Ajay B. Satpute

The Sunny Side of Fairness Preference for Fairness Activates Reward Circuitry (and Disregarding Unfairness Activates Self-Control Circuitry)

Little is known about the positive emotional impact of fairness or the process of resolving conflict between fairness and financial interests. In past research, fairness has covaried with monetary payoff, such that the mental processes underlying preference for fairness and those underlying preference for greater monetary outcome could not be distinguished. We examined self-reported happiness and neural responses to fair and unfair offers while controlling for monetary payoff. Compared with unfair offers of equal monetary value, fair offers led to higher happiness ratings and activation in several reward regions of the brain. Furthermore, the tendency to accept unfair proposals was associated with increased activity in right ventrolateral prefrontal cortex, a region involved in emotion regulation, and with decreased activity in the anterior insula, which has been implicated in negative affect. This work provides evidence that fairness is hedonically valued and that tolerating unfair treatment for material gain involves a pattern of activation resembling suppression of negative affect.

Integrating automatic and controlled processes into neurocognitive models of social cognition

Interest in the neural systems underlying social perception has expanded tremendously over the past few decades. However, gaps between behavioral literatures in social perception and neuroscience are still abundant. In this article, we apply the concept of dual-process models to neural systems in an effort to bridge the gap between many of these behavioral studies and neural systems underlying social perception. We describe and provide support for a neural division between reflexive and reflective systems. Reflexive systems correspond to automatic processes and include the amygdala, basal ganglia, ventromedial prefrontal cortex, dorsal anterior cingulate cortex, and lateral temporal cortex. Reflective systems correspond to controlled processes and include lateral prefrontal cortex, posterior parietal cortex, medial prefrontal cortex, rostral anterior cingulate cortex, and the hippocampus and surrounding medial temporal lobe region. This framework is considered to be a working model rather than a finished product. Finally, the utility of this model and its application to other social cognitive domains such as Theory of Mind are discussed.

Large-scale brain networks in affective and social neuroscience: towards an integrative functional architecture of the brain

Understanding how a human brain creates a human mind ultimately depends on mapping psychological categories and concepts to physical measurements of neural response. Although it has long been assumed that emotional, social, and cognitive phenomena are realized in the operations of separate brain regions or brain networks, we demonstrate that it is possible to understand the body of neuroimaging evidence using a framework that relies on domain general, distributed structure-function mappings. We review current research in affective and social neuroscience and argue that the emerging science of large-scale intrinsic brain networks provides a coherent framework for a domain-general functional architecture of the human brain.

Evidence-based and intuition-based self-knowledge: An fMRI study

Behavioral and neuropsychological studies have suggested multiple self-knowledge systems may exist (i.e., evidence-based and intuition-based self-knowledge); however, little is known about the nature of intuition-based self-knowledge. In a functional magnetic resonance imaging study, the neural correlates of intuition-based and evidence-based self-knowledge were investigated. Participants with high and low experience in different domains (soccer and acting) made self-descriptiveness judgments about words from each domain while being scanned. High-experience domain judgments produced activation in a network of neural structures called the X-system, involved in automatic social cognition, whereas low-experience domain judgments produced activations in a network called the C-system, involved in effortful social cognition and propositional thought. The affective and slow-changing nature of intuition-based self-knowledge is discussed.

Identifying the what, why, and how of an observed action: An fmri study of mentalizing and mechanizing during action observation

Humans commonly understand the unobservable mental states of others by observing their actions. Embodied simulation theories suggest that this ability may be based in areas of the fronto-parietal mirror neuron system, yet neuroimaging studies that explicitly investigate the human ability to draw mental state inferences point to the involvement of a “mentalizing” system consisting of regions that do not overlap with the mirror neuron system. For the present study, we developed a novel action identification paradigm that allowed us to explicitly investigate the neural bases of mentalizing observed actions. Across repeated viewings of a set of ecologically valid video clips of ordinary human actions, we manipulated the extent to which participants identified the unobservable mental states of the actor (mentalizing) or the observable mechanics of their behavior (mechanizing). Although areas of the mirror neuron system did show an enhanced response during action identification, its activity was not significantly modulated by the extent to which the observers identified mental states. Instead, several regions of the mentalizing system, including dorsal and ventral aspects of medial pFC, posterior cingulate cortex, and temporal poles, were associated with mentalizing actions, whereas a single region in left lateral occipito-temporal cortex was associated with mechanizing actions. These data suggest that embodied simulation is insufficient to account for the sophisticated mentalizing that human beings are capable of while observing another and that a different system along the cortical midline and in anterior temporal cortex is involved in mentalizing an observed action.

Personality from a controlled processing perspective: An fMRI study of neuroticism, extraversion, and self-consciousness

Although neuroticism has been central to most theories of personality, self-reported neuroticism has had limited success in predicting expected behavioral outcomes. The reason for this may be due, in part, to the imprecision of self-reports. The purpose of this study was to examine the relationship between neural correlates of control systems and neuroticism, extraversion, and self-consciousness. In response to an oddball task, neuroticism was associated with increased dorsal anterior cingulate cortex (dACC) reactivity, typically associated with discrepancy detection, whereas extraversion and self-consciousness were associated with lateral and medial frontoparietal networks, respectively, typically associated with task-focused (lateral) or self-focused (medial) controlled processes. We also examined whether the neural measure of neuroticism would predict a relevant behavioral outcome better than self-reports would. Interoceptive accuracy, an outcome associated with neuroticism, was better accounted for by dACC reactivity (r2=.74) than by self-reported neuroticism (r2=.16), suggesting that neural reactivities may provide a more direct measure of personality than self-reports do.

