How rats use social information to guide decisions

Living in a group has an adaptive value for a number of reasons. In the lab we focus on social interactions in different contexts, namely when individuals perceive a threat or when they are foraging for food. This talk will have two parts.

In the first part, I will focus on our experiments aimed at understanding how animals use defense behaviors of con-specifics as alarm cues. In particular I will discuss our findings showing that rats use freezing as an alarm cue, which is sensed through a sudden cessation of movement-evoked sound. Using optogenectis and pharmacology, we identified regions of the auditory pathways to amygdala required for rats to freeze in response to silence onset. In addition, there is evidence that prior experience with the aversive shock is important for social transmission of fear between rats. I will discuss experiments under way in our lab that suggest that it is the association between freezing and shock that promotes observational fear suggesting that learning from self-experience with an aversive event is important for rats to respond to freezing displayed by others.

In the second part, I will discuss our work on coordinating cooperative behaviors while foraging for food. To model coordinated behavior in rodents, we developed a task that tests rats in a risky Stag Hunt (SH) game. In the SH players must choose either to cooperate for a high reward, which is risky, as it requires a coordinated cooperative choice, or to defect and receive a moderate safe reward regardless of the other’s choice. The SH has two pure equilibrium strategies, mutual cooperation, which maximizes reward, and mutual defection, which minimizes risk. A third equilibrium is a mixed strategy (MS) where both rats independently cooperate with a probability that renders the utility of cooperating the same as that of defecting, minimizing risk. However, if rats coordinate their cooperative choices they can also increase their gains. We found that they overcame an initial preference for defection establishing high levels of stable cooperation close to the MS equilibria. Dyads rapidly re-established this behavior following a reversal of the assignment of cooperate and defect arms, demonstrating that rats made choices flexibly and had a strong preference for the MS strategy. Manipulating social information revealed that rats use social cues for generating and stabilizing strategic coordinated cooperation that relied on learning the contingencies between the behavior of others and outcomes.

 

From the Champalimaud Center in Lisbon.

Monday 18th of June, 11 a.m. in Inmed

Invited by David Robbe

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