Narun Pornpattananangkul

Cultural Neuroscience: Progress and Promise.

The nature and origin of human diversity has been a source of intellectual curiosity since the beginning of human history. Contemporary advances in cultural and biological sciences provide unique opportunities for the emerging field of cultural neuroscience. Research in cultural neuroscience examines how cultural and genetic diversity shape the human mind, brain, and behavior across multiple time scales: situation, ontogeny, and phylogeny. Recent progress in cultural neuroscience provides novel theoretical frameworks for understanding the complex interaction of environmental, cultural, and genetic factors in the production of adaptive human behavior. Here, we provide a brief history of cultural neuroscience, theoretical, and methodological advances, as well as empirical evidence of the promise of and progress in the field. Implications of this research for population health disparities and public policy are discussed.

Motivated to win: Relationship between anticipatory and outcome reward-related neural activity

Reward-processing involves two temporal stages characterized by two distinct neural processes: reward-anticipation and reward-outcome. Intriguingly, very little research has examined the relationship between neural processes involved in reward-anticipation and reward-outcome. To investigate this, one needs to consider the heterogeneity of reward-processing within each stage. To identify different stages of reward processing, we adapted a reward time-estimation task. While EEG data were recorded, participants were instructed to button-press 3.5s after the onset of an Anticipation-Cue and received monetary reward for good time-estimation on the Reward trials, but not on No-Reward trials. We first separated reward-anticipation into event related potentials (ERPs) occurring at three sub-stages: reward/no-reward cue-evaluation, motor-preparation and feedback-anticipation. During reward/no-reward cue-evaluation, the Reward-Anticipation Cue led to a smaller N2 and larger P3. During motor-preparation, we report, for the first time, that the Reward-Anticipation Cue enhanced the Readiness Potential (RP), starting approximately 1s before movement. At the subsequent feedback-anticipation stage, the Reward-Anticipation Cue elevated the Stimulus-Preceding Negativity (SPN). We also separated reward-outcome ERPs into different components occurring at different time-windows: the Feedback-Related Negativity (FRN), Feedback-P3 (FB-P3) and Late-Positive Potentials (LPP). Lastly, we examined the relationship between reward-anticipation and reward-outcome ERPs. We report that individual-differences in specific reward-anticipation ERPs uniquely predicted specific reward-outcome ERPs. In particular, the reward-anticipation Early-RP (1-.8s before movement) predicted early reward-outcome ERPs (FRN and FB-P3), whereas, the reward-anticipation SPN most strongly predicted a later reward-outcome ERP (LPP). Results have important implications for understanding the nature of the relationship between reward-anticipation and reward-outcome neural-processes.

N200 and P300 as orthogonal and integrable indicators of distinct awareness and recognition processes in memory detection

In an event-related potential (ERP)-based concealed information test (CIT), we investigated the effect of manipulated awareness of concealed information on the ERPs. Participants either committed a mock crime or not (guilty vs. innocent) before the CIT, and received feedback regarding either specific (high awareness) or general (low awareness) task performance during the CIT. We found that awareness and recognition of the crime-relevant information differentially influenced the frontal-central N200 and parietal P300: Probe elicited a larger N200 than irrelevant only when guilty participants were in the high awareness condition, whereas the P300 was mainly responsive to information recognition. No N200-P300 correlation was found, allowing for a combined measure of both yielding the highest detection efficiency in the high awareness group (AUC = .91). Finally, a color-naming Stroop task following the CIT revealed that guilty participants showed larger interference effects than innocent participants, suggesting that the former expended more attentional resources during the CIT.

Constraints, Catalysts and Coevolution in Cultural Neuroscience: Reply to Commentaries

