Biology subjects

van Polanen, V.

Publications and source records attributed to van Polanen, V..

12 recordsLinked to original sources

bioRxiv2022

Transfer of weight information depends differently on used hand and handedness for perception and action

When lifting an object sequentially with the two hands, information about object weight can be transferred from one hand to the other. This information can be used to predictively scale fingertip forces and to form a perceptual estimation about the objects weight. This study investigated how weight information can be transferred between the two hands and how this depends on the used hand and handedness of the participant. Right- and left-handed participants lifted light and heavy objects with the right or left hand in a pseudorandomized order and estimated the objects weight. Results showed that predictive force scaling depended on the previously lifted object, with higher forces rates if a previous object was heavy. This known effect of sensorimotor memory was mostly independent of the used hand and handedness, indicating that weight information could be transferred for fingertip force scaling. Furthermore, a perceptual bias depending on the previous lifted object was found, with lower weight estimations when the previous object was heavy compared to light. In contrast to the results on force scaling, a transfer of this perceptual bias was only found in left-handed participants. In addition, right-handers only showed a bias when they used their dominant hand. These findings indicate that the transfer of weight information depends differently on the used hand and handedness for perceptual estimations and predictive force scaling.

neuroscience↗

bioRxiv2022

The effect of type and context of sensorimotor information on corticospinal excitability

Fingertip force scaling during hand-object interactions typically relies on visual information about the object and sensorimotor memories from previous object interactions. Here, we investigated whether contextual information, that is not explicitly linked to the intrinsic object properties (e.g., size or weight) but is informative for motor control requirements, can mediate force scaling. For this, we relied on two separate behavioral tasks during which we applied transcranial magnetic stimulation (TMS) to probe corticospinal excitability (CSE), as a window onto the primary motor cortex role in controlling fingertip forces. In experiment 1, participants performed a force tracking task, where we manipulated available implicit and explicit visual information. That is, either the force target was fully visible, or only the force error was displayed as a deviation from a horizontal line. We found that participants performance was better when the former condition, in which they had explicit access to predictive information. However, we did not find differences in CSE modulation based on the type of visual information. On the other hand, CSE was modulated by the change in muscle contraction, i.e., contraction vs. relaxation and fast vs. slow changes. In sum, these findings indicate that CSE only reflects the ongoing motor command. In experiment 2, other participants performed a sequential object lifting task of visually identical objects that were differently weighted, in a seemingly random order. Within this task, we hid short series of incrementally increasing object weights. This allowed us to investigate whether participants would scale their forces for specific object weights based on the previously lifted object (i.e., sensorimotor effect) or based on the implicit information about the hidden series of incrementally increasing weights (i.e., extrapolation beyond sensorimotor effects). Results showed that participants did not extrapolate fingertip forces based on the hidden series but scaled their forces solely on the previously lifted object. Unsurprisingly, CSE was not modulated differently when lifting series of random weights versus series of increasing weights. Altogether, these results in two different grasping tasks suggest that CSE encodes ongoing motor components but not sensorimotor cues that are hidden within contextual information. HighlightsO_LIExplicit visual cues and sensorimotor experience are key for object grasping C_LIO_LIInvestigating influence of implicit, contextual information on object grasping C_LIO_LIExplicit but not implicit cues improve motor performance during object grasping C_LIO_LIExplicit but not implicit cues modulate corticospinal excitability C_LI

neuroscience↗

bioRxiv2022

Multisensory information about changing object properties can be used to quickly correct predictive force scaling for object lifting

Sensory information about object properties, such as size or material, can be used to make an estimate of object weight and to generate an accurate motor plan to lift the object. When object properties change, the motor plan needs to be corrected based on the new information. The current study investigated whether such corrections could be made quickly, after the movement was initiated. Participants had to grasp and lift objects of different weights that could be indicated with different cues. During the reaching phase, the cue could change to indicate a different weight and participants had to quickly adjust their planned forces in order to lift the object skilfully. The object weight was cued with different object sizes (Experiment 1) or materials (Experiment 2) and the cue was presented in different sensory modality conditions: visually, haptically or both (visuohaptic). Results showed that participants could adjust their planned forces based on both size and material and in all sensory modality conditions. Furthermore, the findings indicate that visual and haptic information were integrated in the visuohaptic condition, although the multisensory condition did not outperform the conditions with one sensory modality. These results suggest that motor plans can be quickly corrected based on sensory information about object properties from different sensory modalities. These findings provide insights into the information that can be shared between brain areas for the online control of hand-object interactions.

neuroscience↗

bioRxiv2021

Grasp aperture corrections in reach-to-grasp movements do not alter size perception

