Hello again puppets. Add immune system mast cells to our list of puppeteers. Anyone still think we have free will?
In the first study ever to genetically link the immune system to normal behavior, scientists at Rockefeller and Columbia universities show that mast cells, known as the pharmacologic bombshells of the immune system, directly influence how mice respond to stressful situations. The work, to appear this week in The Proceedings of The National Academy of Sciences and to be highlighted in Science, chips away at the increasingly stale idea that the two most complex systems in the body have entirely separate modes of operation.
Eight years ago, scientists from Columbia University discovered that mast cells travel to the brain from other organs early on in development. “We now knew that mast cells resided in the brain but we didn’t know their function,” says Rockefeller University’s Donald Pfaff, head of the Laboratory of Neurobiology and Behavior. “But we know that they synthesize a large number of important chemical mediators that could potentially have severe neurophysiological effects.”
Since the immune system ages and becomes less vigorous that suggests that aging of the immune system alters our emotional reactions.
If aging people could get their immune systems rejuvenated they might become more adventurous.
In their work, Pfaff and postdoc Ana Ribeiro, and the Columbia team, led by senior author Rae Silver and graduate student Kate Nautiyal, bred mice that lacked mast cells and compared their behavior in stressful situations to the behavior of mice that had a full or a moderate arsenal of mast cells. The researchers observed how willing the mice were to navigate open and lit environments and high spaces, which mice find anxiety-producing. In the wild, if a mouse is down in its own burrow, it’s not visible to predation. But if it’s bold, that is, if it has low anxiety, it will go out where it can potentially be seen by predators and hunted.
The results were striking. When the researchers placed the mice in an elevated maze with four long arms -- two simulated a canyon and the other two a cliff -- mice that lacked mast cells preferred to stay in the canyons, entering and investigating the doors to the cliffs significantly fewer times than mice with mast cells. When placed in a square box, mast cell-deficient mice preferred to scuttle against the walls, and were more hesitant to venture out to the center of the box than mice with mast cells. They also defecated more, a physiological sign of anxiety. However, the genetically different mice did not show differences in overall arousal or locomotion, suggesting that their behavioral changes were specific to their anxious state.
So an unhealthy immune system can increase anxiety. Do anxious people get colds and flus more often?
Coming from Professor Semir Zeki and John Romaya of the Wellcome Laboratory of Neurobiology at the University College London, a new research paper in Plos One on how hatred activates and deactivates areas of the brain shows hate creates a unique pattern of brain activates which includes some overlap with brain areas activated by love.
In this work, we address an important but unexplored topic, namely the neural correlates of hate. In a block-design fMRI study, we scanned 17 normal human subjects while they viewed the face of a person they hated and also faces of acquaintances for whom they had neutral feelings. A hate score was obtained for the object of hate for each subject and this was used as a covariate in a between-subject random effects analysis. Viewing a hated face resulted in increased activity in the medial frontal gyrus, right putamen, bilaterally in premotor cortex, in the frontal pole and bilaterally in the medial insula. We also found three areas where activation correlated linearly with the declared level of hatred, the right insula, right premotor cortex and the right fronto-medial gyrus. One area of deactivation was found in the right superior frontal gyrus. The study thus shows that there is a unique pattern of activity in the brain in the context of hate. Though distinct from the pattern of activity that correlates with romantic love, this pattern nevertheless shares two areas with the latter, namely the putamen and the insula.
Hatred does not activate the amygdala which is activated by fear.
It is important to note that the pattern revealed is distinct from that of other, closely related, emotions such as fear, anger, aggression and danger, even though it shares common areas with these other sentiments. Thus, the amygdala which is strongly activated by fear (Noesselt et al. 2005 [9], Morris et al. 2002 [10], Hadjikhani et al. 2008 [11]) and by aggression (Beaver et al., 2008 [12]) was not activated in our study. Nor were the anterior cingulate, hippocampus, medial temporal regions, and orbitofrontal cortex, apparently conspicuous in anger and threat (Denson et al. 2008 [13]; Bufkin and Luttrell 2007 [14]; McClure et al. 2004 [15]), evident in our study. It would thus seem that, though these sentiments may constitute part of the behaviour that results from hatred, the neural pathways for hate are distinct.
The 'hate circuit' includes structures in the cortex and in the sub-cortex and has components that are important in generating aggressive behaviour, and translating this into action through motor planning, as if the brain becomes mobilised to take some action. It also involves a part of the frontal cortex that has been considered critical in predicting the actions of others, probably an important feature when one is confronted by a hated person.
The subcortical activity involves two distinct structures, the putamen and insula. The former, which has been implicated in the perception of contempt and disgust, may also be part of the motor system that is mobilised to take action, since it is known to contain nerve cells that are active in phases preparatory to making a move.
Professor Zeki added: "Significantly, the putamen and insula are also both activated by romantic love. This is not surprising. The putamen could also be involved in the preparation of aggressive acts in a romantic context, as in situations when a rival presents a danger. Previous studies have suggested that the insula may be involved in responses to distressing stimuli, and the viewing of both a loved and a hated face may constitute such a distressing signal.
While love shuts down areas of the brain associated with judgment and reasoning by contrast those consumed with hate have very active reasoning facilities. It takes logic to figure out how to attack your enemy. So that makes sense. Only those in love thing they can afford to let their guard down, become zombies, and feel bliss around the object of their affection.
"A marked difference in the cortical pattern produced by these two sentiments of love and hate is that, whereas with love large parts of the cerebral cortex associated with judgment and reasoning become de-activated, with hate only a small zone, located in the frontal cortex, becomes de-activated. This may seem surprising since hate can also be an all-consuming passion, just like love. But whereas in romantic love, the lover is often less critical and judgmental regarding the loved person, it is more likely that in the context of hate the hater may want to exercise judgment in calculating moves to harm, injure or otherwise extract revenge.
In countries where suspected criminals have no right to privacy or right to keep silent brain scans could be used to determine whether a suspected killer hated his victim and by how much.
"Interestingly, the activity in some of these structures in response to viewing a hated face is proportional in strength to the declared intensity of hate, thus allowing the subjective state of hate to be objectively quantified. This finding may have legal implications in criminal cases, for example."
One could imagine a police state in which opponents of the regime get tested with brain scans and pictures of dictators to identify enemies of the state. With more time it will become possible for governments to turn hatred into love. Then all enemies of the state will get turned into supporters of it. Of course, individuals will try to do this on a smaller scale as well.
Contrast these results with the research into love. See my previous posts Love Deactivates Brain Areas For Fear, Planning, Critical Social Assessment, Love Like Addiction In Brain Scans, What Brain Scans Of People Falling In Love Tell Us, Romantic Love Seen As Motivation Or Drive Rather Than Emotional State, and Love Is Blind: Couples In Love Can't Identify Who Else Is In Love.
A video game designed by McGill University researchers to help train people to change their perception of social threats and boost their self-confidence has now been shown to reduce the production of the stress-related hormone cortisol. The new findings appear in the October issue of the American Psychological Association's Journal of Personality and Social Psychology.
"We already knew that it was possible to design games to allow people to practise new forms of social perception, but we were surprised by the impact this had when we took the games out of the lab and into the context of people's stressful lives," said McGill psychology professor Mark Baldwin.
Prof. Baldwin and his team - McGill PhD graduates Stephane Dandeneau and Jodene Baccus and graduate student Maya Sakellaropoulo - have been developing a suite of video games that train players in social situations to focus more on positive feedback rather than being distracted and deterred by perceived social slights or criticisms. The games are based on the emerging science of social intelligence, which has found that a significant part of daily stress comes from our social perceptions of the world.
These video games could be useful.
