RT Journal Article
A1 Bonnen, Kathryn
A1 Burge, Johannes
A1 Yates, Jacob
A1 Pillow, Jonathan
A1 Cormack, Lawrence K.
T1 Continuous psychophysics: Target-tracking to measure visual sensitivity
JF Journal of Vision
JO JOV
YR 2015
DO 10.1167/15.3.14
JF Journal of Vision
VO 15
IS 3
SP 14
OP 14
SN 1534-7362
AB  We introduce a novel framework for estimating visual sensitivity using a continuous target-tracking task in concert with a dynamic internal model of human visual performance. Observers used a mouse cursor to track the center of a two-dimensional Gaussian luminance blob as it moved in a random walk in a field of dynamic additive Gaussian luminance noise. To estimate visual sensitivity, we fit a Kalman filter model to the human tracking data under the assumption that humans behave as Bayesian ideal observers. Such observers optimally combine prior information with noisy observations to produce an estimate of target position at each time step. We found that estimates of human sensory noise obtained from the Kalman filter fit were highly correlated with traditional psychophysical measures of human sensitivity (R2 > 97%). Because each frame of the tracking task is effectively a “minitrial,” this technique reduces the amount of time required to assess sensitivity compared with traditional psychophysics. Furthermore, because the task is fast, easy, and fun, it could be used to assess children, certain clinical patients, and other populations that may get impatient with traditional psychophysics. Importantly, the modeling framework provides estimates of decision variable variance that are directly comparable with those obtained from traditional psychophysics. Further, we show that easily computed summary statistics of the tracking data can also accurately predict relative sensitivity (i.e., traditional sensitivity to within a scale factor). 
RD 10/13/2019
UL https://doi.org/10.1167/15.3.14