Context processing and context maintenance in healthy aging and early stage dementia of the Alzheimer's type

Declines in the ability to process context information may represent a fundamental mechanism of age-related cognitive changes. Two components of context processing--activation/updating and maintenance--were examined in a sample of healthy younger and older adults, along with individuals suffering from early stage dementia of the Alzheimers type (DAT). All older adult groups showed context activation/updating impairments, whereas context maintenance was only impaired in the oldest adults (age>75 years) and was further exacerbated in DAT individuals. The results suggest that context processing may be composed of functionally dissociable components and point to the utility of this construct in understanding the timecourse of cognitive decline in healthy and pathological aging.

The neural correlates of implicit and explicit self-relevant processing.

Neuroimaging investigations of self-processing have generally focused on the neural correlates of explicit self-reflection. However, very little is known about the neural basis of implicit self-related processes. We utilized the concept of self-schemas to construct a two-task fMRI study that elicited both implicit and explicit self-relevant processes. The sample consisted of 18 participants who were schematic for either athletics or science. In the implicit self-relevance task, individuals made non-self-relevant judgments about affectively neutral scientific and athletic images. In the explicit self-reference task, participants judged the self-descriptiveness of adjectives related to athletics or science. Implicit and explicit processing of self-relevant (schematic) material elicited activity in many of the same regions, including medial prefrontal cortex, posterior cingulate/precuneus, ventromedial prefrontal cortex, subgenual anterior cingulate, amygdala, and ventral striatum. We suggest that processing self-related material recruits similar neural networks regardless of whether the self-relevance is made explicit or not.

A Bayesian Model of Category-Specific Emotional Brain Responses

Understanding emotion is critical for a science of healthy and disordered brain function, but the neurophysiological basis of emotional experience is still poorly understood. We analyzed human brain activity patterns from 148 studies of emotion categories (2159 total participants) using a novel hierarchical Bayesian model. The model allowed us to classify which of five categories—fear, anger, disgust, sadness, or happiness—is engaged by a study with 66% accuracy (43-86% across categories). Analyses of the activity patterns encoded in the model revealed that each emotion category is associated with unique, prototypical patterns of activity across multiple brain systems including the cortex, thalamus, amygdala, and other structures. The results indicate that emotion categories are not contained within any one region or system, but are represented as configurations across multiple brain networks. The model provides a precise summary of the prototypical patterns for each emotion category, and demonstrates that a sufficient characterization of emotion categories relies on (a) differential patterns of involvement in neocortical systems that differ between humans and other species, and (b) distinctive patterns of cortical-subcortical interactions. Thus, these findings are incompatible with several contemporary theories of emotion, including those that emphasize emotion-dedicated brain systems and those that propose emotion is localized primarily in subcortical activity. They are consistent with componential and constructionist views, which propose that emotions are differentiated by a combination of perceptual, mnemonic, prospective, and motivational elements. Such brain-based models of emotion provide a foundation for new translational and clinical approaches.

Identification of discrete functional subregions of the human periaqueductal gray

Significance The periaqueductal gray is a brainstem region that is critical for autonomic regulation and for defensive responses (e.g., “fight,” “flight,” “freeze”). It has been studied extensively in rodents and cats, but less is known about the human periaqueductal gray. The small size and shape of the periaqueductal gray makes it challenging to study using standard noninvasive MRI techniques. We used a high-field strength magnet to examine this region at high resolution while participants viewed emotionally aversive or neutral images. Emotion-related functional activity was concentrated in particular subregions and in ways that are consistent with neurobiological observations in nonhuman animals. This study establishes a technique to uncover the functional architecture of the periaqueductal gray in humans. The midbrain periaqueductal gray (PAG) region is organized into distinct subregions that coordinate survival-related responses during threat and stress [Bandler R, Keay KA, Floyd N, Price J (2000) Brain Res 53 (1):95–104]. To examine PAG function in humans, researchers have relied primarily on functional MRI (fMRI), but technological and methodological limitations have prevented researchers from localizing responses to different PAG subregions. We used high-field strength (7-T) fMRI techniques to image the PAG at high resolution (0.75 mm isotropic), which was critical for dissociating the PAG from the greater signal variability in the aqueduct. Activation while participants were exposed to emotionally aversive images segregated into subregions of the PAG along both dorsal/ventral and rostral/caudal axes. In the rostral PAG, activity was localized to lateral and dorsomedial subregions. In caudal PAG, activity was localized to the ventrolateral region. This shifting pattern of activity from dorsal to ventral PAG along the rostrocaudal axis mirrors structural and functional neurobiological observations in nonhuman animals. Activity in lateral and ventrolateral subregions also grouped with distinct emotional experiences (e.g., anger and sadness) in a factor analysis, suggesting that each subregion participates in distinct functional circuitry. This study establishes the use of high-field strength fMRI as a promising technique for revealing the functional architecture of the PAG. The techniques developed here also may be extended to investigate the functional roles of other brainstem nuclei.