Verified by 
We've all experienced positive and negative moods - whether it's feeling happy after just seeing a really funny movie or feeling sad after receiving some bad news. These moods affect how we feel so it's not so hard to imagine that they might also impact how we think. Indeed, it's a fairly well-established finding that mood can impact our cognitive functioning (i.e., how we think, reason, problem solve). But, how exactly this works is still somewhat of a mystery.
In a study published recently in the journal Psychological Science, researchers from the University of Western Ontario in Canada set out to solve the mood-cognition puzzle - or at least shed some new light on it. They brought people into their laboratory and asked them to watch funny or depressing videos to put them in particular mood states.
People fortunate enough to be assigned to the positive mood condition got to watch segments from the popular comedy show "who's line is it anyway." Folks in the negative mood condition watched news reports about natural disasters or scenes from a movie about a person with terminal cancer.
After the videos, everyone performed one of two tasks. The goal in both tasks was the same: To determine whether a circle presented on a computer screen belonged to Category A or Category B. The circle was filled in with a repeated number of fuzzy dark and light bars and people had to determine which category it belonged to simply by its visual features.
Even though the goal of the two tasks was the same, they were solved in very different ways. One task, the Rule Task, was solvable by finding a single rule that separated the circles into categories - such as the orientation of the bars in the circle (some circles had bars oriented to the left, some to the right). The second task couldn't be solved in this way. More than one visual feature differed between the circles so it was impossible to get a handle - at least a handle you could verbalize - on what really made some circles different from others. Instead, people could only solve this task by going through a number of circles, seeing which circle belonged to which category, and then going with their gut hunch about what separated new circles they saw into the two separate categories.
Why would the researchers use these odd circle tasks to explore the impact of mood on cognition? The reason is that different parts of the brain are thought to support how people learn each of the tasks. Showing that say, a positive mood, has an impact on one task and not the other might tell us something interesting about the types of activities that are enhanced by a happy state of mind.
Sure enough, the researchers found that positive mood enhanced performance, but only on the Rule Task where flexibly testing one hypothesis after another produces the best performance. On the other task, where people were better off going with their gut, mood had no impact on performance.
The prefrontal cortex, the area of the brain that sits just above the eyes and houses our working memory - that mental scratchpad that allows us to "work" with whatever information is held in consciousness - is thought to play a big role in performing the Rule-Task. What this suggests is that only activities that require a heavy dose of the prefrontal cortex will be enhanced by a positive mood.
The take home point? Mood can impact how we function, but a better mood doesn't equal better performance across the board. For situations where you have to flexibly shift between goals or exhaust many different hypotheses - say when solving a difficult logistics issue at work or juggling several different tasks at once - being in a good mood is beneficial. But for activities where you need to just go with your gut, there may be no performance benefit to a positive mood. Indeed, it might even hurt.
Our mood impacts how we think. By knowing a bit of the science behind the relation between cognition and emotion, we can pick the right activity for our mood and optimize our performance.
For more on cognition/emotion interactions, check out my new book Choke.
Follow me on Twitter!
__
Nadler, et al. (2010). Better Mood and Better Performance : Learning Rule-Described Categories Is Enhanced by Positive Mood. Psychological Science.
