Dynamically Adjusting Intertemporal Choice Task in Rodents

Abstract

Temporal discounting refers to the tendency for immediate rewards over delayed ones, assessed through intertemporal choice tasks where subjects choose between immediate low-value or delayed high-value rewards. Traditional rodent tasks often require extensive pre-task training, introducing species-specific biases and thus lower translational utility. We present a novel dynamically adjusting intertemporal choice task, where the delay for a large reward adjusts trial-by-trial based on prior choices. Choosing the large reward increases its delay by 500 ms, while selecting the small reward decreases the large reward delay by 500 ms. In eight Long–Evans rats tested across 50 days, key behavioral measures stabilized early, including the average delay and preference for the large reward. However, training enhanced behavioral flexibility, allowing rats to optimize rewards over time. This task enables rapid assessment of delay preferences while also revealing cognitive flexibility, offering significant advantages for investigating decision-making that may be relevant to real-world behaviors.