Measuring information alignment in hyperscanning research with representational analyses: moving beyond interbrain synchrony.

Hyperscanning, which enables the recording of brain activity from multiple individuals simultaneously, has been increasingly used to investigate the neuropsychological processes underpinning social interaction. Previous hyperscanning research has primarily focused on interbrain synchrony, demonstrating an enhanced alignment of brain waves across individuals during social interaction. However, using EEG hyperscanning simulations, we here show that interbrain synchrony has low sensitivity to information alignment across people.

Movement trajectories as a window into the dynamics of emerging neural representations.

The rapid transformation of sensory inputs into meaningful neural representations is critical to adaptive human behaviour. While non-invasive neuroimaging methods are the de-facto method for investigating neural representations, they remain expensive, not widely available, time-consuming, and restrictive. Here we show that movement trajectories can be used to measure emerging neural representations with fine temporal resolution.

Behavioral dynamics of conversation, (mis)communication and coordination in noisy environments.

During conversations people coordinate simultaneous channels of verbal and nonverbal information to hear and be heard. But the presence of background noise levels such as those found in cafes and restaurants can be a barrier to conversational success. Here, we used speech and motion-tracking to reveal the reciprocal processes people use to communicate in noisy environments.

An online browser-based attentional blink replication using visual objects.

The complex relationship between attention and visual perception can be exemplified and investigated through the Attentional Blink. The attentional blink is characterised by impaired attention to the second of two target stimuli, when both occur within 200 - 500ms. The attentional blink has been well studied in experimental lab settings.

Spatial and temporal (non)binding of audiovisual rhythms in sensorimotor synchronisation.

Human movement synchronisation with moving objects strongly relies on visual input. However, auditory information also plays an important role, since real environments are intrinsically multimodal. We used electroencephalography (EEG) frequency tagging to investigate the selective neural processing and integration of visual and auditory information during motor tracking and tested the effects of spatial and temporal congruency between audiovisual modalities.

Neural tracking of visual periodic motion.

Periodicity is a fundamental property of biological systems, including human movement systems. Periodic movements support displacements of the body in the environment as well as interactions and communication between individuals. Here, we use electroencephalography (EEG) to investigate the neural tracking of visual periodic motion, and more specifically, the relevance of spatiotemporal information contained at and between their turning points.

Unique contributions of perceptual and conceptual humanness to object representations in the human brain.

The human brain is able to quickly and accurately identify objects in a dynamic visual world. Objects evoke different patterns of neural activity in the visual system, which reflect object category memberships. However, the underlying dimensions of object representations in the brain remain unclear.

Lateralised dynamic modulations of corticomuscular coherence associated with bimanual learning of rhythmic patterns.

Human movements are spontaneously attracted to auditory rhythms, triggering an automatic activation of the motor system, a central phenomenon to music perception and production. Cortico-muscular coherence (CMC) in the theta, alpha, beta and gamma frequencies has been used as an index of the synchronisation between cortical motor regions and the muscles. Here we investigated how learning to produce a bimanual rhythmic pattern composed of low- and high-pitch sounds affects CMC in the beta frequency band.

Mapping between sound, brain and behaviour: four-level framework for understanding rhythm processing in humans and non-human primates.

Humans perceive and spontaneously move to one or several levels of periodic pulses (a meter, for short) when listening to musical rhythm, even when the sensory input does not provide prominent periodic cues to their temporal location. Here, we review a multi-levelled framework to understanding how external rhythmic inputs are mapped onto internally represented metric pulses. This mapping is studied using an approach to quantify and directly compare representations of metric pulses in signals corresponding to sensory inputs, neural activity and behaviour (typically body movement).

Dynamic Modulation of Beta Band Cortico-Muscular Coupling Induced by Audio-Visual Rhythms.

Human movements often spontaneously fall into synchrony with auditory and visual environmental rhythms. Related behavioral studies have shown that motor responses are automatically and unintentionally coupled with external rhythmic stimuli. However, the neurophysiological processes underlying such motor entrainment remain largely unknown.

Neural and Behavioral Evidence for Frequency-Selective Context Effects in Rhythm Processing in Humans.

When listening to music, people often perceive and move along with a periodic meter. However, the dynamics of mapping between meter perception and the acoustic cues to meter periodicities in the sensory input remain largely unknown. To capture these dynamics, we recorded the electroencephalography while nonmusician and musician participants listened to nonrepeating rhythmic sequences, where acoustic cues to meter frequencies either gradually decreased (from regular to degraded) or increased (from degraded to regular).

Dynamic modulation of cortico-muscular coupling during real and imagined sensorimotor synchronisation.

People have a natural and intrinsic ability to coordinate body movements with rhythms surrounding them, known as sensorimotor synchronisation. This can be observed in daily environments, when dancing or singing along with music, or spontaneously walking, talking or applauding in synchrony with one another. However, the neurophysiological mechanisms underlying accurately synchronised movement with selected rhythms in the environment remain unclear.

Vocal interaction during rhythmic joint action stabilizes interpersonal coordination and individual movement timing.

