George I. Christopoulos

Neural Correlates of Value, Risk, and Risk Aversion Contributing to Decision Making under Risk

Decision making under risk is central to human behavior. Economic decision theory suggests that value, risk, and risk aversion influence choice behavior. Although previous studies identified neural correlates of decision parameters, the contribution of these correlates to actual choices is unknown. In two different experiments, participants chose between risky and safe options. We identified discrete blood oxygen level-dependent (BOLD) correlates of value and risk in the ventral striatum and anterior cingulate, respectively. Notably, increasing inferior frontal gyrus activity to low risk and safe options correlated with higher risk aversion. Importantly, the combination of these BOLD responses effectively decoded the behavioral choice. Striatal value and cingulate risk responses increased the probability of a risky choice, whereas inferior frontal gyrus responses showed the inverse relationship. These findings suggest that the BOLD correlates of decision factors are appropriate for an ideal observer to detect behavioral choices. More generally, these biological data contribute to the validity of the theoretical decision parameters for actual decisions under risk.

Risk-dependent reward value signal in human prefrontal cortex

When making choices under uncertainty, people usually consider both the expected value and risk of each option, and choose the one with the higher utility. Expected value increases the expected utility of an option for all individuals. Risk increases the utility of an option for risk-seeking individuals, but decreases it for risk averse individuals. In 2 separate experiments, one involving imperative (no-choice), the other choice situations, we investigated how predicted risk and expected value aggregate into a common reward signal in the human brain. Blood oxygen level dependent responses in lateral regions of the prefrontal cortex increased monotonically with increasing reward value in the absence of risk in both experiments. Risk enhanced these responses in risk-seeking participants, but reduced them in risk-averse participants. The aggregate value and risk responses in lateral prefrontal cortex contrasted with pure value signals independent of risk in the striatum. These results demonstrate an aggregate risk and value signal in the prefrontal cortex that would be compatible with basic assumptions underlying the mean-variance approach to utility.

Neuronal distortions of reward probability without choice.

Reward probability crucially determines the value of outcomes. A basic phenomenon, defying explanation by traditional decision theories, is that people often overweigh small and underweigh large probabilities in choices under uncertainty. However, the neuronal basis of such reward probability distortions and their position in the decision process are largely unknown. We assessed individual probability distortions with behavioral pleasantness ratings and brain imaging in the absence of choice. Dorsolateral frontal cortex regions showed experience dependent overweighting of small, and underweighting of large, probabilities whereas ventral frontal regions showed the opposite pattern. These results demonstrate distorted neuronal coding of reward probabilities in the absence of choice, stress the importance of experience with probabilistic outcomes and contrast with linear probability coding in the striatum. Input of the distorted probability estimations to decision-making mechanisms are likely to contribute to well known inconsistencies in preferences formalized in theories of behavioral economics.

Disgust Associated With Culture Mixing: Why and Who?

Humans possess evolved mechanisms to detect and reject contamination by potentially harmful foreign substances. These mechanisms may also function in the rejection of violations in the social order. Here, we propose that the disgust evaluation system may also be sensitive to culture mixing, especially when elements of own and foreign cultures occupy the same space at the same time (culture fusion). Across four studies, we observe support for this prediction. Paralleling disgust ratings for contaminants mixing with pure objects associated with the self (Study 1A), representations of blending and fusion between elements of own and foreign cultures were rated as more disgusting than simultaneous presentation of the same cultural elements without fusion (Studies 1B and 2). Disgust toward culture fusion was observed over and above incongruity associated with mixing two in-group cultural representations (Study 4). Moreover, selective disgust toward in-group–out-group culture fusion was especially pronounced among those endorsing higher levels of patriotism (Studies 1B, 2, and 4), but not when culture fusion involved two foreign representations (Study 3). These findings support the notion that the architecture for pathogenic- and food-based disgust may have been extended to reject external threats to the fidelity of in-group identity markers by out-group influences.

Physiological responses associated with cultural attachment

HighlightsCultural attachment (CA): cultural symbols can function as attachment figures, especially in the face of threat.Threatening stimuli were supraliminally presented while measuring skin conductance responses (SCR).Subliminal CA icons followed threatening stimuli.SCR to threatening stimuli were lowered when cultural icons were displayed (vs. control icons).SCR to cultural icons in the presence of threat dependent on participant’s Need for Cognitive Closure. Abstract Cultural attachment (CA) suggests that cultural symbols can function as attachment figures, in a similar way to prototypical maternal attachment figures. In order to further understand the psychophysiological mechanisms of CA, we examine whether cultural symbols regulate peripheral physiological indicators of arousal in response to symbolic threats. We supraliminally expose participants to neutral or threatening stimuli, followed by the subliminal presentation of CA and control images, while recording their Skin Conductance Responses (SCR). In tandem with previous work, threat increased SCR when the subliminal image was a control. However, the subliminal presence of a cultural symbol reduced this typically high SCR to threat, potentially suggesting that the threat‐related arousal was mitigated. Importantly, metrics related to the way an individual is related to the environment, i.e. the need for cognitive closure, affected physiological responses towards threat and cultural images. Overall, the present study sets the basis for potential emotional mechanisms that could explain how cultural symbols can act as extensions of the prototypical attachment figures and confer the sense of security in the face of threat.

