Romantic love (also refer as ‘being in love’, obsessive love and passionate love) is considered as one of the most overwhelming psychological state, and it includes euphoria, feelings of passion and intimacy for another person. In a study conducted by Jankowiak and Fischer (1992), they found evidence of romantic love in 147 societies out of 166 by simply using a survey. When these anthropologists are asked why they did not found that evidence of romantic love in the remaining 19 cultures, they suggested that the questions asked were ineffective and claimed that it is because the case of an ethnographic oversight. For this reason, it is concluded that romantic love is a ‘human universal’ or ‘nearly universal’ state.
Since, romantic love is a universal experience, it has been studied excessively in the literature. The initial studies about romantic love mainly focused on the humanity and social sides of it rather than studying the neurological components of romantic love. As time passes, romantic love began to draw more attention and it’s neurological and physiological mechanism are started to be discovered. In simpler terms, romantic love starts as an individual begins to consider another individual who is unique and special. In time, the individual begins to focus his/her attention toward the other individual or the beloved. Minimizing the beloved’s flaws or traits, condonation are the common characteristics of romantic love. One significant characteristic of romantic love is that the lover can be emotionally dependent, it is highly likely that the individual can arrange his/her routine according to the beloved, either to make an impression on him/her or just to be in sync with him/her. As the romantic love progresses, individuals show symptoms of increased energy, intrusive thinking (basically means obsessive thinking). Even though, everything seems to be going without any problem, mood swings and despair can be displayed if there is any inconvenience, struggle. Furthermore, through the process of romantic love, the sympathetic nervous system is triggered within the individual. This results in sweating, increase in the heart rate and so on.
Mentioning the romantic love, the two things that come to mind are attraction and attachment since they are the related love processes and all three stages (attraction, attachment, romantic love) can occur at the same time. However, it is shown that the neurological components of romantic love are different, but it may not that easy to differentiate that profile from the neurological profiles of attachment and attraction. In various studies, it is claimed that the attachment system is distinct because there is activation of region in the brain called ventral pallidum and this region is further associated with vasopressin-mediated pair bonding. Moreover, attachment is also linked with the deactivation of stress-related areas including the right anterior insula, hypothalamus, superior frontal gyrus. Yet, attraction is considered as distinct, one reason for that, there is activation in the areas adjacent to primary love areas. Besides from hypothalamus, when romantic love happens, an area of autonomic processing is also active.
To establish the brain areas that are linked with romantic love, studies are usually conducted via functional magnetic resonance imaging (fMRI). In one study, Bartels & Zeki (2000), examined the brain activity in 17 participants by using fMRI. These participants were considering themselves as ‘truly, madly and deeply in love’. The general procedure was consisted of all participants looking at a photograph of their loved ones and looking at photographs of their three friends who are happens to be similar in age, duration of friendship and sex.
The results of the study have shown that, romantic love takes place in the subcortical reward centers to focus on the loved one and to process emotions associated with the beloved, the limbic centers are used. For this reason, romantic love is considered as different from attachment and attraction.
Additionally, other than the reward centers, romantic love showed some deactivations in the brain. For instance, parietal cortex, amygdala (mainly associated with mediating fear, anxiety, grieving), mid-temporal cortex and some areas of the frontal cortex are shut down.
Frontal lobe being shut down implies that there is a relaxation of reasoning and judgment. This can be interpreted as the romantic love takes place, there is an inhibition of functional reasoning, the lover may not think logically.
When the participants viewed a photograph of their loved ones, the ventral tegmental area (VTA) showed activation and this region is considered as the central region of the brain’s reward system. It is associated with euphoria, general arousal, pleasure, focused attention and motivation to attain rewards. All of these states (euphoria, pleasure etc.) are also affected when the context changes from romantic love to the situations involving cocaine, chocolate. The VTA sends projections to multiple brain regions, one of these regions is caudate nucleus. The primary role of caudate nucleus is that it is responsible for “reward detection, expectation, the representation of goals and the integration of sensory input to prepare for action”.
As it is previously stated, attraction has some certain characteristic to it, such as focused attention, increased energy toward a preferred partner. This system of attraction and romantic love also have the characteristics of intrusive thinking, exhilaration and so on.
Previous studies suggested that, this state is associated with high levels of central dopamine and decreased levels of central serotonin. So, this finding suggest that not only romantic love has a distinct neurological profile, but it also has a distinct neurochemical profile. The main neurochemicals linked with romantic love are oxytocin, dopamine, and serotonin. Starting with the dopamine (released from the VTA or substantia nigra), it’s major role includes the motivational component of reward-motivated behavior and in the prefrontal cortex (linked with higher-ordered thinking), release of dopamine has an effect on people’s working memory. In the prefrontal cortex, the dopamine levels are crucial because the levels of dopamine (high or low) can result in memory to be influenced by it. Therefore, it is also associated with learning processes and recalling information.
