Dopaminergic modulation of choice and happiness

Paper out in the Journal of Neuroscience (it's open access - anyone can download the paper) with my UCL colleagues Nikolina Skandali, Peter Dayan, and Ray Dolan.

We report the results of a pharmacology experiment in which subjects made choices between safe and risky options and were repeatedly asked 'how happy are you at this moment?' After boosting dopamine levels with the drug levodopa, a drug commonly used to treat Parkinson's disease, subjects were more likely to take risks to try to get bigger rewards and they also felt happier after they received some of those rewards. These results might help explain why some people receiving dopaminergic treatment can develop gambling problems. Boosting dopamine levels may make people think that some rewards are better than they actually are, helping to clarify the role of dopamine in happiness.

You can read more about the study in the Journal of Neuroscience Press Release and the UCL Press Release and here: The Independent, Medical Daily.

The paper can also be downloaded here. My research is supported by the Max Planck Society and the Wellcome Trust.

A computational and neural model of happiness

Paper out in Proceedings of the National Academy of Sciences (it's open access - anyone can download the paper by clicking on the PDF symbol) with my UCL colleagues Nikolina Skandali, Peter Dayan, and Ray Dolan.

We report the results of an fMRI experiment, two behavioral studies, and a large-scale smartphone-based replication study. We used computational modeling to show that happiness in our experiments is explained not by earnings, but by the combined influence of recent reward expectations and prediction errors resulting from those expectations. That means happiness depends not on how well things are going, but whether things are going better than expected. Here is our happiness equation:

In the fMRI study, we found that measurements of neural activity in a brain area called the striatum could be used to predict how much happiness would change as the result of the decisions that subjects made and the outcomes they received. In the smartphone experiment we showed that we could also predict happiness outside of the lab in 18,420 participants around the world. Thanks to everyone who played 'What makes me happy?' in The Great Brain Experiment on their phones (download the app if you would like to contribute to our ongoing research). Your data (221,040 happiness ratings) are in the paper!

You can read more about the study in the UCL Press Release and here: BBC News, Forbes, The Atlantic, Time, Washington PostTelegraph.

The paper can also be downloaded here. My research is supported by the Max Planck Society and the Wellcome Trust.

Crowdsourcing for cognitive science

Paper out in PLoS ONE with my UCL colleagues Harriet Brown, Peter Zeidman, Peter Smittenaar, Rick Adams, Fiona McNab, and Ray Dolan. This study reports initial analyses from thousands of participants worldwide who downloaded our smartphone app The Great Brain Experiment and played the four games. Three of the games test working memory, impulsiveness, and visual perception. The fourth game 'What makes me happy?' is based on my laboratory research on decision making and happiness.

We found that all four games provide reliable results that match laboratory results, despite being played anonymously on a smartphone. We are now starting to look at how measures from the different games relate to each other and how those measures change across the lifespan. You can read more about the project in the UCL press release and in this recent report on BBC News.

Four new games have been added so there are now eight games in total that you can play. Thank you everyone for playing games for science!

The paper can also be downloaded here. This project was supported by a Brain Awareness Week grant from the Wellcome Trust.