A neural network that may generate the human tendency to be optimistic has been identified by researchers at New York University. As humans, we expect to live longer and be more successful than average, and we underestimate our likelihood of getting a divorce or having cancer. The results, reported in the most recent issue of Nature, link the optimism bias to the same brain regions that show irregularities in depression.
Every report like this one reminds me that we are eventually going to gain the ability to very precisely manipulate our emotions. If we precisely manipulate our own emotions rather than governments or other organizations doing it to us (which is a real possibility) will we become more free?
Anyone want a switch to flip in your brain that activates the optimism circuitry?
The study was conducted by a team of researchers from the laboratory of NYU Professor Elizabeth Phelps. The lead author is Tali Sharot, now a post-doctoral fellow at University College London.
The NYU researchers used functional magnetic resonance imaging (fMRI) to examine brain function while participants thought of possible future life events (such as “winning an award” or “the end of a romantic relationship”).
“When participants imagined positive future events relative to negative ones, enhanced activation was detected in the rostral anterior cingulate and amygdala, which are the same brain areas that seem to malfunction in depression,” said Sharot. “Activation of the rostral anterior cingulate was correlated with trait optimism, with more optimistic participants showing greater activity in this region when imagining future positive events.”
What I wonder: can avoidance of depression somehow be uncoupled from optimism? I'm thinking optimism causes people to mispredict the future and make less than optimal choices.
Remember that scene at the end of Life Of Brian when they are all up on the crosses singing? The updated scientific version of the song would go "use your amygdala and the rostral anterior cingulated cortex to always look on the bright side of life".
Being lonely probably changes the level of expression of over 200 of your genes.
Cole and colleagues at UCLA and the University of Chicago used DNA microarrays to survey the activity of all known human genes in white blood cells from 14 individuals in the Chicago Health, Aging, and Social Relations Study. Six participants scored in the top 15 percent of the UCLA Loneliness Scale, a widely used measure of loneliness that was developed in the 1970s; the others scored in the bottom 15 percent. The researchers found 209 gene transcripts (the first step in the making of a protein) were differentially expressed between the two groups, with 78 being overexpressed and 131 underexpressed. “Leukocyte (white blood cell) gene expression appears to be remodelled in chronically lonely individuals,” said. Cole.
Genes overexpressed in lonely individuals included many involved in immune system activation and inflammation. But interestingly, several other key gene sets were underexpressed, including those involved in antiviral responses and antibody production. “These findings provide molecular targets for our efforts to block the adverse health effects of social isolation,” said Cole.
“We found that what counts at the level of gene expression is not how many people you know, it’s how many you feel really close to over time.” In the future, he said, the transcriptional fingerprint they’ve identified might become useful as a ‘biomarker’ to monitor interventions designed to reduce the impact of loneliness on health.
An obvious follow-up would be to find a way to make a group of lonely people a lot less lonely and then see if their gene expression levels change.
Being lonely is bad for your health and shortens your life expectancy.
It is already known that a person's social environment can affect their health, with those who are socially isolated suffering from higher all-cause mortality, and higher rates of cancer, infection and heart disease. Researchers are trying to determine whether these adverse health consequences result from of reduced social resources (e.g., physical or economic assistance) or from the biological impact of social isolation on the function of the human body. "What this study shows us," said lead author Dr. Steven Cole, of the University of California Los Angeles (UCLA) School of Medicine, "is that the biological impact of social isolation reaches down into some of our most basic internal processes - the activity of our genes."
Does some subgroup of isolated people have an immunity toward the effects of isolation? Do their genes express at levels similar to those of non-lonely people?
Also, why less immune activity in lonely people? Maybe that's an adaptation. If you aren't exposed to other people you are at lower risk of getting a disease from them. So maybe less immune response was needed in the past among lonely people. Though today with more urban environments even lonely people can frequently come into contact with others and therefore be at risk of getting infections.
Anxiety comes in several types and 2 of those types differ in the parts of the brain involved.
CHAMPAIGN, Ill. — All anxiety is not created equal, and a research team at the University of Illinois now has the data to prove it. The team has found the most compelling evidence yet of differing patterns of brain activity associated with each of two types of anxiety: anxious apprehension (verbal rumination, worry) and anxious arousal (intense fear, panic, or both).
Worriers have more activity in their left inferior frontal lobe. Whereas people feeling panic or fear are feeling the effects of activity in the right inferior temporal lobe.
The researchers used functional Magnetic Resonance Imaging (fMRI) to map the brain areas with heightened neural activity during a variety of psychological probes.
As the researchers had predicted, the anxious apprehension group exhibited enhanced left-brain activity and the anxious arousal group had heightened activity in the right brain. The anxious apprehension group showed increased activity in a region of the left inferior frontal lobe that is associated with speech production. The anxious arousal group had more activity in a region of the right-hemisphere inferior temporal lobe that is believed to be involved in tracking and responding to information signaling danger.
Better understanding eventually brings with it better ability to manipulate and control. Picture a future where nanotubes can get extended up arteries into the brain. The nanotubes could be used to locally deliver drugs or electrical pulses to excite or suppress activity in particular parts of the brain.
Of course the ability to stimulate particular kinds of emotions and mental states would enable some pretty severe abuse and manipulation of human behavior. But individuals could use such technology to control crippling emotional conditions. Plus, imagine turning up the motivation to work hard when you want to get more done.
A Wall Street Journal article surveying research on the neurobiology of love reports on the work of Dr. Helen Fisher. Love triggers the dopamine system which is also involved in drug addiction.
Dr. Fisher has studied love by looking at people's brains using magnetic resonance imaging machines. A recent study also looked at 15 subjects who were deeply in love but were nursing broken hearts. While in the scanner, they viewed "neutral" pictures of someone they knew but for whom they didn't have intense romantic feelings. Then they were shown a picture of their beloved.
Those suffering the aftermath of failed relationships have more than just the dopamine system active.
Compared with the neutral photos, a lover's picture triggers the dopamine system in the brain -- the same system associated with pleasure and addiction. But the brain images of those scorned in love also give us clues as to why the breakdown of a relationship can trigger serious health problems. The subjects dealing with failed relationships showed activity in the dopamine system -- suggesting they maintained intense feelings for their loved one. But they also showed activity in brain regions associated with risk taking, controlling anger and obsessive compulsive problems. Notably, the scans showed activity in one part of the brain linked with physical pain.
The article reports on an Italian study that found that love causes the neurotransmitter serotonin to drop to the level found in those with obsessive compulsive disorders. Might obsessive compulsive disorders (OCD) be a side effect of the brain's tendency to fall in love? Do people who fall more deeply in love face a greater risk of OCD?
Jilted lovers who kill. Heartbroken people who who foolish and crazy things. It is no wonder that love causes these behaviors given what it does to emotions.
"It's not a good combination," notes Dr. Fisher. "You're feeling intense romantic love, you're willing to take big risks, you're in physical pain, obsessively thinking about a person and you're struggling to control your rage. You're not operating with your full range of cognitive abilities. It's possible that part of the rational mind shuts down."
I see the human mind as having a lot of obsolete and problematic vestiges. Take, for example, the fight-or-flight response where adrenaline flows and an angry and fearful person wants to either run away or attack. The response is maladaptive in the vast bulk of the situations where it happens. The stress it causes ages us more rapidly. Plus. it causes us to do things that get people fired or thrown in jail or to blow a business deal or romantic relationship. Wouldn't we be better off if we could suppress the neuronal and hormonal chain of events in fight-or-flight?
Our growing ability to figure out how our minds work portends a very different future. The more we understand the better we can intervene. Want to suppress the anger and pain of a romantic break-up? Would doing so make you feel less human? Or would you see the ability to do so as a boon?
People already take anti-depressants and anti-anxiety medicine. The serotonin selective reuptake inhibitors (SSRIs) might even suppress some of the intensity of the feelings of being in love. So Prozac and Zoloft might help mend a broken heart.