Because work songs are ubiquitous around the world, singing while working and performing a task with a coactor is presumably beneficial for both joint action and individual task performance. The present study investigated the impact of interpersonal rhythmic vocal interaction on interpersonal phase relations and on individual motor timing performance, which was evaluated by a synchronization-continuation paradigm requiring whole-body movement with or without visual contact. Participants repeated the syllable "" or remained silent in a manipulation of vocal interaction, and they were oriented toward or away from their partner to manipulate visual interaction.

The influence of a conductor and co-performer on auditory-motor synchronisation, temporal prediction, and ancillary entrainment in a musical drumming task.

Interpersonal coordination is exemplified in ensemble musicians, who coordinate their actions deliberately in order to achieve temporal synchronisation in their performances. However, musicians also move parts of their bodies unintentionally or spontaneously, sometimes in ways that do not directly produce sound from their instruments. Musicians' movements-intentional or otherwise-provide visual signals to co-performers, which might facilitate temporal synchronisation.

Accent-induced Modulation of Neural and Movement Patterns during Spontaneous Synchronization to Auditory Rhythms.

Human rhythmic movements spontaneously synchronize with auditory rhythms at various frequency ratios. The emergence of more complex relationships-for instance, frequency ratios of 1:2 and 1:3-is enhanced by adding a congruent accentuation pattern (binary for 1:2 and ternary for 1:3), resulting in a 1:1 movement-accentuation relationship. However, this benefit of accentuation on movement synchronization appears to be stronger for the ternary pattern than for the binary pattern.

Neural multimodal integration underlying synchronization with a co-performer in music: Influences of motor expertise and visual information.

Sensorimotor synchronization is a general skill that musicians have developed to the highest levels of performance, including synchronization in timing and articulation. This study investigated neurocognitive processes that enable such high levels of performance, specifically testing the relevance of 1) motor resonance and sharing high levels of motor expertise with the co-performer, and 2) the role of visual information in addition to auditory information. Musicians with varying levels of piano expertise (including non-pianists) performed on a single piano key with their right hand along with recordings of a pianist who performed simple melodies with the left hand, synchronizing timing and articulation.

Neural tracking and integration of 'self' and 'other' in improvised interpersonal coordination.

Humans coordinate their movements with one another in a range of everyday activities and skill domains. Optimal joint performance requires the continuous anticipation of and adaptation to each other's movements, especially when actions are spontaneous rather than pre-planned. Here we employ dual-EEG and frequency-tagging techniques to investigate how the neural tracking of self- and other-generated movements supports interpersonal coordination during improvised motion.

The influence of pacer-movement continuity and pattern matching on auditory-motor synchronisation.

People commonly move along with auditory rhythms in the environment. Although the processes underlying such sensorimotor synchronisation have been extensively investigated in the previous research, the properties of auditory rhythms that facilitate the synchronisation remain largely unclear. This study explored the possible benefits of a continuity matching between auditory pacers and the movement produced as well as of a spatial pattern matching that has been previously demonstrated with visual pacers.

Accent-induced stabilization of spontaneous auditory-motor synchronization.

Humans spontaneously synchronize their movements with external auditory rhythms such as a metronome or music. Although such synchronization preferentially occurs toward a simple 1:1 movement-sound frequency ratio, the parameters facilitating spontaneous synchronization to more complex frequency ratios remain largely unclear. The present study investigates the dynamics of spontaneous auditory-motor synchronization at a range of frequency ratios between movement and sound, and examines the benefit of simple accentuation pattern on synchronization emergence and stability.

Preferred frequency ratios for spontaneous auditory-motor synchronization: Dynamical stability and hysteresis.

Humans spontaneously synchronize their movements with external auditory rhythms such as a metronome or music. Although such synchronization preferentially occurs toward simple 1:1 movement-stimulus frequency ratio, the extent to which spontaneous synchronization can also occur toward more complex frequency ratios remains largely unclear. The present study investigates the occurrence and dynamical stability of spontaneous auditory-motor synchronization at multiple frequency ratios.

The influence of visual cues on temporal anticipation and movement synchronization with musical sequences.

Music presents a complex case of movement timing, as one to several dozen musicians coordinate their actions at short time-scales. This process is often directed by a conductor who provides a visual beat and guides the ensemble through tempo changes. The current experiment tested the ways in which audio-motor coordination is influenced by visual cues from a conductor's gestures, and how this influence might manifest in two ways: movements used to produce sound related to the music, and movements of the upper-body that do not directly affect sound output.

Single (1:1) vs. double (1:2) metronomes for the spontaneous entrainment and stabilisation of human rhythmic movements.

Rhythmic movements produced by humans become spontaneously entrained to auditory rhythms in the environment. Evidence suggests that synchronisation to external auditory rhythms can contribute to the stabilisation of movements in time and space, opening new perspectives for motor training and rehabilitation. Here we compared the effects of single (1:1) and double (1:2) metronomes (i.

Effects of pitch and tempo of auditory rhythms on spontaneous movement entrainment and stabilisation.

Human movements spontaneously entrain to auditory rhythms, which can help to stabilise movements in time and space. The properties of auditory rhythms supporting the occurrence of this phenomenon, however, remain largely unclear. Here, we investigate in two experiments the effects of pitch and tempo on spontaneous movement entrainment and stabilisation.