The Neuroscience of Pleasure

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Centuries after the world’s greatest philosophers pondered the secrets to a good life, modern science has made tremendous, cross-disciplinary advances in understanding human flourishing.

For Oxford neuroscientist Morten Kringelbach, this has meant going straight to the source — the brain. For two decades, Kringelbach has invited participants to brain imaging scanners to investigate what happens in the brain when they experience one of the most cherished constituents of well-being: pleasure.

By now, he has studied the neuroanatomy of most pleasures — food, drugs, music, looking at cute babies. Even sex, despite the obvious challenges.

It turns out that there’s a lot we can learn about the human condition from studying pleasure in the brain. For example, neuroscientists can create schemas, or brain models, of underlying neural activity of different brain regions in various states, as billions of neurons and glial cells communicate with each other. These insights, in turn, can be applied in treating conditions that affect the functioning of the pleasure circuit, including neuropsychiatric disorders and addictions. Ultimately, unraveling the brain mechanisms involved in the experience of pleasure, happiness, and various meaningful states could point to what flourishing truly means, and help people experience more of it. This quest has been the guiding motivation of Morten Kringelbach’s research. In his own words, here’s what he has to say about the neuroanatomy of pleasure.

Pleasure is not only a sensation

Pleasure is a way of experiencing the sensory world. When you see, hear, smell or taste something that you deem as pleasurable, the information goes through the sensory cortices of your brain. But that’s not where pleasure is encoded. Thanks to the engagement of various brain regions, it’s something that’s added later on as a hedonic gloss.

Thus, pleasure is not merely a sensation or a thought. Importantly, pleasure consists of cycles of wanting, liking, and learning. A good life relies on a brain system that can go through this cycle of changes in an orderly fashion. Other than having a variety of pleasures, my advice is to share your pleasures with others.

What happens in the brain when you experience pleasure?

If you are a coffee drinker, let’s consider what happens when you get your morning coffee.

The pleasure cycle begins even before you ingest your first sip. It starts with the expectation and anticipation of the event. No information (e.g., sight, smell, taste) has thus far entered through your sensory organs. Yet you know that the coffee is out there, and based on your previous experiences, you have a want.

In this wanting stage, a large part of your brain is engaged in trying to find ways to get to the target. It’s as if your brain is telling you that there’s something important in the environment that needs attending to. As time goes by, you will become increasingly motivated to attend to it, until you finally get up and make yourself a coffee. Once the sensory experiences of seeing, smelling, and tasting kick in, the hedonic hotspots in your brain activate and pleasure intensifies. You are now in the liking stage.

As you drink your coffee, your expectations are constantly being updated. The learning stage includes having your expectations met. When something goes wrong and your expectations are not met (for example, when the coffee tastes off), that’s a roadblock to pleasure. If the network is running smoothly, after a while you’ll become satiated. Your brain will learn from your experience by updating associations and making future predictions. Then the cycle will stop and you’ll move on to other things.

When the pleasure cycle malfunctions: addiction and anhedonia

Instead of going through the wanting-liking-learning circuit where things naturally taper off and one can move on with their day, addicted people are stuck in a loop of repeat. For example, they might experience extreme motivation (wanting) without the reward (liking) and keep going back to the want, because it doesn’t seem to be enough to let them proceed to the enjoyment and satiation stage.

Anhedonia — the condition when one can no longer feel pleasure — is a key symptom of neuropsychiatric disorders. A depressed person, for example, may still be motivated to get coffee, but when they do, they may not feel pleasure from it. This can make things even worse, since they may feel that they should be experiencing joy, but aren’t.

Inside the machine room of pleasure

The orbitofrontal cortex, the part of the brain behind our eyeballs, is a principal player in the machine room of pleasure. Other regions, including the nucleus accumbens and ventral pallidum, are also important. If we remove some of these regions from rat brains, they’ll no longer show the pleasure reaction with their mouths when they are given sweet water. Almost like a voting system, all of these regions need to be engaged with each other for us to feel pleasure. Luckily, the system is made of many parts, so when one region malfunctions, the other parts can work together and compensate.

