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Why can initial biases persist in repeated choice tasks? Previous research has shown that frequent rewards can lure the decision maker into premature exploitation of a supposedly best option, which can result in the persistence of initial biases. Here, we demonstrate that even in the absence of rewards, initial biases can be perpetuated through a positive testing strategy. After eliciting a biased preference for one of two equally rewarding options, participants (N = 203) could sample freely from both options without the lure of any financial rewards. When participants were told to rule out alternatives in this phase, they explored the supposedly worse option and thereby managed to overcome their initial bias. When told to optimize their strategy, however, they exhibited a positive testing strategy resulting in the continued exploitation of the supposedly better option, a bias they maintained in an incentivized choice phase and later judgments. Across all participants, individual tendencies to exploit one option in earlier phases predicted biased behavior in subsequent phases. The findings highlight that not only the pursuit of instrumental rewards can lead to exploitation and the maintenance of initial biases. We discuss potential consequences for interventions.

While there are abundant reasons that might lead us to form wrong first impressions, further interaction (sampling) opportunities should allow us to attenuate such initial biases. Sometimes, however, theses biases persist despite repeated sampling opportunities, such as in superstitions or stereotypes. In two studies (Ns = 100), we investigate this phenomenon.We demonstrate that in a task in which participants could repeatedly choose between two options to gain rewards, erroneous initial impressions about yielded outcomes can lead to persisting biases toward a clearly inferior option. We argue that a premature focus on reward pursuit (exploitation) rather than exploration is the cause of these biases, which persist despite plenty of opportunities and a presumed motivation to overcome them. By focusing on a supposedly best option, participants never give themselves the chance to sufficiently try out alternatives and thereby overcome their initial biases. We conclude that going for the money is not always the best strategy.

Background: Immune checkpoint immunotherapy (ICI) is active against many cancers. Many people are failed by PD1 inhibition alone, but not all patients benefit, nor require combination ICI treatment. UNISoN (NCT03177239) previously reported outcomes in people with non-clear cell renal cell carcinoma (nccRCC) receiving nivolumab (N) monotherapy, and N plus ipilimumab (I) in those whose cancers progressed after N alone. We present the final planned report. Method(s): Population, Intervention, Analysis: Participants (pts) with advanced nccRCC with good performance status (ECOG 0/1) received N 240mg q2w alone (Part 1). Those with cancers refractory to N at 3 months were offered combination I (1mg/kg) + N (3mg/kg) q3w for up to 4 doses, followed by N 240mg q2w for a maximum total of 12 months of N (Part 2). UNISoN was powered to identify a clinically-relevant objective tumor response rate (OTRR) of 30% (assuming 15% was not relevant) among people receiving I+N in Part 2. Result(s): 85 pts with a representative spectrum of nccRCC histologies were enrolled and received N. Amongst the total population enrolled to UNISoN Part 1/2, mOS was 24 (16-28) months and 12m OS was 65% (54%-74%); of those proceeding to Part 2, the mOS was 10 (6-17) months only. Overall, 17% (10%-27%; 14/83) and 10% (3%-23%; 4/41) of pts experienced a response from N alone or I+N, respectively. 41 pts refractory to N received I+N. Overall in Part 2, the median time on treatment was 2.1 (95% CI 1.8, 2.8) months, the median number of cycles was 3; median follow-up at final analysis was 22 (16-30) months. In this population, the median PFS was 2.6 (2.2-3.8) months and 12m PFS was 11% (4%-23%). 13% (7%-22%) of patients were free of progression or death at 24 months. The primary endpoint was not met; only 80% of pts failed by N were assessable for response in Part 2. Overall tumor responses from N alone or I+N were more common in pts with papillary histology; pts with chromophobe histology had poor outcomes.

