Time Course and Magnitude of Movement-Related Gating of Tactile Detection in Humans. III. Effect of Motor Tasks

Abstract

This study investigated the relative importance of central and peripheral signals for movement-related gating by comparing the time course and magnitude of movement-related decreases in tactile detection during a reference motor task, active isotonic digit 2 (D2) abduction, with that seen during three test tasks: a comparison with active isometric D2 abduction (movement vs. no movement) evaluated the contribution of peripheral reafference generated by the movement to gating; a comparison with passive D2 abduction (motor command vs. no motor command; movement generated by an external agent) allowed us to evaluate the contribution of the central motor command to tactile gating; and finally, the inclusion of an active "no apparatus," or freehand, D2 abduction task allowed us to evaluate the potential contribution of incidental peripheral reafference generated by the position detecting apparatus to the results (apparatus vs. no apparatus). Weak electrical stimuli (2-ms pulse; intensity, 90% detected at rest) were applied to D2 at different delays before and after movement onset or electromyographic (EMG) activity onset. Significant time-dependent movement-related decreases in detection were obtained with all tasks. When the results obtained during the active isotonic movement task were compared with those obtained in the three test tasks, no significant differences in the functions describing detection performance over time were seen. The results obtained with the isometric D2 abduction task show that actual movement of a body part is not necessary to diminish detection of tactile stimuli in a manner similar to the decrease produced by isotonic, active movement. In the passive test task, the peak decrease in detection clearly preceded the onset of passive movement (by 38 ms) despite the lack of a motor command and, presumably, no movement-related peripheral reafference. A slightly but not significantly earlier decrease was obtained with active movement (49 ms before movement onset). Expectation of movement likely did not contribute to the results because stimulus detection during sham passive movement trials (subjects expected but did not receive a passive movement) was not different from performance at rest (no movement). The results obtained with passive movement are best explained by invoking backward masking of the test stimuli by movement-related reafference and demonstrate that movement-related reafference is sufficient to produce decreases in detection with a time course and amplitude not significantly different from that produced by active movement.

The effect of chronic low back pain on tactile suppression during back movements

“…Tactile detection was less accurate during both movement conditions (back, arm) than in the no movement condition, further adding to the evidence in support of the phenomenon of tactile suppression (Chapman and Beauchamp, 2006;, Juravle et al, 2010, Post et al, 1994, Voss et al, 2008, Wasaka et al, 2003, Williams and Chapman, 2000, Williams and Chapman, 2002and Williams et al, 1998. The results also revealed that the phenomenon of tactile suppression is not limited to movements of the limbs (most studies used movements of the arms, hands, or fingers), but also emerges during back movements, replicating a previous study (Van Hulle et al, 2013).…”

“…As an example of such a filtering mechanism just take the phenomenon of tactile suppression, which refers to the intriguing observation that voluntary movement results in reduced levels of somatosensation (Chapman andBeauchamp, 2006 andVitello et al, 2010). Tactile suppression has been well documented in studies showing that the execution of a movement attenuates the detection of light, near-threshold tactile stimuli, particularly when delivered to the moving body part (Chapman and Beauchamp, 2006, Juravle et al, 2010, Post et al, 1994, Voss et al, 2008, Wasaka et al, 2003, Williams and Chapman, 2000, Williams and Chapman, 2002and Williams et al, 1998. Whereas tactile suppression has typically been demonstrated for those movements involving the fingers or the hands, a recent study also showed that back movements result in an attenuation of the detection of tactile stimuli administered to the back (Van Hulle et al, 2013).…”

An asymmetry in force perception contingent on motion reversal

“…• Tactile afference suppression: Prior research has indicated that tactile sensations in the hand are suppressed during some movement tasks (e.g., [8,11]). However, the demonstrated suppression effects involve weak stimuli near sensory thresholds, thus do not seem significant enough to explain the results reported here, which involve signals that are far above previously reported force detection thresholds.…”

Voluntary action alters the perception of visual illusions

“…But while it is consistent with the temporal compression hypothesis, this result could also have occurred because impaired discrimination occurred for reasons that had nothing to do with time. There may instead have been sensory overload or numbing of the finger, insofar as the shocks were delivered on the finger that was both the source of the action and the locus of the temporal discrimination (e.g., Williams & Chapman, 2002). Although these perceptual effects suggest that time compression might occur as a result of voluntary action, the inference would be more convincing if a phenomenal or perceptual change were to be manifested in a sensory modality and bodily location that were removed from the action itself.…”