustic features that listeners use to make these judgements are linked to speaker arousal. But to what extent does colaughter inform third party listeners beyond other dynamic information between interlocutors such as overlapping talk? We presented listeners with short segments (1-3 s) of colaughter and simultaneous speech (i.e. cospeech) taken from natural conversations between established friends and newly acquainted strangers. Participants judged whether the pairs of interactants in the segments were friends or strangers. Colaughter afforded more accurate judgements of affiliation than did cospeech, despite cospeech being over twice in duration relative to colaughter on average. Sped-up versions of colaughter and cospeech (proxies of speaker arousal) did not improve accuracy for either identifying friends or strangers, but faster versions of both modes increased the likelihood of tokens being judged as being between friends. Overall, results are consistent with research showing that laughter is well suited to transmit rich information about social relationships to third party overhearers-a signal that works between, and not just within conversational groups.

Speech input is often noisy and ambiguous. Yet listenersusually do not have difficulties understanding it. A keyhypothesis is that in speech processing acoustic-phoneticbottom-up processing is complemented by top-downcontextual information. This context effect is larger when theambiguous word is only separated from a disambiguating wordby a few syllables compared to many syllables, suggesting thatthere is a limited time window for processing acoustic-phoneticinformation with the help of context. Here, we argue that therelative weight of bottom-up and top-down processes may bedifferent for languages that have different phonologicalproperties. We report an experiment comparing two closelyrelated languages, Danish and Norwegian. We show thatDanish speakers do indeed rely on context more thanNorwegian speakers do. These results highlight the importanceof investigating cross-linguistic differences in speechprocessing, suggesting that speakers of different languagesmay develop different language processing strategies.

Language processing depends on the integration of bottom-upinformation with top-down cues from several differentsources—primarily our knowledge of the real world, ofdiscourse contexts, and of how language works. Previousstudies have shown that factors pertaining to both the senderand the receiver of the message affect the relative weighting ofsuch information. Here, we suggest another factor that maychange our processing strategies: perceptual noise. Wehypothesize that listeners weight different sources of top-downinformation more in situations of perceptual noise than innoise-free situations. Using a sentence-picture matchingexperiment with four forced-choice alternatives, we show thatdegrading the speech input with noise compels the listeners torely more on top-down information in processing. We discussour results in light of previous findings in the literature,highlighting the need for a unified model of spoken languagecomprehension in different ecologically valid situations,including under noisy conditions.

Do people adjust their conversational strategies to the specificcontextual demands of a given situation? Prior studies haveyielded conflicting results, making it unclear how strategiesvary with demands. We combine insights from qualitative andquantitative approaches in a within-participant experimentaldesign involving two different contexts: spontaneouslyoccurring conversations (SOC) and task-oriented conversations(TOC). We systematically assess backchanneling, other-initiated repair and linguistic alignment. We find that SOCexhibit a higher number of backchannels, a reduced and moregeneric repair format and higher rates of lexical and syntacticalignment. TOC are characterized by a high number of specificrepairs and a lower rate of lexical and syntactic alignment.However, when alignment occurs, more linguistic forms arealigned. The findings show that conversational strategies adaptto contextual demands.

Purpose: The aim of the study was to use systematic review and meta-analysis to quantitatively assess the currently available acoustic evidence for prosodic production impairments as a result of right-hemisphere damage (RHD), as well as to develop methodological recommendations for future studies. Method: We systematically reviewed papers reporting acoustic features of prosodic production in RHD in order to identify shortcomings in the literature and make recommendations for future studies. We estimated the meta-analytic effect size of the acoustic features. We extracted standardized mean differences from 16 papers and estimated aggregated effect sizes using hierarchical Bayesian regression models. Results: RHD did present reduced fundamental frequency variation, but the trait was shared with left-hemisphere damage. RHD also presented evidence for increased pause duration. No meta-analytic evidence for an effect of prosody type (emotional vs. linguistic) was found. Conclusions: Taken together, the currently available acoustic data show only a weak specific effect of RHD on prosody production. However, the results are not definitive, as more reliable analyses are hindered by small sample sizes, lack of detail on lesion location, and divergent measuring techniques. We propose recommendations to overcome these issues: Cumulative science practices (e.g., open data and code sharing), more nuanced speech signal processing techniques, and the integration of acoustic measures and perceptual judgments are recommended to more effectively investigate prosody in RHD.

