Forget what you had for lunch yesterday? It might not have been the food, but your mood.
A University of Missouri researcher has found that being in a good mood decreases your working memory capacity — your brain’s ability to store information needed to carry out complex cognitive task.
In “The Influence of Positive Mood on Different Aspects of Cognitive Control,” published earlier this year in the journal Cognition and Emotion, Elizabeth Martin, a doctoral student of psychology in the College of Arts and Science, found that forgetfulness may have something to do with being in a good mood.
“Working memory, for example, is the ability to recall items in a conversation as you are having it,” Martin said. “This explains why you might not be able to remember a phone number you get at a party when you are having a good time. This shows that although systems in the brain are connected, it is possible to affect one process but not others.”
Researchers gauged study participants’ mood before and after showing them a video clip. Some participants were shown a segment of a stand-up comedy routine, while others watched an instructional video on how to install flooring. Following the videos, those that viewed the comedy routine were in significantly better moods after viewing the video, while the mood of those that viewed the flooring video had not changed.
After watching the videos, both groups completed a memory test. This test provides several numbers to a participant through headphones at a rate of four numbers per second. After the recording stopped, participants were asked to recall the last six numbers in order. Those that watched the comedy routine and were in a better mood performed significantly worse on the task.
“While working memory storage is decreased, being in a good mood is not all bad,” Martin said. “Being in a good mood has been shown to increase creative problem-solving skills and other aspects of thinking.”
Martin’s research is the first to show that positive mood can negatively impact working memory storage capacity. She said future research should analyze the impact of mood on working memory storage capacity in real life situations, such as a classroom setting.
The research was funded by grants from the National Institute of Mental Health, the National Institute of Drug Abuse and a grant from the MU Research Board.