Intrinsic functional connectivity in the default mode network predicts mnemonic discrimination: A connectome-based modeling approach.

The ability to distinguish existing memories from similar perceptual experiences is a core feature of episodic memory. This ability is often examined using the mnemonic similarity task in which people discriminate memories of studied objects from perceptually similar lures. Studies of the neural basis of such mnemonic discrimination have mostly focused on hippocampal function and connectivity. However, default mode network (DMN) connectivity may also support such discrimination, given that the DMN includes the hippocampus, and its connectivity supports many aspects of episodic memory. Here, we used connectome-based predictive modeling to identify associations between intrinsic DMN connectivity and mnemonic discrimination. We leveraged a wide range of abilities across healthy younger and older adults to facilitate this predictive approach. Resting-state functional connectivity in the DMN predicted mnemonic discrimination outside the MRI scanner, especially among prefrontal and temporal regions and including several hippocampal regions. This predictive relationship was stronger for younger than older adults, primarily for temporal-prefrontal connectivity. The novel associations established here are consistent with mounting evidence that broader cortical networks including the hippocampus support mnemonic discrimination. They also suggest that age-related network disruptions undermine the extent that the DMN supports this ability. This study provides the first indication of how intrinsic functional properties of the DMN support mnemonic discrimination.

Aging relates to a disproportionately weaker functional architecture of brain networks during rest and task states.

Functional connectivity - the co-activation of brain regions - forms the basis of the brain's functional architecture. Often measured during resting-state (i.e., in a task-free setting), patterns of functional connectivity within and between brain networks change with age. These patterns are of interest to aging researchers because age differences in resting-state connectivity relate to older adults' relative cognitive declines. Less is known about age differences in large-scale brain networks during directed tasks. Recent work in younger adults has shown that patterns of functional connectivity are highly correlated between rest and task states. Whether this finding extends to older adults remains largely unexplored. To this end, we assessed younger and older adults' functional connectivity across the whole brain using fMRI while participants underwent resting-state or completed directed tasks (e.g., a reasoning judgement task). Resting-state and task functional connectivity were less strongly correlated in older as compared to younger adults. This age-dependent difference could be attributed to significantly lower consistency in network organization between rest and task states among older adults. Older adults had less distinct or segregated networks during resting-state. This more diffuse pattern of organization was exacerbated during directed tasks. Finally, the default mode network, often implicated in neurocognitive aging, contributed strongly to this pattern. These findings establish that age differences in functional connectivity are state-dependent, providing greater insight into the mechanisms by which aging may lead to cognitive declines.

Valenced appearance-behavior cues affect the extent of impression memory.

Prior work has often shown higher memory for impressions of valenced verbal cues when such valence is congruent with valence conveyed by actors' facial characteristics. The current work examined specific valence contributions to appearance-congruent memory advantages. Untrustworthy and trustworthy faces were paired with positive, negative, and neutral behaviours (Study 1) and traits (Study 2). Negative versus positive trust-related behaviours are more highly diagnostic and weigh more heavily into impressions, suggesting that impressions of negative behaviours should also be more memorable. Consistent with this possibility, an appearance-congruity advantage for memory of impressions formed from behaviours was larger for untrustworthy versus trustworthy faces after correcting for appearance-congruent response biases (Study 1). When forming impressions from traits, verbal cues less contextualised than behaviours, a larger appearance-congruity advantage in impression memory for untrustworthy versus trustworthy faces could be attributed to appearance-congruent responding (Study 2). Across studies, more extremely valenced impressions were better remembered than more neutral impressions regardless of facial trustworthiness. True appearance-congruity advantages in impression memory may thus be larger for untrustworthy faces when verbal cues can be more contextualised. Further, forming impressions of more extremely valenced verbal cues may enhance impression memory regardless of whether cues are incongruent with facial characteristics.

Age differences in specific neural connections within the Default Mode Network underlie theory of mind.