But think about future technologies that will provide more powerful and finer grained control of human emotions. How will people use them? Will people choose to make themselves more rational? Will future humans seem emotion-less to present day humans? Or will humans choose to suppress emotional pain and feelings of obsession and addiction while still giving themselves a fairly wide range of other emotions?
Will most humans make themselves less easy to anger? Will some humans see their own anger as always so justified that they'll oppose attempts to suppress it?
The emotionless mind is not optimal for achievement. A mind totally devoid of emotion would lack in motivation. If you do not fear poverty or death or a dark alley in a bad part of a city how are you going to stay alive? If you do not have desire for higher status then you won't strive as hard to advance in your career or to start a company.
How to succeed gloriously in the future age of emotion-controlling neurotechnologies? Tune your emotions for maximum productivity. You'll want ambition but at a level that is not too distracting. You'll want to limit the amount of time you spend feeling anger or resentment or depression since too high a dose of any of those emotions becomes debilitating. You'll want to stay highly rational in dealing with others. Avoid excessive amounts of anger, fear, resentment or, for that matter, complacency. But each emotion has some adaptive value even today. Do not turn them down altogether.
Neuroscientists using functional Magnetic Resonance Imaging (fMRI) brain scans have discovered a connection between two parts of the brain that allows one part of the brain to dampen down emotional conflicts so that the brain's ability to think does not become impaired.
New York, NY (Sept. 20, 2006) – Columbia University Medical Center researchers have identified an emotional control circuit in the human brain which keeps emotionally intense stimuli from interfering with mental functioning. These results significantly enhance understanding of the neurobiology underlying psychiatric disorders involving emotional control, such as post traumatic stress disorder (PTSD) or depression.
The ability to prevent PTSD and depression would eliminate the brain damage that those mental diseases cause and therefore cause a substantial portion of the population to function at a higher level than would otherwise be the case.
Negative emotions are processed by the amygdala and the scientists decided to figure out which part of the brain exerted a dampening effect upon feelings of fear. They previously had found that people who are more anxious tend to react more to fearful stimuli if they are not consciously aware that they see something fearful.
The current findings extend on a previous Neuron paper (Dec 16, 2004) in which Drs. Etkin, Kandel and Hirsch found that anxious individuals show more activity in the amygdala, a central brain region involved in the processing of negative emotions, when unconsciously perceiving fearful stimuli (please click here to read the Columbia press release). When these stimuli were perceived consciously, however, the amygdalas of subject with both high and low levels of anxiety responded similarly.
Dr. Hirsch explained that this previous finding suggested that subjects were somehow able to control their conscious emotional responses, but that their unconscious responses may be more automatic. “Following the discovery of the amygdala’s role in fear response, we decided to explore the finer points of the neurocircuitry of fear – how it is regulated and controlled in the brain,” said Dr. Hirsch.
The scientists were able to identify the brain circuitry that resolves emotional conflicts.
To study emotional regulation, Dr. Etkin collaborated with Tobias Egner, Ph.D., a post-doctoral fellow in Dr. Hirsch’s lab, who has used fMRI to study non-emotional forms of attentional control. In the 2006 Neuron paper, subjects were asked to identify the facial expressions in photos shown to them as either happy or fearful. Across each face were the words FEAR or HAPPY, and were either congruent or conflicting from the facial expressions. When the word and face clashed, subjects experienced an emotional conflict, which slowed their performance and made them less accurate in identifying facial expressions.
Using a clever behavioral trick, however, the researchers were able to discriminate between brain circuitry that detected this emotional conflict from circuitry that resolved this conflict. They found that the amygdala generates the signal telling the brain that an emotional conflict is present; this conflict then interferes with the brains ability to perform the task. The rostral anterior cingulate cortex, a region of the frontal lobe, was activated to resolve the conflict. Critically, the rostral cingulate dampened activity in the amygdala, so that the emotional response did not overwhelm subjects’ performance, thus achieving emotional control.
Do people with anxiety problems have smaller or less active rostral anterior cingulate cortexes? Or is the connection from that region to the amygdala smaller?
Seems to me this study suggests where we could intervene in the brain to reduce distractions caused by emotional conflicts. Imagine a brain stimulator device that sends a signal to the amygdala saying "chill out dude".
The greater our understanding of human emotions becomes the better we'll be able to manipulate our own emotions. Will most people decide to function under the influence of biotechnologically manipulated emotions?
If people decide to manipulate their emotions which types of manipulations will they choose? On the one hand, I can see competitive pressures for people to manipulate their emotions so that they work harder and get more done. On the other hand, I can imagine a future in which very large numbers of people manipulate their emotions so that they do not feel the need to compete and so that they feel happy and satisfied with less material goods and lower social statuses.
Emotionally powerful distractions hobble memory formation.
For the first time, researchers have seen in action how the "hot" emotional centers of the brain can interfere with "cool" cognitive processes such as those involved in memory tasks. Their functional magnetic resonance imaging (fMRI) images of human volunteers exposed to emotional distraction revealed a "see-saw" effect, in which activation of emotional centers damped activity in the "executive" centers responsible for such processing.
The findings of the Duke University Medical Center researchers provide insight into the basic brain mechanisms responsible for the distraction caused by emotional stimuli that are irrelevant to a task. Moreover, they said, the findings offer a new approach to understanding how people with depression and post-traumatic stress disorder cope with traumatic events and memories. It is known that people with such problems are far more affected by emotional distraction.
The researchers compared the effects of three different kinds of distracters on the ability to memorize faces.
In their experiments, the researchers asked volunteer subjects to memorize sets of images of three human faces. Next, they exposed the subjects to one of three types of distracters -- emotional images such as injured people or aggressive behavior; neutral images such as people shopping or working; and scrambled images that meant nothing. The subjects were then showed a face image and asked to determine whether it was one of the original "to-be-memorized" faces or a new face.
Throughout the tests, the subjects' brains were scanned using fMRI. This widely used technique involves using harmless magnetic fields and radio waves to scan the brain to detect levels of blood flow, which indicates increased or decreased brain activity.
Stimuli that evoke an emotional reaction not only activate the ventral system of the brain but also reduce activity in the dorsal regions involved in rational thinking.
In earlier studies, the researchers had found that emotional images activated a "ventral affective system" in the brain that encompasses regions involved in emotional processing. In contrast, they found, cognitive tasks involving memory processes activated a "dorsal executive system." To their surprise, the researchers also found that the emotional distracters not only activated the ventral system, but also deactivated the dorsal regions.
In the new study, the researchers observed the same patterns of activation and deactivation of the regions. The emotional images produced greater activation of the ventral system and deactivation of the dorsal system than did the neutral or scrambled images, they found.
But most importantly, they found graded behavioral effects of the images. The emotional distracters produced the most detrimental effect on memory performance, the neutral distracters impaired performance to a lesser extent; and the scrambled images impaired performance very little. "Along with the fMRI results, these findings provide the first direct evidence concerning the neural mechanisms mediating cognitive interference by emotional distraction," said Dolcos.
Emotional distracter: That sounds like a technical term for "girlfriend".
People who could inhibit their emotional response were less distracted.
The researchers also found individual differences among the subjects in their response to the images. Those people who showed greater activity in a brain region associated with the inhibition of response to emotional stimuli rated the emotional distracters as less distracting. Said Dolcos, "One interpretation of this finding is that, because this region is associated with inhibitory process, people who engage that region more could cope better with distracting emotions."
I bet that genetic variations are partially responsible for people differing in their abilities to inhibit their emotional responses. For some inhibition of their emotions comes easy and surely the ability exists on a sliding scale. Also, there's probably not a single ability to inhibit all emotions. Some probably can more easily inhibit sadness and others anger and so on. If you have a particular form of emotion you have a hard time inhibiting then when you need to think clearly you are best off avoiding situations that will present stimuli that'll trigger that emotion.
