Just noticeable differences in affect: estimating the minimum change in positive and negative affect that meaningfully impact people’s subjective experience of emotions
Positive and negative affect are two components of experienced emotions that are the foundation of our subjective well-being, with important influences on mental and physical health. Self-report measures have been developed to quantify positive and negative affect, which can then be statistically compared within or across groups. They are used as indicators of subjective well-being in large surveys of European populations and as outcome measures in thousands of research studies. We can establish whether there has been a statistically significant change in affect over time, or whether there is a statistically significant difference between people. But, using the results of surveys and research to shape social policies or medical treatments requires the answer to a crucial yet unanswered question: How much do measurements of change in affect reflect people’s meaningful experiences? 
One way to gauge the meaningfulness of a statistical change in affect is to determine whether people subjectively perceive the difference in their emotional experience—whether they feel different. The proposed project addresses this question using the just noticeable difference approach, from psychophysics, in a first ever application to estimate the minimum change in positive and negative affect that meaningfully impacts people’s subjective experience of emotions, also examining potential cross-cultural variability. 
Researchers, policy decision makers, and the public can use this project’s results to evaluate findings from surveys and research studies in terms of meaningfulness. The methods may be adapted for other fields interested in people’s subjective experience and used to estimate the smallest change in an outcome measure that may be considered meaningful.
The researcher has relevant expertise in the project’s domain and the host provides the perfect environment for the successful implementation of the research and training activities, ensuring the researcher’s career advancement.