..he who understands also loves, notices, sees… The more knowledge is inherent in a thing, the greater the love…Anyone who imagines that all fruits ripen at the same time as the strawberries knows nothing about grapes. – Paracelsus
My sons and I put the mechanics of nature in motion by sowing seeds in our garden a few months ago during late spring. While tending to the garden today, I noticed seedlings already starting to emerge from the soil. The ingredients provided by nature, proper temperature, enough water, enough sunlight, and the appropriate soil conditions created the context that led to those seeds germinating.
It got me thinking about emotions, specifically love, and how the garden has been a common symbol to describe it. We provide ingredients by which we cultivate love. Perhaps the weather in relationships signifies the time, setting, and context that provide hope for a growing relationship. The soil represents all of our past experiences that contain the nutrients to permit the seeds to germinate and the seedlings to grow. The sunlight may be the maturing of an individual’s mind that allows one to be capable of radiant love. The water represents the circumstances and decisions, both planned (like watering the soil) and unplanned (drought, rain, flooding) that allow for further growth of the plant. Like every plant has its own growth characteristics, spacing, watering, sunlight needs, and ripening time, so too does love.
It is in this garden that I have experienced what it is like to nurture a flower or let weeds grow and how I can bolster the environment that contains love – starting with myself.
What is precisely going on in our brains when we feel love? Is love registered as dependence or addiction in our brains? And when is it healthy and when is it unhealthy?
Let’s start with the various parts of our nervous system that are involved in emotions: the sensory and motor cortex of the brain, the frontal lobe, the thalamus, the amygdala for emotion-based decision processing the sympathetic nervous system. Associated with these components are neural signals known as neurotransmitters and organ signals known as hormones. The brain is the beginning and end of the pathway – both coordinating and responding to these signals.
When one experiences love, anger, or fear, the brain activates similar neural circuitry. In each of these experiences, the heart rate increases, the pupils may dilate, and the brain focuses on the stimulus. Involved in these reactions is the interplay of neurotransmitters and hormones, such as cortisol, epinephrine, norepinephrine, serotonin, dopamine, glutamate, and gamma-aminobutyric acid (GABA).
Is there a signature brain activity or location for a singular emotion? No
In the early 1990’s, with the availability of magnetic resonance imaging to diagnose abnormalities in the brain, scientists developed a tool known as Functional MRI (fMRI). Neuronal activity in the brain increases the cerebral blood flow in the respective region, which can be evaluated. This technology merges a detailed anatomic view of the brain with an ability to detect brain activity. What followed was the birth of a new era of neuroscience capable of more quantitatively evaluating the brain’s response to various neurologic stimuli. The current method is the BOLD technique (Blood Oxygen Level Dependent) developed by Seiji Ogawa, which is completely noninvasive.
Contrary to popular belief, studies have supported that there is no individual region that represents a specific source of emotion (Barrett, 2006a). However, the study of various emotional states and fMRI has demonstrated signature patterns, referred to as multivariate pattern analysis and classification (MVPV). Within this concept, varying quantifiable intensities of signals (voxels) enable the determination of a pattern or signature for different emotions.
An interesting study captured the functional MRI patterns from persons who viewed photos of their significant others. The functional MRI indicated an increase in activity in the dopamine centers, specifically the caudate nucleus and the ventral tegmental area (VTA). The pathways connected to the award circuit, including the amygdala, the hippocampus, and the prefrontal cortex. Incidentally, these areas are also seen active in other behaviors that lead to a pleasure response, such as sex, drug use, and food consumption.
Yes – in many ways falling in love with someone has a similar response on the brain as developing an addiction – the primary pathways involved are those of reward and motivation. Several neurotransmitters are activated: Dopamine is a sensitizer (e.g. craving) for the reward system and is geared to move a person toward a stimulus; Oxytocin has several key roles in both female and male sexual organ function, including that it is a trigger to uterine contractions and lactation. In men, it plays a role in testosterone production and the movement of sperm. Beyond this, it may play a role in bonding and sexual arousal. Vasopressin may be associated with long-term relationships.
Helen E. Fisher, an anthropologist and researcher on the emotion of love, described three types of relationship pathways occurring in human evolution: the sex drive; romantic love; and attachment to a long-term partner. Certainly, these forms are not mutually exclusive. The sensation of love causes one to do things that might be considered irrational. It isn’t out of the realm of reason to imagine that maladaptive behaviors could spawn from romantic love.