When grasping an object, the opening between the fingertips (grip aperture) scales with the size of the object. If an object changes in size, the grip aperture has to be corrected. In this study, it was investigated whether such corrections would influence the perceived size of objects. The grasping plan was manipulated with a preview of the object, after which participants initiated their reaching movement without vision. In a minority of the grasps, the object changed in size after the preview and participants had to adjust their grasping movement. Visual feedback was manipulated in two experiments. In experiment 1, vision was restored during reach and both visual and haptic information was available to correct the grasp and lift the object. In experiment 2, no visual information was provided during the movement and grasps could only be corrected using haptic information. Participants made reach-to-grasp movements towards two objects and compared these in size. Results showed that participants adjusted their grasp to a change in object size from preview to grasped object in both experiments. However, a change in object size did not bias the perception of object size or alter discrimination performance. In experiment 2, a small perceptual bias was found when objects changed from large to small. However, this bias was much smaller than the difference that could be discriminated and could not be considered meaningful. Therefore, it can be concluded that the planning and execution of reach-to-grasp movements do not affect the perception of object size.

neuroscience↗

bioRxiv2020

Motor resonance is modulated by an object's weight distribution

Transcranial magnetic stimulation (TMS) studies showed that corticospinal excitability (CSE) is modulated during observation of object lifting, an effect termed motor resonance. Specifically, motor resonance is driven by movement features indicating object weight, such as object size or observed movement kinematics. We investigated in 16 humans (8 females) whether motor resonance is also modulated by an objects weight distribution. Participants were asked to lift an inverted T-shaped manipulandum with interchangeable center of mass after first observing an actor lift the same manipulandum. Participants and actor were instructed to minimize object roll and rely on constrained digit positioning during lifting. Constrained positioning was either collinear (i.e., fingertips on the same height) or noncollinear (i.e., fingertip on the heavy side higher than the one on the light side). The center of mass changed unpredictably before the actors lifts and participants were explained that their weight distribution always matched the actors one. Last, TMS was applied during both lift observation and planning of lift actions. Our results showed that CSE was similarly modulated during lift observation and planning: when participants observed or planned lifts in which the weight distribution was asymmetrically right-sided, CSE recorded from the thumb muscles was significantly increased compared to when the weight distribution was left-sided. During both lift observation and planning, this increase seemed to be primarily driven by the weight distribution and not specifically by the (observed) digit positioning or muscle contraction. In conclusion, our results indicate that complex intrinsic object properties such as weight distributions can modulate activation of the motor system during both observation and planning of lifting actions. Highlights* Motor resonance is observation-induced activity in the observers motor system * We used a dyadic lifting task of objects with asymmetrical weight distribution * We investigated which movement features modulate motor resonance * Motor resonance is modulated by the objects weight distribution * Motor resonance is driven by observed and planned digit positioning

neuroscience↗

bioRxiv2020

Lift observation conveys object weight distribution but partly enhances predictive lift planning

Observation of object lifting allows updating of internal object representations for object weight, in turn enabling accurate scaling of fingertip forces when lifting the same object. Here, we investigated whether lift observation also enables updating of internal representations for an objects weight distribution. We asked participants to lift an inverted T-shaped manipulandum, of which the weight distribution could be changed, in turns with an actor. Participants were required to minimize object roll (i.e., lift performance) during lifting and were allowed to place their fingertips at self-chosen locations. The center of mass changed unpredictably every third to sixth trial performed by the actor and participants were informed that they would always lift the same weight distribution as the actor. Participants observed either erroneous (i.e., object rolling towards its heavy side) or skilled (i.e., minimized object roll) lifts. Lifting performance after observation was compared to lifts without prior observation and to lifts after active lifting, which provided haptic feedback about the weight distribution. Our results show that observing both skilled and erroneous lifts convey an objects weight distribution similar to active lifting, resulting in altered digit positioning strategies. However, minimizing object roll on novel weight distributions was only improved after observing error lifts and not after observing skilled lifts. In sum, these findings suggest that although observing motor errors and skilled motor performance enables updating of digit positioning strategy, only observing error lifts enables changes in predictive motor control when lifting objects with unexpected weight distributions. New and noteworthyIndividuals are able to extract an objects size and weight by observing interactions with objects and subsequently integrate this information in their own motor repertoire. Here, we show that this ability extrapolates to weight distributions. Specifically, we highlighted that individuals can perceive an objects weight distribution during lift observation but can only partially embody this information when planning their own actions.

neuroscience↗

bioRxiv2020

Effects of TMS over the anterior intraparietal area on anticipatory fingertip force scaling and the size-weight illusion