Theory of mind (i.e., the ability to infer others' mental states) - a fundamental social cognitive ability - declines with increasing age. Prior investigations have focused on identifying task-evoked differences in neural activation that underlie these performance declines. However, these declines could also be related to dysregulation of the baseline, or 'intrinsic', functional connectivity of the brain. If so, age differences in intrinsic connectivity may provide novel insight into the mechanisms that contribute to poorer theory of mind in older adults. To examine this possibility, we assessed younger and older adults' theory of mind while they underwent task-based fMRI, as well as the intrinsic functional connectivity measured during resting-state within the (task-defined) theory of mind network. Older adults exhibited poorer theory of mind behavioral performance and weaker intrinsic connectivity within this network compared to younger adults. Intrinsic connectivity between the right temporoparietal junction and the right temporal pole mediated age differences in theory of mind. Specifically, older adults had weaker intrinsic connectivity between right temporoparietal junction and right temporal pole that explained their poorer theory of mind behavioral performance. These findings broaden our understanding of aging and social cognition and reveal more specific mechanisms of how aging impacts theory of mind.

Neural response to evaluating depression predicts perceivers' mental health treatment recommendations.

Nonstigmatized perceivers' initial evaluations of stigmatized individuals have profound consequences for the well-being of those stigmatized individuals. However, the mechanism by which this occurs remains underexplored. Specifically, what beliefs about the stigmatized condition (stigma-related beliefs) shape how nonstigmatized perceivers evaluate and behave toward stigmatized individuals? We examined these questions with respect to depression-related stigmatization because depression is highly stigmatized and nondepressed individuals' behavior (e.g., willingness to recommend treatment) directly relates to removing stigma and increasing well-being. In Study 1, we identified common stigma-related beliefs associated with depression (e.g., not a serious illness, controllable, threatening), and found that only perceptions that depression is a serious condition predicted nondepressed perceivers' willingness to recommend mental health treatment. Moreover, perceivers' beliefs that depression is a distressing condition mediated the relationship between perceived seriousness and treatment recommendations (Study 1). In Study 2, we used fMRI to disentangle the potential processes connecting distress to nondepressed perceivers' self-reported treatment intentions. Heightened activity in the dorsomedial prefrontal cortex (dmPFC)-a region widely implicated in evaluating others-and the ventrolateral prefrontal cortex (vlPFC)-a region widely implicated in regulating negative emotions-emerged when nondepressed perceivers evaluated individuals who were ostensibly depressed. Beliefs that depression is a distressing condition mediated the relationship between dmPFC (but not vlPFC) activity and nondepressed individuals' self-reported treatment recommendations.

Dynamic neural mechanisms underlie race disparities in social cognition.

Race disparities in behavior may emerge in several ways, some of which may be independent of implicit bias. To mitigate the pernicious effects of different race disparities for racial minorities, we must understand whether they are rooted in perceptual, affective, or cognitive processing with regard to race perception. We used fMRI to disentangle dynamic neural mechanisms predictive of two separable race disparities that can be obtained from a trustworthiness ratings task. Increased coupling between regions involved in perceptual and affective processing when viewing Black versus White faces predicted less later racial trust disparity, which was related to implicit bias. In contrast, increased functional coupling between regions involved in controlled processing predicted less later disparity in the differentiation of Black versus White faces with regard to perceived trust, which was unrelated to bias. These findings reveal that distinct neural signatures underlie separable race disparities in social cognition that may or may not be related to implicit bias.

Similarity to the self influences cortical recruitment during impression formation.

Prior work has shown that whether or not someone is similar to the self influences person memory--a type of self-reference effect for others. In this study, we were interested in understanding the neural regions supporting the generation of impressions and subsequent memory for targets who vary in similarity to the self. Participants underwent fMRI scanning while forming positive or negative impressions of face-behavior pairs. We tested participants' memory for their generated impressions and then back-sorted the impression trials (encoding) into different levels of self-similarity (high, medium, low) using a self-similarity posttest that came after recognition. Extending prior behavioral work, our data confirmed our hypothesis that memory would be highest for self-similar others and lowest for self-dissimilar others. Dorsal anterior cingulate cortex (dACC) activity increased with self-similarity (high > medium > low) to targets, regardless of later memory for them. An analysis of regions supporting impression memory revealed a double dissociation within medial temporal lobe regions: for similar others, amygdala recruitment supported memory, whereas for dissimilar others, hippocampal activation supported memory. These results suggest that self-similarity influences evaluation and memory for targets but also affects the underlying neural resources engaged when thinking about others who vary in self-similarity.

Neural correlates of personal space intrusion.

