A Light-Responsive Neural Circuit Suppresses Feeding.

Light plays an essential role in a variety of physiological processes, including vision, mood, and glucose homeostasis. However, the intricate relationship between light and an animal's feeding behavior has remained elusive. Here, we found that light exposure suppresses food intake, whereas darkness amplifies it in male mice. Interestingly, this phenomenon extends its reach to diurnal male Nile grass rats and healthy humans. We further show that lateral habenula (LHb) neurons in mice respond to light exposure, which in turn activates 5-HT neurons in the dorsal Raphe nucleus (DRN). Activation of the LHb→5-HTDRN circuit in mice blunts darkness-induced hyperphagia, while inhibition of the circuit prevents light-induced anorexia. Together, we discovered a light-responsive neural circuit that relays the environmental light signals to regulate feeding behavior in mice.

An examination of the effects of eye-tracking on behavior in psychology experiments.

Eye-tracking is emerging as a tool for researchers to better understand cognition and behavior. However, it is possible that experiment participants adjust their behavior when they know their eyes are being tracked. This potential change would be considered a type of Hawthorne effect, in which participants alter their behavior in response to being watched and could potentially compromise the outcomes and conclusions of experimental studies that use eye tracking. We examined whether eye-tracking produced Hawthorne effects in six commonly used psychological scales and five behavioral tasks. The dependent measures were selected because they are widely used and cited and because they involved measures of sensitive topics, including gambling behavior, racial bias, undesirable personality characteristics, or because they require working memory or executive attention resources, which might be affected by Hawthorne effects. The only task where Hawthorne effects manifested was the mixed gambles task, in which participants accepted or rejected gambles involving a 50/50 chance of gaining or losing different monetary amounts. Participants in the eye-tracking condition accepted fewer gambles that were low in expected value, and they also took longer to respond for these low-value gambles. These results suggest that eye-tracking is not likely to produce Hawthorne effects in most common psychology laboratory tasks, except for those involving risky decisions where the probability of the outcomes from each choice are known.

The mental burden of stay-at-home order extensions during COVID-19.

This study evaluates the psychological impact of stay-at-home extension orders during COVID-19 and its relationship with individuals' expectations on the duration of the extensions. An online survey was administered to 1259 US adult residents to measure symptoms of post-traumatic stress disorder (PTSD), anxiety and stress induced by different stay-at-home order extensions using hypothetical length scenarios. We find that individuals exposed to two 2-week order extensions exhibit higher levels of stress and anxiety compared to those exposed to a single 4-week extension. We also find that subjects with longer expected extensions exhibit more signs of psychological damage than those with shorter expected extensions. Furthermore, we find that the negative psychological consequences of providing two shorter extensions is observed only among subjects with extension expectations of four weeks or less. Our results demonstrate that people's expectations affect the level of psychological damage caused by lockdown mandates. Our findings suggest that whenever lockdown extensions are necessary, reduced psychological distress may be possible by implementing a one-time restriction, rather than extending multiple smaller extensions perhaps due to manipulation of personal expectations.

The unintended detrimental effects of pursuing a professional vocation: The case of veterinarians.

Pursuing one's life calling can be personally fulfilling and professionally rewarding, but it also requires sacrifice. We provide evidence of a strong vocational drive using veterinary students as a case study and find that they willingly contribute higher monetary donations for helping animals relative to students in other fields. We also find a significant reduction in the cognitive performance of veterinarian students when exposed to an animal-in-need manipulation. The performance of non-veterinary students in the cognitive task is unaffected by the manipulation. Our results highlight the need for programs to address the economic, financial, and mental health well-being of students and professionals to promote sustainable vocational career commitment. "You owe it to all of us to get on with what you're good at." W.H. Auden.

Health versus income amid COVID-19: What do people value more?

Public efforts to battle COVID-19 have been portrayed as a trade-off between health and the economy in the U.S. public discourse. We investigate how the U.S. general public prioritizes the health and the income dimensions amid COVID-19 using an incentivized instrument with real monetary consequences. We also employ between-subject information treatments highlighting negative health and income consequences of the pandemic. Specifically, participants have to divide monetary contributions between two charitable organizations representing either the health or the income dimension. An overwhelming majority of participants supports both dimensions, with higher monetary contributions to the health dimension (56%) compared to income (44%), but the difference is not large. Only a small fraction of respondents contributes exclusively to the health (10%) or income (5%) dimensions. Increasing the salience of negative health outcomes of COVID-19 raises differential token allocations in favor of the health-oriented charity. This finding is important since the course of COVID-19 will be shaped by the policies governments implement and how the general public reacts to these policies.

Does eye-tracking have an effect on economic behavior?

Eye-tracking is becoming an increasingly popular tool for understanding the underlying behavior driving human decisions. However, an important unanswered methodological question is whether the use of an eye-tracking device itself induces changes in participants' behavior. We study this question using eight popular games in experimental economics chosen for their varying levels of theorized susceptibility to social desirability bias. We implement a simple between-subject design where participants are randomly assigned to either a control or an eye-tracking treatment. In seven of the eight games, eye-tracking did not produce different outcomes. In the Holt and Laury risk assessment (HL), subjects with multiple calibration attempts demonstrated more risk averse behavior in eye-tracking conditions. However, this effect only appeared during the first five (of ten) rounds. Because calibration difficulty is correlated with eye-tracking data quality, the standard practice of removing participants with low eye-tracking data quality resulted in no difference between the treatment and control groups in HL. Our results suggest that experiments may incorporate eye-tracking equipment without inducing changes in the economic behavior of participants, particularly after observations with low quality eye-tracking data are removed.

