attachment and love
Monicarodr
I posted/updated the readings and the syllabus. For this class each of
you read 2 articles for presenting either in the topic of development/
attachment, or romantic/adult love. Of course, you are welcome to read
and/or present more if you wish. It would be ideal if you can post
which you will be working on so we have maximum coverage. Have a great
rest of the weekend!
Monica
--
Subscription settings: http://groups.google.com/group/socialneuro780/subscribe?hl=en
Stuart Daman
Ortigue (2006)! Stuart
Camille Barnes
-Camille
Jenny Perella
Jen Vosilla
beka strock
I couldn't get the newest version of the syllabus to download correctly. Would someone be willing to attach it to an email and send it my way?
Also, are there enough articles for everyone to do 2 or should I plan for some overlap??
--
Lindsay C. Morton, MS
Psychology Department
University at Albany
1400 Washington Avenue
Albany, NY 12222
(973) 534-0530
Monica L. Rodriguez
Here is the syllabus
I couldn't get the newest version of the syllabus to download correctly. Would someone be willing to attach it to an email and send it my way?
Also, are there enough articles for everyone to do 2 or should I plan for some overlap??
On Mon, Apr 19, 2010 at 12:30 PM, Jen Vosilla <jenvo...@gmail.com> wrote:
Lindsay Morton
Also, are there enough articles for everyone to do 2 or should I plan for some overlap??
beka strock
Lindsay Morton
David Dinwiddie
beka strock
This covers Biachi-Demiecheli et al with a taste of Aron et al...
Bianchi-Demicheli et al (2006) examined the effects of passionate love on task performance, and found results supporting the idea that priming of a loved-one’s name or passion-related words increases performance on recognition of real words (not fake ones) specifically for those high on the passionate love scale (PLS). While I found their hypothesis and results interesting, I must say that I was disappointed with the lack of distinctive logic in the discussion and the possible erroneous conclusions drawn from the results. Based on their very narrow definition of love and similarly narrow operationalized facilitation on very specific tasks, they for some reason thought this was sufficient to make broad, sweeping claims about love in general and how it must influence all possible tasks one might perform. Only once in the entire article do the authors caveat that there is a distinction between passionate love (based on the PLS they use to measure love in their study) and companionate love (p. 93), both as apply to love between romantic partners and that distinction appears in the methods section, never in the introduction or discussion. Saying “intense love” implies degree of love rather thay qualitative type, but is used repeatedly to refer to passionate love although it is not synonymous .
Most misleading is the authors’ choice of words for their main IV: “women in love” vs “women out of love.” I thought that this categorization was particularly inappropriate because it is suggestive of a control group (e.g., not in love with any romantic partner) rather than a continuum (which is what they were actually measuring, e.g, how much do you feel these particular passionate feeling about your romantic partner) which was absolutely in conflict with their definition of the variable (higher or lower scores on the PLS). Thus despite the fact that both groups “women in love” and “women out of love” might characterize themselves as being “in love” and certainly would characterize themselves as being in a romantic relationship, this was not at all clear in the terms used to discuss this. In addition, the repeated use of these labels was incredibly misleading to readers. Furthermore, this mis-labeling seems to be purposeful, since the discussion and conclusion similarly lead readers to believe that “in love” and “out of love” is then generalizable to all romantic relationships, all types of love, and affects all sorts of tasks. While these conclusions may or may not be correct, the results presented are CERTAINLY not sufficient to draw these conclusions.
