Biology subjects

Keller, P. E.

Publications and source records attributed to Keller, P. E..

5 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↗

bioRxiv2025

Neural oscillatory dynamics in joint action: distinct contributions of entrainment and beta modulation to self/other integration

Temporal coordination plays a pivotal role in human activities, enabling effective communication and collaboration. Yet, the neural mechanisms supporting this ability remain poorly understood. Recent research suggests that synchronized beta modulation across individual brains, as measured via EEG hyperscanning, may reflect a shared sensorimotor framework underpinning interpersonal synchronization. Building on the idea that self-other integration is a key mechanism in this process, behavioral studies have shown that adopting a partners first-person visual perspective (1P) enhances interpersonal coordination, as opposed to the natural second-person perspective (2P). Here, we used the body-swap illusion in immersive virtual reality to directly manipulate embodied perspective and investigate its neural consequences. Specifically, we examined how this illusion modulates beta activity and neural entrainment during joint rhythmic action. Forty participants (N=40), randomly paired into twenty dyads, performed a joint finger-tapping task while wearing head-mounted displays for immersive virtual environments. In coupled conditions, the visual scene was manipulated so that participants viewed their partners hand from a 1P perspective, as if it belonged to their own body, or from a natural 2P perspective. In uncoupled control conditions, participants saw their own hand in 1P and 2P, without perceiving any information about their partners tapping. EEG hyperscanning revealed that both neural entrainment (measured as the convergence of low-frequency oscillations) and beta modulation (changes in [~]20 Hz power linked to partner- generated movements) occurred in 1P and 2P visually coupled conditions. However, only beta modulation was selectively enhanced when participants experienced their partners hand from a 1P perspective. These findings suggest that while neural entrainment reflects a general mechanism for tracking a partners rhythmic behavior, beta modulation specifically supports the integration of the others effector into ones bodily representation.

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bioRxiv2020

Lateral prefrontal cortex as a hub for music production with gradation from structural rules to movement sequences

Complex sequential behaviours, such as speaking or playing music, often entail the flexible, rule-based chaining of single acts. However, it remains unclear how the brain translates abstract structural rules into concrete series of movements. Here we demonstrate a multi-level contribution of anatomically distinct cognitive and motor networks to the execution of novel musical sequences. We combined functional and diffusion-weighted neuroimaging to dissociate high-level structural and low-level motor planning of musical chord sequences executed on a piano. Fronto-temporal and fronto-parietal neural networks were involved when sequences violated pianists structural or motor plans, respectively. Prefrontal cortex is identified as a hub where both networks converge within an anterior-to-posterior gradient of action control linking abstract structural rules to concrete movement sequences.

neuroscience↗

bioRxiv2020

Attention affects overall gain but not selective contrast at meter frequencies in the neural processing of rhythm

When listening to music, humans spontaneously perceive and synchronize movement to periodic pulses of meter. A growing body of evidence suggests that this widespread ability is related to neural processes that selectively enhance meter periodicities. However, to what extent these neural processes are affected by the attentional state of the listener remains largely unknown. Here, we recorded EEG while participants listened to auditory rhythms and detected small changes in tempo or pitch of the stimulus, or performed a visual task. The overall neural response to the auditory input decreased when participants attended the visual modality, indicating generally lower sensitivity to acoustic information. However, the selective contrast at meter periodicities did not differ across the three tasks. Moreover, this selective contrast could be trivially accounted for by biologically-plausible models of subcortical auditory processing, but only when meter periodicities were already prominent in the acoustic input. However, when meter periodicities were not prominent in the auditory input, the EEG responses could not be explained by low-level processing. This was also confirmed by early auditory responses that originate predominantly in early auditory areas and were recorded in the same EEG. The contrast at meter periodicities in these early responses was consistently smaller than in the EEG responses originating mainly from higher-level processing stages. Together, these results demonstrate that selective contrast at meter periodicities involves higher-level neural processes that may be engaged automatically, irrespective of behavioral context. This robust shaping of the neural representation of rhythm might thus contribute to spontaneous and effortless synchronization to musical meter in humans across cultures.

neuroscience↗

bioRxiv2019

Hysteresis in the selective synchronization of brain activity to musical rhythm

When listening to musical rhythm, people tend to spontaneously perceive and move along with a periodic pulse-like meter. Moreover, perception and entrainment to the meter show remarkable stability in the face of dynamically changing rhythmic structure of music, even when acoustic cues to meter frequencies are degraded in the rhythmic input. Here we show that this perceptual phenomenon is supported by a selective synchronization of endogenous brain activity to the perceived meter, and that this neural synchronization is significantly shaped by recent context, especially when the incoming input becomes increasingly ambiguous. We recorded the EEG while non-musician and musician participants listened to nonrepeating rhythmic sequences where acoustic cues to meter frequencies either gradually decreased (from regular to ambiguous) or increased (from ambiguous to regular). We observed that neural activity selectively synchronized to the perceived meter persisted longer when the sequence gradually changed from regular to ambiguous compared to the opposite, thus demonstrating hysteresis in the neural processing of a dynamically changing rhythmic stimulus. This dependence on recent context was weaker in the neural responses of musicians, who also showed greater ability to tap along with a regular meter irrespective of stimulus ambiguity, thus reflecting greater stability relative to current and recent stimulus in musicians. Together, these asymmetric context effects demonstrate how the relative contribution of incoming and prior signals is continuously weighted to shape neural selection of functionally-relevant features and guide perceptual organization of dynamic input.\n\nSignificance statementWhen listening to musical rhythm, people tend to spontaneously perceive and move along with a periodic pulse-like meter. Moreover, perception and entrainment to the meter seem to show remarkable stability in the face of dynamically changing rhythmic structure of music. Here we show that this is supported by a selective synchronization of brain activity at meter frequencies. This selective neural synchronization persists longer when a nonrepeating sequence gradually transforms from a regular to an ambiguous rhythm compared to the opposite. This asymmetric context effect suggests that the brain processes rhythm based on a flexible combination of sensory and endogenous information. Such continuously updated neural emphasis on meter periodicities might therefore guide robust perceptual organization of a dynamic rhythmic input.

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