Biology subjects

Stupacher, J.

Publications and source records attributed to Stupacher, J..

4 recordsLinked to original sources

bioRxiv2026

Computational markers of rhythmic timing in Parkinson's disease

Sensorimotor synchronization requires the nervous system to predict upcoming events while continuously correcting the timing of ongoing actions. Parkinson's disease (PD) is associated with impaired temporal processing, but it remains unclear which cognitive-computational mechanisms underlie rhythmic timing deficits. Here, we applied the Adaptation and Anticipation Model (ADAM) to synchronized finger-tapping data from participants with PD and controls across four steady tempi. After data screening, analyzes included 35 participants with PD and 28 controls. PD was associated with reduced synchronization accuracy and stability, reflected in larger absolute asynchronies and higher variability of asynchronies. ADAM parameter estimates indicated lower phase correction (coupling strength) and higher central timekeeper noise in the PD group, whereas period correction (tempo matching) and peripheral motor noise showed no robust group differences. Across participants, timekeeper noise predicted synchronization accuracy. Phase correction, timekeeper noise, and motor noise predicted synchronization stability, but their associations differed between groups: phase correction was more closely associated with stability in PD, whereas timekeeper and motor noise were more closely associated with stability in controls. These findings suggest that sensorimotor synchronization deficits in PD reflect reduced use of recent timing errors to guide upcoming movements and less precise internal timekeeping. Error correction and timekeeper noise thus emerge as candidate computational markers of altered rhythmic timing in PD, with potential relevance for understanding individual differences in responses to rhythmic auditory cueing.

neuroscience↗

bioRxiv2026

Cultural echoes in social bonding: Universal and culture-specific effects of movement synchrony and music on connectedness, likeability, and well-being

Social bonds are essential for well-being, and moving together to music is a universal means of promoting prosocial behavior and positive affect. However, the functions and interpretations of movement synchrony and music can vary across cultures and may depend on personal values. We examined how interpersonal synchrony and music affect social bonding in participants from individualistic (Denmark, N = 137) and collectivistic (China, N = 226) cultures. Participants watched videos of virtual stick figures - representing themselves (virtual-self) and an unknown person (virtual-other) - moving either synchronously or asynchronously to music or a metronome. After each video, participants rated three indicators of social bonding: their momentary feeling of social connectedness with the virtual-other (Inclusion of Other in the Self, IOS), likeability of the virtual-other, and well-being as the virtual-self. Personal values were measured using the Portrait Value Questionnaire. Music and synchrony promoted all three indicators of social bonding in both cultures, whereas cultural differences emerged in asynchronous conditions. Chinese participants rated the asynchronous virtual-other more likeable than Danish participants, aligning with the collectivistic emphasis on social harmony. Moreover, Chinese participants rated their own well-being higher than Danish participants when the virtual-self moved asynchronously, suggesting greater self-forgiveness in maintaining group harmony. The personal values of benevolence, conformity, and universalism interacted with movement synchrony and cultural background, underscoring the important role of values in interpretations of social interactions. Our findings highlight the universal prosocial effects of music and movement synchrony, while also emphasizing cultural nuances in how these effects are experienced.

neuroscience↗

bioRxiv2026

Universality Meets Cultural Nuances: Affective Responses to Rhythmic and Harmonic Complexity Across Cultures

The pleasurable urge to move to music - known as groove - has been linked to rhythmic and harmonic complexity via an inverted-U relationship, consistent with predictive coding theory of music. This link has been demonstrated mainly in Western listeners, leaving its cultural generality unclear. Given reports of heightened pitch and harmony sensitivity in Chinese listeners, we predicted stronger responses to harmonic complexity and weaker responses to rhythmic complexity compared with Western listeners. We conducted two online experiments measuring "pleasure" and "wanting to move" ratings for musical excerpts varying in rhythmic and harmonic complexity, comparing Chinese and Danish participants as representatives of Eastern and Western traditions. In Experiment 1, which manipulated both dimensions, both groups showed inverted-U responses to rhythmic complexity, but Danish participants exhibited a sharper curve, indicating greater affective differentiation. No inverted-U pattern emerged for harmonic complexity, and Chinese participants did not show enhanced harmonic sensitivity. Experiment 2 focused on rhythmic complexity using ecologically valid stimuli with finer gradations. Again, Danes showed greater sensitivity to rhythmic variation, reflected in a sharper curvature of their inverted U responses, though peak responses did not differ between groups. Our findings support the universality of predictive responses to rhythmic complexity, while highlighting the modulatory role of cultural exposure in shaping musical affective experiences.

neuroscience↗

bioRxiv2021

Beat Perception in Polyrhythms: Time is Structured in Binary Units

In everyday life, we group and subdivide time to understand the sensory environment surrounding us. Our perceptual system establishes hierarchical structures by nesting different groups of time intervals. Organizing time in units such as diurnal rhythms, phrases, and beat patterns, is fundamental to everyday behavior, speech, and music. When listening to music, we extract rhythmic regularities to create a hierarchical metrical structure that enables us to predict the timing of the next events. Foot tapping and head bobbing to musical rhythms are observable evidence of this process. In the special case of polyrhythms, at least two metrical structures compete to become the reference for these temporal regularities, rendering several possible beats with which we can synchronize our movements. While there is general agreement that tempo, pitch, and loudness influence beat perception in polyrhythms, we focused on the yet neglected influence of beat subdivisions. In three online experiments, 300 participants listened to a range of polyrhythms and tapped their index fingers in time with the perceived beat. The polyrhythms consisted of two simultaneously presented isochronous pulse trains with different ratios (2:3, 2:5, 3:4, 3:5, 4:5, 5:6) and different tempi. For ratios 2:3 and 3:4, we additionally manipulated the pitch of the pulse trains. Results showed a highly robust influence of subdivision grouping on beat perception manifested as a propensity towards beats that are subdivided into two or four equally spaced units, as opposed to beats with three or more complex groupings of subdivisions. Additionally, lower pitched pulse trains were more likely to be perceived as the beat. Our findings suggest that subdivisions, not beats, are the basic unit of beat perception, and that the principle underlying the binary grouping of subdivisions reflects a propensity towards simplicity. This preference for simple grouping is widely applicable to human perception and cognition of time.

neuroscience↗