Forward modeling allows feedback control for fast reaching movements

“…this (Bayesian) sensorimotor integration process, the brain adjusts how model predictions should respond to novel evidence by ‘gating’ sensory data, depending on the current context (Desmurget & Grafton, 2000; Friston et al., 2010;Körding & Wolpert, 2004; Sober & Sabes, 2005; Talsma et al., 2010).”

“Adults’ pre-shaping of their hand when reaching for differently sized target objects is taken as a hallmark example for feedforward motor control, guided by the target object’s visual features (e.g., Desmurget & Grafton, 2000).”

“In essence, the cerebellum has been argued to use internal copy signals to implement a forward model of the limb (Fig. 1; Wolpert and Miall 1996; Desmurget and Grafton 2000; Shadmehr and Krakauer 2008).”

“…cerebellum domains that process arm proprioceptive feedback (Prevosto et al., 2010a; see above), are suitable neural substrates for transmission to MIP of the proprioceptive signals required for planning and online correction of reaching (Desmurget & Grafton, 2000; Buneo & Andersen, 2006).”

“It is important to note that sensory feedback information is extensively used for learning, i.e. for building up internal models (Kawato 1999; Arbib et al. 2000; Desmurget and Grafton 2000).”

“…cerebellum would hold internal models related to the automatic control of movement (Wolpert, Ghahramani, & Jordan, 1995), it has been suggested that the parietal cortex holds internal models related to the awareness of movement and intention (Blakemore & Sirigu, 2003; Desmurget & Grafton, 2000).”

“166 Planning and controlling motor actions need to dynamically keep track of the spatial relations between different body parts, 167–169 which is referred to as body schema.”

“However, arm movements are regulated by both feedforward (motor planning and prediction) and feedback (sensorimotor correction) processes (Desmurget and Grafton, 2000).”

“ThisdistinctionisalsomadeinAdams’ 1971)closedloop of models assume different functions (Desmurget and Grafton, 2000).”

“These results also indicate that the torque profile of human arm reaching seems to be insensitive to the SDN and enables the suppression of the expected value of the energy cost, which might be an important finding, although not only open-loop control (Khan et al., 2003) as assumed in our simulation, but also closed-loo…”

“…Knox Division of Orthoptics, University of Liverpool, Liverpool, UK Present address: P. Bernardis Department of Neurosciences, Faculty of Medicine and Surgery, University of Parma, Via Volturno 39/E, 43100 Parma, Italy hand–eye coordination in reaching see Carey 2000; Desmurget and Grafton 2000).”

“Many other brain regions such as the motor cortex have also been proposed to compute internal models 176 and to compare them with sensory feedback to generate motor corrections 176–182 .”

“But evidence that humans do integrate information from the efference copy with sensory feedback in the forward model to achieve a more accurate prediction of behavioral effect has already been shown in several studies (Desmurget and Grafton 2000; Shadmehr et al. 2010; Wolpert et al. 1995).”

“Movement updating can occur during the movement itself and/or after the movement is completed (Desmurget & Grafton, 2000; Kawato, 1999).”

“In this vein, the posterior parietal cortex appears to be involved in the real-time control of movements by constantly updating the internal motor program associated with the observed actions (Wolpert et al., 1995; Desmurget and Grafton, 2000).”

“…movements (Jeannerod, 1988), and that accurate kinesthetic guidance of an effector depends on the integration of feedforward and feedback signals (Desmurget & Grafton, 2000), this result would suggest that the integration of kinesthetic feedback and feedforward operates less efficiently in the…”

“Thus predicting future states based on efference copies of motor commands can be used as an internal reference to circumvent processing delays, a finding that has been demonstrated in adults (Desmurget and Grafton 2000; Tseng et al. 2007; Wagner and Smith 2008; Wolpert and Flanagan 2001).”

“Furthermore, manipulations of sensory information have separated kinematics-based from dynamics-based learning (Krakauer et al. 1999) and defined important distinctions in the on-line control of reaching motions regarding the roles of motor and parietal regions (Desmurget and Grafton 2000).”

“On the one hand, planning movements accurately beforehand is often too hard, on the other feedback control i s often too slow to affect control appropriately [5][6].”

“An ensuing action generates afferent feedback that is required for action monitoring and modification (Kawato, 1999), until its execution becomes optimal (Desmurget and Grafton, 2000).”

“Thus, participants would have had enough time to perform such adjustments (e.g., Desmurget & Grafton, 2000; Paillard, 1996).”

