The Art of Delicate Sadness

Sad Noh masks (from Fig. 1 of Osaka et al., 2012).


Noh is a traditional style of Japanese theater where the actors wear masks to convey facial expressions. Many of the masks are known for their ambiguity:

As it is often difficult to tell the actual feelings expressed in a noh mask, it is said to be made with a “neutral” expression. The mask carver tries to instill a variety of emotions in the mask.

It is up to the performer to imbue the mask with emotion. One of the techniques used in this task is to slightly tilt the mask up or down. With terasu (tilting upwards) the mask appears to be slightly smiling or laughing and the expression lightens somewhat. While kumorasu (tilting downwards), produces a slight frown and can express sadness or crying. Basically, by using minute movements, the performer is able to express very fully.

Three pictures of the same nō 'hawk mask' showing how the expression changes with a tilting of the head. The mask was afixed to a wall with constant lighting and only the camera moved.


Professor Michael Lyons has an excellent site explaining The Noh Mask Effect: A Facial Expression Illusion, which you really should see for yourself.


Delicate Sadness

A recent neuroimaging study by Osaka et al., (2012) set out to examine how the amygdala (a limbic structure important for emotion) would respond while participants viewed masks portraying "delicate sadness" -- "a Noh mask that is elegant and artistically polished, and designed to express sadness." To choose the most appropriate stimuli, a separate group of subjects rated a set of 70 masks on a scale of 1 (not at all sad) to 7 (highly sad). The six most "highly sad" masks were selected for comparison to six "neutral" masks. But as we already learned, the neutral masks can be ambiguous.

The amygdala (LeDoux, 2007) is predominantly known for its role in fear conditioning, but it is also activated by other emotions (e.g., Kober et al., 2008). Therefore, the comparison of viewing sad vs. "neutral" masks in the present study could yield minimal differences in the amygdala.

And that is what happened (in my estimation). However, the authors presented their results in a more positive light: a region of interest (ROI) in the right amygdala showed activation in the sad vs. neutral contrast at p<.05 (uncorrected). The ROI in the left amygdala, as well as bilateral "reward-related" ROIs in the nucleus accumbens, caudate nucleus, and putamen did not reach that level of significance. They concluded that:

...viewing Noh masks with expressions of elegant sadness effectively stimulates the right amygdala of the limbic system. Thus, the sadness evoked by such masks seems to be processed by the limbic system in a way similar to the way in which it processes negative emotions such as fear and disgust. Understanding the neurological processing of these facial expressions could effectively contribute to an appreciation of Noh performances in an artistic way.

But I'm not so sure the present finding illuminates the aesthetic and emotional experience of Noh theater. I think we need to understand more about how the brain processes basic emotions before we make neuroaesthetic claims.

I originally thought the study was interesting from the perspective of emotional ambiguity, where even the static images of those elegantly carved masks could capture multiple expressions simultaneously. A recent über meta-analysis of neuroimaging studies of emotion did not find support for the "locationist approach" where "discrete emotion categories can be consistently and specifically localized to distinct brain regions" (Lindquist et al., 2012). Hence, looking at amygdala and striatal regions in isolation will miss important aspects of emotional and aesthetic experiences engendered by viewing traditional Japanese Noh masks.


References

Kober H, Barrett LF, Joseph J, Bliss-Moreau E, Lindquist K, Wager TD. (2008). Functional grouping and cortical-subcortical interactions in emotion: a meta-analysis of neuroimaging studies. Neuroimage 42:998-1031.

LeDoux J. (2007). The amygdala. Current Biology 17: R868-R874.

Lindquist KA, Wager TD, Kober H, Bliss-Moreau E, Barrett LF. (2012). The brain basis of emotion: a meta-analytic review. Behav Brain Sci. 35:121-43.

Osaka N, Minamoto T, Yaoi K, & Osaka M (2012). Neural correlates of delicate sadness: an fMRI study based on the neuroaesthetics of Noh masks. Neuroreport, 23 (1), 26-9 PMID: 22113213