Everyday life abounds with information from a multitude of sources. But how do individuals discern important information from that which can or should be disregarded? Most of the research on learning in humans and other animals has focused on models in which information is acquired via first-hand experience. Direct exposure to an event, however, is not the only way that individuals gather knowledge or form memories. Evidence suggests that humans and other primates can develop fear associations from a social context, by observing or interacting with others. For example, a person may have an intense fear of snakes despite having never come across a live snake. In today's society, the likelihood of witnessing traumatic episodes and indirectly acquiring fear is magnified by the omnipresence of technology and constant access to the news and social media. Like humans, rats are very social animals and learn to infer information about their environment through their interactions with other rats. The PI's laboratory has recently developed a procedure by which rats acquire fear through social transmission (a model called fear conditioning by proxy). Fear conditioning by proxy provides a sensitive means of examining how social information is transferred between individuals. A different model, social transmission of food preference, allows the investigators to examine the transmission of appetitive or rewarding information. By executing the two different and complementary paradigms in parallel (fear conditioning by proxy and social transmission of food preference), the investigators will be able to isolate factors that selectively underlie social transmission of information from those which are specific to a given paradigm. This is important, because identifying the social and mechanistic factors contribute to how people acquire fear could also lead to interventions that extinguish or diminish fears that are socially acquired.
The objective of the project is to identify the social factors and neural mechanisms that foster transmission of information between members of a species, and determine what accounts for the broad variability in individuals' propensity to learn via social transmission. First, the investigators will identify factors (e.g., dominance status, kinship) that promote social transmission of information using two complementary behavioral paradigms: fear conditioning by proxy and social transmission of food preference. Second, the investigators will disambiguate the neural networks that are unique to social transmission of information, and those that are shared with learning through direct experience, using a sophisticated technique that allows selective labeling of cells involved in a given task at a specific time. Third, the investigators will test their prediction that a specific population of cells in the lateral hypothalamus accounts for individual differences in fear conditioning by proxy and social transmission of food preference. This project combines sophisticated and thorough behavioral tests, as well as complementary cellular and anatomical methods to address the neural mechanisms that drive behavioral differences. A strength of these techniques is that they will provide high spatial and temporal resolution, while allowing for on-going sampling of behavior, to understand how knowledge is transferred between individuals.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
