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The reward theory of attraction claims that people are attracted to individuals exhibiting behaviors that are rewarding to them or whom they associate with rewarding events. [1] Individuals seek to develop strong relationships with those who provide positive and fulfilling interactions that require little to nothing in return. [2]
According to the reward theory, people are attracted to those that they find it satisfying and gratifying to be with. [1] The reward theory also explains why people are more attracted to those in close proximity to them. Furthermore, they are drawn to people that are more physically attractive, similar to them, and reciprocate their feelings. [3] According to the theory of attraction, proximity is rewarding. An example could be the likelihood that the cost of living and working nearby would be less. [4] People like those they are attracted to because they perceive that the other person offers desirable traits. As a result, they believe that associating themselves with conventionally attractive people, will benefit them. [5] This is known as the physical attractiveness stereotype.
Conditioning creates positive feelings towards things and people linked with rewarding events. [1] In 1985,Pawel Lewicki tested this liking-by-association principle by conducting an experiment on students at the University of Warsaw. In the experiment, two pictures of women were given to the students. The students had to choose which of the two pictured women, "woman A" or "woman B", looked friendlier to them. The results showed an equal amount of students had chosen the picture of "woman A" over "woman B" to be friendlier. The students in the group who chose "woman A" had interacted with a warm and friendly experimenter who resembled "woman A" before choosing a picture. They ended up choosing "woman A" at a margin of 6 to 1. In a follow-up study, a researcher acted unfriendly toward half of the participants. The participants were then instructed to choose one out of the two pictures. They almost always avoided the one who looked like the "unfriendly" experimenter.
In Griffit's study college students that evaluated strangers in a pleasant room liked them better than students who evaluated strangers in an uncomfortably hot room.[ full citation needed ]
Helen Fisher and her colleagues conducted a neuroimaging study on men and women that had just "fallen madly in love". She hypothesized that there could be a connection between higher levels of central dopamine, or norepinephrine and less activity of central serotonin when an individual experiences romantic infatuation. Using functional magnetic resonance imaging (fMRI), they collected data on 10 women and 7 men that reported being in love an average of 7.4 months. These participants were in between the ages of 18 and 26 years old. Each participant was shown a picture of their loved one and in addition, a photograph of an emotionally neutral person. After they saw the picture, each person had to engage in a task to distract themselves and allow their mind to clear of strong emotions. For example, the subjects were given a large number, such as 9,471, and were instructed to begin counting in receding order in increments of 7. Over the course of the experiment, this procedure ran for a duration of twelve minutes and repeated six times. [6]
Fisher found that several regions in the brain had been activated. There was an increase in activity in the right ventral tegmental area (VTA), caudate nucleus, and postero-dorsal body. Several regions of our brains receive the chemical dopamine because of the activated cells in the right ventral tegmental area (VTA) that produce and distribute it. The ventral tegmental area (VTA) is fundamental to the "reward system" in our brain. This is known as the neural network connected with our sense of pleasure, arousal, focus, and motivation to seek and obtain rewards. Behaviors related to motivation and goal setting were found to be linked to the caudate nucleus that is part of the reward system stimulated by dopamine as well. [6]
In the year 2000, animal studies were conducted in which attraction is positively associated with elevated activity in central dopamine. In the experiment, a female lab-raised prairie vole was mated with a male, and formed a distinct preference for him associated with a 50% increase of dopamine. [7] When a dopamine antagonist was injected into the reward region of the brain, she no longer had the preference for the male. [6]
In 2005, Fisher and her colleagues conducted a second fMRI study to research the effect of romantic rejection and gain a better understanding of human emotions, motivations, and behaviors related to this kind of love. In the experiment, the subjects consisted of 10 women and 5 men that had been rejected by their person of interest but still had romantic feelings for them. These participants were shown a picture of their previous partner and of an emotionally neutral individual as well. Afterwards, the subjects were directed to engage in a distracting task in order to clear their minds from any intense emotions. Once the results were analyzed, Fisher observed that there were significant effects on the individual's nucleus accumbens, lateral orbitofrontal cortex, and anterior cortex as well. These regions in the brain were found to be linked with the body's dopaminergic reward system. Fisher's research suggested that dopamine remained activated in people that had been recently rejected romantically. Such activity, in part, corresponded to the neural regions in the brain that are connected to people's ability to take risks, experience physical pain, and regulate their emotions. [6]
A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a synapse. The cell receiving the signal, or target cell, may be another neuron, but could also be a gland or muscle cell.