This report of how emotional stimuli shut down areas of the brain involved in rational thought reminds me of another recent post of mine: "Political Partisans Addicted To Irrational Defense Of Their Tribes". This latest report throws more light on that previous report. People who are emotionally worked up about politics have a hobbled ability to think rationally.
Functional Magnetic Resonance Imaging (fMRI) brain scans of people in the early stages of romantic love show romantic love is less about emotions and more about rewards and the parts of the brain that control motivation.
BETHESDA, Md. (May 31, 2005) – You just can't tell where you might find love these days. A team led by a neuroscientist, an anthropologist and a social psychologist found love-related neurophysiological systems inside a magnetic resonance imaging machine. They detected quantifiable love responses in the brains of 17 young men and women who each described themselves as being newly and madly in love.
The multidisciplinary team found that early, intense romantic love may have more to do with motivation, reward and "drive" aspects of human behavior than with the emotions or sex drive. Brain systems were activated that humans share with other mammals. So the researchers think "early-stage romantic love is possibly a developed form of a mammalian drive to pursue preferred mates, and that it has an important influence on social behaviors that have reproductive and genetic consequences."
People in romantic love showed no consistent pattern of emotional activation in areas of the brain known to govern emotions. But they did show consistent activation of brain areas associated with motivation and goal-seeking mental states.
"Most of the participants in our study clearly showed emotional responses," noted Arthur Aron of the State University of New York-Stony Brook, "but we found no consistent emotional pattern. Instead, all of our subjects showed activity in reward and motivation regions. To emotion researchers like me, this is pretty exciting because it's the first physiological data to confirm a connection between romantic love and motivation networks in the brain.
"As it turns out, romantic love is probably best characterized as a motivation or goal-oriented state that leads to various specific emotions, such as euphoria or anxiety," Aron noted. "With this view, it becomes clearer why the lover expresses such an imperative to pursue his or her beloved and protect the relationship."
Romantic love happens in the basal ganglia region of the brain.
Aron reported that, using functional magnetic resonance imaging (fMRI) and other measurements, he and his colleagues found support for their two major predictions: (1) early stage, intense romantic love is associated with subcortical reward regions rich with dopamine; and (2) romantic love engages brain systems associated with motivation to acquire a reward.
Brown explains some of these findings, commenting that "when our participants looked at a photo of his/her beloved, specific activation occurred in the right ventral tegmental area (VTA) and dorsal caudate body. These regions were significant compared to two control conditions, providing strong evidence that these brain areas, which are associated with the motivation to win rewards, are central to the experience of being in love."
Brown noted that "an important concept is that the caudate probably integrates huge amounts of information, everything from early personal memories to one's personal notions of beauty. Then, this brain region (and related regions of the basal ganglia) helps to direct one's actions toward attaining one's goals. For neuroscientists," she said, "these findings about the diverse regional functions of the basal ganglia in humans have remarkable implications."
Romantic love happens on the right side of the brain while facial attraction happens on the left side.
Another important discovery, Brown said, was that "to our surprise, the activation regions associated with intense romantic love were mostly on the right side of the brain, while the activation regions associated with facial attractiveness were mostly on the left.
"We didn't predict such a striking lateralization," Brown reported. "It is well known that speech is largely a left-sided cortical function. But our data indicate that lateralization also occurs in lower parts of the brain. Moreover, different kinds of rewards (in this case, the "rush" of romantic love, compared with the pleasing experience of looking at a pretty or handsome face) is also lateralized. These results give us a lot to think about how the normal human brain learns and remembers and functions in general," Brown added.
Humans form attachments to each other using the same part of the brain that prairie voles use for pair-bonding.
Another breakthrough, Brown noted, was that "we found several brain areas where the strength of neural activity changed with the length of the romance. Everyone knows that relationships are dynamic over time, but we are beginning to track what happens in the brain as a love relationship matures."
Helen E. Fisher, a research anthropologist at Rutgers University, New Jersey, noted that not only did the brain change as romantic love endured, but that some of these changes were in regions associated with pair-bonding in prairie voles. The fMRI images showed more activity in the ventral pallidum portion of the basal ganglia in people with longer romantic relationships. It's in this region where receptors for the hormone vasopressin are critical for vole pair-bonding, or attachment.
"Humans have evolved three distinct but interrelated brain systems for mating and reproduction – the sex drive, romantic love, and attachment to a long term partner," Fisher said, "and our results suggest how feelings of romantic love might change into feelings of attachment. Our results support what people have always assumed – that romantic love is one of the most powerful of all human experiences. It is definitely more powerful than the sex drive."
People consider rejection in love as more important than rejection for sex.
For instance, Fisher point out, "If someone rejects your sexual overtures, you don't harm yourself or the other person. But rejected men and women in societies around the world sometimes kill themselves or someone else. In fact, studies indicate that some 40% of people who are rejected in love slip into clinical depression. Our study may also suggest some of the underlying physiology of stalking behavior," she added.
Fisher sees love as a product of natural selection.
"Darwin and many of his intellectual descendants have studied the myriad physiological ornaments that one sex of a species have evolved to attract members of the opposite sex, like the peacock's fancy tail feathers that attract the peahen," Fisher noted. "But no one has studied what happened in the brain of the viewer, the individual that becomes attracted to these traits. Our study indicates what happens in the brain of the viewer as he or she becomes physiologically attracted to these traits."
She added, "This brain system probably evolved for an important reason – to drive our forebears to focus their courtship energy on specific individuals, thereby conserving precious mating time and energy. Perhaps," she hypothesized, "even love-at-first-sight is a basic mammalian response that developed in other animals and our ancestors inherited in order to speed up the mating process."
What does the future hold for love? Greater knowledge of a phenomenon very often brings with it the ability to manipulate and control it. I expect the development of drugs and other treatments that cause people to fall in and out of love and to recover more easily from lost love.
Some people will choose to immunize themselves from love by using treatments that prevent the love process from developing in the first place. A person with history of heart breaks might decide that the possibility of a new love is just too painful to bear. Or someone who wants to devote their time to career might decide to innoculate themselves from the risk of romantic distractions. Still others of a more cerebral sort will decide that love is just a costly cognition distorting evolutionary vestige that they are best off without.
The ability to manipulate love medically will inevitably lead to misuse via surreptious reprogramming of the love state of others. Someone who wants to ditch their mate will be tempted to surreptitiously deliver medicine that will cause the mate to fall out of love. Or imagine the case where a suitor is rejected because the object of their love is in love with someone else. Inevitably some suitors will look for ways to surreptiously deliver a medical treatment that will cause the object of their love to fall out of love with someone else and thereby open up the possibility of forming a new love bond with them.
Motives also exist to cause people to fall in love with each other. This might be done by someone who has unrequited love for another. One can also very easily imagine members of couples (married or otherwise) using love potions to revive flagging marriages by returning their partner to an earlier state of love. But one can also imagine third parties (e.g. parents wanting to form a dynastic alliance of some sort) deciding to secretly do this as well.
The ability to surreptitiously cause people to fall in and out of love will inevitably lead to suspicions by those falling in and out of love. Can they trust their feelings as legitimate? Is pharmaceutically induced love less legitimate than natural love? If so, why? Will it be possible to develop technologies that check for unnaturally induced feelings of love?
Also see my previous posts "Love Deactivates Brain Areas For Fear, Planning, Critical Social Assessment", Hormone Levels Change When Falling In Love, and What Brain Scans Of People Falling In Love Tell Us.
Having one or two copies of the short version of the serotonin transporter gene prevents enough connections from being formed in the brain between the cingulate and amygdala. As a result fearful and stressful situations cause the amygdala to be too active and the neural circuitry in the cingulate lacks the connectivitiy needed to dampen down the amygdala fear response, leading to anxiety and depression.
