Ito says this finding is important because the conventional thinking is that these areas, along with another part called the dentate gyrus, form a circuit through which information flow occurs in one direction. Information processed by the dentate gyrus gets passed along to the CA3, and then on to CA1. In other words, the CA1 and CA3 should carry out the same function because they’re both part of the same information processing circuit. “But that’s not the case, the CA1 and CA3 in the ventral hippocampus seem to do very opposite things in relation to conflict processing,” says Ito. “It’s this strange bi-directional or oppositional effect, and that goes against traditional thinking of how information processing takes place in this part of the brain,” she says. Because of its possible role in basic motivational behaviour, it may also offer important insights into a range of mental health illnesses. Addiction, for example, could be linked to deficits of approach motivation. Anxiety and depression on the other hand could be linked to avoidance behaviours, all of which could manifest itself in this part of the brain. - utsc.utoronto.ca