Laughter is a nonverbal vocalization occurring in every known culture, ubiquitous across all forms of human social interaction. Here, we examined whether listeners around the world, irrespective of their own native language and culture, can distinguish between spontaneous laughter and volitional laughter-laugh types likely generated by different vocal-production systems. Using a set of 36 recorded laughs produced by female English speakers in tests involving 884 participants from 21 societies across six regions of the world, we asked listeners to determine whether each laugh was real or fake, and listeners differentiated between the two laugh types with an accuracy of 56% to 69%. Acoustic analysis revealed that sound features associated with arousal in vocal production predicted listeners' judgments fairly uniformly across societies. These results demonstrate high consistency across cultures in laughter judgments, underscoring the potential importance of nonverbal vocal communicative phenomena in human affiliation and cooperation.

How do solution strategies spread in teams? Inspired by the 80s sci-fi movie Close encounters of the third kind, weset up a networked multiplayer game where participants had to signal peace to invading aliens from space by playingmusic. In each round of the game, participants were matched in dyads and through chat had to jointly construct a four-tone melody. Melodies translated to points according to a rugged landscape score system. We compared three networktopologies: a lattice network (participants only play with immediate neighbours), a fully connected network, and dyads.Furthermore, we manipulated the nature of the problem being either open-ended or with fixed solutions by making themaximum possible score known or not. With known maximum score, lattice networks show an advantage with increasedpropensity to explore and diffusion of good solutions, compared to fully connected networks. No effects are observedwhen the maximum score is unknown.

Abstraction lies at the heart of human cognition. While most approaches to abstraction implicitly take the individual as astarting point, we hypothesize abstraction to be contingent on the interactive sharing of diverse perspectives. Interactivealignment, however, can reduce diversity making group members’ contributions more similar and redundant, especially ifthey have not had time to form their own impressions and opinions. We report an experiment investigating the conditionsunder which participants arrive at a superior, abstract rule-based solution to a problem: inferring the direction of the lastgear from the rotation of the first in a series of connected gears. Participants were assigned to three different conditions:1) individual, 2) dyadic, 3) combined: dyad members start individually but are joint mid through the experiment. We findthat performance is significantly higher in the dyadic than in the individual condition, but highest in the combined.

Dating back as far as 100 ka, the Blombos ochre and the Diepkloof ostrich egg engravings are considered among theearliest fossilized evidence of human symbolic behavior. Of special interest to this study is the temporal trajectory spanningmore than 30 thousand years from earlier simpler parallel line patterns to later complex cross-hatchings suggesting adaptivecompositional development. Through a series of three psychophysical experiments we test the hypotheses that the line engrav-ings at each site evolved to become 1) more salient to the human perceptual system, 2) more discriminable from each other, and3) increasingly associated with symbolic intent. Our findings suggest that just as instrumental tools have been found to undergocumulative refinements in adaptation to their function, the ochre and egg shell engravings evolved adaptively to become morefit for their cognitive function as signs.