In skilled object lifting, fingertip forces need to be carefully scaled to object weight, which can be inferred from object properties, such as size or material. This anticipatory force scaling ensures smooth and efficient lifting movements. However, even with accurate motor plans, weight perception can still be biased. In the size-weight illusion, objects of different size but equal weight are perceived to differ in heaviness, with the small object perceived to be heavier than the large object. The neural underpinnings of the size-weight illusion and anticipatory force scaling to object size are largely unknown. In this study, we hypothesized a possible role of the anterior intraparietal cortex (aIPS) in predictive force scaling and the size-weight illusion, which we investigated by applying continuous theta burst stimulation (cTBS) prior to participants lifting objects designed to induce the size-weight illusion. Participants received cTBS over aIPS, the primary motor cortex (control area), or sham stimulation. We found no evidence that aIPS stimulation affected the size-weight illusion. Small effects were, however, found on anticipatory force scaling, where grip force was less tuned to object size during initial lifts. These findings suggest that, while aIPS might be peripherally involved in sensorimotor prediction, other brain areas underpin the processes that mediate the size-weight illusion.

neuroscience↗

bioRxiv2019

The role of the anterior intraparietal sulcus and the lateral occipital cortex in fingertip force scaling and weight perception during object lifting

Skillful object lifting relies on scaling fingertip forces according to the objects weight. When no visual cues about weight are available, force planning relies on recent lifting experience. Recently, we showed that previously lifted objects also affect weight estimation, as objects are perceived to be lighter when lifted after heavy objects compared to light ones. Here, we investigated the underlying neural mechanisms mediating these effects. We asked participants to lift objects and estimate their weight. Simultaneously, we applied transcranial magnetic stimulation (TMS) during the dynamic loading or static holding phase. Two subject groups received TMS of either the anterior intraparietal sulcus (aIPS) or lateral occipital area (LO), known to be important nodes in object grasping and perception. We hypothesized that TMS-induced disruption of aIPS and LO would alter force scaling and weight perception. Contrary to our hypothesis, we did not find effects of aIPS or LO stimulation on force planning or weight estimation caused by previous lifting experience. However, we found that TMS of both areas increased grip forces, but only when applied during dynamic loading, and decreased weight estimation, but only when applied during static holding, suggesting time-specific effects. Interestingly, our results also indicate that TMS over LO, but not aIPS, affected load force scaling specifically for heavy objects, which further indicates that planning of load and grip forces might be controlled differently. These findings provide new insights on the interactions between brain networks mediating action and perception during object manipulation. NEW & NOTEWORTHYThis article provides new insights into the neural mechanisms underlying object lifting and perception. Using transcranial magnetic stimulation during object lifting, we show that effects of previous experience on force scaling and weight perception are not mediated by the anterior intraparietal sulcus nor the lateral occipital cortex (LO). In contrast, we highlight a unique role for LO in load force scaling, suggesting different brain processes for grip and load force scaling in object manipulation.

neuroscience↗

bioRxiv2019

Sensorimotor expectations bias motor resonance during observation of object lifting: The causal role of pSTS

Transcranial magnetic stimulation (TMS) studies have highlighted that corticospinal excitability (CSE) is increased during observation of object lifting, an effect termed motor resonance. This facilitation is driven by movement features indicative of object weight, such as object size or observed movement kinematics. Here, we investigated in 35 humans (23 females) how motor resonance is altered when the observers weight expectations, based on visual information, do not match the actual object weight as revealed by the observed movement kinematics. Our results highlight that motor resonance is not robustly driven by object weight but easily masked by a suppressive mechanism reflecting the correctness of the weight expectations. Subsequently, we investigated in 24 humans (14 females) whether this suppressive mechanism was driven by higher-order cortical areas. For this, we induced virtual lesions to either the posterior superior temporal sulcus (pSTS) or dorsolateral prefrontal cortex (DLPFC) prior to having participants perform the task. Importantly, virtual lesion of pSTS eradicated this suppressive mechanism and restored object weight-driven motor resonance. In addition, DLPFC virtual lesion eradicated any modulation of motor resonance. This indicates that motor resonance is heavily mediated by top-down inputs from both pSTS and DLPFC. Altogether, these findings shed new light on the theorized cortical network driving motor resonance. That is, our findings highlight that motor resonance is not only driven by the putative human mirror neuron network consisting of the primary motor and premotor cortices as well as the anterior intraparietal sulcus, but also by top-down input from pSTS and DLPFC. Significance StatementObservation of object lifting activates the observers motor system in a weight-specific fashion: Corticospinal excitability is larger when observing lifts of heavy objects compared to light ones. Interestingly, here we demonstrate that this weight-driven modulation of corticospinal excitability is easily suppressed by the observers expectations about object weight and that this suppression is mediated by the posterior superior temporal sulcus. Thus, our findings show that modulation of corticospinal excitability during observed object lifting is not robust but easily altered by top-down cognitive processes. Finally, our results also indicate how cortical inputs, originating remotely from motor pathways and processing action observation, overlap with bottom-up motor resonance effects.

