Aversive View Memory and Navigational Risk Sensitivity in the Desert Ant, Cataglyphis Velox

Many ant species are able to establish routes between goal locations by learning views of the surrounding visual panorama. Route formation models have, until recently, focused on the use of attractive view memories, which experienced foragers orient towards to return to the nest or known food sites. However, aversive views have recently been uncovered as a key component of route learning. Here, Cataglyphis velox rapidly learned aversive views, when associated with a negative outcome, a period of captivity in brush, triggering an increase in hesitation behavior. These memories were based on the accumulation of experiences over multiple trips with each new experience regulating foragers hesitancy. Foragers were also sensitive to captivity time differences, suggesting they possess some mechanism to quantify duration. Finally, we characterized foragers perception of risky (variable) versus stable aversive outcomes by associating two sites along the homeward route with two distinct schedules, a fixed duration of captivity or a variable captivity duration, with the same mean time over training. Foragers exhibited significantly less hesitation to the risky outcome compared to the fixed, indicating they perceived risky outcomes as less severe. Results align with a logarithmic relationship between captivity duration and hesitation response, suggesting that foragers perception of the aversive stimulus is a logarithm of its actual value. We conclude by characterizing how view memory and risk perception can be executed within the mushroom bodies neural circuitry.