It's Halloween. You're listening to some creepy, scary music. Maybe it sounds like something like this* - SCARY! You are lying still, attending to the emotional qualities of the music. Next, you close your eyes and listen to the same scary track. Do you feel more frightened by the music when your eyes are closed? And what is your brain doing throughout all this scariness?
In the name of science, subjects of a study listened to either negative or neutral music clips while either keeping their eyes open or closed. While they were doing these tasks, they laid very still so that an fMRI scanner could see what areas of their brains showed the most response to the different conditions.
Before performing this experiment, Lerner et al. hypothesized that closing the eyes while listening to music would result in an increased emotional response to the music. Following this logic, scary music would seem scarier when the eyes of the participants were closed. They also predicted these increased negative feelings during closed eye listening sessions would cause a greater level of activation in the brain region called the amygdala. Since the amygdala is a brain region commonly linked to memory and emotional responses such as fear, the researchers predicted that it would show greater brain activation during the closed eye sessions of negative music listening when compared to its activation during the opened eye negative music listening sessions.
The study started by asking the subjects to rate the positivity or negativity of different neutral or negative musical clips after listening to them with eyes open or with eyes closed. There was only a significant difference in the ratings for the negative music clips when the eyes were closed -- these negative clips were rated much more negatively when listening with closed eyes than with open eyes.
Next, the subjects in the study listened to the same neutral or negative clips with their eyes either opened or closed while lying in the brain scanner. Their scans found more amygdala activation while listening to the negative music clips with eyes closed than when listening to those same negative clips with their eyes open. However, for the neutral musical clips, there was no increased amygdala activation while listening with the eyes closed vs. listening with the eyes open. So here it seems that the amygdala reacts more strongly to the spooky music when the eyes are closed, which lines up nicely with the study participants' more negative ratings of spooky music when listening with their eyes closed.
To build the story further, the researchers also examined the activation patterns of two other regions of the brain -- the prefontal cortex (PFC) and the locus coeruleus (LC). The researchers picked these two regions as candidates for investigation because they were interested in whether a physiological fear response or a higher level response was more responsible for the increased amygdala activity. Higher level functions such as attention are more likely to show up as increased activation in the PFC, while lower level functions that are more physiological reactions are more likely to show up as increased activation in the LC, which is located in the more primitive brainstem.
They found that the LC was significantly co-activated with the amygdala when subjects listened to the negative music with their eyes closed, suggesting that lower level functions play a role in the response of the amygdala. An additional analysis indicated that the amygdala seemed to be causing the response of the LC. They also found that the PFC was connected with the amygdala during the negative music, eyes-closed condition, and that the amygdala was more influential on the activation of the PFC.
In this study, Lerner et al. learned that a bit of scary music listening allows a bit of a clearer picture into the inner workings of our brains. This Halloween when you're watching scary movies or listening to scary music, think about your amygdala, locus coeruleus, and prefrontal cortex all working together to give you an enhanced spooky experience when you close your eyes.
If you're interested in hearing what the negative (or neutral) music sounded like, check out the stimulus sounds here.
*Scary music in the first paragraph is Stimulus S3 from the paper.
Lerner Y., Papo D., Zhdanov A., Belozersky L. & Hendler T. (2009). Eyes wide shut: amygdala mediates eyes-closed effect on emotional experience with music., PloS one, PMID: 19603072
Amygdala photo via Wikimedia Commons.