The undershoot bias: learning to act optimally under uncertainty.
Learning in stochastic environments is increasingly viewed as an important psychological ability. To extend these results from a perceptual to a motor domain, we tested whether participants could learn to solve a stochastic minimal-time task using exploratory learning. The task involved moving a cursor on a computer screen to a target. We systematically varied the degree of random error in movement in three different conditions; each condition had a distinct time-optimal solution. We found that participants approximated the optimal solutions with practice. The results show that adults are sensitive to the stochastic structure of a task and naturally adjust the magnitude of an undershoot bias to the particular movement error of a task.
University of Massachusetts, Amherst 01003, USA.
Sascha E
SE
Engelbrecht
Neil E
NE
Berthier
Laura P
LP
O'Sullivan
D000328:Adult; D001288:Attention; D004193:Discrimination Learning; D005260:Female; D006801:Humans; D008297:Male; D009949:Orientation; D010364:Pattern Recognition, Visual; D011337:Probability Learning; D011340:Problem Solving; D011597:Psychomotor Performance; D011601:Psychophysics; D013269:Stochastic Processes