Because of their sweeping claims and generalizations, I went back and looked for other problems with sampling data to see if there might be a strong bias due to subject selection, but without the ability to drill down into subjects individual data, the selection seemed reasonably widespread. On a note of practicality, it is hard for me to imagine from their description of feeling “butterflies” and “love at first sight” that members of seriously long term relationships (e.g., married 20+ years) would describe themselves in this way. I suspected that perhaps their claims were based on biased sampling of younger participants, shorter relationships, and stages of love since their conceptual definition of love seemed to be based on what others refer to as early-stage love, however there was no evidence to show that this was definitively the case. While the subject group means did trend in this direction by group, the differences seem relatively minor, and there is no way to further examine whether this is significantly different based on the summary statistics alone. Although the overall means (33 years old versus 35 years old) and ranges (18-56 years old/15 days to 13 years in love versus 23-47 years old/10 days to 30 years in love) seemed acceptably similar, there may have been clustering at higher or lower ends of the spectrum of relationship length (means are not given for relationship length, only range). Even so, I was so unconvinced by their interpretation of the results that I started thinking of various alternative explanations that might account for the effects found, for instance: what if people who score more highly on the PLS are simply more emotionally reactive in general, and therefore react more strongly to passion-related words, which could cause arousal and thus improve performance for these individuals. I just don’t think the authors ruled out a lot of other possible explanations.
It was interesting, however, that in the second study, passionate hobby words were able to elicit facilitation for both groups showing that passion for a person (love) could have similar effects to passion for an activity (hobby). However, consistent with my alternate explanation of higher reactivity, the “in love” group was facilitated more than the “out of love” group.
Neurally, the authors propose that (my addition: at least this subdefinition of) romantic love might be connected with the reward/motivation neural networks (aka the domaminergic system, p. 99; such as the antero-medial caudate nucleus and septum fornix regions, including medial insula, caudate nucleus, putamen/pallidum, ventra tegmenatl area, ACC, hippocampus, frontal gyrus, middle temporal gyrus, right parietal lobe, cerebellum, ) and may depend on dopamine and norepinephrine which are also implicated in “euphoria, craving, addiction, heightened attention, [and] sleeplessness” (p 92). They claim that cognitive facilitation is evidence that love is goal-directed and not just an emotion, but do not flesh out or support this argument. They also note that shorter relationships exhibit higher activations (e.g., stronger “passionate” love) which doesn’t really come into the discussion again despite its relevance to interpretation.
Ultimately, what Bianchi-Demicheli and colleagues did test, and were able to show, is that passionate (priming with lover’s name or passion words) seems to have particular facilitative effects on specified task performance (increased reaction time on lexical decision tasks). And that is ALL they were able to show.
Aron et al (2005) presented a much more nuanced view of romantic love, classifying the “physiological, psychological, and behavioral indices” they were interested in examining as “early-stage romantic love.” I think this distinction is particularly critical given the many types and expressions of love (e.g., maternal, sibling, friend) and even within romantic love, particularly (e.g., passionate versus companionate). Unlinke Bianchi-Demicheli and colleagues, Aron and colleagues were careful to keep their conclusions in context. Aron and colleagues did a much better job stating and proving their case, which was also showing that romantic (early-stage) love can be categorized as goal-directed and activates similar neural systems (particularly the caudate nucleus).
Stuart Daman
associated with "early stage" romantic love. They expected activation
in reward areas, such as the ventral tegmental area (VTA), ventral
striatum/nucleus accumbens, and the anterior caudate nucleus.
They had participants provide a photograph of a loved one
(relationship duration b/t 1-17 mos.) and a "familiar, emotionally
neutral acquaintance of the same age and sex as the beloved". They
also completed the passionate love scale (PLS) and the affect
intensity measure (AIM). Participants then thought about events that
occurred with each of these people while viewing their pictures and
being scanned via fMRI.
They found unique activation in reward areas, including the right
medial caudate, bilaterally in the right dorsal caudate body, and in
the right BA30/ retrosplenial cortex for the loved one. There were
basically no differences between the photo of the unloved person and
the countback task placed between viewings as a control. The degree of
activation also correlated with PLS scores (note on correlations with
other variables). Activation was slightly different in participants
whose relationship had only been going on for 1-7 months vs. 8-17.
There was also higher activation in the left mid-insular cortex for
persons with higher AIM scores.
In summary, early-stage romantic love may be associated with increased
activation in reward centers of the brain. They believe dopamine is
involved. Emotion may be what relates to the activations the varied
with levels of questionnaire scores. They suggest that activation in
the VTA may be lateralized in two aspects of reward; wanting and the
right VTA vs. liking and the left VTA, and base this in their results.