“Thus, the forward model can operate in the absence of online sensorimotor feedback (e.g., Desmurget and Grafton 2000).”

“When learning about the dynamics, the person learns about the relationships between control signals and the expected responses to these signals (Miall and Wolpert, 1996; Flanagan and Wing, 1997; Johansson, 1998; Desmurget and Grafton, 2000).”

“…influences of visual information on movement performance suggest that the visuomotor control loop during ongoing movements may take less time than previously assumed (as in Bushan and Shadmehr 1999, see also reviews about fast visuomotor control loops: Desmurget and Grafton 2000; Paillard 1996).”

“Parietal-cerebellar circuits also form a faster subcortical pathway for translating sensory error information into corrective motor commands relayed to motor cortex [88, 89].”

“The impact of sensory information in the motor process differs between two general components of movements: ballistic and refinement (Desmurget and Grafton, 2000; Elliott et al., 2001, 2010; Urbin et al., 2011).”

“This view affords the hypothesis that the elderly have a reduced capacity to adapt the faster time scales in both feedback and feedforward processes (Desmurget & Grafton, 2000 ; Sosnoff & Newell, 2008 ).”

“During imagined movements, forward models generate the prediction of movement timing, but do so via central commands in the absence of sensory feedback which likely accounts for the greater variability in the timing of imagined actions compared with physical actions.(17,48) This is particularly evident in successful l…”

“According to the dual models of motor control (Arbib 1981; Desmurget and Grafton 2000; Glover 2004; Meyer et al. 1988), upper limb movements are generally segmented into two components.”

“…processes are particularly involved in contributing to the higher frequency processes of control in a constant force level task goal (Newell, Broderick, Deutsch, & Slifkin, 2003) and the regulation of movement control at intermittencies shorter than a reaction time (cf. Desmurget & Grafton, 2000).”

“Although previous research has suggested that the PPC plays a crucial role in updating motor programs and spatial representations [8,9,12,21,24,29,34,35,37,38,42,43], it is likely that this kind of updating occurs in a much more automatic way.”

“This new evidence is also compatible with a hypothetical scheme in which movements are generated based on a moment by moment comparison of current and desired arm postures (Desmurget and Grafton 2000; Soechting and Flanders 2002).”

“The scheme presented in Figure 8 in which we hypothesize different controllers but similar predictors raises a question: why do participants exhibit worse hand-tracking performance with the left hand, if prediction is supposedly as accurate for right and left hand movements? It has been proposed that forward modeling…”

“By combining the clinical tool and gait performance measurements, it is possible to examinewhether functional improvement is accompanied by a change in gait kinematics suggestive of motor control changes.(19) The outcomes of the 10-m walk test, gait velocity, stride length, gait symmetry ratio, and double-support peri…”

“It also largely contributes to forming internal representations of the body and its kinematics, which are key components of internal forward models that adjust and refine movement in real time (Wolpert et al. 1995; Wolpert 1997; Desmurget and Grafton 2000; Shadmehr and Krakauer 2008).”

“…that combine efference copy motor commands, sensory feedback (visual and proprioceptive), and an internal model regarding the dynamics of the arm (BattagliaMayer et al. 2013; Buneo and Andersen 2006; Desmurget et al. 1999; Desmurget and Grafton 2000; Vesia and Crawford 2012; Wolpert et al. 1998).”

“Optimal movement control likely reflects a combination of both feedback and feedforward processes (Desmurget and Grafton, 2000).”

“Such a control pattern is consistent with the idea of an internal model for the control of reach actions [40,41].”

“…that there are several other roles of forward models in action control, such as compensation of sensory processing delays, cancellation of self-generated stimuli; for a general discussion, see Desmurget and Grafton (2000), Miall, Weir, Wolpert, and Stein (1993), and Wolpert and Ghahramani (2004).”

“comparing on-line predicted and observed events (Desmurget and Grafton 2000).”

“The existence of ubiquitous hybrid control loops involving cerebellum with brain-stem, pre-motor systems and parietal lobes is particularly interesting for adaptive goal-directed movement control [16].”

“It has been proposed that online control of fast movements relies on a forward model that estimates the current position of the effector by integrating initial movement conditions, efferent motor signals, and sensory signals (Andersen and Cui, 2009; Chen-Harris et al., 2008; Desmurget and Grafton, 2000).”

