Optimizing a Changing Rewards Task


Engineering and Applied Sciences



Project Summary

The changing conditions of the environment in which we make decisions affects the outcome of our decision.  Each individual may have a different aptitude to adapt to changing conditions. This study aims to see how humans adapt themselves to the changing conditions and evidence while in the process of decision-making.

For my summer research project at the Gold lab, I helped pilot a prediction and reward task that might explain how people adapt to changes and see if it is affected by psychiatric disorders. In the task, participants choose from the targets presented on the screen and get an associated amount of reward based on their choices. The location of the reward changes as participants advance through the trials thus making the decision-maker keep track of previous choices and reward amounts while making their next choice.

We acquired data from tracking pupil size changes in presence of stimuli and reward. We also recorded eye movements, but the size changes were what helped us the most in analyzing individual responses to changing rewards. I also helped make the task isoluminant so that we control pupil size changes related to varying brightness, eliminating noise in our data.

After we controlled for luminance differences, we further optimized our task by me helping run the full experiment on participants in order to study the effects of changing reward on people’s choices. I will show how different parameters and training affected  our results while piloting the task, since I also helped test two different training demos to assess how well people perform. This body of work build together to a larger project in the lab which involves testing the optimized task in larger human populations and animals which aims to establish a greater psychophysical and behavioral foundation.

The work I did in the lab to help optimize the experiment made me learn a lot than I could ever imagine in a short time. From using a photometer to measure the luminance of a screen, to gamma correct a display, to collecting eye data and conducting behavioral experiments, I had a great experience doing real science and research which have really shaped my analytical skills and the way I solve certain problems.