The gene codes for the serotonin transporter, the protein in brain cells that recycles the chemical messenger after it's been secreted into the synapse, the gulf between cells. Since the most widely prescribed class of antidepressants act by blocking this protein, researchers have focused on possible functional consequences of a slight variation in its DNA sequence across individuals. Everyone inherits two copies of the gene, one from each parent, which comes in two common versions: short and long. The short version makes less protein, resulting in less recycling, increased levels of serotonin in the synapse, and more serotonin-triggered cellular activity. Previous NIMH-supported studies had shown that inheriting the short variant more than doubles risk of depression following life stresses,** boosts amygdala activity while viewing scary faces,*** and has been linked to anxious temperament. Yet, how it works at the level of brain circuitry remained a mystery.
The NIMH research team first scanned 114 healthy subjects using magnetic resonance imaging (MRI). Those with at least one copy of the short variant had less gray matter, neurons and their connections, in the amygdala-cingulate circuit than those with two copies of the long variant.
Next, using functional magnetic resonance imaging (fMRI), the researchers monitored the brain activity of 94 healthy participants while they were looking at scary faces, which activates fear circuitry. Those with the short variant showed less functional connectivity, in the same circuit.
Nearly 30 percent of subjects' scores on a standard scale of "harm avoidance," an inherited temperament trait associated with depression and anxiety, was explained by how well the mood-regulating circuit was connected.
"Until now, it's been hard to relate amygdala activity to temperament and genetic risk for depression," said Dr. Andreas Meyer-Lindenberg, a lead author. "This study suggests that the cingulate's ability to put the brakes on a runaway amygdala fear response depends upon the degree of connectivity in this circuit, which is influenced by the serotonin transporter gene."
Since serotonin activity plays a key role in wiring the brain's emotion processing circuitry during early development, the researchers propose that the short variant leads to stunted coupling in the circuit, a poorly regulated amygdala response and impaired emotional reactivity – resulting in increased vulnerability to persistent bad moods and eventually depression as life's stresses take their toll.
One can imagine a couple of ways that future biotechnological advances will provide ways to treat this problem. First off, cell therapies, gene therapies, or nerve growth factor therapies could be used to encourage the growth of neurons between the cingulate and the amygdala. Another more "cyborg-ish" possibility would be to implant electrodes in the brain to deliver artificial signals into the amygdala to suppress the fear response.
Note how these scientists combined genetic test results with brain scan results. Once DNA sequencing and testing costs drop by orders of magnitude brain scan tests will be comparable to all the genetic variations in the genome to find other genetic variations that influence emotions and other aspects of cognition.
Now, researchers at Johns Hopkins have discovered that sudden emotional stress can also result in severe but reversible heart muscle weakness that mimics a classic heart attack. Patients with this condition, called stress cardiomyopathy but known colloquially as "broken heart" syndrome, are often misdiagnosed with a massive heart attack when, indeed, they have suffered from a days-long surge in adrenalin (epinephrine) and other stress hormones that temporarily "stun" the heart.
"Our study should help physicians distinguish between stress cardiomyopathy and heart attacks," says study lead author and cardiologist Ilan Wittstein, M.D., an assistant professor at The Johns Hopkins University School of Medicine and its Heart Institute. "And it should also reassure patients that they have not had permanent heart damage."
In the Hopkins study, to be published in The New England Journal of Medicine online Feb. 10, the research team found that some people may respond to sudden, overwhelming emotional stress by releasing large amounts of catecholamines (notably adrenalin and noradrenalin, also called epinephrine and norepinephrine) into the blood stream, along with their breakdown products and small proteins produced by an excited nervous system. These chemicals can be temporarily toxic to the heart, effectively stunning the muscle and producing symptoms similar to a typical heart attack, including chest pain, fluid in the lungs, shortness of breath and heart failure.
Upon closer examination, though, the researchers determined that cases of stress cardiomyopathy were clinically very different from a typical heart attack.
"After observing several cases of 'broken heart' syndrome at Hopkins hospitals - most of them in middle-aged or elderly women - we realized that these patients had clinical features quite different from typical cases of heart attack, and that something very different was happening," says Wittstein. "These cases were, initially, difficult to explain because most of the patients were previously healthy and had few risk factors for heart disease."
For example, examination by angiogram showed no blockages in the arteries supplying the heart. Blood tests also failed to reveal some typical signs of a heart attack, such as highly elevated levels of cardiac enzymes that are released into the blood stream from damaged heart muscle. Magnetic resonance imaging (MRI) scans confirmed that none of the stressed patients had suffered irreversible muscle damage. Of greatest surprise, the team says, was that recovery rates were much faster than typically seen after a heart attack. Stressed patients showed dramatic improvement in their hearts' ability to pump within a few days and had complete recovery within two weeks. In contrast, partial recovery after a heart attack can take weeks or months and, frequently, the heart muscle damage is permanent.
The researchers collected detailed histories and conducted several tests, including blood work, echocardiograms, electrocardiograms, coronary angiograms, MRI scans and heart biopsies, on a total of 19 patients who came to Hopkins between November 1999 and September 2003. All had signs of an apparent heart attack immediately after some kind of sudden emotional stress, including news of a death, shock from a surprise party, fear of public speaking, armed robbery, a court appearance and a car accident. Eighteen of the stressed patients were female, between the age of 27 and 87, with a median age of 63. The results were then compared to seven other patients, all of whom had suffered classic, severe cases of heart attack, called a Killip class III myocardial infarction.
When results from both groups were compared, the researchers found that initial levels of catecholamines in the stress cardiomyopathy patients were two to three times the levels among patients with classic heart attack, and seven to 34 times normal levels.
Catecholamine metabolites, such as metanephrine and normetanephrine, were also massively elevated, as were other stress-related proteins, such as neuropeptide Y, brain natriuretic peptide and serotonin. These results provided added confirmation that the syndrome was stress induced. Heart biopsies also showed an injury pattern consistent with a high catecholamine state and not heart attack.
Note that 18 out of the 19 patients diagnosed with stress cardiomyopathy were women. Do men suppress their emotional responses and thereby lower their risk of stress cardiomyopathy?
I predict that some day people will have embedded drug dispensers in their bodies that have integrated sensors that will be able to detect the chemicals released by a severe emotional stress episode. The sensor devices embedded in a body will have integrated drug dispensers that together will act like an extension of the endocrine system. The artificial endocrine organs will be able to react to the severe stress reaction by releasing compounds that will damp down the stress response to put the stress response back within a safe range by neutralizing the catecholamines and other compounds released in response to severe emotional stress.
Severe emotional stress is bad for your health. To the extent that it is practically possible structure your life to avoid circumstances and events that will elicit intense emotional feelings of stress.
People who were in love and other people who were not in love were asked to view film clips of couples interacting who were in different levels of emotional involvement. The viewers who were in love were least able to identify which viewed couples were in love.
"Love is truly blind," said Frank J. Bernieri, professor and chair of the Department of Psychology at Oregon State University and one of the authors of the study. "People in the study who had the longest relationships, were immersed in reading romance novels and spent lots of time watching romantic movies just loved this research. They all were quite confident of their ability to identify others in love."
"And without exception," he added, "they were, by far, the least accurate in their assessment."
The study was just published in the Journal of Nonverbal Behavior. Bernieri co-authored the paper with lead investigator Maya Aloni, who was an honors undergraduate at the University of Toledo when Bernieri was on the faculty there. She is now at State University of New York-Buffalo pursuing graduate studies.
A team of clinical psychologists at McGill University in Montreal filmed 25 couples for another study and used a battery of common assessment tools -- including the Sternberg Love Scale, the Hatfield Passion Scale and other relationship measures -- to determine the depth of couples' affection for one another. All of the couples had been together for at least three weeks; many for several months.
