Theories of Person Perception Predict Patterns of Neural Activity During Mentalizing.

Social life requires making inferences about other people. What information do perceivers spontaneously draw upon to make such inferences? Here, we test 4 major theories of person perception, and 1 synthetic theory that combines their features, to determine whether the dimensions of such theories can serve as bases for describing patterns of neural activity during mentalizing. While undergoing functional magnetic resonance imaging, participants made social judgments about well-known public figures. Patterns of brain activity were then predicted using feature encoding models that represented target people's positions on theoretical dimensions such as warmth and competence. All 5 theories of person perception proved highly accurate at reconstructing activity patterns, indicating that each could describe the informational basis of mentalizing. Cross-validation indicated that the theories robustly generalized across both targets and participants. The synthetic theory consistently attained the best performance-approximately two-thirds of noise ceiling accuracy--indicating that, in combination, the theories considered here can account for much of the neural representation of other people. Moreover, encoding models trained on the present data could reconstruct patterns of activity associated with mental state representations in independent data, suggesting the use of a common neural code to represent others' traits and states.

Neural evidence that three dimensions organize mental state representation: Rationality, social impact, and valence.

How do people understand the minds of others? Existing psychological theories have suggested a number of dimensions that perceivers could use to make sense of others' internal mental states. However, it remains unclear which of these dimensions, if any, the brain spontaneously uses when we think about others. The present study used multivoxel pattern analysis (MVPA) of neuroimaging data to identify the primary organizing principles of social cognition. We derived four unique dimensions of mental state representation from existing psychological theories and used functional magnetic resonance imaging to test whether these dimensions organize the neural encoding of others' mental states. MVPA revealed that three such dimensions could predict neural patterns within the medial prefrontal and parietal cortices, temporoparietal junction, and anterior temporal lobes during social thought: rationality, social impact, and valence. These results suggest that these dimensions serve as organizing principles for our understanding of other people.

Neural Representations of Belief Concepts: A Representational Similarity Approach to Social Semantics.

The present experiment identified neural regions that represent a class of concepts that are independent of perceptual or sensory attributes. During functional magnetic resonance imaging scanning, participants viewed names of social groups (e.g. Atheists, Evangelicals, and Economists) and performed a one-back similarity judgment according to 1 of 2 dimensions of belief attributes: political orientation (Liberal to Conservative) or spiritualism (Spiritualist to Materialist). By generalizing across a wide variety of social groups that possess these beliefs, these attribute concepts did not coincide with any specific sensory quality, allowing us to target conceptual, rather than perceptual, representations. Multi-voxel pattern searchlight analysis was used to identify regions in which activation patterns distinguished the 2 ends of both dimensions: Conservative from Liberal social groups when participants focused on the political orientation dimension, and spiritual from Materialist groups when participants focused on the spiritualism dimension. A cluster in right precuneus exhibited such a pattern, indicating that it carries information about belief-attribute concepts and forms part of semantic memory-perhaps a component particularly concerned with psychological traits. This region did not overlap with the theory of mind network, which engaged nearby, but distinct, parts of precuneus. These findings have implications for the neural organization of conceptual knowledge, especially the understanding of social groups.

Consistent Neural Activity Patterns Represent Personally Familiar People.

How does the brain encode and organize our understanding of the people we know? In this study, participants imagined personally familiar others in a variety of contexts while undergoing fMRI. Using multivoxel pattern analysis, we demonstrated that thinking about familiar others elicits consistent fine-grained patterns of neural activity. Person-specific patterns were distributed across many regions previously associated with social cognition, including medial prefrontal, medial parietal, and lateral temporoparietal cortices, as well as other regions including the anterior and mid-cingulate, insula, and precentral gyrus. Analogous context-specific patterns were observed in medial parietal and superior occipital regions. These results suggest that medial parietal cortex may play a particularly central role in simulating familiar others, as this is the only region to simultaneously represent both person and context information. Moreover, within portions of medial parietal cortex, the degree to which person-specific patterns were typically instated on a given trial predicted subsequent judgments of accuracy and vividness in the mental simulation. This suggests that people may access neural representations in this region to form metacognitive judgments of confidence in their mental simulations. In addition to fine-grained patterns within brain regions, we also observed encoding of both familiar people and contexts in coarse-grained patterns spread across the independently defined social brain network. Finally, we found tentative evidence that several established theories of person perception might explain the relative similarity between person-specific patterns within the social brain network.

