Bartels and Zeki. The neural correlates of maternal and romantic love. Flashcards
How did they measure romantic love?
- recruited volunteers who professed to be madly and deeply in love
- during the scan, each subject viewed colored pictures of the faces of four people on a neural background: their boy/girlfriend and 3 friends of the same sex as their loved partner. All four were similar of age and duration of friendship was not shorter than the one of the loving relationships.
- subjects provided these photos
- subjects were viewed
How did they measure love-related BOLD repsonses?
BOLD: Blood oxygen dependent level is an index of blood flow so it is an indirect measurement of neural activity.
- Stimulus conditions were compared to a control or baseline condition
- Controlling for 3 variables: visual complexity of a face, stimulus category (faces) and familiarity with the person in the photo.
- using photos of a child of the same age and acquainted for the same amount of time controls for familiarity
- These two conditions differ only in the independent variable - emotional response to the face
What control stimuli did they use and what did these stimuli control for?
Photographs of a child the same age as their own child whom they were acquainted with for the same amount of time
- their best friend (average 13 years)
- another person they were acquainted with (Average 5 years)
Pictures controlled for familiarity and friendly feelings.
What regions were activated by maternal love only?
cortical regions
- lateral obitofrontal *
- lateral fusiform cortex
- occipital cortex adn a region close to the frontal eye fields
subcortical regions
- PAG of the midbrain *
- postero-ventral part of the thalamus
What regions were activated by romantic love only?
- dendrate gyrus/hippocampus
- hypothalamus
What regions were activate by both types of love? (shared)
cortical regions
- medial insula *
- anterior cingulate cortex (more prominent in romantic love)
subcortical regions
- striatum * (putament, globus pallidus, caudate nucleus)
Name some of the structures in the reward pathway that were activated and some of the structures involved in the negative emotions that were deactivated, by maternal love.
Reward Pathway
- recognizing that regions in addition to the core regions (SN, NAcc, SLEA) such as the striatum and other regions receiving projections from the core regions play a direct role in human reward
PAG may be specifically involved in human maternal (and not pairbonding) behavior. PAG receives direct connections from the limbic areas (including those activated here), and contains a high density of vasopressin and oxytocin receptors.
PAG has direct connections with the orbitofrontal cortex which
perhaps accounts for the equally specific activation of the latter with
maternal love. The lateral orbitofrontal cortex is activated with
pleasant visual, tactile and olfactory stimuli, with its response
depending on pleasantness rather than intensity of stimulation
Negative Emotions
- deactivations reduced negative emotions as well as social judgement
- similiar to that observed with romantic love
- typical pattern: bilateral and affected the right hemisphere
- focused on mPRC, parieto-occipital junction/superior temportal sulcus, medial prefrontal/paracingualte cortex and temporal poles
- also involed posterios cingulate gyrus, medial ceneus and amygdloid region
Bartels and Zeik found that this same area was more active when mothers looked at photographs of their own infants vs. other familiar infants. This area is the
PAG
What evidence do Bartel & Zeik provide that OT and AVP are related to maternal and romantic love in humans
- Overlapping regions of activation in the striatum (putamen, globus pallidus, caudate nucleus) the middle insula and the dorsal parts of the anterior cortex
- the activated regions belonging to the reward system are known to contain a high density of OT and AVP receptors, suggesting that neurohormonal control of these strong forms of attachment observed in animals (like rats) also applied to humans. Results show that most regions charted by autoradiography to contain receptors of these neuropeptides are activated by both types of love.
- Specific activation of PAG in maternal love. PAG received direct connections from the limbic areas, may account for activation with maternal love
- the specific activation of the dentrate gyrus/hippocampus with romantic love for AVP constitutes the first evidence for similar functional/neurohormonal associations in the human.
Based on what you’ve learned in this course, do you think looking at photographs of loved ones could trigger OT secretion? Why or Why not?
Yes, looking at photos of loved ones can trigger OT release.
The PAG and the lateral orbitofrontal cortex is a region activated specifically to maternal love.
PAG has direct connections with the orbitofrontal cortex which
perhaps accounts for the equally specific activation of the latter with
maternal love. The lateral orbitofrontal cortex is activated with
pleasant visual, tactile and olfactory stimuli, with its response
depending on pleasantness rather than intensity of stimulation
Experiment by Seltzer et. al (2010) that found a mother’s voice could trigger OT release
- touch is known to cause OT release in peopel so, if social touch and social vocalization can do it, it seems likely that social images (faces) can too.
If visual stimuli can trigger OT release, this might influence the responses measured by Bartels & Zeik. How can one determine whether OT secretion was having an effect on the BOLD signals in these experiments?
- Look at whether administering an OT antagonist drug prior to the fMRI experiment would affect the BOLD response to viewing photographs of loved ones. Compare the response after giving either a placebo or the OT antagonist.
