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PSYC23H3S – Lecture 4 02-02-12
Oxytocin and tending
Prairie voles were bonding and had long lasting relationships whereas the montane voles had multiple
and different relationships. The question of how that affects care giving behaviour is interesting. There’s
link between pair bonding and how you take care of offspring. There are biological reasons for what
those are what they are. If you haven’t given birth yet you’ll spend time with a pup that’s thrown at you.
If you have given birth you’ll spend an equal amount of time. PV oxytocin don’t shift dramatically. The
montane voles their oxytocin levels are really low and half the level of what the prairie voles are. Their
levels do rise however when they become a parent. They will end up having a similar level even though
their behaviour isn’t similarly high.
OXytocin during pregnancy
The women will show significant elevation in third trimester in terms of the oxytocin levels. You can see
that as you increase leveis of oxytocin at pregnancy the cortisol levels are decline pretty dramatically.
We want to see whether these hormone changes affect their behaviour in caring for their offspring. The
more O level that you had at the third trimester it was moderately related to the increase of the
maternal behaviour to the pup. Since O levels and C are inversely related; more O less C; those who had
lower C levels had negative association here; had greater maternal behaviour in the third trimester.
These data are partly consistent with the vole data we saw a moment ago.
Mutual Regulation vs. Self-Regulation
There’s a lot going on in terms of how they regulate their stress system. What is the parent doing to
facilitate the freeing up of energy; the increase of complexity; the creation of more associations; and the
formation of more complex neural representations? We can take the infant parent dyad and stop them
from sending any signals to the infant.
Still-face Face-to-face paradigm
How long can you stare someone down and not react. It’s difficult. The parent in this case has to do it.
They do it pretty well. They’re just looking like they came from mars and have no relation to the child.
The child gets curious maybe smiles. “What’s going on?” Cooing occurs. They will do these stress coping
strategies once they become aroused and look away. Eventually the negative effects will skyrocket. How
quickly can they recover once the still face is turned off? Although they do recover in terms of
physiological signals i.e. heart rate, they still show some lingering affect. Tronik is expert at this.
This is something we studied 30 40 years ago. We didn’t think infants can engage in social interaction.
There are reciprocal greetings between the mother and the infant. They’re working to coordinate their
emotions. Then we want the mother to not respond to the baby. The infant picks up on this and tries to
get the mother back. They lose control of the posture because of the stress. It’s a little like the good the