Appreciating Phantom of the Opera through Neuroscience
One day, when I was singing the song “Music of the Night” from the classical musical Phantom of the Opera on the global karaoke app Smule (headquartered in San Francisco), I noticed something special about the first verse of the lyrics:
Nighttime sharpens, heightens each sensation
Darkness stirs and wakes imagination
Silently the senses abandon their defenses
I’ve sung this song multiple times with people across the globe, but I never realized there is some interesting cognitive neuroscience behind the phenomenon until that moment. Therefore, I reviewed the topic of “sensation & perception”, which normally appears in the early chapters of a college course in cognitive psychology.
In the human body, sensory processing changes at night due to alterations in attention and environmental stimuli. Let’s break it down for each sensation, with examples.
For sight or vision, it’s based on anatomical affordance and physiological adaptation.
First, in darkness, more rods than cones in the retina are engaged. Rods and cones are two different types of photosensitive cells. Rods have higher sensitivity to light in low-light conditions and can detect different shades of gray, as opposed to different RGB colors.
Second, the brain relies more on contrast and motion rather than sharp visual details when there isn’t abundant light as input. This change not only results from the large numbers of rods put into work, but also indicates the brain will work in a different mode than during the day. I wouldn’t say some neurons in the visual cortex are doing their night shift while other neurons are resting after a long day’s work. Neither the brain nor the circadian circle works that way actually. Even when you are asleep, the majority of your neurons aren’t completely idle; they are just engaged in other chores. Poor neurons… By the way, if someone tells you that one particular neuron only needs to perform one specific task and nothing else, that person may be considered “old school”. This kind of uni-functional role is already difficult to find in modern society. Similarly, I wish I only needed to focus on writing and digital creation daily, but I still have to learn social media tools and communicate with people. That’s reality.
For all other various senses, the easiest explanation for their increased acuity at night is compensation for the overall loss of visual input at night.
For sound or audition, the quiet environment at night results in a lack of visual stimuli, which means more processing power of your brain can be reserved for other channels, the auditory system in particular. Increased sensitivity to sounds means your brain will focus more on auditory cues, activating areas like the auditory cortex more than it does in the daytime. The peripheral auditory system, including the ears, will also be more alert due to top-down regulation. One thing worth mentioning is that at night, there is objectively less sound in the external environment due to urban regulation. Traffic sounds are largely gone. If you live in a peaceful suburb, you won’t be disturbed by entertainment sound sources, like karaoke, concerts, or bar fights. Unless you live in a war zone, you won’t be scared and startled by bombardments. Some countries prefer to attack their neighboring countries at night, which is tactical yet despicable.
For touch or tactile sensation, the reduction in visual and auditory distractions can allow the attention to shift to physical sensations. This shift increases the “readiness” and “resolution” of the tactile sensation on the receiving end, and one may observe heightened activity in the somatosensory cortex through brain imaging. Touch may involve a bunch of variables such as pressure, vibration, texture, temperature, and duration. Sadly this isn’t something I have much expertise in, as my academic research background only involved the visual and auditory systems. Moreover, labs studying tactile sensation alone are less easy to find compared to labs studying the motor system in your brain or the sensorimotor system as a whole.
When combining auditory and tactile compensation, one common example that comes to my mind is those massage therapists who are blind. Based on my observation, they can decipher fast-paced text-to-speech signals from their phone or other devices. They are also very good at feeling the knots in the patients’ muscles and applying the right amount of pressure to the right tissues, whether barehanded or using a tool.
For the sense of smell, the compensation mechanism is similar. In the absence of abundant visual and auditory inputs, the brain enhances olfactory sensitivity. My personal experience is that I can smell the fragrance of flowers more clearly at night. With less distraction, I can form a virtual image for that fragrance. Nocturnal animals need to use smell to hunt for prey at night, even if they already have good night vision. Because the olfactory system involves chemicals, instead of physical signals, the research methods are quite different. Again, this is out of my expertise. You can try some essential oils or perfume; then compare what you receive when your eyes are open vs when your eyes are closed. I doubt you will have a definitive answer for every odor.
For the sense of taste, it’s actually out of the context of this song. I doubt the characters are eating anything during that song. However, let’s still talk about the gustatory system. Again, it’s compensation, similar to smell, and this process involves the tongue, and all the way up to the relevant cortical area. The best example I can think of is wine tasting. One can compare the taste of certain drinks with their eyes open or closed. If this song was from a musical, such as Little Shop of Horrors, or Dracula, then try some blood perhaps (just kidding). If you want something exotic, why not try some durian from Malaysia?
When I was preparing for this material, a friend also mentioned emotion: it’s undeniable that emotional intensity (another term psychologists typically use is arousal) may increase due to decreased external stimuli. One simplistic explanation is that the brain’s limbic system (amygdala, hippocampus, cingulate cortex, and so on), which is responsible for emotions, becomes more active when the “mainstream” cortical regions have less information to process in that period. This leads to the emotional experience preoccupying one’s body more, figuratively speaking. As my readers may remember, in my memoir The Snowy Battlefield of Ohio, I mentioned my id (/id/) was taking over my body one night before I sent out that crucial second email. One can understand in this way: the part of the brain responsible for rational decision-making was too tired to continue, and the limbic system, which took over the leading position, might be radiating anger in that situation. (The previous sentence still reads very awkward to me personally because there’s no legitimate reason to map the subconscious to the subcortical area arbitrarily. As you can see, I’m not a big fan of tying classical psychoanalytic theories to neuroanatomy.)
Regarding the word “imagination” in the original lyrics, I don’t think it should be taken literally, as if “your” brain was still conducting a conscious simulation of a scenario, which would surely take up a lot of space in the “RAM” of your brain. In my opinion, it may refer to high-level perception, or even a dreaming state.
Finally, I have to state that if you go to genius.com, you will find out that the original lyrics should be interpreted very differently than what I am doing for you. That’s because we need to put it into context— the entire story of the musical. Some say the “night” may be metaphorical to begin with. I’ll leave that to the audience.
Disclaimer: This article follows a similar policy to that of my book. The discussion here may not meet the standards of academic rigor and should not be used as scientific facts. It should be seen as an attempt to bridge performance art and science, and to inspire readers to chew on the lyrics from an unconventional angle.
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