On film, the couples were seen interacting casually. Bernieri showed snippets of each couple to a series of volunteers and ask them to assess the depths of the filmed couples' feelings for each other.
"The range of accuracy was really extraordinary," Bernieri said. "Those who were best at it were about twice as good as those who did the worst. Imagine observing 10 couples and trying to identify the five who love each other the most, and the five who loved each other the least. If you were in love at the time of the study, you would only get three or four out of 10 couples -- so you'd be wrong twice as much as you'd be right."
"But if you weren't in love, you'd get it right six or seven times out of 10," he added. "That, in my book, is a huge difference."
If being drunk on alcohol at the time of getting married can be grounds for annulment then why can't being in love also be grounds for annument? After all, people in love are in an obviously naturally drugged mental state and they obviously can't think straight. So shouldn't people in love be treated as suffering from a mental handicap or a special form of mental incapacitation? Should the law treat lovers as legally competent to enter into the serious and important contract of marriage?
Another interesting point about this study: Some people are especially skilled at identifying which couples are in love. Well, there are also rare individuals who have exceptional talent at identifying when someone is telling a truth or a falsehood. The technique these researchers used could be applied to a much larger set of subjects to identify people who are exceptionally skilled at telling who is in love. This has all sorts of practical applications in the war between the sexes. Imagine a woman who is uncertain if her boyfriend really loves her. She could arrange to have a dinner party or other meeting and pay this expert relationship evaluator to attend to figure out whether the boyfriend is just having a fling or more committed.
One can also imagine use of expert relationship evaluators in marriage counseling. It would save a lot of time to be able to simply say "Jill obviously doesn't love Jack any more but she is reluctant to admit it." Or "Hey, these people hate each other and love each other at the same time".
Another neat application would be in the spy business both real and fictional. Imagine Alias star Jennifer Garner as Sydney Bristow pretending to be in love with a fellow agent while on a mission. The Covenant (who whatever shadowy international group is the current enemy of the CIA in Alias - I've lost track) could have some corrupt psychologist recruit a talented observer who would detect that Sydney is faking her love for some guy at an embassy reception. Then a big gun battle would ensue.
In the long run I predict drugs will be developed that will induce and halt the feeling of being in love.
Update: The brain changes in physically measurable ways when people fall in love. See my previous posts Love Deactivates Brain Areas For Fear, Planning, Critical Social Assessment and What Brain Scans Of People Falling In Love Tell Us and Hormone Levels Change When Falling In Love.
Using a high-resolution version of functional magnetic resonance imaging (fMRI) the researchers observed a structure in the brain important for emotional processing - the amygdala - lights up with activity when people unconsciously detected the fearful faces.
Although the study was conducted in people who had no anxiety disorders, the researchers says that the findings should also apply to people with anxiety disorders.
“Psychologists have suggested that people with anxiety disorders are very sensitive to subliminal threats and are picking up stimuli the rest of us do not perceive,” says Dr. Joy Hirsch, professor of neuroradiology and psychology and director of the fMRI Research Center at Columbia University Medical Center, where the study was conducted. “Our findings now demonstrate a biological basis for that unconscious emotional vigilance.”
A part of the brain involved in the feeling of anxious reactions responded to fearful pictures even if the pictures were flashed up too quickly for the conscious mind to become aware of the pictures.
In the study, the researchers presented images of fearful facial expressions, which are powerful signals of danger in all cultures, to 17 different subjects. None of the 17 volunteers had any anxiety disorders, but their underlying anxiety varied from the 6th to the 85th percentile of undergraduate norms, as measured by a well-validated questionnaire.
“These are the type of normal differences that would be apparent if these people got stuck in an elevator,” Dr. Hirsch says. “Some of them would go to sleep; some would climb the walls.”
While the subjects were looking at a computer, the researchers displayed an image of a fearful face onto the monitor for 33 milliseconds, immediately followed by a similar neutral face. The fearful face appeared and disappeared so quickly that the subjects had no conscious awareness of it.
But the fMRI scans clearly revealed that the brain had registered the face and reacted, even though the subjects denied seeing it. These scans show that the unconsciously perceived face activates the input end of the amygdala, along with regions in the cortex that are involved with attention and vision.
Brain activity varies with level of anxiety
The researchers also noticed that the amount of brain activity varied from person to person, depending on their scores on the anxiety quiz.
The amygdalas of anxious people was far more active than the amygdalas of less anxious people. And anxious subjects showed more activity in the attention and vision regions of the cortex, which manifested itself in faster and more accurate answers when the subjects were asked questions about the neutral face.
“What we think we’ve identified is a circuit in the brain that’s responsible for enhancing the processing of unconsciously detected threats in anxious people,” says Amit Etkin, the study’s first author. “An anxious person devotes more attention and visual processing to analyze the threat. A less anxious person uses the circuit to a lesser degree because they don’t perceive the face as much as a threat.”
Unconscious vs. conscious processing of fearful faces
In contrast to unconscious processing of fearful faces, the researchers found that when subjects looked at the fearful faces for 200 milliseconds, long enough for conscious recognition, a completely different brain circuit was used to process the information. And the activity in that circuit did not vary according to the subject’s level of anxiety.
“Our study shows that there’s a very important role for unconscious emotions in anxiety,” Etkin says.
This reminds me of claims decades ago that some movie theaters were supposedly splicing pictures of food in with movies using durations too short to be consciously registered but still long enough to make someone want to go buy some popcorn and candy. Well, can the flashing up of food pictures for periods too short to be registered by the conscious mind still manage to provoke a hunger pang just like these scary faces provoke the beginning of an anxiety reaction?
This technique could be used in movies to create anxious reactions to scary scenes. Though how well it worked would depend on each movie watcher's proneness to anxiety.
Also, could this technique be used in interrogations to increase the anxiety of a subject of interrogation? Would that help the interrogators succeed in getting useful information? Imagine the subject being left in a room to watch a seemingly soothing TV show that has 33 millisecond flashes of anxious faces spliced into the video stream.
Then there are the anxious and fearful people of the world: They shouldn't look at each other's faces. They probably feed off of each other's fear. They should have pictures of happy and relaxed people on walls near their work desks and at home.
Andreas Bartels and Semir Zeki of the Wellcome Department of Imaging Neuroscience, University College London have found using Functional Magnetic Resonance Imaging (fMRI) that love turns down activity in some areas of the brain in part so that we will not see flaws in the object of our affections.
However the key result was that it's not just that certain shared areas of the brain are reliably activated in both romantic and maternal love, but also particular locations are deactivated and it's the deactivation which is perhaps most revealing about love.
Among other areas, parts of the pre-frontal cortex – a bit of the brain towards the front and implicated in social judgment – seems to get switched off when we are in love and when we love our children, as do areas linked with the experience of negative emotions such as aggression and fear as well as planning. The parts of the brain deactivated form a network which are implicated in the evaluation of trustworthiness of others and basically critical social assessment.
The scientists recruited mothers and used pictures of their children as well as pictures of other people and watched how the women responded to the pictures. The researchers also reanalysed data they had previously collected for previously published research involving women in love.
We are fools for love because love disables our about to do critical social assessment.
He said: "Our research enables us to conclude that human attachment employs a push-pull mechanism that overcomes social distance by deactivating networks used for critical social assessment and negative emotions, while it bonds individuals through the involvement of the reward circuitry explaining the power of love to motivate and exhilarate."
