Jan B. Engelmann

Embedding Reward Signals into Perception and Cognition

Despite considerable interest in the neural basis of valuation, the question of how valuation affects cognitive processing has received relatively less attention. Here, we review evidence from recent behavioral and neuroimaging studies supporting the notion that motivation can enhance perceptual and executive control processes to achieve more efficient goal-directed behavior. Specifically, in the context of cognitive tasks offering monetary gains, improved behavioral performance has been repeatedly observed in conjunction with elevated neural activations in task-relevant perceptual, cognitive and reward-related regions. We address the neural basis of motivation-cognition interactions by suggesting various modes of communication between relevant neural networks: (1) global hub regions may integrate information from multiple inputs providing a communicative link between specialized networks; (2) point-to-point interactions allow for more specific cross-network communication; and (3) diffuse neuromodulatory systems can relay motivational signals to cortex and enhance signal processing. Together, these modes of communication allow information regarding motivational significance to reach relevant brain regions and shape behavior.

Motivation sharpens exogenous spatial attention.

Although both attention and motivation affect behavior, how these 2 systems interact is currently unknown. To address this question, 2 experiments were conducted in which participants performed a spatially cued forced-choice localization task under varying levels of motivation. Participants were asked to indicate the location of a peripherally cued target while ignoring a distracter. Motivation was manipulated by varying magnitude and valence (reward and punishment) of an incentive linked to task performance. Attention was manipulated via a peripheral cue, which correctly predicted the presence of a target stimulus on 70% of the trials. Taken together, our findings revealed that the signal detection measure, reflecting perceptual sensitivity, increased as a function of incentive value during both valid and invalid trials. In addition, trend analyses revealed a linear increase in detection sensitivity as a function of incentive magnitude for both reward and punishment conditions. Our results suggest that elevated motivation leads to improved efficiency in orienting and reorienting of exogenous spatial attention and that one mechanism by which attention and motivation interact involves the sharpening of attention during motivationally salient conditions.

From Bad to Worse: Striatal Coding of the Relative Value of Painful Decisions

The majority of decision-related research has focused on how the brain computes decisions over outcomes that are positive in expectation. However, much less is known about how the brain integrates information when all possible outcomes in a decision are negative. To study decision-making over negative outcomes, we used fMRI along with a task in which participants had to accept or reject 50/50 lotteries that could result in more or fewer electric shocks compared to a reference amount. We hypothesized that behaviorally, participants would treat fewer shocks from the reference amount as a gain, and more shocks from the reference amount as a loss. Furthermore, we hypothesized that this would be reflected by a greater BOLD response to the prospect of fewer shocks in regions typically associated with gain, including the ventral striatum and orbitofrontal cortex. The behavioral data suggest that participants in our study viewed all outcomes as losses, despite our attempt to induce a status quo. We find that the ventral striatum showed an increase in BOLD response to better potential gambles (i.e., fewer expected shocks). This lends evidence to the idea that the ventral striatum is not solely responsible for reward processing but that it might also signal the relative value of an expected outcome or action, regardless of whether the outcome is entirely appetitive or aversive. We also find a greater response to worse gambles in regions previously associated with aversive valuation, suggesting an opposing but simultaneous valuation signal to that conveyed by the striatum.

Evidence for Countercyclical Risk Aversion: An Experiment with Financial Professionals

A key ingredient of many popular asset pricing models is that investors exhibit countercyclical risk aversion, which helps explain major economic puzzles such as the strong and systematic variation in risk premiums over time and the high volatility of asset prices. There is, however, surprisingly little evidence for this assumption because it is difficult to control for the host of factors that change simultaneously during financial booms and busts. We circumvent these control problems by priming financial professionals with either a boom or a bust scenario and by subsequently measuring their risk aversion in two experimental investment tasks with real monetary stakes. Subjects who were primed with a financial bust were substantially more risk averse than those who were primed with a boom. Subjects were also more fearful in the bust than in the boom condition, and their fear is negatively related to investments in the risky asset, suggesting that fear may play an important role in countercyclical risk aversion. The mechanism described in this paper is relevant for theory and has important implications, as it provides the basis for a self-reinforcing process that amplifies market dynamics.

