| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Rehabilitation, U de Montreal, Montreal, Canada; Physiology, U de Montreal, Montreal, Canada
2 Physiology, U de Montreal, Montreal, Canada
* To whom correspondence should be addressed. E-mail: c.elaine.chapman{at}umontreal.ca.
Abstract The purpose of this study was to determine the extent to which motor commands and peripheral reafference differentially control the detection of near-threshold, tactile stimuli. Detection of weak electrical stimuli applied to the index finger (D2) was evaluated with two bias-free measures of sensory detection, the index of detectability (d’) and the proportion of stimuli detected. Stimuli were presented at different delays prior to and during two motor tasks, D2 abduction and elbow extension; both tasks were tested in two modes, active and passive. For both active tasks, the peak decrease in tactile suppression occurred at the onset of electromyographic activity. The time-course for the suppression of detection during active and passive D2 abduction was identical, and preceded the onset of movement (respectively, -35 and -47 ms). These results suggest that movement reafference alone, acting through a mechanism of backward masking, could explain the modulation seen with D2 movement. In contrast, tactile suppression was significantly earlier for active elbow movements (-59 ms) as compared to passive (-21 ms), an observation consistent with both the motor command and peripheral reafference contributing to the suppression of detection of stimuli applied to D2 during movements about a proximal joint. A role for the motor command in tactile gating during distal movements cannot be discounted, however, since differences in the strength and distribution of the peripheral reafference may also have contributed to the proximo-distal differences in the timing of the suppression.
This article has been cited by other articles:
|
|
 |
|
  I. Kurtzer, J. A. Pruszynski, and S. H. Scott Long-Latency Responses During Reaching Account for the Mechanical Interaction Between the Shoulder and Elbow Joints J Neurophysiol, November 1, 2009; 102(5): 3004 - 3015. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Seki, S. I. Perlmutter, and E. E. Fetz Task-Dependent Modulation of Primary Afferent Depolarization in Cervical Spinal Cord of Monkeys Performing an Instructed Delay Task J Neurophysiol, July 1, 2009; 102(1): 85 - 99. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. G. Green Temperature perception on the hand during static versus dynamic contact with a surface Atten Percept Psychophys, July 1, 2009; 71(5): 1185 - 1196. [Abstract] [PDF]
|
|
|
|
|
|
J. Costa, J. Valls-Sole, F. Valldeoriola, and J. Rumia Subcortical Interactions Between Somatosensory Stimuli of Different Modalities and Their Temporal Profile J Neurophysiol, September 1, 2008; 100(3): 1610 - 1621. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
