Special processes recruited during the recognition of personally familiar people have been assumed to reflect the rich episodic and semantic information that selectively represents each person. However, the processes may also include person nonselective ones, which may require interpretation in terms beyond the memory mechanism. To examine this possibility, we assessed decrease in differential activation during the second presentation of an identical face (repetition suppression) as an index of person selectivity. During fMRI, pictures of personally familiar, famous, and unfamiliar faces were presented to healthy subjects who performed a familiarity judgment. Each face was presented once in the first half of the experiment and again in the second half. The right inferior temporal and left inferior frontal gyri were activated during the recognition of both types of familiar faces initially, and this activation was suppressed with repetition. Among preferentially activated regions for personally familiar over famous faces, robust suppression in differential activation was exhibited in the bilateral medial and anterior temporal structures, left amygdala, and right posterior STS, all of which are known to process episodic and semantic information. On the other hand, suppression was minimal in the posterior cingulate, medial prefrontal, right inferior frontal, and intraparietal regions, some of which were implicated in social cognition and cognitive control. Thus, the recognition of personally familiar people is characterized not only by person-selective representation but also by nonselective processes requiring a research framework beyond the memory mechanism, such as a social adaptive response.

Memory for person identity information consists of three main components: face-related information, name-related information, and person-related semantic information, such as the person's job title. Although previous studies have demonstrated the importance of the anterior temporal lobe (ATL) in the retrieval of associations between these kinds of information, there is no evidence concerning whether the ATL region contributes to the encoding of this memory, and whether ATL roles are dissociable between different levels of association in this memory. Using fMRI, we investigated dissociable roles within the ATL during successful encoding of this memory. During encoding, participants viewed unfamiliar faces, each paired with a job title and name. During retrieval, each learned face was presented with two job titles or two names, and participants were required to choose the correct job title or name. Successful encoding conditions were categorized by subsequent retrieval conditions: successful encoding of names and job titles (HNJ), names (HN), and job titles (HJ). The study yielded three main findings. First, the dorsal ATL showed greater activations in HNJ than in HN or HJ. Second, ventral ATL activity was greater in HNJ and HJ than in HN. Third, functional connectivity between these regions was significant during successful encoding. The results are the first to demonstrate that the dorsal and ventral ATL roles are dissociable between two steps of association, associations of person-related semantics with name and with face, and a dorsal–ventral ATL interaction predicts subsequent retrieval success of memory for person identity information.

Elucidating the neural mechanisms involved in aversive conditioning helps find effective treatments for psychiatric disorders such as anxiety disorder and phobia. Previous studies using fMRI and human subjects have reported that the amygdala plays a role in this phenomenon. However, the noxious stimuli that were used as unconditioned stimuli in previous studies (e.g., electric shock) might have been ecologically invalid because we seldom encounter such stimuli in daily life. Therefore, we investigated whether a face stimulus could be conditioned by using a voice that had negative emotional valence and was collected from a real-life environment. A skin conductance response showed that healthy subjects were conditioned by using these stimuli. In an fMRI study, there was greater amygdala activation in response to the faces that had been paired with the voice than to those that had not. The right amygdala showed transient activity in the early stage of acquisition. A psychophysiological interaction analysis indicated that the subcortical pathway from the medial geniculate body to the amygdala played a role in conditioning. Modulation of the subcortical pathway by voice stimuli preceded the transient activity in the amygdala. The finding that an ecologically valid stimulus elicited the conditioning and amygdala response suggests that our brain is automatically processing unpleasant stimuli in daily life.

People living in multicultural environments often encounter situations which require them to acquire different cultural schemas and to switch between these cultural schemas depending on their immediate sociocultural context. Prior behavioral studies show that priming cultural schemas reliably impacts mental processes and behavior underlying self-concept. However, less well understood is whether or not cultural priming affects neurobiological mechanisms underlying the self. Here we examined whether priming cultural values of individualism and collectivism in bicultural individuals affects neural activity in cortical midline structures underlying self-relevant processes using functional magnetic resonance imaging. Biculturals primed with individualistic values showed increased activation within medial prefrontal cortex (MPFC) and posterior cingulate cortex (PCC) during general relative to contextual self-judgments, whereas biculturals primed with collectivistic values showed increased response within MPFC and PCC during contextual relative to general self-judgments. Moreover, degree of cultural priming was positively correlated with degree of MPFC and PCC activity during culturally congruent self-judgments. These findings illustrate the dynamic influence of culture on neural representations underlying the self and, more broadly, suggest a neurobiological basis by which people acculturate to novel environments.