The striatum, or corpus striatum, is a nucleus in the subcortical basal ganglia of the forebrain. The striatum is a critical component of the motor and reward systems; receives glutamatergic and dopaminergic inputs from different sources; and serves as the primary input to the rest of the basal ganglia.
Dopamine is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical of the catecholamine and phenethylamine families. Dopamine constitutes about 80% of the catecholamine content in the brain. It is an amine synthesized by removing a carboxyl group from a molecule of its precursor chemical, L-DOPA, which is synthesized in the brain and kidneys. Dopamine is also synthesized in plants and most animals. In the brain, dopamine functions as a neurotransmitter—a chemical released by neurons to send signals to other nerve cells. Neurotransmitters are synthesized in specific regions of the brain, but affect many regions systemically. The brain includes several distinct dopamine pathways, one of which plays a major role in the motivational component of reward-motivated behavior. The anticipation of most types of rewards increases the level of dopamine in the brain, and many addictive drugs increase dopamine release or block its reuptake into neurons following release. Other brain dopamine pathways are involved in motor control and in controlling the release of various hormones. These pathways and cell groups form a dopamine system which is neuromodulatory.
The mesolimbic pathway, sometimes referred to as the reward pathway, is a dopaminergic pathway in the brain. The pathway connects the ventral tegmental area in the midbrain to the ventral striatum of the basal ganglia in the forebrain. The ventral striatum includes the nucleus accumbens and the olfactory tubercle.
The nucleus accumbens is a region in the basal forebrain rostral to the preoptic area of the hypothalamus. The nucleus accumbens and the olfactory tubercle collectively form the ventral striatum. The ventral striatum and dorsal striatum collectively form the striatum, which is the main component of the basal ganglia. The dopaminergic neurons of the mesolimbic pathway project onto the GABAergic medium spiny neurons of the nucleus accumbens and olfactory tubercle. Each cerebral hemisphere has its own nucleus accumbens, which can be divided into two structures: the nucleus accumbens core and the nucleus accumbens shell. These substructures have different morphology and functions.
Dopaminergic pathways in the human brain are involved in both physiological and behavioral processes including movement, cognition, executive functions, reward, motivation, and neuroendocrine control. Each pathway is a set of projection neurons, consisting of individual dopaminergic neurons.
The ventral tegmental area (VTA), also known as the ventral tegmental area of Tsai, or simply ventral tegmentum, is a group of neurons located close to the midline on the floor of the midbrain. The VTA is the origin of the dopaminergic cell bodies of the mesocorticolimbic dopamine system and other dopamine pathways; it is widely implicated in the drug and natural reward circuitry of the brain. The VTA plays an important role in a number of processes, including reward cognition and orgasm, among others, as well as several psychiatric disorders. Neurons in the VTA project to numerous areas of the brain, ranging from the prefrontal cortex to the caudal brainstem and several regions in between.
The midbrain is anatomically delineated into the tectum (roof) and the tegmentum (floor). The midbrain tegmentum extends from the substantia nigra to the cerebral aqueduct in a horizontal section of the midbrain. It forms the floor of the midbrain that surrounds below the cerebral aqueduct as well as the floor of the fourth ventricle while the midbrain tectum forms the roof of the fourth ventricle. The tegmentum contains a collection of tracts and nuclei with movement-related, species-specific, and pain-perception functions. The general structures of midbrain tegmentum include red nucleus and the periaqueductal grey matter.
Motivational salience is a cognitive process and a form of attention that motivates or propels an individual's behavior towards or away from a particular object, perceived event or outcome. Motivational salience regulates the intensity of behaviors that facilitate the attainment of a particular goal, the amount of time and energy that an individual is willing to expend to attain a particular goal, and the amount of risk that an individual is willing to accept while working to attain a particular goal.
