Cognitive Daily

If you have normal hearing and an amygdala, you can probably tell which of these two songs is “happy,” and which is “scary.”

Song 1

Song 2

However, for extreme cases of epilepsy, one treatment is to surgically remove the amygdala, the area of the brain which processes, among other things, the sensation of fear. People who have had this surgery fail to recognize fearful facial expressions. A 1978 study in which experimenters stimulated patients’ amygdalas directly with electrodes caused them to behave as if they were afraid.

But other efforts to induce fear reactions in patients whose amygdalas have been damaged or removed have had mixed results. One study found that people with damage to the amygdala could not recognize fear in faces, but could recognize fear in voices. Some studies measuring healthy individuals found that screams and yells do activate the amygdala, but others have found no impact of fearful speech prosody (the musical aspects of speech) on the amygdala.

A team led by Nathalie Gosselin devised an experiment to clarify the role of the amygdala in music perception. They had a composer create 56 musical excerpts, each designed to express one of four emotions: happiness, fear, sadness, and peacefulness. These excerpts were played for sixteen patients whose epilepsy had been cured by one of two types of surgery: left or right temporal resection, which removed the entire amygdala along with parts of the corresponding temporal lobe. Each clip was rated on a scale of 1 to 10 for how well it expressed each of the four emotions. A group of normal individuals rated the same clips. This graph charts the results for two types of music clips: fearful or happy.

i-03a1c2ad24bd6344c210595e1e468f4e-musicamyg.jpg

For happy music, the responses of normal and amygdala-free people were the same. But for scary music, while normal individuals rated it higher for “scary” than any other emotion 86 percent of the time, patients who had undergone the left temporal resection only rated it highest for “scary” 38 percent of the time. Results for the other surgery were similar. Surgery patients also had significant difficulty recognizing peaceful music.

But perhaps the surgery impairs music recognition in general. To test this, the experimenters included several clips with errors — obvious flubs that sounded like the pianist had stopped and restarted playing. The patients were as good as normal individuals at detecting the errors.

Gosselin’s team argues that this research shows that the amygdala plays a crucial role in recognizing scary music. One possible explanation is that the music mimics sounds that people use to alert each other to danger.

So, were you able to identify which song was scary and which was happy? Let us know in the comments.

Gosselin, N., Peretz, I., Noulhiane, M., Hasboun, D., Beckett, C., Baulac., M., & Samson, S. (2005). Impaired recognition of scary music following unilateral temporal lobe excision. Brain, 128, 628-640.

Comments

  1. #1 Scott Belyea
    April 13, 2006

    Well … sure, I can tell what the “right” answer is. However, if this sample is representative, the test is so simplistic that I wonder about value of the results.

    Example – if I had heard the first piece and been asked what emotion it conveyed, something as simple and “negative” as “scary” would not have come to mind.

    Speculation – any clues as to whether the results would be different depending on how much and what types of music the subjects listen to? I listen to a lot of (mostly) Western classical music and jazz; and I suspect that this test is one of those that would make me want to answer “none of the above” as often as not. I’m sure you know the kind of “dumbed-down” survey questions I mean (“Would you rather have lower taxes or more social services?” “Yes.”).

  2. #2 Dave Munger
    April 13, 2006

    if I had heard the first piece and been asked what emotion it conveyed, something as simple and “negative” as “scary” would not have come to mind.

    Well, that’s not precisely what the study was asking: it was asking respondents to rate the song on a scale of 1 to 10 for how well it conveyed each of four different emotions. So nothing needs to “come to mind,” you just adjust the scales according to your perception. People without amygdalas, even when the music is very simple like this stuff, don’t come up with “scary” nearly as often as people with normal brains.

    You’re right, though — it would be interesting to learn if people raised in different cultural traditions would respond differently (this study was conducted in France) — is there something fundamental to the structure of the music that invokes fear, or do we learn what music is “scary” within a particular musical tradition?

    Some of these same researchers have studied different musical traditions, and found that very little training is necessary to recognize different musical styles. It’s hard to say if the same results would apply to emotions.

  3. #3 SkookumPlanet
    April 13, 2006

    If the rattler had rattled I’d have another excuse to travel to New Mexico via editing today. If I’d heard that, rather than seen it, the hair on the back of my neck would still stick out horizontally six years later.

    Could scary music be called “amygdala music”? Has a nice sound. The name, not the music.

  4. #4 Nathan Myers
    April 13, 2006

    You probably would learn more from analyzing reactions to music that’s not so obviously skewed one way or another. E.g., which participants can pick out the creepy vibe in an apparently happy song?

  5. #5 Anna Haynes
    April 13, 2006

    I thought the temporal lobe was where music ‘was sited’; in which case – since the surgery affected both it and the amygdala – it’s not clear that the amygdala (or its absence) is necessarily playing a role in the results.

  6. #6 Scott Belyea
    April 13, 2006

    if I had heard the first piece and been asked what emotion it conveyed, something as simple and “negative” as “scary” would not have come to mind.

    Well, that’s not precisely what the study was asking: it was asking respondents to rate the song on a scale of 1 to 10 for how well it conveyed each of four different emotions. So nothing needs to “come to mind,” you just adjust the scales according to your perception. People without amygdalas, even when the music is very simple like this stuff, don’t come up with “scary” nearly as often as people with normal brains.

    Yes, you’re right, of course. What I should have used a few more words to explain was that my impression was that regardless of which side you approach it from, I have the feeling that there’s a lot of cultural/life experience influence here that might overwhelm what the researchers are looking for.

    One more example – I despised the cutesy selection #2 on first hearing, and I didn’t find #1 scary at all. So … if I were answering based on my own gut reaction rather than on what I can intellectually determine is the “right” answer, I might well pick #2 as the “scary” one.

    Let me poke around here and see if my amygdala is still there …

  7. #7 Shane Horan
    April 15, 2006

    Well the titles are a dead giveaway if you speak French, “epeurant” and “gai”!