And some other stuff.
I had a couple issues with the study. They say that PLS, AIM, sex and
relationship length were not correlated, but do not report any
numbers.Then they report that none of these variables were correlated
with the quality of the photos saying "(all Ps > .14)". Why didn't
they show this with other correlations? I suspect that some of these
correlations would have been significant, had their sample been more
appropriate for correlating questionnaires (i.e. typical minimum 20
persons per variable). To not even show the lowest p-value for the
first set makes it look shady when you show the others and they are
kinda low for such a small sample. If some of these correlations are
actually there, it would confound the results and discussions about
activation and PLS/AIM/sex/relationship duration.
They also rambled about some other aspects of the fMRI analyses and
anatomical localization with which I was not familiar. I wonder if
this was because of too much error in their scans, or because of how
small some of the specific areas they targeted are.
All in all, neat stuff. One of their final points is particularly
interesting to me. They suggest that romantic love may not be a
specific emotion like many researchers suggest and believe, but that
it may also include a crucial motivational state (towards the loved
person). This is one in which we not only have emotions for the other
person, but are distinctively motivated to seek this person out to
experience the emotions and such associated with that person.
On Biachi-Demicheli, Grafton & Ortigue (2006). Demicheli is a cool
name. I think the study begs the important question, which is never
addressed in their discussion: what about men? Do you expect romantic
love to operate differently in them or not? Why? If not, why not
include men as well? Could there be intensity differences between men
and women? Others? I wish they had also looked at whether intensity of
love was continuously related to reaction times (such as PLS scores),
rather than simply having them split into love and not-love ("out-of-
love") groups. This might get at the question, is there more benefit
for being more in love, or is it a qualitative distinction between
love and not-love? Also, I was confused by a sentence in their
discussion, "the present study demonstrates a causal linkage between
the state of being in love and human cognition" (p. 100). I'm not sure
they mean that being in love is related to specific patterns of
thinking (cognition), as their and the other study I comment on
suggest, or something else. Are they simply saying that there are
thinking patterns that are characteristic of being in love? I don't
see how this second possible meaning is causal. Their wording isn't
very straightforward here.
I also firmly agree with Beka's comments on their perhaps limited
definition of love, as well as generalizations of RTs to a lexical
decision task to other cognitions. A lexical decision task is a very
limited view of cognition in general. Some of Beka's other comments
have some credence, although I can't help but wonder if the culture of
the participants in the first study may be different from ours, in
terms of how love is conceptualized and such (French-speaking Swiss
participants, I believe). In the second study, the characteristics of
the sample were different (US participants, I think), making me wonder
how much they should be compared as having the same feelings/
characteristics. Finally, Beka makes an interesting point about the
possibility that high PLS scores may also be indicative of high
emotionality. The other study I commented on suggests "no" with their
not-significant correlation based on 17 people (grain of salt,
anyone?).
David Dinwiddie
Lindsay Morton
Siegel (2001) presents a theoretical account of the developing brain from the perspective of social-developmental psychology. Attachment is defined as “a basic, in-born, biologically adaptive motivational system that drives the infant to create a few, selective attachments in life.” It is explained that, unlike original conceptualizations of attachment, the individuals to whom the infant becomes attached can be any adult that is present and interacts with the developing infant with no necessity for shared biology or specific gender. The major point of the article seems to be that early attachment experiences with caregivers fundamentally shape the both the physiological connections formed in the brain (i.e., brain specialization and organization) as well as the development of the “mind.” Of interest, the author discusses neural plasticity, or the concept that the brain grows and changes in response to experience throughout the lifespan. At the same time, the argument presented focuses on the importance of early experience when many of these systems are first developing (although it is recognized that attachment classifications and neural circuitry can change later in life).
