Researchers have found that the maternal instinct can override the brain's decision-making regions to prioritize caring for their young. Most interestingly, they found this could even be the case for mothers addicted to cocaine.
For their study, the researchers used a local anesthetic to temporarily inactivate various parts of rats' prefrontal cortices, the part of the brain responsible for decision making. They then tested the rats to see whether they preferred their pups or cocaine.
Before inactivation, 40% of rats preferred spending time in a room associated with cocaine, while another 40% preferred being in a room associated with their pups. Meanwhile, 20% preferred being in a neutral room.
After inactivating the rats' infralimbic cortices (the part of the prefrontal cortex associated with emotional responses like fear), 75% of the rats preferred the cocaine room and 25% the neutral room, while none preferred the pup room. They also found that inactivating this region decreased the mothers' maternal behaviors towards her pups.
The opposite happened though when the prelimbic cortex was inactivated. In this case, the researchers noticed that 71% of rats preferred the pup room, 29% the neutral room, and none the cocaine room.
Thus, the researchers conclude that during motherhood, the brain's infralimbic cortex overtakes other decision-making mechanisms to ensure the mother prioritizes her offspring.
Although interesting findings, it is worth noting that as human and rat brains are not analogous, whether or not the same process occurs in humans is unknown.
That said, the findings nevertheless shed new light on how the maternal brain processes information about their young, and how it is used to bias decision-making. Given the dangers of cocaine abuse to both mother and infants, these findings may be important for future research avenues that better safeguard both mother and infant health.