Biology subjects

Marneweck, M.

Publications and source records attributed to Marneweck, M..

3 recordsLinked to original sources

bioRxiv2026

Hybrid virtual reality object lifting matches real-world object lifting

Visual feedback and prior experience support anticipatory force control, its learning, and online force adjustments during dexterous object manipulation. How proprioceptive reliability contributes to object manipulation remains poorly understood. Hybrid virtual reality (VR), which pairs physical object interaction with virtual visual feedback, permits controlled visuo-proprioceptive offsets, offering a promising experimental model of proprioceptive unreliability. Since replacing direct vision with virtual visual feedback could itself affect manipulation, we compared real-world object manipulation with no-offset hybrid-VR manipulation in 15 healthy young adults. Participants lifted a visually symmetric inverted T-shaped object with an asymmetric mass distribution, either viewed directly or through VR, while preventing tilt toward the weighted side. After either one or five lifts, the mass distribution switched to the opposite side. Across environments, anticipatory torque increased with repeated lifts, and five preceding lifts produced greater post switch error than one (i.e., repetition-induced anterograde interference). We detected no significant differences between environments in the learning rate of anticipatory force control, trial-to-trial position-force adjustment, or switch-related interference. These findings characterize behavioral patterns across the two environments and provide a necessary foundation for future studies using controlled visuo-proprioceptive offsets to test how proprioceptive unreliability affects object manipulation.

neuroscience↗

bioRxiv2024

Neural Encoding of Direction and Distance across Reference Frames in Visually Guided Reaching

Goal-directed actions require transforming sensory information into motor plans defined across multiple parameters and reference frames. Substantial evidence supports the encoding of target direction in gaze- and body-centered coordinates within parietal and premotor regions. However, how the brain encodes the equally critical parameter of target distance remains less understood. Here, using Bayesian pattern component modeling of fMRI data during a delayed reach-to-target task, we dissociated the neural encoding of both target direction and the relative distances between target, gaze, and hand at early and late stages of motor planning. This approach revealed independent representations of direction and distance along the human dorsomedial reach pathway. During early planning, most premotor and superior parietal areas encoded a targets distance in single or multiple reference frames and encoded its direction. In contrast, distance encoding was magnified in gaze- and body-centric reference frames during late planning. These results emphasize a flexible and efficient human central nervous system that achieves goals by remapping sensory information related to multiple parameters, such as distance and direction, in the same brain areas. Significance statementMotor plans specify various parameters, e.g., target direction and distance, each of which can be defined in multiple reference frames relative to gaze, limb, or head. Combining fMRI, a delayed reach-to-target task, and Bayesian pattern component modeling, we present evidence for independent goal-relevant representations of direction and distance in multiple reference frames across early and late planning along the dorsomedial reach pathway. Initially, areas encoding distance also encode direction, but later in planning, distance encoding in multiple reference frames was magnified. These results emphasize central nervous system flexibility in transforming movement parameters in multiple reference frames crucial for successful goal-directed actions and have important implications for brain-computer interface technology advances with sensory integration.

neuroscience↗

bioRxiv2024

Sensory context of initiation-cue modulates action goal-relevant neural representations

The ability to produce goal-directed movement relies on the integration of diverse sources of sensory information specific to the task goal. Neural representations of goal-relevant features, such as target location and gaze direction, have been well studied in sensorimotor areas. It remains less clear whether goal-relevant motor representations are influenced by sensory changes to initiation-relevant information, such as a go-cue that provides no information about target location. We used Bayesian pattern component modelling of fMRI data during a delayed reach task with either visual or audiovisual go-cues to explore whether neural representations of goal-related features in sensorimotor areas are modulated by changes to initiation-relevant sensory information. We found that representations of target direction and gaze direction in the primary sensory areas, motor areas, and posterior parietal cortex, were sensitive to whether a reach was cued with a visual or audiovisual go-cue. These findings indicate that the central nervous system flexibly delegates the tasks of where to move and when to move based on available sensory context, even if initiation-relevant stimuli provide no additional information about target location.

neuroscience↗