Expert Financial Advice Neurobiologically ''Offloads'' Financial Decision-Making under Risk

Background Financial advice from experts is commonly sought during times of uncertainty. While the field of neuroeconomics has made considerable progress in understanding the neurobiological basis of risky decision-making, the neural mechanisms through which external information, such as advice, is integrated during decision-making are poorly understood. In the current experiment, we investigated the neurobiological basis of the influence of expert advice on financial decisions under risk. Methodology/Principal Findings While undergoing fMRI scanning, participants made a series of financial choices between a certain payment and a lottery. Choices were made in two conditions: 1) advice from a financial expert about which choice to make was displayed (MES condition); and 2) no advice was displayed (NOM condition). Behavioral results showed a significant effect of expert advice. Specifically, probability weighting functions changed in the direction of the experts advice. This was paralleled by neural activation patterns. Brain activations showing significant correlations with valuation (parametric modulation by value of lottery/sure win) were obtained in the absence of the experts advice (NOM) in intraparietal sulcus, posterior cingulate cortex, cuneus, precuneus, inferior frontal gyrus and middle temporal gyrus. Notably, no significant correlations with value were obtained in the presence of advice (MES). These findings were corroborated by region of interest analyses. Neural equivalents of probability weighting functions showed significant flattening in the MES compared to the NOM condition in regions associated with probability weighting, including anterior cingulate cortex, dorsolateral PFC, thalamus, medial occipital gyrus and anterior insula. Finally, during the MES condition, significant activations in temporoparietal junction and medial PFC were obtained. Conclusions/Significance These results support the hypothesis that one effect of expert advice is to “offload” the calculation of value of decision options from the individuals brain.

Individual Differences in Risk Preference Predict Neural Responses during Financial Decision-Making

We investigated the neural correlates of subjective valuations during a task involving risky choices about lotteries. Because expected value was held constant across all lotteries, decisions were influenced by subjective preferences, which manifest behaviorally as risk-seeking or risk-averse attitudes. To isolate structures encoding risk preference during choice, we probed for areas showing increased activation as a function of selected risk-level. Such response patterns were obtained in anterior (ACC) and posterior cingulate cortex (PCC), superior frontal gyrus, caudate nucleus, and substantia nigra. Behavioral results revealed the presence of risk-averse and risk-neutral individuals. In parallel, brain signals revealed modulation of activity by risk attitude during choice. Correlations between risk-seeking attitudes and neural activity during risky choice were obtained in superior and inferior frontal gyri, medial and lateral orbitofrontal cortex, and parahippocampal gyrus, while correlations with risk-averse attitudes were found in the caudate. The dynamics of neural responses relevant to each stage of the task (decision, anticipation, outcome) were investigated via timeseries and conjunction analyses. Though the networks engaged in each of the task stages were mostly distinct, regions within ACC, PCC and caudate were consistently activated during each decision-making phase. These results demonstrate (1) that subjective assessments of risk, as well as individual attitudes toward risk, play a significant role in modulating activity within brain regions recruited during decision-making, and (2) that ACC, PCC and caudate are relevant during each phase of a decision-making task requiring subjective valuations, strengthening the role of these regions in self-referential subjective valuations during choice.

Differential neurobiological effects of expert advice on risky choice in adolescents and adults

We investigated behavioral and neurobiological mechanisms by which risk-averse advice, provided by an expert, affected risky decisions across three developmental groups [early adolescents (12-14 years), late adolescents (15-17 years), adults (18+ years)]. Using cumulative prospect theory, we modeled choice behavior during a risky-choice task. Results indicate that advice had a significantly greater impact on risky choice in both adolescent groups than in adults. Using functional magnetic resonance imaging, we investigated the neural correlates of this behavioral effect. Developmental effects on correlations between brain activity and valuation parameters were obtained in regions that can be classified into (i) cognitive control regions, such as dorsolateral prefrontal cortex (DLPFC) and ventrolateral PFC; (ii) social cognition regions, such as posterior temporoparietal junction; and (iii) reward-related regions, such as ventromedial PFC (vmPFC) and ventral striatum. Within these regions, differential effects of advice on neural correlates of valuation were observed across development. Specifically, advice increased the correlation strength between brain activity and parameters reflective of safe choice options in adolescent DLPFC and decreased correlation strength between activity and parameters reflective of risky choice options in adult vmPFC. Taken together, results indicate that, across development, distinct brain systems involved in cognitive control and valuation mediate the risk-reducing effect of advice during decision making under risk via specific enhancements and reductions of the correlation strength between brain activity and valuation parameters.