The olfactory tubercle (OT), also known as the tuberculum olfactorium, is a multi-sensory processing center that is contained within the olfactory cortex and ventral striatum and plays a role in reward cognition. The OT has also been shown to play a role in locomotor and attentional behaviors, particularly in relation to social and sensory responsiveness, and it may be necessary for behavioral flexibility. The OT is interconnected with numerous brain regions, especially the sensory, arousal, and reward centers, thus making it a potentially critical interface between processing of sensory information and the subsequent behavioral responses.
The theory of a biological basis of love has been explored by such biological sciences as evolutionary psychology, evolutionary biology, anthropology and neuroscience. Specific chemical substances such as oxytocin are studied in the context of their roles in producing human experiences, emotions and behaviors that are associated with love.
The medial forebrain bundle (MFB) is a neural pathway containing fibers from the basal olfactory regions, the periamygdaloid region and the septal nuclei, as well as fibers from brainstem regions, including the ventral tegmental area and nigrostriatal pathway.
The islands of Calleja are a group of neural granule cells located within the ventral striatum in the brains of most animals. This region of the brain is part of the limbic system, where it aids in the reinforcing effects of reward-like activities. Within most species, the islands are specifically located within the olfactory tubercle; however, in primates, these islands are located within the nucleus accumbens, the reward center of the brain, since the olfactory tubercle has practically disappeared in the brains of primates. Both of these structures have been implicated in the processing of incentives as well as addictions to drugs. Projections to and from the islands supplement this knowledge with their involvement in the reward pathways for both cocaine and amphetamines.
The reward system is a group of neural structures responsible for incentive salience, associative learning, and positively-valenced emotions, particularly ones involving pleasure as a core component. Reward is the attractive and motivational property of a stimulus that induces appetitive behavior, also known as approach behavior, and consummatory behavior. A rewarding stimulus has been described as "any stimulus, object, event, activity, or situation that has the potential to make us approach and consume it is by definition a reward". In operant conditioning, rewarding stimuli function as positive reinforcers; however, the converse statement also holds true: positive reinforcers are rewarding.
The ventral pallidum (VP) is a structure within the basal ganglia of the brain. It is an output nucleus whose fibres project to thalamic nuclei, such as the ventral anterior nucleus, the ventral lateral nucleus, and the medial dorsal nucleus. The VP is a core component of the reward system which forms part of the limbic loop of the basal ganglia, a pathway involved in the regulation of motivational salience, behavior, and emotions. It is involved in addiction.
Cocaine addiction is the compulsive use of cocaine despite adverse consequences. It arises through epigenetic modification and transcriptional regulation of genes in the nucleus accumbens.
Addiction is a state characterized by compulsive engagement in rewarding stimuli, despite adverse consequences. The process of developing an addiction occurs through instrumental learning, which is otherwise known as operant conditioning.
Even though intimacy has been broadly defined in terms of romantic love and sexual desire, the neuroanatomy of intimacy needs further explanation in order to fully understand their neurological functions in different components within intimate relationships, which are romantic love, lust, attachment, and rejection in love. Also, known functions of the neuroanatomy involved can be applied to observations seen in people who are experiencing any of the stages in intimacy. Research analysis of these systems provide insight on the biological basis of intimacy, but the neurological aspect must be considered as well in areas that require special attention to mitigate issues in intimacy, such as violence against a beloved partner or problems with social bonding.
Bita Moghaddam is an Iranian-American neuroscientist and author. She is currently the Ruth Matarazzo Professor of Behavioral Neuroscience at Oregon Health & Science University. Moghaddam investigates the neuronal processes underlying emotion and cognition as a first step to designing strategies to treat and prevent brain illnesses.
Ilana B. Witten is an American neuroscientist and professor of psychology and neuroscience at Princeton University. Witten studies the mesolimbic pathway, with a focus on the striatal neural circuit mechanisms driving reward learning and decision making.