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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).

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.

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.

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.

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.

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.