Figure 1.

Our novel diet-search task. A, Schematic of task. Subjects freely search through a display of diamonds on a computer monitor. They can pay a 400 ms time cost to inspect (reveal) the offer values hidden behind any diamond. Maintaining fixation on a revealed offer for 300 ms more results in reward delivery; breaking fixation before 300 ms is up returns the subject to free search. Bottom, Example offer sizes. Percentage indicates percentage of subject's maximum value per offer. B, Plot of all diamond positions for all trials superimposed on image of screen (for details, see Materials and Methods). C, Illustration of recording position. An example coronal slice of a structural MRI of Subject T with area 14 (vmPFC) superimposed in purple. Recording sites were distributed evenly throughout this region. D, Trial durations for 4 option and 7 option trials. Scalloped patterns reflect choices of each sequentially fixated option.