What is Love? (Baby Don't Hurt Me)

by Alana Duffy

Ah, love. That crazy feeling that makes people do all sorts of crazy things. What did I know about it before writing this article? Not a whole lot, except that it sometimes sucks. What do I know about it now? That it’s even more complex than I previously thought.

Much research has been done on the topic of love and affection, but so far the results haven’t been very conclusive. There is a general agreement on which neurotransmitters play a role in this sometimes inconvenient emotion. However, the reasons behind the release of these transmitters are unclear. In addition, some research has shown an overlap between sexual responses and romantic love. It’s kind of comforting to know that we, the general population, aren’t the only ones who have a hard time distinguishing between the two.

Three major neurotransmitters are related to feelings of love: dopamine, norepinephrine (AKA noradrenaline), and phenylethylamine (PEA). Dopamine is a neurotransmitter associated with pleasure and our brain’s reward circuits. It is released during pleasurable activities such as having sex, eating, taking drugs, or even listening to your favourite song. Dopamine is also strongly associated with drug addiction, as it encourages us to repeat the enjoyable behaviour that caused its initial release. Several behavioural aspects of love suggest that it can be very similar to cocaine-reward exhilaration, sleeplessness, and loss of appetite. Dopamine is also highly involved with our libido, the first stage of sexual attraction and desire, so it’s no wonder we sometimes confuse the feelings of love and lust.

Norepinephrine, or noradrenaline, is typically only present in the initial stages of a relationship or romantic feelings. It is the chemical responsible for our “flight or fight” response. Just as this term suggests, norepinephrine is responsible for the racing heart, sweaty palms, and dry mouth that so many of us experience when we’re stressed about the  first date, or if we happen to find ourselves confessing our feelings.

PEA, on the other hand, has more of an indirect role as it is essentially a releasing agent of the other two chemicals. Our initial feelings of attraction towards a person cause us to produce more PEA, which then triggers the realease of dopamine and norepinephrine. This results in the overwhelming feelings associated with romantic love and sexual attraction. Fun fact: PEA is also found in chocolate. Let it be known that  being a chocoholic actually has some sort of basis in pharmacology.
           
As we’ve just established, there seems to be a strong relationship between the reward pathway, the stress pathway, and love. These correlations are typically studied by exposing someone who is in love to a picture of their partner, and measuring their brain’s reaction through functional magnetic resonance imaging (fMRI). Studies have shown that the ventral tegmental area (VTA) and ventral striatum/nucleus accumbens are activated when shown such pictures. This makes sense, as they are linked together by dopaminergic neurons, and are both vital parts of the brain’s reward circuit. The VTA functions as a relay station, receiving information from several other areas of the brain about how well our needs are being met. The VTA then uses dopamine, the reward neurotransmitter, to send this information to the nucleus accumbens and various other brain regions, which reinforces the behaviours that are causing this satisfaction.

​​Interestingly enough, studies have demonstrated a noticeable difference in activation of the left and right VTA. The left VTA is associated with seeing a picture of a random person who is aesthetically pleasing (liking), whereas right VTA activation increased during presentation of a face that the participant loved and would work to see longer (wanting). So for those of you who have been wondering, there is indeed a difference between finding a person attractive, and actually wanting them. Another area of the brain that demonstrates this lateralization is the caudate nucleus. More specifically, the right anterior caudate nucleus is activated when shown pictures of the beloved. This grey matter structure is involved with reward detection and expectation, representation of goals, and integration of sensory input to prepare for action. The right caudate nucleus is also active during anticipation of monetary reward, reward-based learning, and spatial discrimination tasks. These results suggest that the caudate nucleus is associated with visual and perhaps attentional aspects of romantic love. Intense, focused, and sometimes over-obsessive attention on an individual person is one of the key features of love. So your housemates might think you’re acting crazy sometimes, but really it’s just the chemistry of your brain, and there’s not much anyone can do about that.

Visual stimuli of a strictly sexual nature also turn on the caudate nucleus (pun intended) . This is what I mean when I say there is some overlap between romantic love and sexual attraction; however it is somewhat reassuring to know that when comparing various studies, this is one of few areas that shows activation in both situations. So the next time you’re obsessing over some guy you met at Stages two weeks ago, remember that there is a distinction between sexual attraction and actually having feelings. Even if you are having a hard time figuring out which one of these emotions you are experiencing, your brain activity knows what’s up. Unfortunately, there doesn’t seem to be one study that directly examines and compares brain activation in both scenarios. This is good news for me because I’ve been looking for thesis inspiration, however it is mostly just inconvenient for those of us who wish to understand love and attraction.

This is a very, very brief overview of some of the brain structures that are involved with romantic love. There are many cortical areas that also play a role, but they are even less understood than what has been summarized here. I could write thirty pages on the subject and still only capture about 0.01% of what there is to know. Remember when I said love is even more complex that I used to think? This is why I wish I could be of more help, but I’m no love guru, just a fish in the sea trying to navigate these dark and confusing waters. Good luck to us all.

---