Neural activity associated with self, other, and object-based counterfactual thinking.

Previous research has shown that autobiographical episodic counterfactual thinking-i.e., mental simulations about alternative ways in which one's life experiences could have occurred-engages the brain's default network (DN). However, it remains unknown whether or not the DN is also engaged during impersonal counterfactual thoughts, specifically those involving other people or objects. The current study compares brain activity during counterfactual simulations involving the self, others and objects. In addition, counterfactual thoughts involving others were manipulated in terms of similarity and familiarity with the simulated characters. The results indicate greater involvement of DN during person-based (i.e., self and other) as opposed to object-based counterfactual simulations. However, the involvement of different regions of the DN during other-based counterfactual simulations was modulated by how close and/or similar the simulated character was perceived to be by the participant. Simulations involving unfamiliar characters preferentially recruited dorsomedial prefrontal cortex. Simulations involving unfamiliar similar characters, characters with whom participants identified personality traits, recruited lateral temporal gyrus. Finally, our results also revealed differential coupling of right hippocampus with lateral prefrontal and temporal cortex during counterfactual simulations involving familiar similar others, but with left transverse temporal gyrus and medial frontal and inferior temporal gyri during counterfactual simulations involving either oneself or unfamiliar dissimilar others. These results suggest that different brain mechanisms are involved in the simulation of personal and impersonal counterfactual thoughts, and that the extent to which regions associated with autobiographical memory are recruited during the simulation of counterfactuals involving others depends on the perceived similarity and familiarity with the simulated individuals.

Turning I into me: Imagining your future self.

A widely endorsed belief is that perceivers imagine their present selves using a different representational format than imagining their future selves (i.e., near future=first-person; distant future=third-person). But is this really the case? Responding to the paucity of work on this topic, here we considered how temporal distance influences the extent to which individuals direct their attention outward or inward during a brief imaginary episode. Using a non-verbal measure of visual perspective taking (i.e., letter-drawing task) our results confirmed the hypothesized relation between temporal distance and conceptions of the self. Whereas simulations of an event in the near future were dominated by a first-person representation of the self, this switched to a third-person depiction when the event was located in the distant future. Critically, this switch in vantage point was restricted to self-related simulations. The theoretical and practical implications of these findings are considered.

Disclosing information about the self is intrinsically rewarding.

Humans devote 30-40% of speech output solely to informing others of their own subjective experiences. What drives this propensity for disclosure? Here, we test recent theories that individuals place high subjective value on opportunities to communicate their thoughts and feelings to others and that doing so engages neural and cognitive mechanisms associated with reward. Five studies provided support for this hypothesis. Self-disclosure was strongly associated with increased activation in brain regions that form the mesolimbic dopamine system, including the nucleus accumbens and ventral tegmental area. Moreover, individuals were willing to forgo money to disclose about the self. Two additional studies demonstrated that these effects stemmed from the independent value that individuals placed on self-referential thought and on simply sharing information with others. Together, these findings suggest that the human tendency to convey information about personal experience may arise from the intrinsic value associated with self-disclosure.

Spontaneous mentalizing predicts the fundamental attribution error.

When explaining the reasons for others' behavior, perceivers often overemphasize underlying dispositions and personality traits over the power of the situation, a tendency known as the fundamental attribution error. One possibility is that this bias results from the spontaneous processing of others' mental states, such as their momentary feelings or more enduring personality characteristics. Here, we use fMRI to test this hypothesis. Participants read a series of stories that described a target's ambiguous behavior in response to a specific social situation and later judged whether that act was attributable to the target's internal dispositions or to external situational factors. Neural regions consistently associated with mental state inference-especially, the medial pFC-strongly predicted whether participants later made dispositional attributions. These results suggest that the spontaneous engagement of mentalizing may underlie the biased tendency to attribute behavior to dispositional over situational forces.