One of the most interesting points in the paper (in my opinion) deals with the findings that early sensory experiences are not nearly as important to healthy development as interpersonal interactions. Both neurobiological and developmental research support the conclusion that the use of videos, such as Baby Einstein, are not necessary, as only a minimal amount of sensory stimulation is needed for adaptive development in infants. On the other hand, if a caregiver relies solely on such videos and programs rather than collaboratively interacting with their child, the likelihood for suboptimal development increases. Siegel explains that it is through these early collaborative interactions that the infant develops the capacity for self-regulation, theory of mind, and a sense of self. Siegel also touches on research that has found that suboptimal attachment experiences may actually alter the brain’s neuroendocrine response to stress. At the same time, he develops a list of ways to yield secure attachment, which includes collaborative interaction, reflective dialogue, repair of misunderstandings, coherent temporal narratives, and emotional communication. For Seigel, emotional communication seems to be one of the more important factors as this guides the infant’s experiences in his or her preverbal world. Specifically, the importance of non-verbal communication and emotion sharing between the infant and caregiver in the pre-verbal years is believed to impact the development of an array of implicit processes that will remain throughout one’s life. Basically although most individuals do not have an explicit memory of their infancy, that implicit memories are formed during this time. With new research abounding on the impact of implicit processes, this is the first time that I have seen anyone discuss the possible development of such processes (which even if I’m not sure I totally buy – due to lack of empirical evidence- it seems worthy of note). In addition, Siegel points to the importance of the orbitofrontal cortex for the individual’s capacity for response flexibility, or adaptive self-regulation. Of note is the fact that he recognizes that this region is uniquely positioned within the brain so as to have direct communication with limbic areas, other cortex areas, and the brain stem, thus allowing it to functionally regulate such widely distributed input and output in order to achieve response flexibility.
The Lemche et al. (2006) article for this week also focuses on attachment, but their work was designed to capture the neurological correlates of attachment-related reactions. The researchers used a newly validated measure of attachment in which participants were subliminally primed with maternal rejection/separation distress or neutral sentences and reaction times to post-presentation target sentences are recorded. Larger mean reaction times to the target sentence were taken as evidence of insecure attachment. Skin conductance, a known autonomic response indicator, was also measured. The main finding of this work was that the amygdala mediates the autonomic responses associated with attachment insecurity in healthy adult humans. In other words, fMRI evidence demonstrated a positive correlation between bilateral amygdala activation and insecure attachment as well as a positive correlation between bilateral amygdala activation and skin conductance. It was also found that the magnitude of skin conductance (i.e., autonomic response) was positively correlated to insecure attachment in the maternal rejection/separation distress condition. This research adds to a growing body of mammalian studies that suggest that the amygdala is important to attachment.
Jen Vosilla
Gillath, Bunge, Shaver, Wendelken & Mikulincer (2005)
This article looked at attachment-style differences in brain regions associated with emotion, emotion-regulation and memory.
Prior to the fMRI session, participants filled out 3 questionnaires assessing attachment anxiety and avoidance (measured by the Experiences in Close Relationships scale- ECR), neuroticism (a subscale from the Big Five Inventory) and trait anxiety (Spielberger ‘s Trait Anxiety Inventory- STAI). Twenty female participants were chosen that had either a “relatively” high score on one attachment dimension and a score close to the median on the other or low scores on both attachment dimensions (secure attachment). For a study looking for individual differences, the sample size was too low and their only explanation for using only women was “to eliminate gender-related variance”. Is that usually a problem in these types of studies? Also, in choosing participants what constituted a relatively high score or low on the ECR scale? The women also had to be in serious long-term relationships, but this is not defined either. One of my friends considers a relationship that lasts a month as long-term and serious, but I have a different opinion.
