Every day, people struggle to make healthy eating decisions. Nutrition labels have been used to help people properly balance the tradeoff between healthiness and taste, but research suggests that these labels vary in their effectiveness. Here, we investigated the cognitive mechanism underlying value-based decisions with nutrition labels as modulators of value.

More specifically, we used a binary decision task between products along with two different nutrition labels to examine how salient, color-coded labels, compared to purely information-based labels, alter the choice process. Using drift-diffusion modeling, we investigated whether color-coded labels alter the valuation process, or whether they induce a simple stimulus-response association consistent with the traffic-light colors irrespective of the features of the item, which would manifest in a starting point bias in the model. We show that color-coded labels significantly increased healthy choices by increasing the rate of preference formation (drift rate) towards healthier options without altering the starting point. Salient labels increased the sensitivity to health and decreased the weight on taste, indicating that the integration of health and taste attributes during the choice process is sensitive to how information is displayed. Salient labels proved to be more effective in altering the valuation process towards healthier, goal-directed decisions.

The study of foraging success in marine predators is complicated by a lack of direct observations and relies mostly on proxy measures of foraging success. This study assessed spatial and temporal patterns of changes in body condition of southern elephant seals (Mirounga leonina) from Marion Island, based on changes in drift rates (which are related to gains and losses of blubber). Seals showed substantial individual variation in condition changes throughout migrations, which was not explained by age-, sex- or reproductive stages. Substantial variation was also evident in the spatial patterns of condition changes, although an area south of the Antarctic Polar Front (APF) between 10°E and 35°E was evidently associated with moderate, yet consistent gains in condition. Seals that foraged more distantly from Marion Island displayed more extreme gains and losses in condition, suggesting a possible risk/reward trade-off associated with foraging further afield versus closer to the island. Increased condition was consistently negatively related to sea surface temperature, suggesting that seals were generally improving their condition faster in cooler water masses. These results support previous studies predicting that continued warming of the Southern Ocean will result in changes to the habitat use patterns exhibited by southern elephant seals at sea.