Assessing the social competence of anthropomorphic artificial agents developed to produce engaging social interactions with humans has become of primary importance to effectively compare various appearances and/or behaviours. Here we attempt to objectify the social competence of artificial agents, across different dimensions, using human brain neurophysiology. Whole brain activity is recorded with functional Magnetic Resonance Imaging (fMRI) while participants, naïve to the real purpose of the experiment, discuss either with a human confederate or with an artificial agent, presently the robotic conversational head Furhat controlled with a Wizard of Oz procedure. This allows a direct comparison of local brain responses, not only at the cortical level but also in subcortical structures associated with motivational drive and impossible to investigate with non-invasive neurophysiology techniques such as surface recordings. The present data (n=21 participants) demonstrates the feasibility of this approach, and results confirm an increased activity in subcortical structures, in particular the amygdala involved in emotional processing and the hypothalamus, known to secrete, among others, the Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than ACM must be honored. Abstracting with credit is permitted. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from Permissions@acm.org.