This paper examines the use of iconic words in earlyconversations between children and caregivers. Thelongitudinal data include a span of six observations of 35children-parent dyads in the same semi-structured activity.Our findings show that children’s speech initially has a highproportion of iconic words, and over time, these wordsbecome diluted by an increase of arbitrary words. Parents’speech is also initially high in iconic words, with a decreasein the proportion of iconic words over time – in this casedriven by the use of fewer iconic words. The level anddevelopment of iconicity are related to individual differencesin the children’s cognitive skills. Our findings fit with thehypothesis that iconicity facilitates early word learning andmay play an important role in learning to produce new words

A crucial aspect of everyday conversational interactions is ourability to establish and maintain common ground.Understanding the relevant mechanisms involved in suchsocial coordination remains an important challenge forcognitive science. While common ground is often discussedin very general terms, different contexts of interaction arelikely to afford different coordination mechanisms. In thispaper, we investigate the presence and relation of threemechanisms of social coordination – backchannels,interactive alignment and conversational repair – across freeand task-oriented conversations. We find significantdifferences: task-oriented conversations involve higherpresence of repair – restricted offers in particular – andbackchannel, as well as a reduced level of lexical andsyntactic alignment. We find that restricted repair isassociated with lexical alignment and open repair withbackchannels. Our findings highlight the need to explicitlyassess several mechanisms at once and to investigate diversesocial activities to understand their role and relations.

Purpose: Linguistic prosody is affected in Parkinson's disease (PD), which implicates the basal ganglia's role in the production of prosody. However, there is no recent systematic synthesis of the available acoustic evidence of prosodic impairment in PD. This study aimed to identify the acoustic features of linguistic prosody that are consistently affected in PD. Method: The authors systematically reviewed articles that reported acoustic features of prosodic production in PD. Articles focused on fundamental frequency (F0) and its variability, intensity and its variability, speech and articulation rate, and pause duration and ratio. From a total of 648 records identified, 36 met criteria for inclusion and exclusion. For each acoustic measurement and task, data from people with PD (PwPD) were compared with those from controls to extract effect sizes. Pooled effect sizes were estimated using robust Bayesian hierarchical regression models. Results: PD was associated with decreased F0 variability and increased pause duration. There was limited evidence of reduced intensity variability and speech rate in PwPD. No evidence was found to suggest that PD affects articulation rate or pause ratio. Conclusions: The primary acoustic parameters of prosody affected by PD are F0 variability and pause duration. The identification of these acoustic parameters has important clinical implications for the selection of PD management strategies. The association of F0 variability and pause duration with PD suggests that the neural circuits controlling these parameters are at least partly shared and might include the basal ganglia. While the current study focused on the phonetic realization of prosodic cues, future studies should examine whether and how PD affects prosody at higher levels of processing. [ABSTRACT FROM AUTHOR]

Laughter is a nonverbal vocal expression that often communicates positive affect and cooperative intent in humans. Temporally coincident laughter occurring within groups is a potentially rich cue of affiliation to overhearers. We examined listeners' judgments of affiliation based on brief, decontextualized instances of colaughter between either established friends or recently acquainted strangers. In a sample of 966 participants from 24 societies, people reliably distinguished friends from strangers with an accuracy of 53-67%. Acoustic analyses of the individual laughter segments revealed that, across cultures, listeners' judgments were consistently predicted by voicing dynamics, suggesting perceptual sensitivity to emotionally triggered spontaneous production. Colaughter affords rapid and accurate appraisals of affiliation that transcend cultural and linguistic boundaries, and may constitute a universal means of signaling cooperative relationships.

What capacities enable linguistic interaction? While severalproposals have been advanced, little progress has been made incomparing and articulating them within an integrative frame-work. In this paper, we take initial steps towards a connec-tionist framework designed to systematically compare differ-ent cognitive models of social interactions. The frameworkwe propose couples two simple-recurrent network systems(Chang, 2002) to explore the computational underpinnings ofinteraction, and apply this modeling framework to predict thesemantic structure derived from transcripts of an experimen-tal joint decision task (Bahrami et al., 2010; Fusaroli et al.,2012). In an exploratory application of this framework, wefind (i) that the coupled network approach is capable of learn-ing from noisy naturalistic input but (ii) that integration of pro-duction and comprehension does not increase the network per-formance. We end by discussing the value of looking to tra-ditional parallel distributed processing as flexible models forexploring computational mechanisms of conversation.

