Force-field adaptation without proprioception: Can vision be used to model limb dynamics?

Abstract

Because our environment and our body can change from time to time, the efficiency of human motor behavior relies on the updating of the neural processes transforming intentions into actions. Adaptation to the context critically depends on sensory feedback such as vision, touch or hearing. Although proprioception is not commonly listed as one of the main senses, its role is determinant for the coordination of daily gestures like goal-directed arm movements. In particular, previous work suggests that proprioceptive information is critical to update the internal representation of limb dynamic properties. Here, we examined the motor behavior of a deafferented patient, deprived of proprioception below the nose, to assess adaptation to new dynamic conditions in the absence of limb proprioception. The patient, and age-matched control participants, reached toward visual targets in a new force field created by a rotating platform. Full vision of the limb and workspace was available throughout the experiment. Although her impairment was obvious in baseline reaching performance, the proprioceptively deafferented patient clearly adapted to the new force conditions. In fact, her time course of adaptation was similar to that observed in controls. Moreover, when tested in the normal force field after adaptation to the new force field, the patient exhibited after-effects similar to those of controls. These findings show that motor adaptation to a modified force field is possible without proprioception and that vision can compensate for the permanent loss of proprioception to update the central representation of limb dynamics.

Delayed Visual Feedback Affects Both Manual Tracking and Grip Force Control When Transporting a Handheld Object

“…After the first 5 s of each trial, the delay increased linearly from 0 to 300 ms in 60 s, then decreased linearly back to 0 ms in 60 s and then remained null for the last 5 s. Right after the six DELAY trials, participants performed three NORMAL trials (similar to the first three trials). Despite the fact that any residuals of motor adaptation were potentially washed off (the visual delay being reset to 0 at the end of each DELAY trial), comparisons between POST-test and PRE-test trials were investigated to assess the presence of aftereffects (Held and Freedman 1963;Sarlegna et al 2010;Shadmehr and Wise 2005). For each participant, breaks were given between trials to avoid fatigue.…”

Effects of Kinesthetic and Cutaneous Stimulation During the Learning of a Viscous Force Field

“…In this setting, small proprioceptive errors were used during the exposure phase but always in the presence of kinesthetic information. Another important finding is presented by Sarlegna et al in [44]. They examined the motor behavior of a deafferented patient, deprived of proprioception below the nose, to assess adaptation to new dynamic conditions in the absence of limb proprioception.…”

State dependence of adaptation of force output following movement observation

“…This seems appropriate since learned dynamics have been shown to be strongly represented in intrinsic-frame, joint coordinates (Shadmehr and Mussa-Ivaldi 1994). Interestingly, studies of deafferented patients suffering from several impaired or unreliable proprioception have found that visual information could be used both to improve the feedforward control and accuracy of unperturbed reaching movements (Ghez et al 1995) and, recently, to adapt to a haptic environment (Sarlegna et al 2010). Although deafferented subjects still strongly differ from observers in that they have access to self-generated motor plans, descending motor commands, and other movement-related signals among other aspects, the above studies suggest that visual signals can at least partially compensate for the absence of proprioception in motor control and learning.…”