Happiness and the Brain

That night in Paris, the day in Madrid, that one time you fit into pants from elementary school. These are the good moments, the happy ones. Write about that one moment that was the happiest. It could even be writing this essay, though for your sake, let’s hope not.

This week’s topic had me wondering:  what’s going on in our brains when we’re happy?  A little bit of quick research revealed what I believe to be some interesting findings that I will share with you today.

There seem to be two basic approaches to studying emotion in the brain.  Some scientists focus of the chemicals and neurotransmitters that are released in different situations, whereas others use imaging techniques like fMRI and PET scans to take a look at which areas of the brain become active in response to emotion-evoking stimuli.

Happiness Chemicals

The human brain is an incredible organ, capable of an enormous number of simultaneous calculations, responses, actions, and thoughts.  Our brains contain on the order of 10^11 neurons, specialized brain cells that communicate with a combination of electrical and chemical signals.  Neurons, in their resting state, are charged up and ready for a chemical signal.  When a neighbouring neuron releases a neurotransmitter, the chemical travels across the synapse (the space between the neurons) and once it is received, the neuron fires and sends off neurotransmitters to other neurons.  Each neuron is believed to connect to thousands of other neurons, meaning that average humans have on the order of 10^14 synapses.  This makes for some incredibly complicated circuitry, hence the brain’s amazing power and the difficulty of studying the brain.

The following is a list of some of the chemicals involved in positive emotions.  This list is by no means exhaustive and researchers are still struggling to fully understand the actions of these chemicals.

Dopamine

This relatively small chemical (with the formula C8H11NO2) packs a powerful happiness punch.  It is a neurotransmitter frequently used by parts of the brain involved in reward systems.  When you do something good, your brain wants to reward you, so it releases a lot of dopamine and this makes you feel good.  Many stimulants (like cocaine and amphetamines) take advantage of this pathway by artificially stimulating neurons to release extra dopamine.

Serotonin

Besides its role in the human digestive tract, serotonin is an important neurotransmitter.  It is involved in everything from pain to apetite and even has effects on mood and memory.  It is believed that serotonin doesn’t necessarily cause moods, but does act to enhance them.  Again, some psychedelic drugs take advantage of this effect.  The active ingredient in Magic Mushrooms (psilocybin), for example, promotes serotonin release in the brain.

Oxytocin

This chemical is a hormone, and is released by the pineal gland to make its way through the body via blood.  It seems oxytocin is like the mother hormone.  It aids in childbirth and breastfeeding, sexual attraction, and pair-bonding.  In one interesting study, researchers gave oxytocin or placebo nasal sprays to men and those who received oxytocin and were in monogamous relationships stayed 10-15cm further away from an attractive female research assistant.  This suggests that oxytocin helps keep men away from those femmes fatales.  It also increases generosity, trust, and empathy.

Endorphins

Short for endogenous morphine, endorphins are exhilarating feel-good chemicals.  Where oxytocin seems to be responsible for some of the gentler feelings, endorphins dull pain, create a sense of well-being, and are released during exercise, excitement, and orgasm.  Runner’s high, for example, is caused by endorphins.  They dull the pain of prolonged exertion and actually create a euphoria.  While it sounds and probably feels great, this can be dangerous because muscles can become over-worked and damaged.

Happy Areas

Functional Magnetic Resonance Imaging (fMRI) is an amazing technology.  Developed at the end of the 90s, it allows scientists to peer into the brains of patients by detecting where the blood is flowing.  It has been shown that regions of the brain that are active require blood, so regions that are full of blood are full of activity.  fMRIs basically create movies of brain activity and they have been used for some interesting research in fields as varied as music cognition and brain surgery.

Many studies have focused on trying to find the areas in the brain that are activated by emotion.  In 2001, researchers at the University of Michigan aggregated data from 55 different studies and came to some general conclusions about the location of emotions in the brain.  The upshot is that emotions in general are processed in part by the medial prefrontal cortex and that happiness in particular happens in basal ganglia.  While I don’t think it’s particularly important for everyday life to know exactly where things are happening in your brain or to remember the names of these locations, I do find it very interesting that some of the most important and memorable moments in our lives were a consequence of chemicals and bloodflow to the brain.

The prefrontal cortex - where the (emotional) magic happens.
The prefrontal cortex – where the (emotional) magic happens.
Sounds gross, but thank your stars you have one, otherwise you'd have a pretty sad life
Sounds gross, but thank your stars you have one, otherwise you’d have a pretty sad life

Some may find that a little depressing, but I prefer to think of it positively.  Our brains and bodies are such incredible and complex machines that they can create these wonderful experiences for us.  Slugs probably don’t get to think back fondly on their first kiss or the first time they ate Gruyere (although slugs likely don’t kiss or eat Gruyere, but that’s beside the point).  We are amazing and understanding how we work does not diminish that amazingness.  Science and discovery bring it into sharper focus.

Oxytocin Study:

Oxytocin Modulates Social Distance between Males and Females.  The Journal of Neuroscience, 14 November 2012, 32(46): 16074-16079;doi: 10.1523/​JNEUROSCI.2755-12.2012

Emotion Activation Area Meta-Analysis:

Functional neuroanatomy of emotion: a meta-analysis of emotion activation studies in PET and fMRI. NeuroImage [1053-8119] Phan yr.2002 vol.16 iss.2 pg.331 -48

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