Flexibility of reinforcement biases and reaction times in competitive zero-sum games

In competitive zero-sum games with mixed equilibria, two rational players should make each of their game choices randomly, with no contingencies between their choices. However, people often deviate from this equilibrium by following a reinforcement heuristic of repeating moves that won on the previous round (win-stay) and avoiding the repetition of moves that did not win (lose-shift). In this thesis, I examine the flexibility of these reinforcement biases, and the speed of decision-making: under what circumstances do people make biased choices, and under what circumstances do people choose quickly or stop to deliberate? In Chapter 1, I review the current state of knowledge on how well people can produce or detect randomness, how reinforcement biases influence decision-making, and how processing speeds might differ between different game situations. In Chapters 2 and 3 I present four experiments where I examined performance in the games Rock, Paper & Scissors (RPS; Chapter 2, Experiments 1 and 2) and Matching Pennies (MP; Chapter 3, Experiments 3 and 4). Surprisingly, I found no reinforcement biases in RPS, but consistent reinforcement biases in MP. Additionally, participants made slower decisions after losses when they succeeded in the game due to finding an appropriate strategy to exploit an opponent’s pattern (Chapter 2), but not when they succeeded no matter what they did (Chapter 3). In Chapter 4, I present two experiments (Experiments 5 and 6) directly comparing performance in RPS and MP, designed to replicate the findings from Chapters 2 and 3, and examine why the previous studies only found reinforcement biases in MP. The results of these two last experiments suggest that reinforcement biases differ between RPS and MP due to different cognitive demands, and that there is considerable variability in reinforcement biases both between individuals and between the two types of bias. In Chapter 5, I discuss the contributions of the findings on the wider literature on bias and randomness detection, the generality of the reinforcement biases, and present some suggestions for future studies

Are Utilitarian/Deontological Preferences Unidimensional?

Utilitarian versus deontological inclinations have been studied extensively in the field of moral psychology. However, the field has been lacking a thorough psychometric evaluation of the most commonly used measures. In this paper, we examine the factorial structure of an often used set of 12 moral dilemmas purportedly measuring utilitarian/deontological moral inclinations. We ran three different studies (and a pilot) to investigate the issue. In Study 1, we used standard Exploratory Factor Analysis and Schmid-Leimann (g factor) analysis; results of which informed the a priori single-factor model for our second study. Results of Confirmatory Factor Analysis in Study 2 were replicated in Study 3. Finally, we ran a weak invariance analysis between the models of Study 2 and 3, concluding that there is no significant difference between factor loading in these studies. We find reason to support a single-factor model of utilitarian/deontological inclinations. In addition, certain dilemmas have consistent error covariance, suggesting that this should be taken into consideration in future studies. In conclusion, three studies, pilot and an invariance analysis, systematically suggest the following. (1) No item needs to be dropped from the scale. (2) There is a unidimensional structure for utilitarian/deontological preferences behind the most often used dilemmas in moral psychology, suggesting a single latent cognitive mechanism. (3) The most common set of dilemmas in moral psychology can be successfully used as a unidimensional measure of utilitarian/deontological moral inclinations, but would benefit from using weighted averages over simple averages. (4) Consideration should be given to dilemmas describing infants.Peer reviewe

Breaking the bonds of reinforcement : Effects of trial outcome, rule consistency and rule complexity against exploitable and unexploitable opponents

In two experiments, we used the simple zero-sum game Rock, Paper and Scissors to study the common reinforcement-based rules of repeating choices after winning (win-stay) and shifting from previous choice options after losing (lose-shift). Participants played the game against both computer opponents who could not be exploited and computer opponents who could be exploited by making choices that would at times conflict with reinforcement. Against unexploitable opponents, participants achieved an approximation of random behavior, contrary to previous research commonly finding reinforcement biases. Against exploitable opponents, the participants learned to exploit the opponent regardless of whether optimal choices conflicted with reinforcement or not. The data suggest that learning a rule that allows one to exploit was largely determined by the outcome of the previous trial.Peer reviewe

Does the brain’s reward response occur even without actual reward? A response to Fielding et al. (2017)

A recent paper by Fielding, Fu & Franz (2017) argued that the brain’s reward response could occur without the presentation of actual reward. We suggest that since a) the event-related potentials reported in this paper are atypical of the previous literature, and, b) a simpler account of the data in terms of sensitivity to outcome frequency cannot be ruled out, the extent to which the brain’s reward response can occur without the presentation of actual reward should remain an open question

Individual Differences in Moral Disgust Do Not Predict Utilitarian Judgments, Sexual and Pathogen Disgust Do

The role of emotional disgust and disgust sensitivity in moral judgment and decision-making has been debated intensively for over 20 years. Until very recently, there were two main evolutionary narratives for this rather puzzling association. One of the models suggest that it was developed through some form of group selection mechanism, where the internal norms of the groups were acting as pathogen safety mechanisms. Another model suggested that these mechanisms were developed through hygiene norms, which were piggybacking on pathogen disgust mechanisms. In this study we present another alternative, namely that this mechanism might have evolved through sexual disgust sensitivity. We note that though the role of disgust in moral judgment has been questioned recently, few studies have taken disgust sensitivity to account. We present data from a large sample (N=1300) where we analyzed the associations between The Three Domain Disgust Scale and the most commonly used 12 moral dilemmas measuring utilitarian/deontological preferences with Structural Equation Modeling. Our results indicate that of the three domains of disgust, only sexual disgust is associated with more deontological moral preferences. We also found that pathogen disgust was associated with more utilitarian preferences. Implications of the findings are discussed.Peer reviewe