In 1906, Ramon y Cajal described the brain as “a world consisting of a number of unexplored continents and great stretches of unknown territory” (Santiago, 1920). Nearly a century later, human neuroscience researchers have sought to map the structural and functional features of the brain, much as Magellen in 1520 circumnavigated the globe discovering for the first time great stretches of ocean and land that compose our physical world. Yet many opportunities and challenges in cultural neuroscience make much of this contemporary scientific journey ongoing and perpetual. For instance, scientific models depend on identifying and discovering evidence for causal mechanisms—such as how genetic and experiential factors constrain and evoke neural development within and across generations; yet the technology or access to technology for testing causal mechanisms in gene, brain, or behavior remains limited. Novel biological theories such as culture-gene coevolutionary theory provide a fresh lens for contemporary psychologists and neuroscientists to view the human mind and brain as a by-product not only of gene–environment interactions but also of human culture. What is human culture? The notion of human diversity has compelled intellectual inquiry for centuries and at the nexus of anthropology and psychology, scholars agree that at minimum, culture refers the sets of values, practices, and beliefs that define groups and people within and across geography. Culture is both created and transmitted by human behavior; as such culture–gene coevolutionary theory argues that cultural traits, like genetic traits, can be selected on by evolutionary forces. Furthermore, when culture is created, this niche construction can alter environmental factors or pressures that interact with genetic mechanisms in the production of psychological and biological processes that give rise to human behavior. In broadest stroke, the study of culture has progressed in leaps and bounds in ways that enable us to better understand how to conceptualize and study the how and why of human nature. In our target article, we presented from a historical perspective conceptual developments that led to the emergence of cultural neuroscience as a field, and articulated a framework for examining cultural and biological interactions of human behavior. We then presented empirical advances in how culture affects neural mechanisms of cognitive, affective, and social processes as well as the role that culture–gene interactions across evolutionary, developmental, and situational timescales play in shaping mental and neural architecture. As the field of cultural neuroscience is still in its infancy, there are key constraints on our existing knowledge and empirical approaches to how cultural influences on the human brain are studied, and the commentaries to our target article are testament that scientific ingenuity and conscientiousness will simultaneously guide us toward better understanding the legacy of cultural and genetic inheritance on mind, brain, and behavior.

Willing to wait: Elevated reward-processing EEG activity associated with a greater preference for larger-but-delayed rewards

While almost everyone discounts the value of future rewards over immediate rewards, people differ in their so-called delay-discounting. One of the several factors that may explain individual differences in delay-discounting is reward-processing. To study individual-differences in reward-processing, however, one needs to consider the heterogeneity of neural-activity at each reward-processing stage. Here using EEG, we separated reward-related neural activity into distinct reward-anticipation and reward-outcome stages using time-frequency characteristics. Thirty-seven individuals first completed a behavioral delay-discounting task. Then reward-processing EEG activity was assessed using a separate reward-learning task, called a reward time-estimation task. During this EEG task, participants were instructed to estimate time duration and were provided performance feedback on a trial-by-trial basis. Participants received monetary-reward for accurate-performance on Reward trials, but not on No-Reward trials. Reward trials, relative to No-Reward trials, enhanced EEG activity during both reward-anticipation (including, cued-locked delta power during cue-evaluation and pre-feedback alpha suppression during feedback-anticipation) and reward-outcome (including, feedback-locked delta, theta and beta power) stages. Moreover, all of these EEG indices correlated with behavioral performance in the time-estimation task, suggesting their essential roles in learning and adjusting performance to maximize winnings in a reward-learning situation. Importantly, enhanced EEG power during Reward trials, as reflected by stronger 1) pre-feedback alpha suppression, 2) feedback-locked theta and 3) feedback-locked beta, was associated with a greater preference for larger-but-delayed rewards in a separate, behavioral delay-discounting task. Results highlight the association between a stronger preference toward larger-but-delayed rewards and enhanced reward-processing. Moreover, our reward-processing EEG indices detail the specific stages of reward-processing where these associations occur.

Posterior versus frontal theta activity indexes approach motivation during affective autobiographical memories

Research has recently identified a promising neurophysiological marker of approach motivation involving posterior versus frontal (Pz – Fz) electroencephalographic (EEG) theta activity PFTA; Wacker, Chavanon, & Stemmler (Journal of Personality and Social Psychology 91:171-187, 2006). Preliminary evidence indicated that PFTA is modulated by dopaminergic activity, thought to underlie appetitive tendencies, and that it indexes self-reported behavioral activation system (BAS) sensitivity. To date, research has largely relied on resting indices of PFTA and has yet to examine the relationship between PFTA and specific approach-related affective states generated by emotionally salient laboratory tasks. Accordingly, the present study evaluated PFTA both at rest and during an ecologically valid autobiographical memory task in which participants recalled personal life experiences involving a goal-striving, an anxious apprehension, a low-point (i.e., difficult), and a neutral memory while EEG data were recorded. In line with prediction, elevated PFTA was observed during both goal-striving and anxious apprehension autobiographical memories. PFTA was particularly elevated during anxious apprehension memories coded as being high on approach-related tendencies. Elevated PFTA during anxious apprehension is consistent with a growing literature indicating that anxious apprehension is associated with elevated approach- and reward-related brain function. Lastly, elevated resting PFTA was positively correlated with self-reported trait anger, a negatively valenced emotion characterized by approach-related tendencies. These results have implications for (a) enhancing our understanding of the neurophysiology of approach-related emotions, (b) establishing PFTA as an index of appetitive motivational states, and (c) clarifying our understanding of the neurophysiology and approach-related tendencies associated with both anxious apprehension and anger.

