Manipulating multisensory integration for reach planning using tendon vibration
Keywords
Loading...
Authors
Issue Date
2020-03-10
Language
en
Document type
Journal Title
Journal ISSN
Volume Title
Publisher
Title
ISSN
Volume
Issue
Startpage
Endpage
DOI
Abstract
To plan a movement, integration of di erent sensory inputs is necessary to form an
estimate of the current state of the body relative to the environment. Reaching movements
with the hand are a very common and essential part of human interaction with
the environment. Motor planning for these reaching movements relies on input from
visual and proprioceptive senses. These di erent senses can be integrated to obtain an
informative estimate of hand position in order to be able to plan a goal-directed reach.
At subsequent stages of planning the two senses need to be integrated with di erent
relative weightings allowing for optimal integration of the two estimates. The integration
weighting is dependent on the respective properties of the di erent motor planning
stages.
Here, we aim to study this integration process by manipulating the proprioceptive
estimate of hand position. As the estimate of hand position can be described as a likelihood
distribution around a location, we were interested in studying both manipulation
of the precision and accuracy of this estimate. For the former, we developed a simultaneous
agonist-antagonist vibration paradigm to test whether this can decrease precision
of proprioceptive input after vibration cedes, with the muscle spindles adapting to the
varying e ect of vibration. We tested 6 healthy adults on their accuracy and precision in
a hand positioning task during agonist-antagonist vibration. They were tested in a baseline
setup without vibration, then in 4 alternate blocks of applying 100 Hz vibration or
no vibration during task performance. We analysed precision of nal position estimates,
but also accuracy. The results suggest that precision is not decreased, and therefore that
agonist-antagonist vibration does not decrease the quality of the proprioceptive input
in this paradigm.
Previous research indicates that unilateral tendon vibration induces an illusory displacement
of the respective joint. In a second experiment, we used this knowledge to
manipulate accuracy of the proprioceptive estimate of the hand to study the role of
proprioception in multisensory integration for motor planning in a reaching task, using
tendon vibration either on the biceps brachii or the triceps brachii. We tested 20 healthy
adults in this paradigm. Participants had to reach from a central start position through
eight circularly arranged target positions in the horizontal plane. Biceps, triceps and
no-vibration trials were pseudorandomly interleaved. We analysed tangential reach direction
at movement initiation (40% of maximum velocity). For most target directions
there was a signi cant e ect of biceps and triceps vibration on the initial error in reach
direction relative to no-vibration trials. These results support the important role of
proprioception in estimating hand position and planning hand movements, where proprioception
plays an especially large role when transforming planned movement vectors
into executable motor commands.
Description
Citation
Supervisor
Faculty
Faculteit der Sociale Wetenschappen