Failure generates impulsivity only when outcomes cannot be controlled

Verbruggen, Chambers, Lawrence & McLaren (2017) recently challenged the view that individuals act with greater caution following the experience of a negative outcome by showing that a gambled loss resulted in faster reaction time on the next trial. Over three experiments, we replicate and establish the boundary conditions of this effect in the context of a simple game (Rock, Paper, Scissors). Choice responding against unexploitable opponents replicated the link between failure and faster responding. However, individuals with high win-rates against exploitable opponents initiated slower rather than faster responding following loss. The data suggest that the link between failure and impulsivity is limited to contexts where participants cannot exert control over outcomes

General Attitudes Towards Robots Scale (GAToRS): A New Instrument for Social Surveys

Psychometric scales are useful tools in understanding people's attitudes towards different aspects of life. As societies develop and new technologies arise, new validated scales are needed. Robots and artificial intelligences of various kinds are about to occupy just about every niche in human society. Several tools to measure fears and anxieties about robots do exist, but there is a definite lack of tools to measure hopes and expectations for these new technologies. Here, we create and validate a novel multi-dimensional scale which measures people's attitudes towards robots, giving equal weight to positive and negative attitudes. Our scale differentiates (a) comfort and enjoyment around robots, (b) unease and anxiety around robots, (c) rational hopes about robots in general (at societal level) and (d) rational worries about robots in general (at societal level). The scale was developed by extracting items from previous scales, crowdsourcing new items, testing through 3 scale iterations by exploratory factor analysis (Ns 135, 801 and 609) and validated in its final form of the scale by confirmatory factor analysis (N: 477). We hope our scale will be a useful instrument for social scientists who wish to study human-technology relations with a validated scale in efficient and generalizable ways.Peer reviewe

Socio‐cognitive biases in folk AI ethics and risk discourse

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More Than Meets the Eye: Scientific Rationale behind Molecular Imaging and Therapeutic Targeting of Prostate-Specific Membrane Antigen (PSMA) in Metastatic Prostate Cancer and Beyond

Simple SummaryProstate-specific membrane antigen (PSMA) is a transmembrane protein that is overexpressed in prostate cancer and correlates with the aggressiveness of the disease. PSMA is a promising target for imaging and therapeutics in prostate cancer patients validated in prospective trials. However, the role of PSMA in prostate cancer progression is poorly understood. In this review, we discuss the biology and scientific rationale behind the use of PSMA and other targets in the detection and theranostics of metastatic prostate cancer.Prostate cancer is the second most common cancer type in men globally. Although the prognosis for localized prostate cancer is good, no curative treatments are available for metastatic disease. Better diagnostic methods could help target therapies and improve the outcome. Prostate-specific membrane antigen (PSMA) is a transmembrane glycoprotein that is overexpressed on malignant prostate tumor cells and correlates with the aggressiveness of the disease. PSMA is a clinically validated target for positron emission tomography (PET) imaging-based diagnostics in prostate cancer, and during recent years several therapeutics have been developed based on PSMA expression and activity. The expression of PSMA in prostate cancer can be very heterogeneous and some metastases are negative for PSMA. Determinants that dictate clinical responses to PSMA-targeting therapeutics are not well known. Moreover, it is not clear how to manipulate PSMA expression for therapeutic purposes and develop rational treatment combinations. A deeper understanding of the biology behind the use of PSMA would help the development of theranostics with radiolabeled compounds and other PSMA-based therapeutic approaches. Along with PSMA several other targets have also been evaluated or are currently under investigation in preclinical or clinical settings in prostate cancer. Here we critically elaborate the biology and scientific rationale behind the use of PSMA and other targets in the detection and therapeutic targeting of metastatic prostate cancer

Treatments approved, boosts eschewed : Moral limits of neurotechnological enhancement

In six vignette-based experiments, we assessed people's moral reactions towards various cognition-enhancing brain implants, including their overall approval and perceived fairness, as well as the dehumanization of brain-implanted agents. Across the domains of memory (Studies 1-4, 6), general intelligence (Study 5A), and emotional stability (Study 5B), people in general approved of alleviating ailments, and even of attaining optimal human performance, but expressed greater opposition towards superhuman levels of enhancement. Further analyses of individual differences indicated that the tendency to condemn transhumanist technologies, such as brain implants, was linked to sexual disgust sensitivity and the binding moral foundations - two characteristic correlates of a conservative worldview. In turn, exposure to science fiction was tied to greater approval of brain implants. We also examined potential idiosyncrasies associated with our stimulus materials and did not find reliable effects of any secondary factors on moral attitudes. Taken together, our studies reveal certain moral boundaries to neurotechnological enhancement, strong among those with conservative affective and moral dispositions but relaxed among those familiar with science fiction themes.Peer reviewe