First impressions can be biased and influence future decision-making behavior where people tend to exploit one option rather than engaging in exploration (Mehlhorn et al., 2015). The present study investigates whether, in a reward-rich environment, the individuals will form pseudocontingency biases towards a treatment option and maintain it in a free sampling task. The research is a conceptual replication of the study by Harris et al. (2020), investigating the underlined concept in a health context. In a two-armed bandit task, the participants sample between two smoking cessation treatments to minimize their nicotine symptoms. The results supported our first hypothesis as the participants sampled the frequent treatment option based on their pseudocontingency bias. However, our second hypothesis stating that the initial biases will persist in a free sampling phase was not supported. The participants sampled both the treatments and engaged in exploration. Finally, the third hypothesis tested was also supported. We observed that the intervention group in the free sampling phase maintained their initial biases in later trials. Hence, even though people form biases in reward-rich environments, these biases are not necessarily always influential in their subsequent decision making. Moreover, the initial biases were upheld in a reward-rich environment. Therefore, we could not draw firm conclusions regarding the maintenance of initial biases because we observe two groups with contrasting sampling behaviour. Thus, future research should investigate further by exploring different health contexts.

In the current article, we test the prediction that an initial bias favoring 1 of 2 equally rewarding options—either based on a genuine contingency or a pseudocontingency in a small sample of initial observations—can survive over an extended period of further sampling from both options, when the reward structure fosters exploitation. Specifically, we argue and demonstrate that in reward-rich envi- ronments where two options predominantly— but equally frequently—yield positive outcomes, the initial bias should be upheld because exploitation of the allegedly superior option reinforces the biased preference. In contrast, in reward-impoverished environments, where both options yield predominantly negative outcomes, initial biases can be expected to be eradicated through exploration, which increases the chance of recognizing the equality of the initially nonpreferred option. In 3 experiments, initial evidence in a guided-sampling phase was set up for participants to perceive an actual contingency (Experiment 1) or infer a pseudocontingency (Experiment 2a and b) that made 1 option look more rewarding. In a subsequent free-sampling phase this led to a sustained bias toward this option when the environment contained mostly positive but not when it contained mostly negative outcomes. We argue that biased sampling in reward-rich environments could be responsible for false beliefs about the outcomes of behavioral options, and as such could be relevant to a broad range of topics including social interactions or health contexts.

Background: Renal cell carcinomas (RCC) are predominantly the clear cell (cc) subtype, with a unique biology, characterized by sensitivity to angiogenesis inhibition. However vascular endothelial growth factor-tyrosine kinase inhibitors elicit modest responses in people with rare variant non-clear cell (ncc) RCC. Immune checkpoint inhibitors (ICI) are active against many cancers, but people with rare variant nccRCC have been excluded from frontline trials despite experiencing a more aggressive disease course and poorer prognosis compared to those with ccRCC. UNISON (NCT03177239) aims to test 2 ideas; the activity of ICI in nccRCC, and the novel sequencing strategy of anti-programmed cell death protein (PD)1 immunotherapy, followed by the combination of anti-PD1 and anti-cytotoxic T-lymphocyte-associated protein (CTLA)4 blockade, in people failed by single agent treatment. Method(s): This single-arm, two-part trial recruits people of good performance status suffering metastatic or locally advanced unresectable rare variant nccRCC, including but not limited to papillary (type 1/2), chromophobe, sarcomatoid, Xp11 translocation, collecting duct, and unclassified histological subtypes. Participants are offered fixed dose nivolumab at 240mg every two weeks in Part 1 of the trial. If they experience progressive disease, eligible participants may proceed to Part 2 consisting of nivolumab (3mg/kg) plus ipilimumab (1 mg/kg) every 3 weeks for up to 4 doses. People experiencing disease control after single-agent or combined ICI are eligible to continue treatment for up to 1 year. UNISON is powered to distinguish a clinically nonrelevant objective tumor response rate (OTRR) of 15% in people taking combination ICI whose cancers are refractory to single-agent PD1, versus a clinically-relevant OTRR of 30% at 5% level of significance with 80% power. 85 participants were recruited in Part 1, on the assumption that 55% of those entering Part 1 will be eligible for inclusion in Part 2.