Equitable decision making is associated with neural markers of intrinsic value.

Standard economic and evolutionary models assume that humans are fundamentally selfish. On this view, any acts of prosociality--such as cooperation, giving, and other forms of altruism--result from covert attempts to avoid social injunctions against selfishness. However, even in the absence of social pressure, individuals routinely forego personal gain to share resources with others. Such anomalous giving cannot be accounted for by standard models of social behavior. Recent observations have suggested that, instead, prosocial behavior may reflect an intrinsic value placed on social ideals such as equity and charity. Here, we show that, consistent with this alternative account, making equitable interpersonal decisions engaged neural structures involved in computing subjective value, even when doing so required foregoing material resources. By contrast, making inequitable decisions produced activity in the anterior insula, a region linked to the experience of subjective disutility. Moreover, inequity-related insula response predicted individuals' unwillingness to make inequitable choices. Together, these data suggest that prosocial behavior is not simply a response to external pressure, but instead represents an intrinsic, and intrinsically social, class of reward.

Frontotemporal contributions to social and non-social semantic judgements.

Semantic judgements involve the use of general knowledge about the world in specific situations. Such judgements are typically associated with activity in a number of brain regions that include the left inferior frontal gyrus (IFG). However, previous studies showed activity in brain regions associated with mentalizing, including the right temporoparietal junction (TPJ), in semantic judgements that involved social knowledge. The aim of the present study was to investigate if social and non-social semantic judgements are dissociated using a combination of fMRI and repetitive TMS. To study this, we asked participants to estimate the percentage of exemplars in a given category that shared a specified attribute. Categories could be either social (i.e., stereotypes) or non-social (i.e., object categories). As expected, fMRI results (n = 26) showed enhanced activity in the left IFG that was specific to non-social semantic judgements. However, statistical evidence did not support that repetitive TMS stimulation (n = 19) to this brain region specifically disrupted non-social semantic judgements. Also as expected, the right TPJ showed enhanced activity to social semantic judgements. However, statistical evidence did not support that repetitive TMS stimulation to this brain region specifically disrupted social semantic judgements. It is possible that the causal networks involved in social and non-social semantic judgements may be more complex than expected.

Social-cognitive deficits in normal aging.

A sizeable number of studies have implicated the default network (e.g., medial prefrontal and parietal cortices) in tasks that require participants to infer the mental states of others (i.e., to mentalize). Parallel research has demonstrated that default network function declines over the lifespan, suggesting that older adults may show impairments in social-cognitive tasks that require mentalizing. Older and younger human adults were scanned using functional magnetic resonance imaging while performing three different social-cognitive tasks. Across three mentalizing paradigms, younger and older adults viewed animated shapes in brief social vignettes, stories about a person's moral actions, and false belief stories. Consistent with predictions, older adults responded less accurately to stories about others' false beliefs and made less use of actors' intentions to judge the moral permissibility of behavior. These impairments in performance during social-cognitive tasks were accompanied by age-related decreases across all three paradigms in the BOLD response of a single brain region, the dorsomedial prefrontal cortex. These findings suggest specific task-independent age-related deficits in mentalizing that are localizable to changes in circumscribed subregions of the default network.

Response of dorsomedial prefrontal cortex predicts altruistic behavior.

Human beings have an unusual proclivity for altruistic behavior, and recent commentators have suggested that these prosocial tendencies arise from our unique capacity to understand the minds of others (i.e., to mentalize). The current studies test this hypothesis by examining the relation between altruistic behavior and the reflexive engagement of a neural system reliably associated with mentalizing. Results indicated that activity in the dorsomedial prefrontal cortex--a region consistently involved in understanding others' mental states--predicts both monetary donations to others and time spent helping others. These findings address long-standing questions about the proximate source of human altruism by suggesting that prosocial behavior results, in part, from our broader tendency for social-cognitive thought.

Common brain regions with distinct patterns of neural responses during mentalizing about groups and individuals.