A parietal-frontal network in primates is thought to support many behaviors occurring in the space around the body, including interpersonal interactions and maintenance of a particular "comfort zone" or distance from other people ("personal space"). To better understand this network in humans, we used functional MRI to measure the responses to moving objects (faces, cars, simple spheres) and the functional connectivity of two regions in this network, the dorsal intraparietal sulcus (DIPS) and the ventral premotor cortex (PMv). We found that both areas responded more strongly to faces that were moving toward (vs away from) subjects, but did not show this bias in response to comparable motion in control stimuli (cars or spheres). Moreover, these two regions were functionally interconnected. Tests of activity-behavior associations revealed that the strength of DIPS-PMv connectivity was correlated with the preferred distance that subjects chose to stand from an unfamiliar person (personal space size). In addition, the magnitude of DIPS and PMv responses was correlated with the preferred level of social activity. Together, these findings suggest that this parietal-frontal network plays a role in everyday interactions with others.

Social influences on adaptive criterion learning.

People adaptively shift decision criteria when given biased feedback encouraging specific types of errors. Given that work on this topic has been conducted in nonsocial contexts, we extended the literature by examining adaptive criterion learning in both social and nonsocial contexts. Specifically, we compared potential differences in criterion shifting given performance feedback from social sources varying in reliability and from a nonsocial source. Participants became lax when given false positive feedback for false alarms, and became conservative when given false positive feedback for misses, replicating prior work. In terms of a social influence on adaptive criterion learning, people became more lax in response style over time if feedback was provided by a nonsocial source or by a social source meant to be perceived as unreliable and low-achieving. In contrast, people adopted a more conservative response style over time if performance feedback came from a high-achieving and reliable source. Awareness that a reliable and high-achieving person had not provided their feedback reduced the tendency to become more conservative, relative to those unaware of the source manipulation. Because teaching and learning often occur in a social context, these findings may have important implications for many scenarios in which people fine-tune their behaviors, given cues from others.

Influences of appearance-behaviour congruity on memory and social judgements.

Prior work shows that appearance-behaviour congruity impacts memory and evaluations. Building upon prior work, we assessed influences of appearance-behaviour congruity on source memory and judgement strength to illustrate ways congruity effects permeate social cognition. We paired faces varying on trustworthiness with valenced behaviours to create congruent and incongruent face-behaviour pairs. Young and older adults remembered congruent pairs better than incongruent, but both were remembered better than pairs with faces rated average in appearance. This suggests that multiple, even conflicting, valenced cues improve memory over receiving fewer cues. Consistent with our manipulation of facial trustworthiness, congruity effects were present in the strength of trustworthiness-related but not dominance judgements. Subtle age differences emerged in congruity effects when learning about others, with older adults showing effects for approach judgements given both high and low arousal behaviours. Young adults had congruity effects for approach, prosociality and trustworthiness judgements, given high arousal behaviours only. These findings deepen our understanding of how appearance-behaviour congruity impacts memory for and evaluations of others.

NEURAL RESPONSES TO APPEARANCE-BEHAVIOR CONGRUITY.

Research evidences stronger reactions toward those whose behaviors seem consistent with appearance. To better understand the processes underlying appearance-behavior congruity effects, we assessed regions responding as a function of the congruity between visual (appearance) and abstract (behavior) cues. Using fMRI, trustworthy- and untrustworthy-looking faces were paired with positive, negative, or neutral behaviors. Approach judgments were stronger for congruent over incongruent targets, replicating prior work. Incongruent targets (e.g., untrustworthy face/positive behavior) elicited medial prefrontal (mPFC) and dorsolateral prefrontal (dlPFC) cortex activity more than congruent (e.g., untrustworthy face/negative behavior), suggesting processing incongruent targets requires additional mentalizing and controlled processing. Individual differences in enjoying interpersonal interactions negatively correlated with mPFC activity toward incongruent over congruent targets, suggesting more effortful processing of incongruent targets for individuals with lower levels of social motivation. These findings indicate mPFC contributions to processing incongruent appearance-behavior cues, but suggest that individual differences may temper the extent of this effect.

Perceiver and target partisanship shift facial trustworthiness effects on likability.

The affective polarization characteristic of the United States' political climate contributes to pervasive intergroup tension. This tension polarizes basic aspects of person perception, such as face impressions. For instance, face impressions are polarized by partisanship disclosure such that people form positive and negative impressions of, respectively, shared and opposing partisan faces. How partisanship interacts with other facial cues affecting impressions remains unclear. Building on work showing that facial trustworthiness, a core dimension of face perception, is especially salient for ingroup members, we reasoned that shared and opposing partisanship may also affect the relation between facial trustworthiness characteristics and subsequent likability impressions. A stronger positive relation emerged for shared versus opposing partisan faces across more conservative and liberal perceivers (Experiments 1 and 2). Exploratory analyses showed that this difference links to perceived partisan threat (Experiment 1) and that experimentally manipulating inter-party threat strengthened opposing partisan derogation and shared partisan enhancement patterns (Experiment 2). These findings suggest that partisanship extends from affecting overall face impressions of partisans to affecting the relation between a core dimension of face perception and subsequent impressions. These findings highlight the prevalence of partisanship effects in basic aspects of person perception and have implications for intergroup behavior.

