Remembering first impressions: Effects of intentionality and diagnosticity on subsequent memory

Roee Gilron Angela H. Gutchess 0 ) Department of Psychology, Brandeis University , 415 South Street, MS 062 , P.O. Box 549110, Waltham, MA 02454-9110, USA People rely on first impressions every day as an important tool to interpret social behavior. While research is beginning to reveal the neural underpinnings of first impressions, particularly through understanding the role of dorsal medial prefrontal cortex (dmPFC), little is known about the way in which first impressions are encoded into memory. This is surprising because first impressions are relevant from a social perspective for future interactions, requiring that they be transferred to memory. The present study used a subsequent-memory paradigm to test the conditions under which the dmPFC is implicated in the encoding of first impressions. We found that intentionally forming impressions engages the dmPFC more than does incidentally forming impressions, and that this engagement supports the encoding of remembered impressions. In addition, we found that diagnostic information, which more readily lends itself to forming trait impressions, engages the dmPFC more than does neutral information. These results indicate that the neural system subserving memory for impressions is sensitive to consciously formed impressions. The results also suggest a distinction between a social memory system and other explicit memory systems governed by the medial temporal lobes. - and who we should avoid. They can be a deciding factor in mate choice, trustworthiness judgments, and hiring decisions. Moreover, there is evidence that they may influence court decisions (Zebrowitz & McDonald, 1991; Zebrowitz & Montepare, 2008), election results (Olivola & Todorov, 2010; Verhulst, Lodge, & Lavine, 2010), and professional evaluations (Ambady & Rosenthal, 1993). A growing number of studies are examining the way in which we quickly and automatically make trait impressions of others and use that knowledge (Cloutier, Kelley, & Heatherton, 2010; Uleman, Saribay, & Gonzalez, 2008; Van Overwalle, 2009; Van Overwalle & Labiouse, 2004), but few (Harvey, Fossati, & Lepage, 2007; Mitchell, Macrae, & Banaji, 2004; Schiller, Freeman, Mitchell, Uleman, & Phelps, 2009) have examined the conditions under which we remember these impressions. This is surprising, because the memory of these impressions has the capacity to influence our future actions. Though current research suggests that we are experts at forming quick, automatic impressions, little is known about the processes that support retaining these impressions in long-term memory. Though much can be learned about first impressions from behavioral measures, an investigation of the factors that influence first-impression formation and the corresponding neural underpinnings would allow one to ask more nuanced questions about forming impressions and their storage in memory. Accumulating evidence in the memory literature has suggested that the broad distinction between the neural substrates supporting semantic, episodic, and procedural memory may also extend to distinct classes of elaborative semantic encoding processes, perhaps including those in the social domain. From their review of the literature, Macrae and colleagues suggested that largely disparate neural networks are activated during the successful formation of memories in response to verbal, visual, emotional, and self-referential processing, consistent with the idea that different processes contribute to the formation of distinct varieties of episodic memories (Macrae, Moran, Heatherton, Banfield, & Kelley, 2004). Recent investigations have upheld this division, in particular as it relates to the processing of social and emotional information (Gutchess, Kensinger, & Schacter, 2010; Haas & Canli, 2008; Harvey et al., 2007; Mitchell et al., 2004). Though the hippocampus plays a key role in the encoding network for memory for many classes of information, additional disparate brain regions support specific subcategories. Thus, as in a comparable system that aids in encoding emotional information into memory (Schacter, Gutchess, & Kensinger, 2009), there may be a dedicated system for encoding first impressions (and more broadly, social information) into memory. Given how important social interaction is to the human condition, we would expect to find evidence for the contributions of a social cognition network to the encoding of first impressions into memory. Applying a social neuroscience approach to understand how people form impressions of others advances our understanding of the component processes and the feedforward and feedback loops that shape our perceptions of others (for reviews, see Ames, Fiske, & Todorov, 2011; Rule & Ambady, 2008). A number of neural regions respond to impression formation, reflecting the complexity of the processes involved and the interconnectedness of the network that allows impressions to be invoked so instantaneously. These regions include the amygdala, which responds to emotional and evaluative conditions (Schiller et al., 2009) and to appearance-based cues, such as trustworthiness (Said, Baron, & Todorov, 2009; Winston, Strange, ODoherty, & Dolan, 2002); the caudate nucleus, which responds to reward and feedback (Delgado, Nystrom, Fissell, Noll, & Fiez, 2000); the superior temporal sulcus, which responds to others intentions (Saxe, Xiao, Kovacs, Perrett, & Kanwisher, 2004); and the fusiform gyrus, which is invoked by face processing (Winston, Henson, Fine-Goulden, & Dolan, 2004). The dorsal medial prefrontal cortex (dmPFC), a region of the frontal cortex, has been particularly implicated in impression formation, as well as in a wide array of social processes (Amodio & Frith, 2006; DArgembeau et al., 2007; Harvey et al., 2007; Macrae et al., 2004; Mitchell, Cloutier, Banaji, & Macrae, 2006; Mitchell, Macrae, & Banaji, 2004, 2005, 2006). Furthermore, virtually all studies that have investigated first impressions in their manifestation as trait judgments have implicated the dmPFC (Mason, Dyer, & Norton, 2009; Mitchell, 2008; Mitchell, Ames, Jenkins, & Banaji, 2009; Mitchell, Cloutier, et al., 2006; Mitchell, Macrae, & Banaji, 2004, 2005, 2006; Todorov, Gobbini, Evans, & Haxby, 2007; the exception is Heberlein & Saxe, 2005, whose control was an emotional task, which might also engage dmPFC). Not only does the dmPFC respond to social information, but it also mediates the encoding of first impressions into memory (Mitchell et al., 2004). In Mitchell et al.s (2004) study, participants read sentences depicting actions that were paired with a picture of a face. Participants were asked either to form an impression of the facesentence pair or to remember the sequence of the presented actions. While forming an impression, dmPFC activity was higher when the facestatement pair was later remembered rather than later forgotten. However, activity in this region did not predict successful encoding when participants were orient (...truncated)