This task involves presenting participants with pairs of stimuli, where each stimulus has associated reward values based on various properties. Participants select one of the two stimuli, and the task calculates and presents the reward difference (delta) between the selected and non-selected stimulus.

1. Fixation Cross Trial: A fixation cross is displayed for a short duration. Learning Trials: Participants are presented with two stimuli and must choose one. The stimulus is a polygon with varying properties (number of edges, fill color, edge color, size, and opacity).
2. Reward Trial: After each learning trial, the task displays the difference in 3. reward values (delta) between the two stimuli presented.

• Number of Edges: Varied, each edge contributes 1 to the reward value.
• Fill Color: Red, Blue, Yellow, Green, Orange; each associated with a specific reward value.
• Edge Color: Red, Blue, Yellow, Green, Orange; each associated with a specific reward value.
• Size: Varies among 50, 60, 70, 80, 90; each size associated with a specific reward value.
• Opacity: Varies among 0.2, 0.4, 0.6, 0.8, 1.0; each level of opacity associated with a specific negative reward value.