Contextual and social influences on valuation and choice.

To survive in our complex environment, we have to adapt to changing contexts. Prior research that investigated how contextual changes are processed in the human brain has demonstrated important modulatory influences on multiple cognitive processes underlying decision-making, including perceptual judgments, working memory, as well as cognitive and attentional control. However, in everyday life, the importance of context is even more obvious during economic and social interactions, which often have implicit rule sets that need to be recognized by a decision-maker. Here, we review recent evidence from an increasing number of studies in the fields of Neuroeconomics and Social Neuroscience that investigate the neurobiological basis of contextual effects on valuation and social choice. Contrary to the assumptions of rational choice theory, multiple contextual factors, such as the availability of alternative choice options, shifts in reference point, and social context, have been shown to modulate behavior, as well as signals in task-relevant neural networks. A consistent picture that emerges from neurobiological results is that valuation-related activity in striatum and ventromedial prefrontal cortex is highly context dependent during both social and nonsocial choice. Alternative approaches to model and explain choice behavior, such as comparison-based choice models, as well as implications for future research are discussed.

Emotion perception across cultures: the role of cognitive mechanisms

Despite consistently documented cultural differences in the perception of facial expressions of emotion, the role of culture in shaping cognitive mechanisms that are central to emotion perception has received relatively little attention in past research. We review recent developments in cross-cultural psychology that provide particular insights into the modulatory role of culture on cognitive mechanisms involved in interpretations of facial expressions of emotion through two distinct routes: display rules and cognitive styles. Investigations of emotion intensity perception have demonstrated that facial expressions with varying levels of intensity of positive affect are perceived and categorized differently across cultures. Specifically, recent findings indicating significant levels of differentiation between intensity levels of facial expressions among American participants, as well as deviations from clear categorization of high and low intensity expressions among Japanese and Russian participants, suggest that display rules shape mental representations of emotions, such as intensity levels of emotion prototypes. Furthermore, a series of recent studies using eye tracking as a proxy for overt attention during face perception have identified culture-specific cognitive styles, such as the propensity to attend to very specific features of the face. Together, these results suggest a cascade of cultural influences on cognitive mechanisms involved in interpretations of facial expressions of emotion, whereby cultures impart specific behavioral practices that shape the way individuals process information from the environment. These cultural influences lead to differences in cognitive styles due to culture-specific attentional biases and emotion prototypes, which partially account for the gradient of cultural agreements and disagreements obtained in past investigations of emotion perception.

How learning shapes the empathic brain

Significance Deficits in empathy for out-group members are pervasive, with negative societal impact. It is therefore important to ascertain whether empathy toward out-groups can be learned and how learning experiences change empathy-related brain responses. We used a learning intervention during which participants experienced help from a member of their own social group or of a generally depreciated out-group. Our results show that the intervention successfully increased empathy-related brain responses toward the out-group. These changes in out-group empathy were triggered by the learning signal (prediction error) elicited during the first two positive out-group experiences. Together, our results show that classical learning signals update empathic brain responses and that surprisingly few positive experiences with an out-group member are sufficient to increase out-group empathy. Deficits in empathy enhance conflicts and human suffering. Thus, it is crucial to understand how empathy can be learned and how learning experiences shape empathy-related processes in the human brain. As a model of empathy deficits, we used the well-established suppression of empathy-related brain responses for the suffering of out-groups and tested whether and how out-group empathy is boosted by a learning intervention. During this intervention, participants received costly help equally often from an out-group member (experimental group) or an in-group member (control group). We show that receiving help from an out-group member elicits a classical learning signal (prediction error) in the anterior insular cortex. This signal in turn predicts a subsequent increase of empathy for a different out-group member (generalization). The enhancement of empathy-related insula responses by the neural prediction error signal was mediated by an establishment of positive emotions toward the out-group member. Finally, we show that surprisingly few positive learning experiences are sufficient to increase empathy. Our results specify the neural and psychological mechanisms through which learning interacts with empathy, and thus provide a neurobiological account for the plasticity of empathic reactions.