As the pleasure cycle kicks in, the neurons of these regions begin “talking” to each other in synchronizing and desynchronizing ways. Electrical signals turn to chemical signals at the synaptic junction, before becoming electrical signals again and moving on. It’s a dynamic landscape, with a myriad of routes that the signals travel through. What facilitates this constant movement are the neurotransmitters at the synaptic junction. They make it easier or harder for the signals to pass through various regions. For example, during an orgasm, because of the neurotransmitter release, suddenly it may become much easier for signals to travel between the orbitofrontal cortex and other regions that ordinarily may not be directly linked.

The many flavors of pleasure

The brain is like a machine that’s running all the time. There are many routes that can ignite it. Some are hedonic (to do with pleasure and positive affect), like coffee or sex. Others are more eudaimonic (to do with meaningfulness, engagement, and self-realization), like volunteering or expressing gratitude. Often, eudaimonic activities don’t feel obviously pleasureful at the moment. In fact, they may even feel difficult. It’s only afterward when we look back and construe the experience as meaningful, we might deduce pleasure from them. Importantly, all of these experiences — whether they are “low” or “high” pleasures — are served by the same system and share a common “neural currency.”

Pleasure and pain are closely linked

One of the most fascinating neuroscientific discoveries is the close link between pain and pleasure. Consider the example of phantom limb pain, which is reported initially by about 80% of people who had amputations. Over time, in between 10-25% of patients, phantom limb pain can lead to chronic pain, which is very difficult to treat.

When neurosurgeons take electrodes and perform deep brain stimulation in these patients with 20 Hz (the targeted region receives 20 electrical pulses per second), the patients report almost instantaneous relief. But when we stimulate the same regions with 50 or 100 Hz, the pain worsens. It’s the same network that delivers their relief (pleasure) and their excruciating pain. It’s the same network that’s engaged when intense discomfort during a long run suddenly turns into a runner’s high.

A good life is more than accumulating pleasures

It’s a myth that hedonists are happier than other people. Those who find themselves in a never-ending chase for pleasure for pleasure’s sake are often unhappy. A sense of meaning and an overarching purpose that people feel in their lives is central to flourishing. The meaning may be derived from our relationships, from putting effort into various endeavors, and even from overcoming hardships. The neurobiological affinity between pain and pleasure in our brains may parallel the poignant link between suffering and flourishing in our lives.

The dopamine myth

Dopamine is part of the dance of pleasure. It’s what will motivate me to get up and get the coffee that I keep thinking about. But dopamine is not what gets me the reward when I drink my coffee — it’s the opioids. Pleasure is not so much about dopamine and the opioids themselves but about how the brain communicates between various regions. The neurotransmitters change the wiring of the regions and how they engage with each other.

Pleasure and flourishing

One way to conceptualize flourishing and Dr. Kringelbach’s insights into pleasure is through the metaphor of a beautiful garden.

Imagine that every morning, as you enter your garden, you find yourself in a treasure cove of pleasures. You smell the majestic roses, your bare feet walk on dewy grass, you taste the sun-sweetened berries as the birds sing your love songs. That is joy.

But there’s another joy that your garden offers. A gentler, less tangible joy that simmers quietly in the background of the exuberance delivered to you through your senses. It’s the joy of the realization that you have a garden in the first place. That you, your garden, the bees that dance over your lavender, the birds that nest in your oaks, the humans that eat the fruits that your earth bears, are part of an intricately interconnected system. That compassion, meaning, awe, gratitude, fulfillment, belonging are part of your garden’s abundant harvest. That this garden that you painstakingly tend to every day, through storms and bruised hands, is contributing to the flourishing of other beings.

Just as the wonder of our sentience is born from the interaction of countless neurons in our brains, a good life, perhaps, is woven from an ever-transient constellation of moments: hedonic pleasures that are hidden in plain sight all around us, and eudaimonic joys that we cultivate in the gardens of our hearts.

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