Researchers from the University of Southern California (USC) in Los Angeles recently undertook a rather ambitious, if not amusing project: discovering the neurological processes involved in making a joke.
The study was led by USC doctoral student Ori Amir and Irving Biederman, a professor of psychology and computer science.
Creativity is esoteric by nature. However, it’s perhaps this very mystery that entices researchers to unpick the processes underlying creativity.
Previous studies have taken photos of the brain as it writes poetry, improvises jazz and even draws pictures, but humor is a very unique field. Humor has a clear beginning, middle and end, and takes place over a relatively short period of time. This makes it very convenient for brain imaging, and the end product is easy to assess, “Does it make you laugh?” Subsequently, jokes are much easier to rate than the quality of a doodle, haiku or musical piece, which is arguably more subjective.
For this study, professional and amateur comedians were studied as well as a control group of non-comedians. Each participant viewed a cartoon from the New Yorker without any text and were prompted to come up with their own captions; one version was to be mundane and the other funny.
As they completed their tasks, their brains were scanned using magnetic reasoning imaging (fMRI). After this, a panel assessed each caption the participants wrote for its level of humor.
Once the data had been analyzed, it was revealed that two parts of the brain were particularly active during the creation of the humorous captions. These were:
- Medial prefrontal cortex – an area at the front of the brain thought to be involved in learning associations between locations and events and the appropriate emotional responses. This helps us respond correctly in social interactions.
- Temporal association regions – part of the temporal lobe thought to be involved in the recognition and identification of complex stimuli.
Interestingly, the activation in these particular regions was different depending on the participant’s comedic expertise. According to Amir, “What we found is that the more experienced someone is at doing comedy, the more activation we saw in the temporal lobe.”
The temporal lobe is where the brain receives sensory information and plays a pivotal role in understanding speech and imagery. It also seems to be the area where semantic and abstract information converges with remote associations.
Non-comedians and amateur comedians saw less activity in the temporal lobe and more activity in the prefrontal cortex, an area that deals with executive functions such as complex planning and decision-making. As Amir states, “The professional improv comedians let their free associations give them solutions. The more experience you have doing comedy, the less you need to engage in the top-down control and the more you rely on your spontaneous associations.”
Amir and Biederman both found that independent funniness ratings were highest for captions created when there was more activity in the temporal regions of the brain.
The medial prefrontal cortex usually makes an appearance in studies investigating the neural activity that underpins humor. Amir says, “The question is, what does it do exactly? It seems like it’s not the source of creativity, but rather the cognitive control top-down director of the creative process. The creativity itself appears to occur elsewhere depending on the creative task.”
The current study adds an extra piece of information to research previously conducted at Biederman’s Image Understanding Laboratory. His earlier work examined the cortical basis of high-level visual recognition, and found that the same regions in the temporal lobe were activated. Interestingly, humor and appreciating a beautiful vista both appear to use similar parts of the brain.
Biederman also notes that the activation (and therefore pleasure) related to any experience diminishes with repetition. Consequently, he theorizes that humans tend to be “infovores;” eternally driven to find new experiences, always craving new information, and therefore new jokes.