Moreover, dopamine also responsible for taking an individual from the ‘liking’ state to the ‘wanting’ state. When individuals fall in love, chemicals linked with the reward system floor their brains and this results in various physical and emotional responses. For example, flushed cheeks, sweaty palms, feelings of passion, excessive energy, pounding heart, sleeplessness, obsessive thinking, anxiety etc. The researches on drug abuse showed that, dopamine has a role in the feeling of romantic love. For instance, when the cocaine intake increases the dopamine levels in the brain and this process results in excessive energy, sleeplessness, loss of appetite etc. These reactions are highly similar to the characteristics of romantic love, being in love.
Dopamine’s role in the brain is also linked with high oxytocin levels and low serotonin levels., which make us to take serotonin into consideration. Serotonin’s role seems significant for mood balance. Not only the low levels of serotonin have been associated with depression, it is also claimed to serve for the regulation of social behaviors, mood, sleep, memory, sexual desire, appetite etc. Furthermore, studies have shown that, in individuals who are considered as “being in love”, serotonin levels are similar to those people with obsessive-compulsive disorder (OCD). This low levels of serotonin can lead to intrusive thinking. This result make sense because individuals who are madly in love show characteristics of obsessive thinking, preoccupying thoughts etc. As it is claimed, “Love after all, is a kind of obsession.”
In addition to all, the length of romantic love seems to matter. As discussed earlier, in the study conducted by Bartels & Zeki, the average relationship length for participants who were in love was 28.8 months. This was much longer when compared to the study done by Aron et al.. In their study, the average length of relationships was 7.4 months. The participants in the Bartels & Zeki’s study did not show the same activations with Aron et al.’s study. These activations are anterior cingulate cortex and mid-insular cortex. Therefore, the mid-insular cortex and the anterior cingulate cortex are involved in long-term romantic relationships.
In a study done by Xu et al., they asked what systems are activated for early-stage intense romantic love in Easterners, specifically in Chinese participants. Like other previous studies, they found activations in the VTA and the caudate nucleus. The mid-orbitofrontal cortex and cerebellum were also activated in their study. Amygdala, medial orbitofrontal cortex and medial accumbens showed decreased activity. Again, like the previous studies, they found that midbrain dopamine rich reward/motivation areas were activated by early-stage intense romantic love. However, the importance of their study is that it is the first study that included a follow-up after a period. Eighteen months after scanning, they contacted with their participants again and asked them whether they were still together or not. Thirteen of the participants responded, 10 of them were still together.
They showed that the relational happiness after 18 months was linked with regional neural responses in their scanning sessions. Further, they showed that greater relational happiness was associated with more activity in the superior frontal gyrus, subgenual area and deactivations were observed in the caudate tail, fusiform (face area) and the cerebellum. However, their sample size was too small for a follow-up like that. Therefore, this can be perceived as a limitation of their study. Moreover, after eighteen months, they did not perform a re-scanning session on participants. They only looked at the relational happiness through a Likert Scale.
Another study, (which is like a continuation of the study done by Xu et al. (2011)) they contacted participants from their first study, after 40 months and compared the brain activation during the initial assessment at early-stage romantic love for those who reported still together (there was only 6) and surveyed about their relationship commitment and happiness and compared these with their initial scanning results. Even though, these two follow-up studies suggested that, “neural responses in the early-stage of romantic love can predict relationship stability and quality up to 40 months later in the relationship.”But, again this study only seems to extend the first research that is done by Xu et al. (2011). In their article, they also suggested that the future studies should have a larger sample size and their follow-up was limited because, it only included questions about the relationship happiness, commitment and there was no re-scanning.
Current Study:
A longitudinal neuroimaging is going to be conducted, and the current study will investigate how activation in a variety of regions of the brain change from early stage intense romantic love to the later stages of romantic love. The current study will focus on multiple time-points throughout the romantic relationship.
Materials & Methods
Since it is going to be a longitudinal study, high drop-out rates are expected. To eliminate the risk related to that, the sample size should be larger than the previous studies. Participants in the study should be in the early-intense stage of romantic love to explore the brain activity (using fMRI) of different times and different stages of romantic love.
Stimuli & Procedure
Before the scanning session, each participant will provide a photograph of the beloved (positive stimulus) and a photograph of a familiar, emotionally neutral acquaintance of the same age, same sex as the beloved (neutral stimulus). Photographs are going to be digitized and sized to show the head only. The reason behind using a visual stimulus is coming from a study conducted by Mashek et al. (2000), in that study it is shown that, a photograph of the beloved as a visual stimulus is better in eliciting the feelings of romantic love. A “Passionate Love Scale” (PLS) will be given participants to establish the density of romantic love. The scanning protocol will consist of four tasks in which presented in an alternating block design.
