The observation of explicit and implicit visuomotor cues can drive predictive motor control

Mapping Intimacies ◽

10.1101/664854 ◽

2019 ◽

Author(s):

Guy Rens ◽

Marco Davare

Keyword(s):

Motor Control ◽

Object Representation ◽

Motor Command ◽

Object Weight ◽

Object Lifting ◽

Sixth Trial ◽

Force Scaling ◽

Object Interactions ◽

Fingertip Forces

AbstractRecent studies have highlighted that the observation of hand-object interactions can influence perceptual weight judgements made by an observer. Moreover, observing explicit motor errors during object lifting allows individuals to update their internal sensorimotor representation about object weight. Embodying observed visuomotor cues for the planning of a motor command further enables individuals to accurately scale their fingertip forces when subsequently lifting the same object. However, it is still unknown whether observation of a skilled lift is equally able to mediate predictive motor control in the observer. Here, we tested this hypothesis by asking participants to grasp and lift a manipulandum after observing an actor’s lift. The object weight changed unpredictably (light or heavy) every third to sixth trial performed by the actor. Participants were informed that they would always lift the same weight as the actor and that, based on the experimental condition, they would have to observe skilled or erroneously performed lifts. Our results revealed that the observation of both skilled and erroneously performed lifts allows participants to update their internal sensorimotor object representation, in turn enabling them to predict force scaling accurately. These findings suggest that the observation of explicit as well as implicit visuomotor cues are embodied in the observer’s motor repertoire and can drive changes in predictive motor control.

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Sensorimotor Memory for Object Weight is Based on Previous Experience During Lifting, Not Holding

10.1101/464693 ◽

2018 ◽

Author(s):

Vonne van Polanen ◽

Marco Davare

Keyword(s):

Motor Command ◽

Object Manipulation ◽

Recent Experience ◽

List Type ◽

Holding Period ◽

Object Weight ◽

Object Lifting ◽

Time Period ◽

Sensorimotor Memory ◽

Force Planning

ABSTRACTTo 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 object’s 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.HIGHLIGHTSWhen lifting objects, fingertip force scaling is based on the most recent liftWe investigated what time period is critical for acquiring sensorimotor memorySensorimotor memory is based on weight experienced during previous lift, not holdThe lifting phase is a key period for building up internal models of object lifting

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

10.1101/2020.06.21.163352 ◽

2020 ◽

Author(s):

Guy Rens ◽

Jean-Jacques Orban de Xivry ◽

Marco Davare ◽

Vonne van Polanen

Keyword(s):

Weight Distribution ◽

Haptic Feedback ◽

Center Of Mass ◽

Object Representations ◽

Object Weight ◽

Positioning Strategy ◽

Weight Distributions ◽

Internal Object ◽

Sixth Trial ◽

Fingertip Forces

AbstractObservation 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 object’s 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 object’s 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 object’s 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 object’s weight distribution during lift observation but can only partially embody this information when planning their own actions.

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

Journal of Neurophysiology ◽

10.1152/jn.00374.2020 ◽

2021 ◽

Cited By ~ 1

Author(s):

Guy Rens ◽

Jean-Jacques Orban de Xivry ◽

Marco Davare ◽

Vonne van Polanen

Keyword(s):

Weight Distribution ◽

Haptic Feedback ◽

Center Of Mass ◽

Object Representations ◽

Object Weight ◽

Positioning Strategy ◽

Weight Distributions ◽

Internal Object ◽

Sixth Trial ◽

Fingertip Forces

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 object's 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 object's 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.

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Motor control of downward object-transport movements with precision grip by object weight

Somatosensory & Motor Research ◽

10.1080/08990220.2016.1203304 ◽

2016 ◽

Vol 33 (2) ◽

pp. 130-136 ◽

Cited By ~ 2

Author(s):

Shinji Yamamoto ◽

Yoshihide Shiraki ◽

Shintaro Uehara ◽

Keisuke Kushiro

Keyword(s):

Motor Control ◽

Precision Grip ◽

Object Weight ◽

Object Transport

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Quantifying feedforward control: a linear scaling model for fingertip forces and object weight

Journal of Neurophysiology ◽

10.1152/jn.00065.2015 ◽

2015 ◽

Vol 114 (1) ◽

pp. 411-418 ◽

Cited By ~ 3

Author(s):

Ying Lu ◽

Seda Bilaloglu ◽

Viswanath Aluru ◽

Preeti Raghavan

Keyword(s):