“Isolating the neural mechanisms that implement these processes has, however, proven to be quite challenging, and the superior parietal lobule (SPL), inferior parietal lobule (IPL), and cerebellumhave been implicated in both the feedback and feedforward control of movements (Blakemore and Sirigu, 2003; Desmurget and Gr…”

“…SMG in the transformation of sensory input into motor output, and the sensory guidance of behaviour (Binkofski & Buxbaum, 2012; Della-Maggiore, Malfait, Ostry, & Paus, 2004; Desmurget & Grafton, 2000; Desmurget et al., 2009; Rozzi, Ferrari, Bonini, Rizzolatti, & Fogassi, 2008; Rozzi et al., 2006).”

“There has been an ongoing debate within motor control as to whether movements are entirely preplanned (Plamondon, 1995), continuously regulated by afferent information (e.g. Ulloa & Bullock, 2003) or a combination of the two (i.e. an " integrative hybrid " ; Desmurget & Grafton, 2000).”

“…that transform visual input into motor commands as well as the parameters that are controlled by the motor system in the planning and control of movements are an area of active research (for reviews see: Desmurget & Grafton, 2000; Desmurget et al., 1998; Lacquaniti & Caminiti, 1998; Todorov, 2004).”

“Historically, feedback control for fast movements was not considered significant, although this view is changing (Desmurget and Grafton 2000; Flanders et al. 2003).”

“They can also move the dominant hand accurately to a visual target without vision of the hand, indicating that kinesthetic guidance and/or efference copy of motor commands of hand movement can support visually guided reaching (Bard et al. 1999; Desmurget and Grafton 2000; Vercher et al. 1994).”

“However, models of manual and smooth pursuit tracking typically do not take advantage of this strategy and instead, inputs related to target velocity are used to derive an error signal to drive hand or eye acceleration (Engel and Soechting 2000; Churchland and Lisberger 2001).”

“…with noise and variability of rapid movements by monitoring efference copy and sensory afference and adjusting movements when errors occur or are predicted to occur as a result of natural variability (Gordon and Ghez 1987; Meyer et al. 1988; Messier and Kalaska 1999; Desmurget and Grafton 2000).”

“It has been proposed that the brain uses internal models to predict the sensory consequences of a motor command (Desmurget and Grafton, 2000; Miall and Wolpert, 1996; Wolpert et al., 1998; Wolpert and Flanagan, 2001).”

“With regard to the reafference principle (Blakemore et al., 2000; Desmurget & Grafton, 2000; Wolpert & Flanagan, 2001), it is speculated that acoustic feedback is used together with internal models to predict action consequences and compare them to actual feedback while running.”

“…signals from somatosensory cortex to M1 (see also, in macaques, Brochier et al. 1999; Brovelli et al. 2004; Gardner et al. 2007; Witham et al. 2010), whereas gamma oscillations could intervene in the prediction of sensory consequences of actions (Desmurget & Grafton, 2000; Shadmehr et al. 2010).”

“…of this central part of motor control, researchers have usually focused on the preparatory period, which includes motor program processes, and well-known as Anticipatory Postural Adjustments (APA; Belen’kii et al., 1967; Massion, 1992; Desmurget and Grafton, 2000; Maloney and Mamassian, 2009).”

“…measurements based on explicit peripheral sensing, and is widely accepted (Kalveram 1992; Stroeve 1997; Kalveram 1998; Wolpert and Kawato 1998; Bhushan and Shadmehr 1999; Kawato 1999; Desmurget and Grafton 2000; Flanagan et al. 2003), though not completely uncontroversial (Ostry and Feldman 2003).”

“use feedforward control for fast motions and are still able to perform their tasks accurately [2].”

“Target-directed arm movements are essential components of people’s daily activities, which usually require high levels of motion speed and accuracy [1,2].”

“This confirms earlier findings, suggesting that the initial part of pointing movements are planned on the basis of peripheral retinal coordinates and efference commands to the ocular system ( Desmurget and Grafton 2000; Prablanc et al. 1979a, b). However, gaze was found to remain ‘anchored’ to the first target and thu…”

“Alternatively, fast online error correction may involve a comparison of the spatial location of the goal with the anticipated eye displacement using feedforward control (Shadmehr and Mussa Ivaldi 1994; Bernstein et al. 1995; Wolpert et al. 1995; Desmurget and Grafton 2000; Vaziri et al. 2006) such that any deviations…”

“…tasks of accommodating surface changes are so reduced, overall limb movements during treadmill locomotion could be largely determined by efference copy (von Holst, 1954; von Holst and Mittelstaedt, 1950; see Desmurget and Grafton, 2000; Wolpert, 1997; Wolpert and Ghahramani, 2000 for reviews).”