An individual has a mind; a group does not. Yet humans routinely endow groups with mental states irreducible to any of their members (e.g., "scientists hope to understand every aspect of nature"). But are these mental states categorically similar to those we attribute to individuals? In two fMRI experiments, we tested this question against a set of brain regions that are consistently associated with social cognition--medial pFC, anterior temporal lobe, TPJ, and medial parietal cortex. Participants alternately answered questions about the mental states and physical attributes of individual people and groups. Regions previously associated with mentalizing about individuals were also robustly responsive to judgments of groups, suggesting that perceivers deploy the same social-cognitive processes when thinking about the mind of an individual and the "mind" of a group. However, multivariate searchlight analysis revealed that several of these regions showed distinct multivoxel patterns of response to groups and individual people, suggesting that perceivers maintain distinct representations of groups and individuals during mental state inferences. These findings suggest that perceivers mentalize about groups in a manner qualitatively similar to mentalizing about individual people, but that the brain nevertheless maintains important distinctions between the representations of such entities.

Neural correlates of anchoring-and-adjustment during mentalizing.

Recent studies have suggested that the medial prefrontal cortex (MPFC) contributes both to understanding the mental states of others and to introspecting about one's own mind. This finding has suggested that perceivers might use their own thoughts and feelings as a starting point for making inferences about others, consistent with "simulation" or "self-projection" views of social cognition. However, perceivers cannot simply assume that others think and feel exactly as they do; social cognition also must include processes that adjust for perceived differences between self and other. Recent cognitive work has suggested that such correction occurs through a process of "anchoring-and-adjustment" by which perceivers serially tune their inferences from an initial starting point based on their own introspections. Here, we used functional MRI to test two predictions derived from this anchoring-and-adjustment view. Participants (n = 64) used a Likert scale to judge the preferences of another person and to indicate their own preferences on the same items, allowing us to calculate the discrepancy between the participant's answers for self and other. Whole-brain parametric analyses identified a region in the MPFC in which activity was related linearly to this self-other discrepancy when inferring the mental states of others. These findings suggest both that the self serves as an important starting point from which to understand others and that perceivers customize such inferences by serially adjusting away from this anchor.

The default network distinguishes construals of proximal versus distal events.

Humans enjoy a singular capacity to imagine events that differ from the "here-and-now." Recent cognitive neuroscience research has linked such simulation processes to the brain's "default network." However, extant cognitive theories suggest that perceivers reliably simulate only relatively proximal experiences-those that seem nearby, soon, likely to happen, or relevant to a close other. Here, we test these claims by examining spontaneous engagement of the default network while perceivers consider experiencing events from proximal and distal perspectives. Across manipulations of perspective in four dimensions, two regions of the default network-medial prefrontal cortex and retrosplenial cortex-were more active for proximal than distal events, supporting cognitive accounts that perceivers only richly simulate experiences that seem immediate and that perceivers represent different dimensions of distance similarly. Moreover, stable individual differences in default activity when thinking about distal events correlated with individual variability in an implicit measure of psychological distance, suggesting that perceivers naturally vary in their tendency to simulate far-off or unlikely experiences.

Medial prefrontal cortex predicts intertemporal choice.

People often make shortsighted decisions to receive small benefits in the present rather than large benefits in the future, that is, to favor their current selves over their future selves. In two studies using fMRI, we demonstrated that people make such decisions in part because they fail to engage in the same degree of self-referential processing when thinking about their future selves. When participants predicted how much they would enjoy an event in the future, they showed less activity in brain regions associated with introspective self-reference--such as the ventromedial pFC (vMPFC)--than when they predicted how much they would enjoy events in the present. Moreover, the magnitude of vMPFC reduction predicted the extent to which participants made shortsighted monetary decisions several weeks later. In light of recent findings that the vMPFC contributes to the ability to simulate future events from a first-person perspective, these data suggest that shortsighted decisions result in part from a failure to fully imagine the subjective experience of one's future self.

Dissociating neural correlates of action monitoring and metacognition of agency.

