TY  - JOUR
PY  - 2011//
TI  - Risk-sensitivity in a motor task with speed-accuracy trade-off
JO  - Journal of Neurophysiology
A1  - Nagengast, Arne Johannes
A1  - Daniel, Braun A.
A1  - Wolpert, Daniel M.
SP  - 2668
EP  - 2674
VL  - 105
IS  - 6
N2  - When a racing driver steers a car around a sharp bend there is a trade-off between speed and accuracy, in that high speed can lead to a skid whereas a low speed increases lap time, both of which can adversely affect the driver's payoff function. While speed-accuracy trade-offs have been studied extensively, their susceptibility to risk-sensitivity is much less understood, since most theories of motor control are risk-neutral with respect to payoff, i.e. they only consider mean payoffs and ignore payoff variability. Here we investigate how individual risk-attitudes impact a motor task that involves such a speed-accuracy trade-off. We designed an experiment where a target had to be hit and the reward (given in points) increased as a function of both subject's endpoint accuracy and velocity. As faster movements lead to poorer accuracy, the variance of the reward increased for higher velocities. We tested subjects on two reward conditions that had the same mean reward, but differed in the variance of the reward. A risk-neutral account predicts that subjects should only maximize the mean reward and hence perform identically in the two conditions. In contrast, we found that some (risk-averse) subjects chose to move with lower velocities and others (risk-seeking) with higher velocities in the condition with higher reward variance. This behavior is sub-optimal with regard to maximizing the mean number of points but is in accordance with a risk-sensitive account of movement selection. Our study suggests that individual risk-sensitivity is an important factor in motor tasks with speed-accuracy trade-offs.<p />  <p>Language: en</p>
LA  - en
SN  - 0022-3077
UR  - http://dx.doi.org/10.1152/jn.00804.2010
ID  - ref1
ER  -