The task during the fMRI involved 5 remembered or imagined scenarios that were emotionally neutral (driving alone to Lake Tahoe), neutral but relationship-related (neutral activity with partner), or emotionally negative and relationship-related (conflict with partner, breaking up with partner, and partner dying). For each scenario there were control, think, don’t think and free thinking blocks indicated by colors on a traffic light presented, in which participants pressed a response button during each for varying reasons, when yellow light appeared, shift in thoughts/images, thinking about the forbidden topic and think about formerly forbidden topic, respectively. During the analysis the authors don’t present data from the control and free thinking blocks nor do they assess the 3 emotionally negative and relationship-related scenarios separately, instead always averaging data from all three. What was the point in having 3 of the same condition if the authors didn’t plan to look at them separately, especially considering they vary in how negative they are? My guess is, the results didn’t show any difference between the 3 (which isn’t stated), so they left out predictions about it. Also, I wonder if remembering an actual memory versus imagining the 5 scenarios affected brain activation as the authors did not address this or the intensity of their feelings during the fMRI.
Support for the Main Hypotheses:
1) People with high scores on attachment anxiety have greater activation in emotion-related regions during the emotionally negative, relationship-related scenarios. Results found greater activation in ATP (associated with sadness) and lower activation in OFC (emotion regulation) with a negative correlation between activity in these areas. Authors concluded that people high in attachment anxiety experience high emotional arousal and low ability to down-regulate it
2) People with high scores on attachment anxiety have greater activation in memory-related regions during the emotionally negative, relationship-related scenarios. Results found greater activation in hippocampus (associated with memory retrieval) during the emotionally negative, relationship-related scenarios leading to the conclusion that this increased activation for people high in attachment anxiety is due to recalling a greater number of negative memories.
3) Authors found that attachment avoidant people in comparison to less avoidant people, failed to show as much deactivation in the SCC and LPFC in the Don’t Think block, suggesting that those high in attachment avoidance’s suppression may be less complete or efficient.
Some other criticisms of the article include why they excluded people who scored high on both dimensions of attachment. I could understand the exclusion if they separated the participants into a highly avoidant, highly anxious and secure attachment groups, but they did not and in fact I’d have like to see those comparisons, or even if the highly avoidant and highly anxious were grouped into an insecure attachment group (though according to research that would include those high on both dimensions).
And now for the second article I focused on: (Bartels & Zeki, 2004)
As the title indicates, this article looked at the neural correlates of maternal and romantic love. The authors hypothesized that both maternal and romantic love would share common brain activity due to both having a similar evolutionary origin and biological function, activating brain regions associated with reward (areas rich in oxytocin and vasopressin receptors). For maternal love analysis, 20 mothers (although only 19 included in the analysis) participated in the study, including 2 that were left-handed. Since when is it okay to use lefties? I must have missed the memo that said that there aren’t differences in brain lateralization and even if said memo existed, I would have liked to been told that brain activation in these sinners (I’m lefty so I can say that) did not affect the data analysis. During the fMRI session, participants viewed 4 photographs of either their child, another child that they are acquainted with of the same age, their best friend and one of another person they are acquainted with. Intensity ratings of 8 different emotions were collected after the scan for each of the photographs. Data from Bartels (2000) study was used as the romantic love sample in the analyses. Where did these photographs come from? Maybe it’s just me, but I don’t normally have pictures of child and friend acquaintances and personally I would just print some random pictures I found on Google than actually go take a picture specifically for a study that I’m not getting paid for.
In comparing brain activation in maternal and romantic love participants, the authors found overlapping regions in those associated with the reward system, as well as common deactivation in regions associated with negative emotions, social judgment and ‘mentalizing’. Also, activity in the hypothalamus for romantic love is suggested to be the erotic arousal aspect not found (hopefully) in maternal love. I would have liked to see whether there was a significant difference in levels of activation or deactivation between maternal and romantic love. Both are usually considered strong emotions, but is one more rewarding than the other? Perhaps we can answer the age old question of if you had to sacrifice your husband or your child, which would it be? Speaking of men, future studies should look into similarities and differences between paternal and maternal love. I also agree with David in wondering how a best friend of the opposite gender compares with love for a romantic partner. If as the authors suggest the hypothalamus indicates erotic arousal, then I would predict greater activity for a romantic partner and lower, but still somewhat present, activity for best friends of the opposite gender.
