Do our brains work better when we are happy than when we are sad? Or is it the other way around?

by Hannah Scott

24 Sep 2015

We’re trying to answer this question at the Hungry Mind Lab, where I work as a research assistant. We want to know to what extent changes in our daily mood affect how well our brains perform. But to find out, our team had to first overcome two challenges.

The first challenge was the measurement of mood. We knew soon that we would use items from the Positive and Negative Affect Scale (PANAS; Watson & Tellegen, 1988) to assess mood, because PANAS has solid psychometric properties, is highly validated and freely available for research. But the real problem was where to measure mood.

Moods are influenced by our environments: If you test participants in a lab, for example in dreary research cubicle, their mood will change accordingly: they will feel a little flat, bored and perhaps even anxious, clueless about what to expect from the study. In particular, participants won’t experience the full range of moods that they normally go through over the course of a day. But what we needed for our study was a way of assessing mood that was unobtrusive and so would alter it as little as possible.

Our second challenge was one that is faced by all researchers in psychology. We needed to convince a large number of people to participate in our research, which meant repeatedly completing our mood and brain tests. Doing the same tests repeatedly can become boring, but it wasn’t going to be enough to know people’s mood and cognitive function at just one moment in time. We wanted to test whether changes in mood are coupled with changes in cognitive function, and to do that, we had to come up with something clever.

So with a little help from our friends, we decided to develop an iPhone application for our research. A small British Academy/Leverhulme grant awarded to our lab director Dr. Sophie von Stumm funded a pilot study and the development of our app, which was implemented by the amazing team from PSYT  (link:

We first had to identify the best tests for assessing cognitive function across time. We wanted cognitive measures that were comparable across different assessment occasions and that showed only small training effects. We conducted a pilot study with 98 participants, who came to our testing lab atGoldsmiths each day from Monday through Friday to complete various tests. We analysed this data and chose the three tests that worked best: a measure of short-term memory, of processing speed, and of working memory.

It could be thought that these tests are a bit ‘memory-heavy’ but working memory really focuses on how well your brain can do operations on information that it holds. Short-term memory is about correctly recalling pieces of information, and processing speed marks how fast your brain is working.

We launched our app three weeks ago. We’ve called it moo-Q and at the time of writing, it has been downloaded over 18,000 times with about 2,000 active users each day. This success of moo-Q has gone far beyond our expectations, and we continue to promote moo-Q to the general public.

We have good reason for this: besides helping us with our research, moo-Q is a fantastic tool for people. Would you like to know at what time during the day your brain works best? Perhaps to schedule an important presentation or meeting at work? Or at what day of the week you are in the highest spirits, so that you can make sure to plan your dates then? Complete moo-Q five times by responding to the alerts, and you will get your personalized moo-Q chart that plots your brain power and mood across hours, days and weeks. The more often your complete moo-Q, the clearer picture you’ll get of changes in your own mood and brain function.

The beauty of moo-Q is that you can do it anywhere: on the train, waiting for the bus, on your coffee break. After downloading the app, you will be asked to choose your alert settings (i.e. times during which you want to be asked to do moo-Q). Then you just respond to the alerts – and after five, you get your moo-Q. We will store your data anonymously for our research, and we can’t wait to start crunching the numbers. Being part of the moo-Q research project has shown me how exciting individual differences research can be, especially if it combines an important research question with innovative methodology like an app!

If you’re interested in learning more about moo-Q or the other projects that are underway at the Hungry Mind lab, you can visit our website at


Watson, D., Clark, L. A., & Tellegen, A. (1988). Development and validation of brief measures of positive and negative affect: the PANAS scales. Journal of personality and social psychology54(6), 1063.

Hannah Rachel Scott is the lab coordinator for the Hungry Mind Lab at Goldsmiths, University of London. There, she works on several projects that investigate personality and individual differences, including moo-Q. Having graduated from a BSc Psychology degree at Goldsmiths, she is currently studying for an MSc in Forensic Mental Health Research at King’s College London. The project entitled “Day-to-day within-person variability in cognitive performance and affect” was funded by the British Academy Leverhulme Small Grant Scheme.

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