Conference Agenda

The neurophysiological studies on non-human primates traditionally were carried out by focusing on a single or a few variables, leading to a prevailing view that emphasize the relevance of distinct, task-related neuronal categories representing specific type of information. In particular, classical studies suggest that the anterior intraparietal area (AIP) contributes to the encoding of objects and actions with a variety of neuronal classes (e.g. canonical, motor or mirror neurons), each of which represents specific information (e.g. object features, executed or observed actions). But in everyday life, primates must deal with a multiplicity of stimuli, especially in a social context. Whether AIP generates multidimensional representations by means of distinct sets of neurons that represent a specific type of ethologically-relevant information (e.g. objects and actions) or neurons with mixed selectivity for multiple variables remain unknown. Here, we chronically recorded AIP neuron activity in two macaque monkeys in a variety of tasks and conditions classically employed in separate experiments. Most of the recorded cells specify multimodally the details concerning observed objects, executed and observed actions, as well as the space sector in which potential targets or actions of others are presented. In contrast with the classical view, these findings indicate that mixed selectivity is largely prevalent relative to specialized neural representations in AIP and suggest that distributed multidimensional coding is crucial for action planning and for social interactions.

Motor mimicry is an extremely adaptive phenomenon that is based on the perception-action coupling mechanism possibly mediated by the mirror neuron system. Mimicry regulates dyadic relations, favors the formation of enduring social bonds and promotes behavioral synchrony at group level that in turn enhance reproductive success. In the last decades, many researchers have become increasingly aware that the only possibility to understand even the most complex forms of human empathy was to look at other branches on the evolutionary tree. As a result of this new interest, some convincing data are emerging on similar phenomena in non-human species. In this talk, I will review and present original observational and experimental data showing how mimicry and contagion phenomena are valuable regulators of social interactions and reliable predictors of emotional closeness. An inter-subjective emotional bridge which we share with other social species and that helps us keep in mind that we are, in fact, at base and at most, animals.

Affective touch plays a powerful and evolutionary fundamental role in our daily social interactions. It produces a calming effect, diminishes pain perception, modulates physiological activation, and strengthens affiliative behaviors. It has the unique property of being reciprocal since it entails a person promoting and another receiving the touch. While several studies have investigated the beneficial effects of receiving an affective touch, the affective experience of caressing another individual remains largely unknown.

We investigated the hedonic and autonomic responses (skin conductance and heart rate) of people when they promoted an affective touch. We also examined whether interpersonal relationships, gender, and eye contact modulate these responses. As expected, caressing the partner was perceived as more pleasant than caressing a stranger, especially if the affective touch occurred together with mutual eye contact. Promoting an affective touch to the partner also resulted in a decrease in both autonomic responses and anxiety levels, suggesting the occurrence of a calming effect. Additionally, these effects were more pronounced in females compared to males, indicating that hedonic and autonomic aspects of affective touch are modulated by social relationships as well as by gender.

Thus, these findings suggest that the pleasantness of affective touch is not an isolated construct; it changes as a function of different and crucial social variables such as the relationship between the two individuals, the gender of the person promoting the touch, and mutual eye contact. Caressing a beloved one is not only pleasant but also reduces autonomic responses and anxiety in the person promoting the touch. This might suggest that affective touch has an instrumental role in romantic partners, in promoting and reinforcing their affective bonding.

Social animals - including humans - live and move through spaces shaped by the agency of many other individuals. Neural activity in the hippocampus is known to reflect spatial behavior, however it has not been studied in such dynamic group settings, which are ubiquitous in natural environments. Here, we studied hippocampal activity in groups of bats engaged in collective spatial behavior. We find that under spontaneous conditions a robust spatial structure emerges at the group level where behavior is anchored to specific locations, movement patterns and individual social preferences. Using wireless electrophysiological recordings from both stationary and flying bats, we found that many hippocampal neurons are tuned to key features of group dynamics. These include the presence or absence of a conspecific, but not typically of an object, at takeoff or landing sites, shared spatial locations, individual identities, and sensory signals that are broadcasted in the group setting. Finally, using wireless calcium imaging, we found that social responses are anatomically distributed and robustly represented at the population level. Combined, our findings reveal that hippocampal activity contains a rich representation of naturally emerging spatial behaviors in animal groups which could in turn support the complex feat of collective behavior.