Jenny Perella
read this get a chance to do so. Second, it is late, it’s been a long
day, and I’m tired; hence, this is poorly written, may be slightly
disorganized (I tried), and definitely lacks transitions. Sorry! I
can’t focus anymore but I promise to do a better job at explaining my
articles in class tomorrow:) That being said…
The Insel (1997) article explored the neurobiology of attachment,
specifically in regard to the neuropeptides oxytocin and vasopressin,
and specifically as they relate to pair (male-female) bonding and
mother-infant bonding. Though attachment is likely not defined by a
single neurochemical pathway, oxytocin and vasopressin have been
implicated as mediators. First, some background: oxytocin and
vasopressin are synthesized in the hypothalamus and released into the
bloodstream by the posterior pituitary. They are only found in
mammals, and evolutionarily have been important for reproductive
behaviors. Receptors for these neuropeptides in humans are found
primarily in the limbic system in the forebrain and in autonomic
centers in the brainstem. Specifically, oxytocin is clustered in the
basal forebrain cholinergic nuclei, , the nucleus basalis of Meynert,
the diagonal band of Broca, and in the preoptic area of the
hypothalamus (important for the mediation of reproductive behaviors).
Vasopression receptors are clustered in the lateral septum and
amygdala, and in limbic areas with connections to the hippocampus and
anterior hypothalamus.
Insel extrapolates information from studies of pair bonding in prairie
voles (mice-like animals) and montane voles to infer possible similar
processes in humans. These 2 species are important because, like
humans, prairie voles are monogamous, and montane voles are not.
Prairie voles exhibit many different social bonding behaviors, whereas
montane voles are very anti-social creatures, making them a good
behavioral and neurobiological comparison group. Prairie voles, to
which humans are being compared, and montane voles differ
substantially in their distribution of oxytocin and vasopressin
receptors. Insel describes these pathways in detail, but I am not
going to get into this because at the end of the description he says
that human pathways look nothing like either the montane vole or
prairie vole. However, what is important to note is that (quite
obviously) differences in receptor distribution may be related to how
the species differ in their social behaviors. Interestingly too,
oxytocin and vasopressin have differential effects in male and female
voles (and humans), with females being more susceptible to changes in
oxytocin and vasopressin being more important for males. When female
montane voles actually do behave soctally as parents shortly after the
birth of their offspring, they show oxytocin receptor patterns similar
to those of the prairie vole, suggesting that a) these patterns are
malleable, and b) oxytocin is important for the elicitation of
maternal care-giving behaviors. In addition, oxytocin is released
during mating, and mating facilitates the formation of the pair bond
in prairie voles, further implicating oxytocin in social attachment.
Vasopressin, on the other hand, is associated with male partner-
preference and post-mating aggression to intruders (in prairie voles;
maybe humans too). One thing I thought would be interesting would be
to have montane voles reared by prairie voles (and vice versa), then
see if the montanes show the same stereotypical parenting behaviors as
either the montanes or prairies. Would the montane develop pathways
typical of the prairie (e.g. social behaviors and similar neural
pathways), and vice versa? Despite all this, the role of oxytocin and
vasopressin the formation of human bonds is generally unexplored.
Parental behavior was also a focus of this article. For maternal
behavior, Insel focuses on rat research. Here, we get further insight
into the potential roles of oxytocin and vasopressin in humans
(assuming that this research can be generalized). Research has found
that giving oxytocin to female rats facilitates the onset of maternal
behavior; likewise, blocking oxytocin inhibits maternal behavior.
There has been little study of paternal behavior because rats exhibit
little of it. However, infusions of vasopressin in male prairie voles
were found to increase time spent with pups, suggesting the importance
of vasopressin in male social bonding. In humans, “synthetic oxytocin
is administered intravenously to support uterine contractions in most
deliveries, but there is little research on the effects of this
treatment on the mother-infant relationship.”
Insel notes that oxytocin and vasopressin are not exclusively
“attachment hormones”, and that other systems are likely involved in
social bonding.