As a result of the corona measures, for many people their homes have become the physical environment in which they now live and work or study. The present study investigated the effect of Corona and subsequent home isolation on the eating behavior of people and whether people perceive their home environment as more or less obesogenic than the environments they find themselves normally in. More specifically, it was examined whether perceived obesogenicity affects perceived self-efficacy and the intention to eat healthy. Cross-sectional analyses were used to explore changes in eating behavior and to examine relations between the variables. Descriptive statistics of 210 participants showed that there was much division in the degree to which the home environment affected the eating behavior of people, either positively or negatively. Moreover, findings showed a negative relation between perceived obesogenicity of the environment and the intention to eat healthy, a relation that was fully mediated by perceived self-efficacy. In other words, perceiving the home environment as more obesogenic led to less self-efficacy, which in turn led to less intention to eat healthy. This was in line with expectations. The findings of this study show profound implications for future interventions, where changing people’s home environment would be a valuable way to mitigate possible negative effects of working and/or studying from home and to prevent the development of unhealthy eating habits. However, future research is needed to investigate individual differences and causal relationships.

Previous research has shown that false first impressions can guide subsequent decision making in the form of biased sampling in which people exploit seemingly better alternatives (Harris et al., 2020). The present research tests the hypothesis that pseudocontingency biases towards a certain medicine will be maintained and generalized onto other similar, yet different medicines in a free sampling context. The current research demonstrates that in reward-rich environments, pseudocontingencies between medicine options and health outcomes guide subsequent decision making so that the frequently presented medicine is preferred more than the infrequently presented option. In line with our expectations, people appear to use a strategy of exploitation, however, this was only evident at the beginning of the sampling phase. When providing participants with a virtually identical alternative of the preferred medicine, the previous bias spills over into their sampling of this new medicine. However, explicit preference measures reveal that participants do not prefer this new medicine more than the alternative. The present findings provide evidence that pseudocontingency biases may transfer onto similar alternatives, however, it is still unclear whether this transfer demonstrates generalization. Finally, it cannot be concluded whether the bias towards the new alternative shows a strategy of exploitation or exploration.

Delphin2 is a hover capable torpedo style Autonomous Underwater Vehicle (AUV), developed at the University of Southampton to provide a test bed for research in marine robotics, primarily to enhance the manoeuvring capability of AUVs. This paper describes the mechanical design of the vehicle and its software architecture. The performance of the vehicle is presented as well as preliminary findings from the vehicle’s first fully autonomous video survey issions in Lough Erne, Northern Ireland. It is interesting to note that the low-cost of the vehicle and its development using a succession of MEng and PhD students has provided an excellent training environment for specialists in the growing area of marine autonomous vehicles.

Existing environmental risk assessment procedures are limited in their ability to evaluate the combined effects of chemical mixtures. We investigated the implications of this by analyzing the combined effects of a multicomponent mixture of five estrogenic chemicals using vitellogenin induction in male fathead minnows as an end point. The mixture consisted of estradiol, ethynylestradiol, nonylphenol, octylphenol, and bisphenol A. We determined concentration-response curves for each of the chemicals individually. The chemicals were then combined at equipotent concentrations and the mixture tested using fixed-ratio design. The effects of the mixture were compared with those predicted by the model of concentration addition using biomathematical methods, which revealed that there was no deviation between the observed and predicted effects of the mixture. These findings demonstrate that estrogenic chemicals have the capacity to act together in an additive manner and that their combined effects can be accurately predicted by concentration addition. We also explored the potential for mixture effects at low concentrations by exposing the fish to each chemical at one-fifth of its median effective concentration (EC

The stable, recessive Arabidopsis variegated 3 (var3) mutant exhibits a variegated phenotype due to somatic areas lacking or containing developmentally retarded chloroplasts and greatly reduced numbers of palisade cells. The VAR3 gene, isolated by transposon tagging, encodes the 85.9 kDa VAR3 protein containing novel repeats and zinc fingers described as protein interaction domains. VAR3 interacts specifically in yeast and in vitro with NCED4, a putative polyene chain or carotenoid dioxygenase, and both VAR3 and NCED4 accumulate in the chloroplast stroma. Metabolic profiling demonstrates that pigment profiles are qualitatively similar in wild type and var3, although var3 accumulates lower levels of chlorophylls and carotenoids. These results indicate that VAR3 is a part of a protein complex required for normal chloroplast and palisade cell development.