Figure 1.

Conceptual motivation and behavioral task. a, Schematic of the oculomotor selection process. Target selection may be driven by sensory drive and/or expected reward, after which the selected target is used to guide choice behavior. b, LRS task. Following baseline fixation, two iso-eccentric targets appear at random locations and the subject is immediately free to choose either target. Target reward magnitudes and differences are fixed in blocks of 40–70 trials and reward block transitions are unsignaled. Target luminance magnitudes and differences are randomly chosen on each trial (see Materials and Methods). c, Expected target choice behavior, plotted as a function of luminance contrast and reward difference between the two targets. When both properties favor selection of the same target (congruent condition), we expect a strong choice bias toward that target. When luminance contrast and reward difference each favor a different target (conflict condition), however, it is unclear which target will be selected.