What happens when a person starts getting more serious with another? Many hormones and neurotransmitters are involved in forming an attachment. There is a release of oxytocin and dopamine when a couple holds each other, which causes relaxation, bonding, and a craving to intensify. There is also norepinephrine and serotonin activity, contributing to the physical response to love. The sex hormones estrogen and testosterone intensify the physical relationship. In a woman, estrogen increases longing for closeness and desire for sex. In both men and women, testosterone augments sexual appetite and seductiveness. The neurotransmitter phenylethylamine (PEA), a natural amphetamine produced in the brain, might be what is behind infatuation. In romantic love, the frontal cortex shows decreased activity, possibly accounting for the love “blind” feeling new couples feel for each other.
These neurotransmitters shape future circuitry as the love evolves in two stages, an early phase, one that is less secure, with greater excitation to a later phase, which is calm, more balanced, and safe. One potential attractor to a relationship is that early love shows a stronger inhibitory pathway, specifically to negative thoughts. Romantic love downshifts autonomic reactivity in lovers and provides resilience from stress responses, negative emotions, and even pain. The response to negative emotion trials was studied by Song et al (2016) and suggested love had an inhibitory effect on negative pathways that sculpt a negative experience. This inhibition of negative emotion was strongest in the early love group, followed by the long-term love group, and then the single group.
This has implications with romantic love and addiction, where a person “loves being in love.” Lovers in the early stage and addicts both show increased impulsivity of behavior, increased energy, obsessive thinking, emotional dependence. Functional MRI of early-stage lovers demonstrated an increase in the activity of systems that involve reward and motivation, or dopaminergic pathways. Along this route is likely where love can become dysfunctional or an addiction. The abrupt termination of a love interest, either from a break-up or a death, can induce similar feelings as drug withdrawal, such as lethargy, anxiety, sleep changes, appetite changes, and irritability.
Interestingly, Gabor Mate, in a book that discusses the neurobiology of addiction In the Realm of Hungry Ghosts, articulates poignantly that drug use activates the brain “like a warm, soft hug,” as one user told him. Sadly, it is the same reason that addicts may relapse during dire circumstances, similar to how a non-user might look for someone to hug or talk through. This may be at the core of what is maladaptive love.
However there Zou et al (2016) found some differences between the two: in the oxytocin system for romantic love compared to drug addiction, as well as enhancement in social cognition with love and dysfunction in cognitive control with drug addiction. This may be the basis for love as a pro-social behavior.
“1 Corinthians 13:4 4Love is patient, love is kind. It does not envy, it does not boast, it is not proud. 1 Corinthians 13:7-8 7It always protects, always trusts, always hopes, always perseveres. 8Love never fails. But where there are prophecies, they will cease; where there are tongues, they will be stilled; where there is knowledge, it will pass away.”
There are many references to ideal love in the Bible. If anyone reading the above has been married, they may recognize this verse at their own wedding. 1 Corinthians is one of the most frequently used passages for weddings. Anyone who has been married, also realizes too that “always” isn’t possible.
When the peak levels of dopamine, adrenaline, vasopressin, and oxytocin have worn off after the honeymoon period, a new form of love emerges: the love that is seen with long-term relationships.
Stay tuned for an upcoming post that details more about the neuroscience of long-term relationships.
Bibliography and Suggested Links
Aron A, Fisher H, Mashek DJ, Strong G, Li H, Brown LL. Reward, motivation, and emotion systems associated with early-stage intense romantic love. J. Neurophysiol. 2005. Jl; 94(1):327-37. Epub 2005, May 31.
Barrett LF. Are Emotions Natural Kinds? Perspectives on Psychological Science. 2006a; 1(1):28-58. doi: 10.111/j.1745-6916. 2006.0003.x.
Fisher, Helen. Ted talk TED 2008 The brain in love
Fisher, Helen. Ted talk TED 2006 Why we love, why we cheat
Kragel P, LaBar K. Advancing emotion theory with multivariate pattern classification. Emot Rev. 2014: 6(2): 160-174.
Schneiderman, I., Zilberstein-Kra, Y., Leckman, J. F., and Feldman, R. (2011). Love alters autonomic reactivity to emotions. Emotion 11, 1314-1321.
Zou Z, Song H, Zhang Y, Zhang X. Romantic Love vs. Drug Addiction May Inspire a New Treatment for Addiction. From Psychol. 2016; 7: 1436.