Threat/reward-sensitivity and hypomanic-personality modulate cognitive-control and attentional neural processes to emotional stimuli

Temperamental-traits (e.g. threat/reward-sensitivity) are found to modulate cognitive-control and attentional-processes. Yet, it is unclear exactly how these traits interact with emotional-stimuli in the modulation of cognitive-control, as reflected by the N2 event-related potential (ERP), and attentional-processes, as reflected by the P2 and P3 ERPs. Here in an ERP emotional-Go/NoGo task, 36 participants were instructed to inhibit their response to Fearful- and Happy-faces. Individual-differences in threat-sensitivity, reward-sensitivity and hypomanic-personality were assessed through self-report. Hypomanic-personality was assessed, given its relationship with reward-sensitivity and relevance to mood-disorder symptoms. Concerning cognitive-control, individuals with elevated threat-sensitivity displayed more-negative N2s to Happy-NoGo (relative to Fearful-NoGo) faces, whereas both individuals with elevated reward-sensitivity and hypomanic-personality displayed more-negative N2s to Fearful-NoGo (relative to Happy-NoGo) faces. Accordingly, when cognitive-control is required (during Go/NoGo), a mismatch between ones temperament and the valence of the NoGo-stimulus elevates detection of the need for cognitive-control. Conversely, the modulation of attentional-processing was specific to threat-sensitivity, as there was no relationship between either reward-sensitivity or hypomanic-personality and attentional-processing. Elevated threat-sensitivity was associated with enhanced early (P2s) and later (P3s) attentional-processing to Fearful-NoGo (relative to Happy-NoGo) faces. These latter findings support the negative attentional-bias model relating elevated threat-sensitivity with attentional-biases toward negative-stimuli and away from positive-stimuli.

Psychological constructionism and cultural neuroscience.

Lindquist et al. argue that emotional categories do not map onto distinct regions within the brain, but rather, arise from basic psychological processes, including conceptualization, executive attention, and core affect. Here, we use examples from cultural neuroscience to argue that psychological constructionism, not locationism, captures the essential role of emotion in the social and cultural brain.

Generous to whom? The influence of oxytocin on social discounting

Oxytocin is thought to play an essential role in pro-social behaviors, such as generosity and altruism, in humans. Yet, most research in humans that demonstrated the pro-social effect of oxytocin had participants interact with partners who were total strangers to them. In real life, however, people often interact with others varying in social relatedness with them (a concept known as social distance), ranging from their parents to total strangers. Here we employed the social-discounting framework to investigate whether the effect of oxytocin on prosociality depends on the social distance between the participants and their interaction partners. In a double-blind, placebo-controlled experiment (n=172 participants), we measured the amount of money participants were willing to forgo to another person as a function of social distance. We found that oxytocin administration selectively enhanced amount of money forgone toward total strangers, as opposed to someone closer to participants, suggesting that social distance constrained the pro-social effect of oxytocin.

Social Discounting in the Elderly: Senior Citizens are Good Samaritans to Strangers

Objectives People tend to become more generous as they grow older, which may reflect an increase in their ego-transcending motives (i.e., concern more for the benefit of recipients than of the benefactors). The current study aimed to examine evidence for an enhanced ego-transcending motive among older adults. Methods We adapted the social-discounting framework to quantify generosity toward people of different social distances, ranging from socially close others (e.g., family and close friends) to socially distant others (e.g., total strangers), in both young and older adults. We hypothesized that the normative decrease in generosity as a function of social distance (e.g., less generous towards strangers compared to close friends) will be mitigated in older adults. Results Our results supported that older adults were more generous toward socially distant others (i.e., less social discounting) compared to younger adults. Discussion Thus, consistent with the idea that the elderly are more oriented to ego-transcending goals, older adults are generous even when their generosity is unlikely to be reciprocated.