Laurel J. Trainor

Template-based gaze-to-face registration enables standardized analysis of eye movements by mapping gaze coordinates onto a canonical facial template, reducing variability introduced by manual area-of-interest (AOI) definition across heterogeneous stimuli. However, existing implementations are largely restricted to static images, rely on semi-manual landmark annotation, and depend on proprietary software, limiting scalability and reproducibility. These constraints become increasingly problematic as research shifts toward dynamic stimuli, wearable eye-tracking, and open-source workflows. We present iTemplate2, a fully open-source Python-based redesign of the original system. The framework introduces four key advances: (1) support for dynamic stimuli via frame-wise coordinate transformation, including a normalization module for wearable and scene-based eye-tracking data; (2) integration of MediaPipe’s Face Landmarker for automated detection of 478 facial landmarks per frame, with multi-face tracking and identity persistence mechanisms that reduce manual annotation requirements; (3) a complete Python reimplementation using NumPy, pandas, OpenCV, PyQt6, and Apache Parquet, providing a cross-platform graphical interface without commercial dependencies; and (4) expanded visualization and analysis tools, including interactive heatmaps, snap-to-landmark AOI definition, and extraction of facial blendshape parameters for concurrent expression analysis. The system is applicable across diverse domains, including infant face scanning, cross-cultural gaze research, clinical screening, and naturalistic social interaction paradigms using wearable eye-tracking. It robustly processes complex multi-face video datasets that are difficult to analyze using conventional template-based methods. iTemplate2 modernizes the template-based registration framework for contemporary behavioral research, converting idiosyncratic visual data into a unified, reproducible analytical space. The software is freely available as an open-source tool at https://osf.io/54v9e/overview?view_only=5ac289558a3d4897a02336124ae409a1.

The evolution of music, language, and prosociality has been debated since before Darwin. The social bonding hypothesis proposes that these phenomena may be interlinked: musicality may have facilitated the evolution of social bonding beyond the possibilities of spoken language. Although dozens of experimental studies have argued that synchronised rhythms can promote bonding, methodological issues including publication bias, sample bias, experimenter effects, and appropriateness of experimental controls make it unclear whether synchronous singing reliably and generally enhances bonding relative to speaking. Following a peer-reviewed Stage 1 Registered Report protocol, we collected data from randomized controlled in-person experiments with 1,017 participants singing and speaking in groups of 5-10 in 30 diverse languages (N = 901 participants after planned quality control exclusions). Our results strongly supported all three of our pre-registered confirmatory hypotheses (all Bayes Factors > 30): (i) synchronised group singing enhances self-reported social bonding (20.9% mean increase), a significantly greater increase than (ii) group conversation (12.9% increase) or (iii) synchronous recitation (15.2% increase). Unregistered exploratory analyses suggested that perceived synchronisation and enjoyment are key predictors of social bonding, results are not artefacts of expectancy or group size, and singing’s bonding effects may be stronger in non-Western than Western contexts. Group singing may serve as a better bonding activity than speaking activities in settings such as school or workplace orientation events. Our study provides strong cross-cultural empirical evidence that music is not merely “auditory cheesecake” that is “useless” compared with language (Pinker, 1997). All forms of vocal communication increase social bonding, but group singing bonds us together over 1.5 times more on average than spoken conversation does.

How the presence of an audience shapes skilled performance has been studied for over a century, largely through laboratory tasks testing whether being watched improves or impairs. Music offers a richer test case: a demanding skill performed for others in which how the performance changes can be measured, not only whether it improved. We compared an expert pianist’s performance of the same six-piece programme alone in a private rehearsal and a public concert, measuring her motion, beat-level timing, sound intensity, and pedalling. The two performances were remarkably similar, with the pianist reproducing her expressive interpretation with high fidelity across every feature. Further, the passages she had marked as most expressive in the score were no more affected by the audience than the rest. Despite this overall consistency, audience presence introduced small but reliable changes: greater variability in her motion, timing, and soft pedal use, and at the least intense moments in the music (as rated by listeners) she drew out the tempo and shaped the quietest passages more with the soft pedal in concert. For this performer, an audience did not impair her performance but facilitated it, supporting a faithful execution of her prepared interpretation while increasing expression through enhanced variability.

Early in life, infants are exposed to richly structured audiovisual signals during interactions with caregivers. Although infant-directed speech and singing effectively capture attention, it remains unclear how rhythmic cues across auditory and visual modalities shape the temporal dynamics of infant attention. To address this question, the natural temporal coupling between modalities in infant-directed singing and speech was disrupted by selectively preserving rhythmic information in either the auditory or visual dimension of the recordings while altering the other modality (auditory rhythm-only and visual rhythm-only conditions, respectively). Twelve-month-old infants showed rhythmic modulation of oculomotor behavior, with eye-tracking measures revealing systematic reorientations towards the eyes at the occurrence of auditory (strong beats and stressed syllables) and visual (head-nod) rhythmic cues, albeit in complementary ways. Synchronization was weaker and more reactive in the auditory rhythm-only condition than in the visual rhythm-only condition. However, when auditory and visual rhythmic cues were presented together in the original videos, eye-looking alignment adjusted to the faster tempo defined by the auditory rhythms, which occurred at a higher rate than the visual rhythms. These findings suggest complementary roles for each modality: visual rhythmic cues may act as an attentional elicitor, establishing reliable oculomotor synchronization, whereas auditory rhythms modulate the tempo of that alignment, serving a temporal tuning function. Our results highlight the dynamic nature of infant attention across different forms of infant-directed communication and the increased attention infants allocate to caregivers’ eyes at critical moments. This reallocation of attention toward the eyes may support learning of social and communicative meaning.