Feedforward Control ◽

Peak Load ◽

Rate Of Change ◽

Load Force ◽

Healthy Individuals ◽

Object Weight ◽

Custom Made ◽

Precise Relationship ◽

Log Linear ◽

Fingertip Forces

The ability to predict the optimal fingertip forces according to object properties before the object is lifted is known as feedforward control, and it is thought to occur due to the formation of internal representations of the object's properties. The control of fingertip forces to objects of different weights has been studied extensively by using a custom-made grip device instrumented with force sensors. Feedforward control is measured by the rate of change of the vertical (load) force before the object is lifted. However, the precise relationship between the rate of change of load force and object weight and how it varies across healthy individuals in a population is not clearly understood. Using sets of 10 different weights, we have shown that there is a log-linear relationship between the fingertip load force rates and weight among neurologically intact individuals. We found that after one practice lift, as the weight increased, the peak load force rate (PLFR) increased by a fixed percentage, and this proportionality was common among the healthy subjects. However, at any given weight, the level of PLFR varied across individuals and was related to the efficiency of the muscles involved in lifting the object, in this case the wrist and finger extensor muscles. These results quantify feedforward control during grasp and lift among healthy individuals and provide new benchmarks to interpret data from neurologically impaired populations as well as a means to assess the effect of interventions on restoration of feedforward control and its relationship to muscular control.

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Complex modulation of fingertip forces during precision grasp and lift after theta burst stimulation over the dorsal premotor cortex

Vojnosanitetski pregled ◽

10.2298/vsp151120249d ◽

2017 ◽

Vol 74 (6) ◽

pp. 526-535

Author(s):

Dragana Drljacic ◽

Sanja Pajic ◽

Aleksandar Nedeljkovic ◽

Sladjan Milanovic ◽

Tihomir Ilic

Keyword(s):

Motor Control ◽

Premotor Cortex ◽

Fine Motor ◽

Dominant Hand ◽

Dorsal Premotor Cortex ◽

Grasp Stability ◽

Precision Grasping ◽

Fingertip Forces ◽

Theta Burst

Background/Aim. Adaptive control and fingertip force synchronization of precise grasp stability during unimanual manipulation of small objects represents an illustrative example of highly fractionated movements that are foundation of fine motor control. It is assumed that this process is controlled by several motor areas of the frontal lobe, particularly applicable to the primary motor (M-1) and dorsal premotor cortex (PMd). Aiming to examine the role of PMd during fine coordination of fingertip forces we applied theta burst repetitive magnetic stimulation (TBS) to disrupt neural processing in that cortical area. Methods. Using a single-blind, randomized, crossover design, 10 healthy subjects (29 ? 3.9 years) received single sessions of continuous TBS (cTBS600), intermittent TBS (iTBS600), or sham stimulation, separate from one another at least one week, over the PMd region of dominant hemisphere. Precision grasp and lift were assessed by instrumented device, recording grip (G) and load (L) forces, during three manipulation tasks (ramp-and-hold, oscillation force producing and simple lifting tasks), with each hand separately, before and after interventions. Results. We observed the improvement of task performance related to constant error (CE) in oscillation task with the dominant hand (DH) after the iTBS (p = 0.009). On the contrary, the cTBS reduced variable error (VE) for non-dominant hand (NH), p = 0.005. Considering force coordination we found that iTBS worsened variables for NH (G/L ratio, p = 0.017; cross-correlation of the G and L, p = 0.047; Gain, p = 0.047). Conclusion. These results demonstrate the ability of TBS to modulate fingertip forces during precision grasping and lifting, when applied over PMd. These findings support the role of PMd in human motor control and forces generation required to hold small objects stable in our hands.

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Observation of Both Skilled and Erroneous Object Lifting Can Improve Predictive Force Scaling in the Observer

Frontiers in Human Neuroscience ◽

10.3389/fnhum.2019.00373 ◽

2019 ◽

Vol 13 ◽

Cited By ~ 2

Author(s):

Guy Rens ◽

Marco Davare

Keyword(s):

Object Lifting ◽

Force Scaling

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A few reasons why psychologlsts can adhere to Feldman and Levin's model

Behavioral and Brain Sciences ◽

10.1017/s0140525x00040735 ◽

1995 ◽

Vol 18 (4) ◽

pp. 746-747 ◽

Cited By ~ 2

Author(s):

Mireille Bonnard ◽

Jean Pailhous

Keyword(s):

Cognitive Psychology ◽

Motor Control ◽

Production Control ◽

Motor Command ◽

Control Variables ◽

Theoretical Position ◽

Control Stage ◽

Trajectory Formation ◽

Product Control

AbstractWe emphasize the relevance to cognitive psychology of Feldman and Levin's theoretical position. Traditional views of motor control have failed to clearly separate “production control” at the level of motor command, based on task-independent CV (control variables), from intentional “product control” based on task-dependent parameters. Because F&L's approach concentrates on the first process (trajectory formation), it can distinguish the product control stage.

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