1- Positive Stimuli (Partner) for 30 seconds
2- Serial Countback Task for 40 seconds
3- Neutral Stimuli (Photo of a familiar, neutral acquaintance) for 30 seconds
4- Serial Countback Task 2 for 20 seconds
Since it is difficult to quell the intense feeling of romantic love, a protocol will be applied to participants (after they viewed the positive stimulus) to decrease the carryover effect. This will be a serial countback task, interspersed the positive stimulus and neutral stimulus with distraction. The countback task consists of viewing number such as 7,582 on the screen and mentally counting backward. To provide a similar distraction after the neutral stimulus, participants are going to do the countback task again for 20 seconds. Participants will be given instructions to think about events that happened with their romantic partner (while viewing the positive stimuli) that are also pleasurable, but the events that the participants are going to be thinking about should not be sexual. Moreover, the instructions for the neutral stimuli are also going to be to think about events with the person in that picture. This is to control the event recall.
The first image can be either neutral stimulus or positive stimulus and these are going to counterbalance across participants. Through the scanning procedure, the Blood oxygen level-dependent signal (BOLD) response is going to be measured. The intervals for the current study are going to be 25 months followed by 40 months. This means that, participants are going to re-contacted and asked whether they are still in a relationship or not. The ones who are still in an ongoing relationship are going to be asked to complete the fMRI scanning session. Those individuals who show up to the scanning sessions are going to be asked to fill out the PLS again to establish what their current relationship status are. The questionnaire session will be followed by a scanning session again with the same procedure that was mentioned before.
Expected Results
1) Early-stage intense romantic love- first scanning
As the participants are going to be in early-stages of romantic love in their relationships, it is expected to see some similar results when compared to the previous studies about romantic love. What is expected is that the same brain areas are going to be activated such as the VTA area, caudate nucleus. Amygdala, the area of the frontal cortex, parietal cortex and mid-temporal cortex is expected to show de-activations just like the previous studies. Since, it has been shown through previous studies, when the individuals are fallen in love, chemicals associated with the reward circuit flood to their brains which result in producing various emotional and physical responses such as excessive energy, sleeplessness etc. It is expected to see the same characteristics with the current participants.
Moreover, like previous studies, it is expected to observe low levels of serotonin. These low levels of serotonin affect individuals in a way that it may form the basis or intrusive thinking. It is very higly likely to observe that in the current study, because the individuals are going to be in their early-stage of romantic love, which has characteristics like being obsessed with your beloved, individuals may not stop thinking about their beloved ones.
Cortisol (also known as stress hormone), which is also in a relation with serotonin, and it shows elevation in early-stage intense romantic love. The reason is that, partners are trying to overcome the “crisis” in their life, which is the romantic love itself. The time when the serotonin levels be used up then, the cortisol levels increases. So, it is expected to see high concentration of cortisol in individuals in the current study.
2) Follow-up 25 months after- second scanning
Early-stage intense romantic love is like an infatuation stage for the individuals. In the literature this early-stage of romantic love is usually called “passionate love”. Passionate love includes intense feelings and sexual attraction. It is like “a state of intense longing for union with another”. Even though, this type of love is very powerful, it is also expected that this rollercoaster of emotions and feelings of anxiousness is expected to decelerate in 1 or 2 years. Therefore, the participants that come to the second scanning may have been passing through the stage of passionate love. In the literature, it is mentioned as “the passion is still there, but the stress of it is gone”.
This may lead us to the “compassionate love”, it involves feelings of trust, mutual respect for another. On one hand, passionate love become prominent being intense and urgent, the compassionate love seems to more influenced by levels of intimacy. So, it can be less intense and urgent. Compassionate love also encompasses caring deeply for another individual, knowing him/her very well and committed to the beloved more excessively. In this compassionate love stage, it is expected that the brain areas linked with reward and pleasure will still be active since the loving relationship is still continuing. However, that euphoria, intensity and urgency associated with romantic love expected to be reduced. Moreover, it is expected that the cortisol and serotonin levels will return to normal. The reason is that, the love which is started as an anxious feeling and putting stress on people, now will function like a protective factor, buffer against stress.
Several regions of special interest (i.e. the right mid-insular cortex, the right anterior & posterior cingulate cortex, the right posterior cingulate/ retrosplenial cortex) are expected to experience changes as the relationship is lengthened. This will be consistent with what the previous studies have found, especially Bartels & Zeki (2000). In this stage (25 months follow-up), participants are expected to show increased activity in the ventral pallidum compared to their first scanning session. One reason comes from the research in animal literature, it is found that the ventral pallidum is linked with attachment behaviors in prairie voles.
In addition to all, one study revealed that, it took approximately 4 months for people to perceive their beloved as safe haven. On the other hand, it can take more than 2 years for people to perceive their beloved as their primary secure base. It can be said that, during this second follow-up, participants are expected to be in a more secure.