Music is a powerful social tool, and people tend to feel closer to others who share their music preference. Social bonding through music, however, often unfolds without explicit knowledge of others’ tastes. The present study tested whether shared music preference can promote social bonding during passive listening, even in the absence of such knowledge. Ninety-six undergraduate students were assigned to 24 four-person groups and listened to a playlist of either pop or K-pop. Within each group, all participants were either fans or nonfans of the genre they heard, resulting in four crossed conditions: pop fans, pop nonfans, K-pop fans, and K-pop nonfans. Social bonding was indexed through pre–post changes in interpersonal liking and perceived closeness, alongside measures of mood, cooperation (via a public goods game), and group movement synchrony derived from motion capture. Fans showed greater increases in both liking and closeness from pre- to post-listening than nonfans, as well as higher acceleration-based movement synchrony during listening. Mediation analyses indicated that movement synchrony accounted for the fan-group advantage in interpersonal liking, whereas increases in positive mood mediated the fan-group advantage in perceived closeness. No significant differences were found in cooperation. Together, these findings demonstrate that shared music preference can shape social bonding during passive listening, even without explicit awareness of others’ preferences, through coordinated movement and changes in affective state.

It has long been proposed that the brain integrates pitch and timing cues during auditory perception. If true, the pitch of a sound should influence its perceived timing, and its timing should influence its perceived pitch. Previous research has found that higher-pitched sounds tend to be perceived as faster than lower-pitched sounds, and in the present study we investigated whether sounds that arrive earlier or later than expected are similarly perceived as higher or lower in pitch. In Experiment 1, participants heard isochronous, repeating standard tones followed by a pitch-shifted probe, and indicated if the pitch increased or decreased. We observed a strong biasing effect of the probe’s timing on its perceived pitch, such that later probes were more likely to be perceived as lower than the standard. Correct, bias-conforming responses to mistimed probes were also significantly faster than responses to on-beat probes. In Experiment 2, we used an adaptive difficulty procedure to investigate whether this timing-induced bias strengthens under conditions of low discriminability. We did not find evidence that bias varies with the magnitude of pitch change or with individual differences in pitch sensitivity. In conjunction with past findings of pitch-induced illusory timing changes, our results support the hypothesis that pitch and time are perceptually integrated. We discuss this integration within a Bayesian predictive coding framework, as possibly learned from real-world correlations between pitch and timing that derive from latent properties of sound sources.

The multilab registered report by Grassi et al. represents the largest collaborative effort to date to estimate differences in short-term memory between musicians and nonmusicians, testing 1,200 participants across 33 units in 15 countries in an a priori registered design that adhered to open-science practices. Beyond providing precise effect-size estimates, the project exposed substantial diversity in how experts interpret the same data set, particularly regarding the causal status and practical significance of musicians’ cognitive advantages. Here, we present six independent commentaries, each authored by a subset of researchers of the original team, that articulate these contrasting perspectives. Lima and Schellenberg argue that cross-sectional advantages are best explained by preexisting differences rather than training. Román-Caballero et al. emphasize small but reliable far-transfer effects of musical training on domain-general cognition. Zappa et al. call for greater caution in policy claims about music as a cognitive intervention, and Roncaglia et al. situate musical training alongside other forms of expertise (e.g., chess, physical exercise, bilingualism) as one of several routes to cognitive enhancement. Slevc highlights how coordinated multilab projects can help generate specific and testable predictions in a field that often lacks them, and Grassi and Talamini reflect on the broader methodological value of multilab initiatives for building a more accountable and replicable cognitive science. Together, these commentaries showcase productive theoretical pluralism and outline key directions for future research on musical training, cognition, and large-scale collaborative methods.

The Music Ensemble dataset is a large-scale, cross-national database that provides detailed information about the musical, cognitive, personality, and demographic profiles of young adult musicians and nonmusicians. Data were collected from 1438 participants (aged 18–30) across thirty-five research sites in Europe, North America, South America, and Australia. Participants completed an in-person, in-lab battery of objective tests, including measures of verbal, visuospatial and musical short-term memory, executive functions (updating component), nonverbal reasoning, verbal comprehension, and music perception skills. The battery also included standardized and custom self-report questionnaires assessing music sophistication, music reward, personality traits, socioeconomic status, and demographic characteristics. Music Ensemble was preregistered, and the research protocol followed a standardized procedure across sites. The dataset also includes a large subsample of musicians and nonmusicians that are pair-matched for age, gender, and education (678 pairs). It enables well-powered investigations into the relationship between musical expertise and individual differences in cognition, personality, and demographic variables. It is also suitable for training in statistical and psychometric methods.