Attractiveness Differentially Affects Direct Versus Indirect Face Evaluations in Two Cultures.

Although decades of research have identified facial features relating to people's evaluations of faces, specific features have largely been examined in isolation from each other. Recent work shows that considering the relative importance of these features in face evaluations is important to test theoretical assumptions of impression formation. Here, we examined how two facial features of evolutionary interest, facial attractiveness and facial-width-to-height ratio (FWHR), relate to evaluations of faces across two cultures. Because face evaluations are typically directly measured via self-reports, we also examined whether these features exert differential effects on both direct and indirect face evaluations. Evaluations of standardized photos naturally varying in facial attractiveness and FWHR were collected using the Affect Misattribution Procedure in the United States and Turkey. When their relative contributions were considered in the same model, facial attractiveness, but not FWHR, related to face evaluations across cultures. This positive attractiveness effect was stronger for direct versus indirect evaluations across cultures. These findings highlight the importance of considering the relative contributions of facial features to evaluations across cultures and suggest a culturally invariant role of attractiveness when intentionally evaluating faces.

Age-related differences in the social associative learning of trust information.

Trust is a key component of social interaction. Older adults, however, often exhibit excessive trust relative to younger adults. One explanation is that older adults may learn to trust differently than younger adults. Here, we examine how younger (N = 33) and older adults (N = 30) learn to trust over time. Participants completed a classic iterative trust game with 3 partners. Younger and older adults shared similar amounts but differed in how they shared money. Compared to younger adults, older adults invested more with untrustworthy partners and less with trustworthy partners. As a group, older adults displayed less learning than younger adults. However, computational modeling suggests that this is not because older adults learn differently from positive and negative feedback than younger adults. Model-based fMRI analyses revealed several age- and learning-related differences in neural processing. Specifically, we found that older learners (N = 19), relative to older non-learners (N = 11), had greater reputation-related activity in metalizing/memory areas while making their decisions. Collectively, these findings suggest that older adult learners use social cues differently from non-learners.

Lower-level stimulus features strongly influence responses in the fusiform face area.

An intriguing region of human visual cortex (the fusiform face area; FFA) responds selectively to faces as a general higher-order stimulus category. However, the potential role of lower-order stimulus properties in FFA remains incompletely understood. To clarify those lower-level influences, we measured FFA responses to independent variation in 4 lower-level stimulus dimensions using standardized face stimuli and functional Magnetic Resonance Imaging (fMRI). These dimensions were size, position, contrast, and rotation in depth (viewpoint). We found that FFA responses were strongly influenced by variations in each of these image dimensions; that is, FFA responses were not "invariant" to any of them. Moreover, all FFA response functions were highly correlated with V1 responses (r = 0.95-0.99). As in V1, FFA responses could be accurately modeled as a combination of responses to 1) local contrast plus 2) the cortical magnification factor. In some measurements (e.g., face size or a combinations of multiple cues), the lower-level variations dominated the range of FFA responses. Manipulation of lower-level stimulus parameters could even change the category preference of FFA from "face selective" to "object selective." Altogether, these results emphasize that a significant portion of the FFA response reflects lower-level visual responses.

Appearance-based inferences bias source memory.

Previous research varying the trustworthiness of appearance has demonstrated that facial characteristics contribute to source memory. Two studies extended this work by investigating the contribution to source memory of babyfaceness, a facial quality known to elicit strong spontaneous trait inferences. Young adult participants viewed younger and older babyfaced and mature-faced individuals paired with sentences that were either congruent or incongruent with the target's facial characteristics. Identifying a source as dominant or submissive was least accurate when participants chose between a target whose behavior was incongruent with facial characteristics and a lure whose face mismatched the target in appearance but matched the source memory question. In Experiment 1, this effect held true when older sources were identified, but not own-age, younger sources. When task difficulty was increased in Experiment 2, the relationship between face-behavior congruence and lure facial characteristics persisted, but it was not moderated by target age even though participants continued to correctly identify fewer older than younger sources. Taken together, these results indicate that trait expectations associated with variations in facial maturity can bias source memory for both own- and other-age faces, although own-age faces are less vulnerable to this bias, as is shown in the moderation by task difficulty.

