by Jonah Lehrer / Wired.com
Sigmund Freud gets a bad rap from modern science. (The immunologist Peter Medawar summarized the feeling of many with his remark that psychoanalysis is the “most stupendous intellectual confidence trick of the twentieth century.”) Sure, Freud’s theories mangled a lot of details — we no longer worry about penis envy or the Oedipus complex — but he was shockingly prescient on the big themes. In recent years, it’s become clear that, as Freud always insisted, the unconscious is the dominant force in our mental life. (What Freud called the id is now a network of brain areas associated with emotion, such as the amygdala and nucleus accumbens.) He was mostly right about the logic of dreams, which often regurgitate those parts of experience we store in long-term memory. And he was basically correct to imagine the mind as a set of conflicted drives, with reason competing against the urges of the passions. We expend a lot of neurotic energy holding ourselves back.
But there’s another Freudian theme that deserves a little 21st century appreciation: his obsession with the mother-child relationship and the way it shadowed people throughout life. Freud saw this parental bond as a dominant motive for behavior, influencing both our development as children and our happiness as adults. (The super-ego, for instance, begins to form when the incestuous desires of the child are thwarted by the father.) Although many of Freud’s particular claims feel like cultural relics, modern attachment theory has confirmed the crucial importance of the maternal bond. As Harry Harlow put it, “You’ve got learn how to love before you can learn how to live.” And it’s our mothers who often first teach us how to love. (Thankfully, human parenting is slowly becoming much more gender neutral. But this a recent cultural innovation.)
A new paper in PLoS ONE expands on this Freudian theme. The study involved a team of scientists at Columbia University, Beth Israel Medical Center and Albert Einstein Medical Center who performed fMRI scans on 28 female subjects between the ages of 18 and 30, half of whom were suffering from unipolar depression. (The patients were evaluated using the Beck Depression Inventory II.) While lying in the scanner, the volunteers looked at pictures of their mothers, a few friends and a selection of strangers. The scientists focused their attention on the left anterior paracingulate gyrus (aPCG), a brain area that plays an important role in the regulation of social emotion. Previous studies have linked the bit of cortex to error and conflict resolution and the understanding of intentionality.
By looking at the differential brain responses of depressed and control subjects after viewing those various faces, the scientists came up with an impressive diagnostic tool. In fact, the fMRi scans were able to predict the presence of depression in nearly 90 percent of subjects; the correlation between actual BDI scores and the predicted BDI scores based on fMRI results was 0.55, which is quite strong. Out of the 28 subjects, the fMRI diagnosis generated one false positive and two false negatives.