Judgments of agency refer to people's self-reflective assessments concerning their own control: their assessments of the extent to which they themselves are responsible for an action. These self-reflective metacognitive judgments can be distinguished from action monitoring, which involves the detection of the divergence (or lack of divergence) between observed states and expected states. Presumably, people form judgments of agency by metacognitively reflecting on the output of their action monitoring and then consciously inferring the extent to which they caused the action in question. Although a number of previous imaging studies have been directed at action monitoring, none have assessed judgments of agency as a potentially separate process. The present fMRI study used an agency paradigm that not only allowed us to examine the brain activity associated with action monitoring but that also enabled us to investigate those regions associated with metacognition of agency. Regarding action monitoring, we found that being "out of control" during the task (i.e., detection of a discrepancy between observed and expected states) was associated with increased brain activity in the right TPJ, whereas being "in control" was associated with increased activity in the pre-SMA, rostral cingulate zone, and dorsal striatum (regions linked to self-initiated action). In contrast, when participants made self-reflective metacognitive judgments about the extent of their own control (i.e., judgments of agency) compared with when they made judgments that were not about control (i.e., judgments of performance), increased activity was observed in the anterior PFC, a region associated with self-reflective processing. These results indicate that action monitoring is dissociable from people's conscious self-attributions of control.

Social influence modulates the neural computation of value.

Social influence--individuals' tendency to conform to the beliefs and attitudes of others--has interested psychologists for decades. However, it has traditionally been difficult to distinguish true modification of attitudes from mere public compliance with social norms; this study addressed this challenge using functional neuroimaging. Participants rated the attractiveness of faces and subsequently learned how their peers ostensibly rated each face. Participants were then scanned using functional MRI while they rated each face a second time. The second ratings were influenced by social norms: Participants changed their ratings to conform to those of their peers. This social influence was accompanied by modulated engagement of two brain regions associated with coding subjective value--the nucleus accumbens and orbitofrontal cortex--a finding suggesting that exposure to social norms affected participants' neural representations of value assigned to stimuli. These findings document the utility of neuroimaging to demonstrate the private acceptance of social norms.

Mentalizing under uncertainty: dissociated neural responses to ambiguous and unambiguous mental state inferences.

The ability to read the minds of others (i.e., to mentalize) requires that perceivers understand a wide range of different kinds of mental states, including not only others' beliefs and knowledge but also their feelings, desires, and preferences. Moreover, although such inferences may occasionally rely on observable features of a situation, perceivers more typically mentalize under conditions of "uncertainty," in which they must generate plausible hypotheses about a target's mental state from ambiguous or otherwise underspecified information. Here, we use functional neuroimaging to dissociate the neural bases of these 2 distinct social-cognitive challenges: 1) mentalizing about different types of mental states (beliefs vs. preferences) and 2) mentalizing under conditions of varying ambiguity. Although these 2 aspects of mentalizing have typically been confounded in earlier research, we observed a double dissociation between the brain regions sensitive to type of mental state and ambiguity. Whereas ventral and dorsal aspects of medial prefrontal cortex responded more during ambiguous than unambiguous inferences regardless of the type of mental state, the right temporoparietal junction was sensitive to the distinction between beliefs and preferences irrespective of certainty. These results underscore the emerging consensus that, rather than comprising a single mental operation, social cognition makes flexible use of different processes as a function of the particular demands of the social context.

Repetition suppression of ventromedial prefrontal activity during judgments of self and others.

One useful strategy for inferring others' mental states (i.e., mentalizing) may be to use one's own thoughts, feelings, and desires as a proxy for those of other people. Such self-referential accounts of social cognition are supported by recent neuroimaging observations that a single brain region, ventromedial prefrontal cortex (vMPFC), is engaged both by tasks that require introspections about self and by tasks that require inferences about the minds of others perceived to be similar to self. To test whether people automatically refer to their own mental states when considering those of a similar other, we examined repetition-related suppression of vMPFC response during self-reflections that followed either an initial reflection about self or a judgment of another person. Consistent with the hypothesis that perceivers spontaneously engage in self-referential processing when mentalizing about particular individuals, vMPFC response was suppressed when self-reflections followed either an initial reflection about self or a judgment of a similar, but not a dissimilar, other. These results suggest that thinking about the mind of another person may rely importantly on reference to one's own mental characteristics.