Social relevance enhances memory for impressions in older adults.

Previous research has demonstrated that older adults have difficulty retrieving contextual material over items alone. Recent research suggests this deficit can be reduced by adding emotional context, allowing for the possibility that memory for social impressions may show less age-related decline than memory for other types of contextual information. Two studies investigated how orienting to social or self-relevant aspects of information contributed to the learning and retrieval of impressions in young and older adults. Participants encoded impressions of others in conditions varying in the use of self-reference (Experiment 1) and interpersonal meaningfulness (Experiment 2), and completed memory tasks requiring the retrieval of specific traits. For both experiments, age groups remembered similar numbers of impressions. In Experiment 1 using more self-relevant encoding contexts increased memory for impressions over orienting to stimuli in a non-social way, regardless of age. In Experiment 2 older adults had enhanced memory for impressions presented in an interpersonally meaningful relative to a personally irrelevant way, whereas young adults were unaffected by this manipulation. The results provide evidence that increasing social relevance ameliorates age differences in memory for impressions, and enhances older adults' ability to successfully retrieve contextual information.

Mental Representations of Sickness Positively Relate to Adaptive Health Behaviors.

An ecological approach to social perception states that impressions of faces have functional value in that they guide adaptive behavior ensuring people's survival. For example, people may avoid others whose faces appear sick to avoid an illness representing a survival threat. We broadened the ecological approach in the current work by examining whether merely thinking about what illnesses on faces look like (i.e., how sickness on faces is represented) holds functional value in guiding behavior to ensure survival. Using an example of a real illness threat as proof of concept, we showed that people self-reported performing more adaptive health behaviors in response to COVID-19 if they had sicker representations of COVID-19 on faces (Experiment 1a). These sicker representations of COVID-19 on faces explained, in part, a positive relation between perceptions of COVID-19 as threatening and people's self-reported adaptive health behaviors. We then replicated these patterns when experimentally manipulating illness threat (Experiment 1b). We found that people expected more adaptive health behaviors and had sicker representations of illness on faces in response to illness threats that were more relative to less threatening. These findings suggest that mentally representing sickness on faces is enough to guide people's behaviors in response to illness threats.

Disclosing political partisanship polarizes first impressions of faces.

Americans' increasing levels of ideological polarization contribute to pervasive intergroup tensions based on political partisanship. Cues to partisanship may affect even the most basic aspects of perception. First impressions of faces constitute a widely-studied basic aspect of person perception relating to intergroup tensions. To understand the relation between face impressions and political polarization, two experiments were designed to test whether disclosing political partisanship affected face impressions based on perceivers' political ideology. Disclosed partisanship more strongly affected people's face impressions than actual, undisclosed, categories (Experiment 1). In a replication and extension, disclosed shared and opposing partisanship also engendered, respectively, positive and negative changes in face impressions (Experiment 2). Partisan disclosure effects on face impressions were paralleled by the extent of people's partisan threat perceptions (Experiments 1 and 2). These findings suggest that partisan biases appear in basic aspects of person perception and may emerge concomitant with perceived partisan threat.

Decoding complex emotions and humanization show related face processing effects.

Inferring others' complex emotions is central to ascribing humanness to others. However, little past research has investigated the perceptual processes linking the inference of complex emotions to judging others' humanness. To this end, we disrupted the low-level perceptual processes typically employed in face processing via face inversion. Of interest was whether the inversion-driven deficits in complex emotion judgments and in humanness judgments were related. In three experiments, we find that disrupting efficient face processing via face inversion undermined the accurate decoding of complex emotions from the eyes (Experiments 1a, 1b, and 2) and triggered more dehumanized evaluations of target eye regions (Experiments 1a and 1b) and faces (Experiment 2). Critically, these inversion effects on emotion decoding and dehumanization were positively correlated. People who demonstrated stronger inversion effects on the accuracy of decoding complex emotions also demonstrated stronger inversion effects on dehumanizing evaluations. Taken together, these findings provide novel evidence that sensitivity to complex emotions and (de)humanization are related through a shared perceptual basis in efficient face processing. (PsycInfo Database Record (c) 2022 APA, all rights reserved).