How does the acquisition of a new word affect the successive acquired ones? We model language acquisition interms of foraging in an unprecedentedly fine-grained 1-child corpus (0-3y, RoyEtAl2015). We assess whether successive wordsare learned in close semantic clusters or not (exploitation vs. exploration) and the structure of these clusters. Words are definedin terms of topic distribution in the parental input (Latent Dirichlet Allocation). Distance between successively learned wordsis measured as cosine distance between their topic distribution.Word acquisition can be accurately described as foraging in a sparse resource environment with very local path dependence(power law distribution: alpha=3.9±0.2; detrended fluctuation analysis: alpha=0.6). Words are acquired in semantically closeclusters of 2-4 successive words (Recurrence Quantification Analysis: L=2, LMAX=4, V=2, VMAX=4). The effects remainwhen controlling for shuffled baselines and temporal distance between word acquisition.

In an experimental study, we test the hypothesis that constitutive properties of social interaction - such as diversityin cognitive styles, knowledge and experience - enhance cognitive processes of abstraction. Through three sessions, individualsand dyads categorized aliens based on combinations of features such as the shape and color of their body parts. We manipulatedrelations among the features to elicit increasingly complex categories. Furthermore, to assess the character of participants’evolving categories, after each training session they were presented to a new test set of aliens that differed in appearance, butshared relations among features with aliens from the training set. We found that dyads outcompete individuals in categorizationaccuracy across levels of complexity. We also found that this effect is due to the more abstract and rule-based character ofdyads emerging representations as evidenced by their performance on test items.

Interpersonal physiological entrainment is increasingly arguedto underlie rapport, empathy and even team performance. Weinvestigate the presence, temporal development, possiblemechanisms and impact of interpersonal heart rateentrainment during collective creative LEGO constructiontasks. We observe a statistically significant presence andincrease over time of structured entrainment, which relates tothe actual unfolding and development of behavioralcoordination. Heart rate entrainment does not predict rapportand perceived group competence, but behavioral coordinationdoes. Physiological entrainment, thus, should not beconsidered a universal unmediated proxy for shared emotions,empathy and collective performance. Behavioral coordination– at least in tasks requiring forms of joint action – seems to bea more informative proxy for both physiological entrainmentand collective experience.

Symbolic artifacts present a challenge to theories ofneurocognitive processing due to their dual nature: they areboth physical objects and vehicles of social meanings. Whiletheir physical properties can be read of the surface structure,the meaning of symbolic artifacts depends on theirembeddedness in cultural practices. In this study, participantsbuilt models of LEGO bricks to illustrate their understandingof abstract concepts. Subsequently, they were scanned withfMRI while presented to photographs of their own and others’models. When participants attended to the meaning of themodels, we observed activations associated with socialcognition and semantics. In contrast, when attending to thephysical properties, we observed activations related to objectrecognition and manipulation. Furthermore, when contrastingown and others’ models, we found activations in areasassociated with autobiographical memory and agency. Ourfindings support a view of symbolic artifacts as neurocognitivetrails of human social interactions.

Traditionally different approaches to the study of cognition have been viewed as competing explanatory frameworks. An alternative view, explanatory pluralism, regards different approaches to the study of cognition as complementary ways of studying the same phenomenon, at specific temporal and spatial scales, using appropriate methodological tools. Explanatory pluralism has been often described abstractly, but has rarely been applied to concrete cases. We present a case study of explanatory pluralism. We discuss three separate ways of studying the same phenomenon: a perceptual decision-making task (Bahrami et al., 2010), where pairs of subjects share information to jointly individuate an oddball stimulus among a set of distractors. Each approach analyzed the same corpus but targeted different units of analysis at different levels of description: decision-making at the behavioral level, confidence sharing at the linguistic level, and acoustic energy at the physical level. We discuss the utility of explanatory pluralism for describing this complex, multiscale phenomenon, show ways in which this case study sheds new light on the concept of pluralism, and highlight good practices to critically assess and complement approaches.