The Meany & Moshe (2005) article looked at the effects that early life
experiences have on genetic expression and production of various
phenotypes. Specifically, parental care has been shown to affect
offspring’s autonomic responses to stress. Studies in rats show that
handling of newborn baby rats decreases the degree of hypothalamic-
pituitary-adrenal (HPA) responses to stress in adulthood, suggesting
that, if generalizable, positive interactions between human mother and
baby may predispose the child to appropriately regulate stress in
adulthood.
Basically the research reported in this article are studies about rats
and the effects of low vs. high grooming behaviors toward the
offspring (LG and HG). I’m going to really dumb down the article and
present the main take-home points; we can discuss the details in
class. First, probably as no surprise, high LG moms produce offspring
that are better able to handle stress. Neurobiologically, these rats
show decreased levels of ACTH and corticosterone (stress hormones) in
response to stress. They also show increased levels of hippocampal
slucocorticoid receptor (GR) mRNA and protein synthesis, obviously
associated with increased ability to handle stress. The proposed
mechanism for this biological response is that positive maternal
behaviors increase levels of serotonin and expression of transcription
factor NGFI-A, and these increases lead to the increased hippocampal
GR, which ultimately leads to DNA demethylation and the biological
reduction of stress. Interestingly, there are differences in levels of
NGFI-A during rat infancy (which lead to differences in GR), but in
adulthood these differences are null; only differences in GR remain,
suggesting that this temporary difference in protein transcription
ultimately alters the rat’s genetic expression (thus some behaviors,
e.g. stress responses, are biologically predisposed or constrained).
For this article, the main take-home message is that even brief (here
in rats, only 1 week) experiences early in life have a large impact
our subsequent ability to regulate, in this case to biologically
respond to stress. This ability to regulate is shaped by our
experiences via the production/non-production of various hormones,
proteins, transcription factors, etc., which affect our body’s degree
of DNA methylation. DNA methylation is the proposed mechanism by which
our genes are physically altered, resulting in the expression/non-
expression of certain behaviors.
Monicarodr
Monica Rodriguez
First, thanks to all of you for your thoughtful comments to this
week’s readings on attachment and love. On the love end, we have a
more critical view of studies. Beka and Stuart comment on the Bianch-
DeMicheli and Aron et al, similar studies examining passionate love
and its effects in energizing and motivating behavior and
performance.
I agree with Beka’s and Stuart views that authors here use a very
specific and limited definition of romantic love which tends to be
presented as representative of all forms of romantic love. The types
of questions to determine love (how many waking hours women spent
thinking about their partners and the presence of butterflies in your
stomach) appear to be more characteristic of a 13-year old in love
than of 23-47 year olds! But their main point is that the feeling of
being in love has facilitative effects that correspond to goal
oriented, top-down processes in a neuro-motivational network, as
opposed to an “emotion” only. It appeared to me that the findings
showed an enhanced attentional system which allowed for faster
reaction times in the beloved and neutral conditions with women in
love. I also agree with Stuart and Jen on “Hey, where are the guys
in love”?
Jen focused on Gillath et al, which also examined attachment-style
this article, from which we can conclude that people with anxious
attachment experience high emotional arousal and low ability to down-
regulate this arousal. When dealing with emotionally negative
scenarios, they found greater activation in the hippocampus as they
recalled negative memories. In a second study these authors found
activation in overlapping reward-system regions and deactivation in
regions associated with negative emotions, social judgment, and ToM.
Like Je4n, I would have liked to see the authors hypothesize and
discuss what were the differences in brain region activation or
deactivation when comparing maternal and romantic love.
Lindsay, David and Jenny focused on the attachment or maternal side
of love. Like Lindsay points out, it was when studying this
literature that I had the insight of the tremendous role of social
interactions in development, to the point that cognitive development
may even be the consequence of social behavior. Jenny gives us a very
well described version of some of the most important findings in the
neurobiology of attachment to date. The Meaney et al is a difficult
one (read Jenny’s version, it is great) but it has been critical in
demonstrating that even brief experiences early in life have a large
impact in our subsequent abilities to respond to stress. AS David
points out, the explanations and the process itself is a complex one.