neuroscience↗

bioRxiv2019

Dynamic size-weight changes after object lifting reduce the size-weight illusion

In the size-weight illusion, the smaller object from two equally weighted objects is typically perceived as being heavier. One explanation is that the mismatch between the weight expectation based on object size and actual sensory feedback influences heaviness perception. In most studies, the size of an object is perceived before its weight. We investigated whether size changes would influence weight perception if both would be perceived simultaneously. We used virtual reality to change the size and weight of an object after lifting and asked participants to judge whether objects became lighter or heavier. We found that simultaneous size-weight changes greatly reduced the size-weight illusion to perceptual biases below discrimination thresholds. In a control experiment in which we used a standard size-weight illusion protocol with sequential lifts of small and large objects in the same virtual reality setup, we found a larger, typical perceptual bias. These results show that the size-weight illusion is smaller when size and weight information is perceived simultaneously. This provides support for the prediction mismatch theory explaining the size-weight illusion. Furthermore, these findings suggest that the lifting phase is a critical time window during which brain mechanisms comparing perceived and expected weight mediate the size-weight illusion.

neuroscience↗

bioRxiv2018

Visual delay affects force scaling and weight perception when lifting objects in virtual reality

Lifting an object requires precise scaling of fingertip forces based on a prediction of object weight. At object contact, a series of tactile and visual events arise that need to be rapidly processed online to fine-tune the planned motor commands for lifting the object. The brain mechanisms underlying multisensory integration serially at transient sensorimotor events, a general feature of actions requiring hand-object interactions, are not yet understood. Here we tested the relative weighting between haptic and visual signals when they are integrated online into the motor command. We used a new virtual reality setup to desynchronize visual feedback from haptics, which allowed us to probe the relative contribution of haptics and vision in driving participants movements when they grasped virtual objects simulated by two force-feedback robots. We found that visual delay changed the profile of fingertip force generation and led participants to perceive objects as heavier than when lifts were performed without visual delay. We further modeled the effect of vision on motor output by manipulating the extent to which delayed visual events could bias the force profile, which allowed us to determine the specific weighting the brain assigns to haptics and vision. Our results show for the first time how visuo-haptic integration is processed at discrete sensorimotor events for controlling object lifting dynamics and further highlight the organization of multisensory signals online for controlling action and perception.\n\nNew & NoteworthyDexterous hand movements require rapid integration of information from different senses, in particular touch and vision, at different key time points as movement unfolds. The relative weighting of vision and haptics for object manipulation is unknown. We used object lifting in virtual reality to desynchronize visual and haptic feedback and find out their relative weightings. Our findings shed light on how rapid multisensory integration is processed over a series of discrete sensorimotor control points.

neuroscience↗

bioRxiv2018

Sensorimotor memory for object weight is based on previous experience during lifting, not holding

To allow skilled object manipulation, the brain must generate a motor command specifically tailored to the object properties. For instance, in object lifting, the forces applied by the fingertips must be scaled to the objects weight. When lifting a series of objects, forces are usually scaled according to recent experience from previously lifted objects, an effect often referred to as sensorimotor memory. In this study, we investigated the specific time period during which stored information from previous object manipulation is used to mediate sensorimotor memory. More specifically, we examined whether sensorimotor memory was based on weight information obtained between object contact and lift completion (lifting phase) or during stable holding (holding phase). Participants lifted objects in virtual reality that could increase or decrease in weight after the object was lifted and held in the air. In this way, we could distinguish whether the force planning in the next lift was scaled depending on weight information gathered from either the dynamic lifting or static holding period. We found that force planning was based on the previous object weight experienced during the lifting, but not holding, phase. This suggest that the lifting phase, while merely lasting a few hundred milliseconds, is a key time period for building up internal object representations used for planning future hand-object interactions.\n\nHIGHLIGHTSO_LIWhen lifting objects, fingertip force scaling is based on the most recent lift\nC_LIO_LIWe investigated what time period is critical for acquiring sensorimotor memory\nC_LIO_LISensorimotor memory is based on weight experienced during previous lift, not hold\nC_LIO_LIThe lifting phase is a key period for building up internal models of object lifting\nC_LI

neuroscience↗