7.5 KiB
| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Biology of romantic love | 13/14 | https://en.wikipedia.org/wiki/Biology_of_romantic_love | reference | science, encyclopedia | 2026-05-05T15:53:39.742070+00:00 | kb-cron |
== Brain imaging == Brain imaging techniques such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) have been used to investigate which brain regions are involved in romantic love. Nearly all of these experiments have had participants look at a photograph of their beloved during an fMRI scan, with a few exceptions, although the specific procedures used have not always been identical. The differences in experimental design (e.g. length of time the participants had been in love, or the specific task given to participants during the scan) can be used to explain why the experiment results are sometimes different. In 2000, a study by Andreas Bartels and Semir Zeki of University College London was the first fMRI study of romantic love. The 17 participants were "truly, deeply and madly in love", had been together for a mean of 2.4 years, and were shown either one or two photographs of their loved one during the scan. Two main areas were active in this study: the middle insular cortex, associated with stomach churning or "gut feelings", which could have something to do with the feeling of "butterflies in the stomach", and part of the anterior cingulate cortex, associated with feelings of euphoria. Other activations were areas in the cerebrum, the caudate nucleus, putamen and the cerebellum. A later analysis in 2004 by the same authors also reports activity in the ventral tegmental area (VTA), which produces dopamine. The study also showed key deactivations, areas of the brain that were less active in romantic love compared to friendship love, in the amygdala and medial prefrontal cortex (mPFC). The amygdala is involved with fear and risk detection, and the mPFC is involved with understanding and predicting the intentions of other people, called mentalizing. These deactivations are taken as evidence that "love is blind", or i.e. that people in love discount the risks involved and misunderstand people's intentions, even leading to folly sometimes. In 2005, a study by Arthur Aron, Helen Fisher, Debra Mashek, Greg Strong, Haifang Li, and Lucy Brown was the first fMRI study of early-stage intense romantic love. It has been praised as advancing the scientific understanding of infatuated love, even by a skeptic of fMRI literature. This study differed from Bartels and Zeki in that the 17 participants who had "just fallen madly in love" had been in love for a much shorter mean time of only 7.4 months. These participants were more intensely in love, and spent 85% or more of their waking hours thinking of their loved one. This study also had participants look at a photograph of their loved one during the scan. Reward and motivation areas were active, like the VTA and areas of the caudate. Activity was also found in the insular and cingulate cortex, involved with emotion. Some interesting areas were correlated with the length of the relationship, like the ventral pallidum, implicated in attachment in prairie voles, and the anterior cingulate, implicated in obsessive thinking, cognition and emotion. This study also examined correlations with facial attractiveness to determine that the right VTA was active because of romantic passion rather than because the partner was aesthetically pleasing. Aesthetically pleasing faces elicited more activity in the left VTA, which is more associated with "liking" a reward (i.e. pleasure), whereas the right VTA is more associated with "wanting" a reward (i.e. incentive salience). In 2011, Xu et al. repeated the experiment by Aron et al., but using Chinese participants. Ortigue et al. used fMRI to investigate the subliminal influence of romantic love on motivation, interested in how these implicit neural representations might differ from previous experiments where subjects were consciously aware of the stimulus (viewing a photograph). In Ortique et al.'s study, participants were shown a subliminal prime word for 26ms (either their beloved's name, the name of a friend, or a word describing a personal passion like a hobby), followed by a series of symbols (#) for 150ms, followed by a target word for 26ms. This target was either an English word, non-word or blank, and participants were asked to identify whether it was a word or not. In trials with the love prime or passion prime, participants were faster to identify whether the target was a word or not, and this also correlated with scores on the Passionate Love Scale. The authors believe this shows that love priming activates motivation systems in the brain, rather than just evoking a particular emotion. The fMRI scanning showed brain regions active for love primes similar to previous experiments, including reward and motivation areas like the VTA and caudate, but with some additions. Subliminal love priming additionally activated the bilateral fusiform gyri and angular gyri, involved in integrating abstract representations. The authors relate this to the self-expansion model of interpersonal relationships, where self-expansion by integrating the characteristics of one's beloved into one's self (called inclusion of the other in the self) is a rewarding experience which may promote romantic love feelings. In brain scans of long-term intense romantic love (involving subjects who professed to be "madly" in love, but were together with their partner 10 years or more) led by Bianca Acevedo, attraction similar to early-stage romantic love was associated with dopamine reward center activity ("wanting"), but long-term attachment was associated with the globus palludus, a site for opiate receptors identified as a hedonic hotspot ("liking"). Long-term romantic lovers also showed lower levels of obsession compared to those in the early stage. An fMRI study led by Sandra Langeslag investigated the effect of attention on brain activity related to a loved one. In most other previous experiments, subjects only passively viewed a photograph, but this experiment used an oddball task to distinguish between instances where the loved one was either the intended target of the subject's attention or a distraction. Participants were given trials where they were presented with a random face for only 250ms (usually an unknown person) and instructed to watch for either a loved one or a friend, then press a button if the face was the intended target for a given run. In some runs, the loved one would be the intended target for a button press, while the friend would be a distractor causing participants to press the button by mistake sometimes, while in other runs the friend would be the target and the loved one a distractor. This experiment found that activity in the dorsal striatum (an area of the reward system) was modulated by whether or not participants were instructed to pay attention to their loved one. That is, the dorsal striatum showed more response to the loved one than to the friend, but only when the loved one was the target. This led the authors to conclude that "the dorsal striatum is not activated by beloved-related information per se, but only by beloved-related information that is attended". This activity also tended to be smaller when participants had been in love or been in a relationship for longer. The dorsal striatum is implicated in reinforcement learning, so the authors interpret the increase in brain activity as reflecting prior reinforcement of social actions which leads the infatuated individuals to pay preferential attention to their loved one.