However, the bottom line is that “a large part of the bond is due to
an evolutionary preference for the scent, feel and sound of one’s
mother”.
Below are some notes and general background that I have obtained from
readings on the early attachment development in mammals and its
social, biological, and neural consequences. These may add and
possibly greatly overlap to your notes:
Evolution has ensured that caregivers and infants establish a most
powerful social bond and have strong preference for each other to
facilitate the infants’ facilitate survival, reproduction, and
adaptation to stressful and changing environmental demands. A complex
and flexible bio behavioral attachment system of mother-infant
interaction keeps them in close proximity, provides infants with a
reliable and secure base from which to explore, and shields them from
external threats.
It is not surprising then that the neurochemical systems involved in
social attachment are related to the neural systems for reproduction
and rewards. In rodent, primate, and human mothers, a crucial hormone
for birth and lactation, oxytocin, promotes maternal affiliation and
the formation and maintenance of social bonding. Maternal behaviors
(e.g., grooming, physical contact) are, in turn, involved in the
regulation of many physiological processes in the infant (e.g., heart
rate, respiratory rate, protein synthesis). Receptors for oxytocin (or
vasopressin in males) are also found in the infants’ developing brain.
In rat pups, it has been found that by an administration of oxytocin
or vasopressin, the infants’ distress responses when separated from
their mothers are reduced. Oxytocin and opioids also facilitate the
classical conditioning of maternal odors and play a role in infants’
early affiliative behaviors. Many of these early postnatal behaviors
that bring the infant closer to its mother (e.g., attraction to
maternal odors, approach behaviors) are now believed to be learned
prenatally in rodents.
Early mother-infant regulatory processes can significantly alter
biological stress response in the infant. Studies have shown
heightened fearfulness, increased corticotrophin (CRH) releasing
hormone in the amygdala and locus coeruleus, a reduced number of
glucorticoid receptors, and increased and more prolongued corticoid
and adreno-corticotropic hormone (ACTH) responses to stressors as a
function of maternal deprivation (Meaney, Plotsky, etc). These effects
can be long-lasting: early maternal separation has been found to
increase hypertension as well as vulnerability to gastric ulcer in
adult rats. Variations in normal levels of maternal investment (e.g.,
licking, grooming) appear to systematically regulate the stress
response of their offspring.
Limbic structures related to rewards have been shown to be critically
involved in the modulation of affiliative behaviors in both mothers
and infants. For instance, studies have demonstrated that repeated
separation experiences in rat pups transiently elevate dopaminergic
receptors and serotonergic receptors in the prefrontal cortex,
hippocampus, and amygdale. In studies of pups’ long term social
isolation a reduced dopaminergic innervation in the anterior cingulate
and orbito-frontal cortex related to social reward has been found.
The reward circuitry or mesocorticolimbic pathway is also associated
with the formation of social attachment and regulated by
neuropeptides. For example, rearing animals in social isolation alters
the response of prefrontal cortical neurons to stimulation of the
ventral tegmental area (VTA). Oxytocin receptor levels are enriched in
the VTA, and oxytocin infusion is related to increased maternal
interaction with pups; lesions in the nucleus accumbens and VTA, the
source for the mesocorticolimbic dopamine system, result in pup
retrieval deficits and reduction in maternal approach and interaction
with pups. In the same vein, dopamine receptor blockers increase
negative withdrawal tendencies in the mother, and suppress the
expression of pup licking/grooming.
During ongoing mother-infant interactions biological and social
processes are recruited that are delicately interlinked and
reciprocally influence each other. Naturally, early experiences of
maternal deprivation, marked abuse, neglect, and other chronic
stressors can alter the psychobiological short and long term
functioning of the offspring, particularly in their responses to
stress and learning. But caregiving experiences are ongoing and
involve continuous “updating”. Therefore, the negative influences of
negligent or abusive care on the psychobiological systems related to
stress may be undone by later positive caregiver-child experiences
which may unfold in development.