Bartels has the full text of the research paper on his web site. When we fall in love we become blinded to faults and at the very same time we become flooded with rewarding feelings. (PDF format)
Romantic and maternal love are highly rewarding experiences. Both are linked to the perpetuation of the species and therefore have a closely linked biological function of crucial evolutionary importance. Yet almost nothing is known about their neural correlates in the human. We therefore used fMRI to measure brain activity in mothers while they viewed pictures of their own and of acquainted children, and of their best friend and of acquainted adults as additional controls. The activity specific to maternal attachment was compared to that associated to romantic love described in our earlier study and to the distribution of attachment-mediating neurohormones established by other studies. Both types of attachment activated regions specific to each, as well as overlapping regions in the brain’s reward system that coincide with areas rich in oxytocin and vasopressin receptors. Both deactivated a common set of regions associated with negative emotions, social judgment and ‘mentalizing’, that is, the assessment of other people’s intentions and emotions. We conclude that human attachment employs a push– pull mechanism that overcomes social distance by deactivating networks used for critical social assessment and negative emotions, while it bonds individuals through the involvement of the reward circuitry, explaining the power of love to motivate and exhilarate.
...
Maternal and romantic love share a common and crucial evolutionary purpose, namely the maintenance and perpetuation of the species. Both ensure the formation of firm bonds between individuals, by making this behavior a rewarding experience. They therefore share a similar evolutionary origin and serve a similar biological function. It is likely that they also share at least a core of common neural mechanisms. Neuro-endocrine, cellular and behavioral studies of various mammalian species ranging from rodents to primates show that the neurohormones vasopressin and oxytocin are involved in the formation and main-tenance of attachment between individuals, and suggest a tight coupling between attachment processes and the neural systems for reward (Carter, 1998; Insel and Young, 2001; Kendrick, 2000; Pedersen and Prange, 1979). This is confirmed by lesion, gene expression and behavioral studies in mammals (Numan and Shee-han,
Perhaps it is not a coincidence that many lovers call each other "babe" and there is a great deal of overlap between the brain's feelings of romantic and maternal love.
Note that regions rich with vasopressin receptors are involved in maternal and romantic love. This brings us to another recent report where scientists have found that gene therapy to deliver vasopressin receptor genes into the ventral pallidum part of the brain made male meadow voles become uncharacteristically monogamous.
ATLANTA -- Researchers at the Yerkes National Primate Research Center of Emory University and Atlanta's Center for Behavioral Neuroscience (CBN) have found transferring a single gene, the vasopressin receptor, into the brain's reward center makes a promiscuous male meadow vole monogamous. This finding, which appears in the June 17 issue of Nature, may help better explain the neurobiology of romantic love as well as disorders of the ability to form social bonds, such as autism. In addition, the finding supports previous research linking social bond formation with drug addiction, also associated with the reward center of the brain.
In their study, Yerkes and CBN post-doctoral fellow Miranda M. Lim, PhD, and Yerkes researcher Larry J. Young, PhD, of the Department of Psychiatry and Behavioral Sciences at Emory University's School of Medicine and the CBN, attempted to determine whether differences in vasopressin receptor levels between prairie and meadow voles could explain their opposite mating behaviors. Previous studies of monogamous male prairie voles, which form lifelong social or pair bonds with a single mate, determined the animals' brains contain high levels of vasopressin receptors in one of the brain's principal reward regions, the ventral pallidum. The comparative species of vole, the promiscuous meadow vole, which frequently mates with multiple partners, lacks vasopressin receptors in the ventral pallidum.
The scientists used a harmless virus to transfer the vasopressin receptor gene from prairie voles into the ventral pallidum of meadow voles, which increased vasopressin receptors in the meadow vole to prairie-like levels. The researchers discovered, just like prairie voles, the formerly promiscuous meadow voles then displayed a strong preference for their current partners rather than new females. Young acknowledges many genes are likely involved in regulating lifelong pair bonds between humans. "Our study, however, provides evidence, in a comparatively simple animal model, that changes in the activity of a single gene profoundly can change a fundamental social behavior of animals within a species."
According to previous research, vasopressin receptors also may play a role in disorders of the ability to form social bonds, such as in autism. "It is intriguing," says Young, "to consider that individual differences in vasopressin receptors in humans might play a role in how differently people form relationships."
And, Lim adds, past research in humans has shown the same neural pathways involved in the formation of romantic relationships are involved in drug addiction. "The brain process of bonding with one's partner may be similar to becoming addicted to drugs: both activate reward circuits in the brain."
The researchers' next step is to determine why there is extensive variability in behaviors among individuals within a species in order to better understand the evolution of social behavior.
Well, consider the possibilities. Want to solve the soaring divorce rate problem? Bioengineer a virus to infect the population to deliver the vasopressin gene into the ventral pallidum at the base of the brain. After years of ineffective moralizing and countless social science studies the problem of disintegrating marriages would be solved.
Another possibility would be the use of such a gene therapy by someone who is in love to make the object of their affections primed to fall in love. Of course, the lover surreptiously treated with emotional brain engineering genetic therapy might fall in love with the next person they accidentally bump into in the supermarket. So such a gene therapy would not be foolproof once it becomes feasible.
But since love causes brain changes that have some similarities to what addictive drugs do to the brain an argument can be made for the proposition that love is just another form of addiction for which humans need an effective treatment that will end the craving.
Oxytocin and vasopression receptors show up only in the reward areas of the brain.
In their research, funded by the National Institute of Mental Health, Larry Young, PhD., associate professor of psychiatry and behavioral sciences at Emory University School of Medicine and an affiliate scientist at Yerkes National Primate Research Center; graduate student Miranda Lim; and Anne Murphy, PhD., associate professor of biology at Georgia State University, examined the distribution of two brain receptors in the ventral forebrain of monogamous prairie voles that have been previously tied to pair bond formation: oxytocin (OTR) and vasopressin V1a receptor (V1aR). Using receptor audiographic techniques, the scientists found that these receptors are confined to two of the brain's reward centers, the nucleus accumbens and the ventral pallidum. V1aR receptors, which are thought to be activated in the male vole brain during pair bond formation, were confined largely to the ventral pallidum. OTR receptors, which play a crucial role in pair bond formation in females, were found mainly in the nucleus accumbens.
Perhaps a person with more oxytocin and vasopressin receptors finds life to be more rewarding in general. But are they more or less prone to drug addiction?
Donatella Marazziti of the University of Pisa has found looking at hormone levels that people in love are under more stress and the gap between male and female levels of testosterone converges.
The first finding was that both men and women in love have considerably higher levels of the stress hormone cortisol, indicating that courtship can be somewhat stressful. "But the most intriguing finding is related to testosterone," says Marazziti.
Split the difference
Men who were in love had lower levels of the male sex hormone testosterone - linked to aggression and sex drive - than the other men. Love-struck women, in contrast, had higher levels of testosterone than their counterparts, the team will report in Psychoneuroendocrinology.
If stress and altered hormone levels are not for you and if you agree with Peter Wolf that "Love Stinks" there may be hope in the form of pharmaceuticals. The Selective Serotonin Reuptake Inhibitors (SSRIs) such as Prozac and Paxil may suppress the feeling of romantic love and attachment in at least some people.
Dr. Helen E. Fisher, an anthropologist at Rutgers, presented findings that suggest, she says, that common antidepressants that tinker with serotonin levels in the brain can also disrupt neural circuits involved in romance and attachment.
SSRIs are probably too dangerous for children to use to get over puppy love. But they might be useful for those depressed people who are feeling real romantic pain.
It would be interesting to know whether men taking testosterone are less likely to fall in love.
Rutgers University evolutionary anthropologist Helen Fisher has writtern a new book titled Why We Love : The Nature and Chemistry of Romantic Love In a very interesting interview she discucsses results of her functional MRI (fMRI) brain scans of people in the early intense stages of falling in love.
