Vicarious reward unblocks associative learning about novel cues in male rats

Abstract

6 Marijn van Wingerden, Jochen Hoog and Sander van Gurp were supported by the Volkswagen Stiftung Freigeist fellowship, 7 AZ88216 8 Abstract 9Many species, including humans, are sensitive to social signals and their valuation is important in social learning. 10When social cues indicate that another is experiencing reward, they could convey vicarious reward value and 11 prompt social learning. Here, we introduce a task that investigates if vicarious reward delivery in male rats can 12 drive reinforcement learning in a formal associative learning paradigm. Using the blocking/unblocking paradigm, 13we found that when actor rats have fully learned a stimulus-self reward association, adding a cue that predicted 14 additional partner reward unblocked associative learning about this cue. In contrast, additional cues that did not 15 predict partner reward remained blocked from acquiring associative value. Preventing social signal exchange 16 between the partners resulted in cues signaling partner reward remaining blocked. Taken together, these 17 results suggest that vicarious rewards can drive reinforcement learning in rats, and that the transmission of 18 social cues is necessary for this learning to occur. 24prompting questions why actor engage in them (de Waal and Suchak

Anterior Cingulate Cortex Signals Attention in a Social Paradigm that Manipulates Reward and Shock

“…It might be argued that the main reason why, here, ACC seems to encode social attention, but not vicarious emotion, is that rats performing the current task did not exhibit empathy. This is certainly possible, as we will discuss in the next paragraph, but it is important to point out that our rats did freeze, suppress food cup behavior, and approach when the other rat froze during shock-other trials, which other studies have used as evidence for empathy in rodents [16,36,37,40,42,44,[46][47][48]51]. Moreover, also consistent with previous work, we show that, when a rat is not experiencing shock, they exhibit less empathetic behavior [37,42,45,47].…”

“…In monkey ACC, neurons fire when reward is allocated to a conspecific, to oneself, or in both contexts [24]. Although recent work has shown the influence of social cues on reward learning [46], to the best of our knowledge, this has not been explored in rodents; thus, it is possible that rodent ACC is not responsive to rewards delivered to others. However, we speculate that the presence of shock stimuli may have diluted neural effects due to lower social engagement during reward-other trials.…”

5-HT1A receptor agonism in the basolateral amygdala increases mutual-reward choices in rats

“…Our results support the idea that the BLA integrates social information and contributes to the selection of appropriate social actions. We have recently argued that this selection of social actions might be the result of social reinforcement learning 7,14,37,38,49 . According to this framework, BR-choices of the actor might prompt the emission of appetitive social signals by the partner rat, which in turn reinforce the behaviors of the actor associated with these signals, eventually increasing the probability of BR-choices.…”

“…The SB score expresses the percent difference of BR-choices in the partner relative to the toy condition, using the following equation: SB scores greater than zero indicate more BR-choices in the partner than in the toy condition, scores equal to zero indicate equal choices in both conditions, and scores below zero more BR-choices in the toy condition. Because the reward delivered to the actor after BR-and OR-choices was always identical, SB scores higher than zero can be interpreted to reflect the added social value of a reward delivered to the conspecific 6,37,38 .…”

Social Neuroscience: How the Brain Attends to the Joys and Pains of Others

“…The reasoning of this study [10] is based on the observation that rats not only adopt the negative affective state of a conspecific in pain, but also attach positive vicarious value to rewards received by others [11][12][13][14]. Thus, if ACC neurons really represent good and bad outcomes to self and others as a common code, as proposed by the emotional mirror hypothesis, then they should reflect signed outcome valence.…”