Stability of Risk Preferences During COVID-19: Evidence From Four Measurements.

This article studies the stability of risk-preference during the COVID-19 pandemic. The results differ between risk-preference measurements and also men and women. We use March 13, 2020, when President Trump declared a national state of emergency as a time anchor to define the pre-pandemic and on-pandemic periods. The pre-pandemic experiment was conducted on February 21, 2020. There are three on-pandemic rounds conducted 10 days, 15 days, and 20 days after the COVID-19 emergency declaration. We include four different risk-preference measures. Men are more sensitive to the pandemic and become more risk-averse based on the Balloon Analogue Risk Task (BART). Women become more risk-averse in the Social and Experience Seeking domains based on the results from the Domain-Specific Risk-Taking (DOSPERT) and Sensation Seeking Scales (SSS). Both men's and women's risk-preference are stable during COVID-19 based on a Gamble Choice (GC) task. The results match our hypotheses which are based on the discussion about whether the psychological construct of risk-preference is general or domain-specific. The differential outcomes between incentivized behavioral and self-reported propensity measures of risk-preference in our experiment show the caveats for studies using a single measure to test risk-preference changes during COVID-19.

General Public Preferences for Allocating Scarce Medical Resources During COVID-19.

COVID-19 has overwhelmed healthcare systems across the globe with an unprecedented surge in the demand for hospitalizations. Consequently, many hospitals are facing precarious conditions due to limited capacity, especially in the provision of ventilators. The governing ethical principles of medical practice delineated in (1) favor prioritizing younger patients, largely because of their relatively higher expected life years. We conduct a survey of the general public in the United States to elicit their preferences for the allocation of a limited number of ventilators. The results show that the general public views align with the established ethical principles, which favor younger patients. JEL Classification: C91.

Can episodic future thinking affect food choices?

Episodic future thinking, defined as the ability to project oneself into the future, has proven useful to pre-experience the future consequences of present actions. We investigate how episodic future thinking influences the food choices of normal weight, overweight, and obese individuals. In doing so, we conduct a controlled laboratory experiment in which participants are presented with representations of weight-increased and weight-reduced modified images of themselves before performing a food choice task. This allows subjects to vividly imagine the future consequences of their actions. We also test the effect of providing health-related information on food choices to compare with the episodic future thinking effect. Our results suggest that while providing health-related information increases the number of lite snack choices of overweight and obese individuals, engaging in episodic future thinking has a positive impact on the food choices of the obese only. These findings are supported by eye-tracking data showing how visual attention and emotional arousal (measured by pupil size) impact individuals' food choices.

The effect of food anticipation on cognitive function: An eye tracking study.

By randomizing the order in which participants perform a cognitive test and a food choice task in a controlled experiment, we investigate whether cognitive capacity can be enhanced by the simple act of anticipating food intake. Our findings show that overweight and obese participants exhibit an anticipatory food reward effect, which helped enhance their mental resources and improve their performance in a cognitive test. However, we find no anticipation effect among normal weight participants. Furthermore, eye tracking data reveal that food temptation, in the form of visual attention and emotional arousal is higher for overweight and obese individuals when they are cognitively impaired.

Conveniently dependent or naively overconfident? An experimental study on the reaction to external help.

The rapid development and diffusion of new technologies such as automation and artificial intelligence makes life more convenient. At the same time, people may develop overdependence on technology to simplify everyday tasks or to reduce the level of effort required to accomplish them. We conduct a two-phase real-effort laboratory experiment to assess how external assistance affects subsequent revealed preferences for the convenience of a lower level of effort versus monetary rewards requiring greater effort. The results suggest that men treated with external help in the first phase tend to choose more difficult options with potentially higher monetary rewards. In contrast, after being treated with external help, women exhibit a stronger propensity to utilize the convenience of an easier task and are less likely to choose a more difficult option that carries higher potential earnings.

Correction: Does California's Low Carbon Fuel Standards reduce carbon dioxide emissions?

[This corrects the article DOI: 10.1371/journal.pone.0203167.].

Does California's Low Carbon Fuel Standards reduce carbon dioxide emissions?

The Low Carbon Fuel Standards (LCFS) represents a new policy approach designed to reduce carbon dioxide emissions by applying standards to all stages of motor fuel production. We use the synthetic control and difference-in-differences econometric methods, and Lasso machine learning to analyze the effect of the LCFS on emissions in California's transportation sector. The three different techniques provide robust evidence that the LCFS reduced carbon dioxide emissions in California's transportation sector by around 10%. Furthermore, our calculations show that improved air quality, due to the application of the LCFS, may have benefited California in the magnitude of hundreds of millions of dollars through an increase in worker's productivity.

Reducing Brain Signal Noise in the Prediction of Economic Choices: A Case Study in Neuroeconomics.

In order to reduce the noise of brain signals, neuroeconomic experiments typically aggregate data from hundreds of trials collected from a few individuals. This contrasts with the principle of simple and controlled designs in experimental and behavioral economics. We use a frequency domain variant of the stationary subspace analysis (SSA) technique, denoted as DSSA, to filter out the noise (nonstationary sources) in EEG brain signals. The nonstationary sources in the brain signal are associated with variations in the mental state that are unrelated to the experimental task. DSSA is a powerful tool for reducing the number of trials needed from each participant in neuroeconomic experiments and also for improving the prediction performance of an economic choice task. For a single trial, when DSSA is used as a noise reduction technique, the prediction model in a food snack choice experiment has an increase in overall accuracy by around 10% and in sensitivity and specificity by around 20% and in AUC by around 30%, respectively.