On average, men tended to show more activity in two regions in the brain: One was associated with the integration of visual stimuli and the second was with penile erection. This really shouldn't come as a surprise. Everybody knows that men are highly visual -- men spend their lives commenting on women, looking at porn, and the like. I believe these visual networks evolved 1 or 2 million years ago because men needed to look at a woman and size up her ability to give him healthy babies. If he saw that she was young and healthy and happy, it would be adaptive for him to become aroused to start the mating process. Men definitely fall in love faster than women -- there's good psychological data on that. And I think that's because they are more visual.
And women?
Several regions associated with memory recall became active. And I couldn't figure out why at first, and then I thought to myself, my goodness -- for millions of years women have been looking for someone to help them raise their babies, and in order to do that you really can't look at someone and know whether they're honest or trustworthy or whether they can hit the buffalo in the head and share the meat with you. You've got to remember what they said yesterday, what they said three weeks ago, what they gave your mother two months ago at the midwinter festival. For millions of years women have had the hardest job on earth -- raising tiny helpless babies for as long as 20 years. That is an enormous job. There's no other animal on earth for whom motherhood is so complex. And if their husband died they'd have to expend an enormous amount of metabolic energy to find another one, and they're that much older, and the clock is ticking -- it's an adaptive strategy to remember all these details.
Fisher comments that the use of Selective Serotonin Reuptake Inhibitors (SSRIs) as antidepressants may reduce the capacity for falling in love by blocking some of the changes in serotonin metabolism that normally happen while one is falling in love. Regardless of just how well existing SSRIs produce this effect if they can do it at all this suggests that drugs can be developed in the future that can totally block falling in love. It also seems likely that the opposite effect could be aimed for. The love potion of mythical tales may eventually be attainable through coming advances in pharmaceuticals.
Fisher is also the author of Anatomy of Love: A Natural History of Mating, Marriage, and Why We Stray.
Update: Fisher's interview reminds me of an idea that I've been wanting to get out into the public realm for a long time: We need drugs that will keep people happily married. The cost of divorce and illegitimacy for society is terrible. In some societies marriage for child-rearing is becoming the exception. This means childen are less well cared for and they do not turn out as well in terms of educational attainment, crime rates, and general success in life. Split ups of households lower the living standards as it costs more to maintain two separate households. If we accept the evolutionary psychology argument about why people fall in and out of love it seems to me that the problem is that humans have not been selected for to behave in a way most optimal for extended child-raising and this problem needs to be fixed pharmacologically. Everything from the declining strength of religious belief to the mass media portrayals of tempting objects of affections are reducing forces holding marriage together with tragic results.
We can not fix this problem with gene therapy because that is going to take a lot longer to develop. Many potential gene therapies will have to be done on fetuses and therefore their results will not be felt until the babies grow to be adults. Also, many people might oppose the idea of genetically engineering their children to be highly monogamous and faithful by nature But we might be able to keep people together with pharmaceuticals.
Take whatever biochemical state people have in the initial flush of love. Imagne being able to maintain that feeling for years with both partners agreeing to do so together. Imagine a drug which. if you took it while looking at a particular person, that person would, as a result, look very sexy to you. Think about how much happier everyone would be if they weren't all walking around thinking that the grass looked greener on that unattainable other side of the river. Imagine that the sexiness of a lover never wore out or got old. A lot of married people would stay together a lot longer and long enough to raise kids to adulthood of they could use drugs to maintain their attraction to each other.
Science may eventually be able to produce the love potions of mythical stories and modern fantasy TV shows and movies. Love drugs could help prevent and reverse the decline of marriage. If this became possible the benefits would be substantial.
Victoria Bourne and Brenda Todd of the University of Sussex in England have found that women hold babies on the side of their bodies that connect to that side of the brain which is dominant in the processing of emotions.
The right side of the brain controls the left side of the body and usually helps to process emotions, explains Bourne. So holding the baby on the left-hand side may help to direct the sight of emotionally charged information, such as tears or laughter, to the specialized right hemisphere for processing, she says.
Keep in mind that the left brain gets input from the right side of the body and the right brain gets input from the left side. It is interesting to note that the heart is traditionally associated with the seat of emotions and it happens to be on the left side of the body and that side is the side that connects to the center of emotional processing in the brain in most people.
If you want to find out which side of your brain does most of your emotional processing then take this quick test. The test is too short to be definitive. If anyone knows of a longer test with more pictures please post a link to it in the comments.
The abstract for the research paper more clearly explains what they did. The researchers used both people who have left-brain dominance for emotional processing and people who did not.
Previous research has indicated that 70-85% of women and girls show a bias to hold infants, or dolls, to the left side of their body. This bias is not matched in males (e.g. deChateau, Holmberg & Winberg, 1978; Todd, 1995). This study tests an explanation of cradling preferences in terms of hemispheric specialization for the perception of facial emotional expression. Thirty-two right-handed participants were given a behavioural test of lateralization and a cradling task. Females, but not males, who cradled a doll on the left side were found to have significantly higher laterality quotients than right cradlers. Results indicate that women cradle on the side of the body that is contralateral to the hemisphere dominant for face and emotion processing and suggest a possible explanation of gender differences in the incidence of cradling.
One thing that would be interesting to discover is whether less emotionally intense women are less likely to prefer one side over the other for holding a baby.
Since this story is written for the layman they use the term "cell birth". But what is really happening is that adult stem cells in the hippocampus divide. One cell remains an adult stem cell and stays in the hippocampus. The other travels up into the brain and converts itself into a nerve cell. Well, this process is probably happening in order to form new memories, possibly new reflexes, and to replace damaged cells that die. Suppression of this process may either cause depression or possibly it doesn't cause the initial depression but does prolong it. Anti-depressants are known to stimulate hippocampal adult stem cells to divide and so the thinking is that this stimulation may be one of the ways that anti-depressant drugs relieve depression. There are now many scientists pursuing this line of thought and looking for drugs that will more quickly stimulate hippocampal adult stem cells to divide.
Stress, which plays a key role in triggering depression, suppresses neurogenesis in the hippocampus.
Antidepressants, on the other hand, encourage the birth of new brain cells.
Animals must take antidepressants for two or three weeks before they bump up the birth rate of brain cells, and the cells take another two weeks to start functioning. That's consistent with the lag time antidepressants show before they lift moods in people.
If an antidepressant is given during a period of chronic stress, it prevents the decline in neurogenesis that normally occurs.
You can also fiind the previous article here.
In a related report stress hampers learning ability in female rats but Prozac prevents stress's effects:
Shors and her research team, Benedetta Leuner, Jacqueline Falduto and Sabrina Mendolia, studied adult female rats treated with the antidepressant Prozac and a control group that received no treatment. They found that after a stressful event, learning was impaired in the control group but not in the group treated with Prozac. The researchers also found that only chronic treatment with Prozac was effective, which is consistent with reported efficacy of Prozac in patients with depression and other mental disorders.
"Importantly," Shors pointed out, "unstressed females treated with Prozac did not differ from unstressed, untreated females, indicating that Prozac itself did not affect learning."
Shors noted that males and females differ in their responses to stressful experiences. The researchers have found that exposure to a stressful experience that impairs new learning in females actually enhances new learning in males.
These results also suggest a reason why depression is more common in old folks: their adult stem cells are also aged and very likely not as able to divide and differentiate into nerve cells. In order to rejuvenate people and make their bodies young again it will be essential to rejuvenate the adult stem cells in various adult stem cell reservoirs throughout the body. If hippocampal adult stem cells could be rejuvenated it might be possible to reduce the incidence of depression, improve memory, and even to raise intelligence. Since the demand for more effective anti-depressant treatments is so large this theory about hippocampal adult stem cells having a role in prolonging depression may cause depression researchers to develop methods to rejuvenate hippocampal adult stem cells. Hence attempts to develop more advanced anti-depressant treatments may contribute to the development of anti-aging therapies.