Turning Two Uninvited Guests Into Prominent Speakers: Toward a Dynamic Culture Neuroscience

It is with assurance that we can state that LéviStrauss would have been more than satisfied by reading the target article by Chiao and colleagues (this issue). The authors review and outline the most recent advances in the burgeoning field of cultural neuroscience (CN). The article provides convincing evidence demonstrating the interplay between biology, behavior, and culture as a response to evolutionary and societal pressures. The human mind is no longer an uninvited guest; in fact, it is a prominent speaker. But Chiao et al. (this issue) move a step forward to right another injustice. If the human mind had been an uninvited guest to culture conferences, then culture was sitting outside of closed doors in neuroscience meetings. To be fair, one of the main reasons pertaining to the weakened recognition of the role of culture in neuroscience studies could be purely financial, as the cost of neuroimaging studies limited the possibilities for cross-cultural research. However, potentially following the psychological tradition, neuroscientists in general are quick to assign universality to their conclusions. Yet the present report demonstrates that there is a deep change in neuroscience circles. There is yet more light and truth. Here is what we think should be one of the principal considerations stemming from the rich conclusions offered by Chiao et al. (this issue): It is not only neuroscience helping us understand the cultural phenomenon but, critically, the tools provided by CN hold a matchless potential to understand the human mind, brain, and behavior, and their links to evolution. De jure, CN emerges as a potentially unique discipline that can offer a common platform for understanding and, possibly, testing the mechanisms through which the human mind, brain, and behavior dynamically integrate to adjust to a changing environment. In the next paragraphs, we explain our interpretation of Chiao et al.’s (this issue) message and offer our opinion on the directions that CN could take to boldly move on to answer more global questions. Specifically, we claim that research in CN would greatly benefit if the following concepts are integrated in the research rationale:

Melatonin and health: an umbrella review of health outcomes and biological mechanisms of action

BackgroundOur aims were to evaluate critically the evidence from systematic reviews as well as narrative reviews of the effects of melatonin (MLT) on health and to identify the potential mechanisms of action involved.MethodsAn umbrella review of the evidence across systematic reviews and narrative reviews of endogenous and exogenous (supplementation) MLT was undertaken. The Oxman checklist for assessing the methodological quality of the included systematic reviews was utilised. The following databases were searched: MEDLINE, EMBASE, Web of Science, CENTRAL, PsycINFO and CINAHL. In addition, reference lists were screened. We included reviews of the effects of MLT on any type of health-related outcome measure.ResultsAltogether, 195 reviews met the inclusion criteria. Most were of low methodological quality (mean -4.5, standard deviation 6.7). Of those, 164 did not pool the data and were synthesised narratively (qualitatively) whereas the remaining 31 used meta-analytic techniques and were synthesised quantitatively. Seven meta-analyses were significant with P values less than 0.001 under the random-effects model. These pertained to sleep latency, pre-operative anxiety, prevention of agitation and risk of breast cancer.ConclusionsThere is an abundance of reviews evaluating the effects of exogenous and endogenous MLT on health. In general, MLT has been shown to be associated with a wide variety of health outcomes in clinically and methodologically heterogeneous populations. Many reviews stressed the need for more high-quality randomised clinical trials to reduce the existing uncertainties.

A Psychosocial Approach to Understanding Underground Spaces

With a growing need for usable land in urban areas, subterranean development has been gaining attention. While construction of large underground complexes is not a new concept, our understanding of various socio-cultural aspects of staying underground is still at a premature stage. With projected emergence of underground built environments, future populations may spend much more of their working, transit, and recreational time in underground spaces. Therefore, it is essential to understand the challenges and advantages that such environments have to improve the future welfare of users of underground spaces. The current paper discusses various psycho-social aspects of underground spaces, the impact they can have on the culture shared among the occupants, and possible solutions to overcome some of these challenges.

An In-Depth Analysis of Workers’ Attitudes Towards an Underground Facility in USA with a Focus on Breaks and Breakrooms

With the increase in urbanization and industrialization and the ever-increasing problem of space, sustainable solutions such as underground work places are on the rise. However, considering the huge investments required to make such spaces a success, in-depth studies regarding various aspects of underground workplaces (UW) need to be made. One such factor that determines this success is breakrooms. Though several studies have identified breakrooms to be a major factor in employee health and satisfaction, this hasn’t been explored in the context of UW.

Digging Deep: The Effect of Design on the Social Behavior and Attitudes of People Working in Underground Workplaces in Europe

With the cities of the world grappling with the ever-increasing challenge of land scarcity, sustainable solutions such as Underground Workplaces (UW) have been getting renewed interest. However, considering the hefty investments that will go into building UW and since the success of this solution relies on the wellbeing of the people who are to occupy it, there is a need to examine existing UW from a human factor point of view. In this paper, we present an analysis of how design factors in UW affect the attitudes and social behavior of employees and how these perceptions and attitudes towards the workplace vary across different work types. According to our analysis organic elements, art, architecture and lighting affect social behavior and attitudes. These factors can be manipulated according to the type of work and environment in a way that is in line with company values. The paper also attempts to create a framework for how the significance of the work environment varies with the type of work and workplaces.