title: Action-perception coupling in kinesthesia: a new approach.
abstract: According to recent findings, intentional motor actions are controlled by resetting the referent position, R, at which neuromuscular elements, including reflexes, begin to act. It is suggested that somatosensory afferents inform the brain about the deviation (P) of body segments from the centrally set referent position. To perceive the actual position (Q) of body segments and form the position sense (PS), the central and afferent signals are combined: Q=R+P. In previous studies, the R has been shown to remain invariant during involuntary changes in the wrist position elicited by sudden unloading of muscles, suggesting that only the afferent component is responsible for the PS during this reflex. In contrast, the central PS component, R, is predominantly responsible for PS during intentional motion in isotonic conditions. We tested the hypothesis that the R and P are interchangeable PS components such that involuntary changes in wrist position elicited by the unloading reflex can easily be reproduced by making intentional changes in wrist position in isotonic conditions, in the absence of vision. The PS rule also suggests that PS is independent of sense of effort, which was tested by asking subjects to reproduce elbow joint angles under different constant loads. We also tested the hypothesis that tendon vibration may elicit motion that may not be perceived by subjects (no-motion illusion). These hypotheses were confirmed in three experiments. It is concluded that the R and P are additive components of PS and that, contrary to the conventional view, PS is independent of the sense of effort or efference copy. The PS rule also explains kinesthetic illusions and the phantom limb phenomenon. This study advances the understanding of action-perception coupling in kinesthesia.
authors.affiliation: Department of Neurosciences, University of Montreal, Montreal, PQ, Canada H3S 2J4; Centre for Interdisciplinary Research in Rehabilitation (CRIR), Institut de réadaptation Gingras-Lindsay de Montréal, 6300 Darlington, Montreal, PQ, Canada H3S 2J4; Jewish Rehabilitation Hospital, Laval, PQ, Canada. Electronic address: feldman@med.umontreal.ca.
authors.forename: Anatol G
authors.initials: AG
authors.lastname: Feldman
authors.forename: Nabil
authors.initials: N
authors.lastname: Ilmane
authors.forename: Samir
authors.initials: S
authors.lastname: Sangani
authors.forename: Helli
authors.initials: H
authors.lastname: Raptis
authors.forename: Nima
authors.initials: N
authors.lastname: Esmailzadeh
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D004550:Elbow / Q000294:innervation; D004576:Electromyography; D005260:Female; D006801:Humans; D033182:Intention; D007699:Kinesthesis / Q000502:physiology*; D008297:Male; D009038:Motion; D010465:Perception / Q000502:physiology*; D010812:Physical Stimulation; D013710:Tendons / Q000294:innervation; D014732:Vibration; D014955:Wrist Joint / Q000294:innervation; D055815:Young Adult
keywords: Afferent feedback; Body scheme; Kinesthetic illusions; Phantom limb; Position sense; Referent body configuration; Sense of effort