Ever wonder why some people don’t even want to sit on a motorcycle with the engine turned off, while others are willing to break their family’s hearts and destroy everything good in life just to go on something fast without doors because “it feels cool.”
Well, it might come down to your caudate nucleus, which is a part of your brain involved in emotional decision-making.
In a study on animals (published in the journal Neuron), researchers found that they could manipulate pessimism and risk-reward calculations by stimulating the caudate nucleus.
The researchers gave the animals a reward and an unpleasant stimulus, and gauged how big a reward it would take for them to accept the unpleasant stimulus. Cost-benefit stuff.
At some point, the unpleasant stimulus accompanying the reward got bad enough that the animals would refuse the reward.
Now, when the researchers messed with the caudate nucleus, they found that the animals started to focus less on the reward and more on the unpleasant stimulus — even though the reward and stimulus were exactly the same as before.
So now, the animals refused to go after the reward because they were so focused on the unpleasant stimulus. Their “cost-benefit calculation became skewed, and the animals began to avoid combinations that they previously would have accepted.”
Graybiel is now working with psychiatrists at McLean Hospital to study patients who suffer from depression and anxiety, to see if their brains show abnormal activity in the neocortex and caudate nucleus during approach-avoidance decision-making. Magnetic resonance imaging (MRI) studies have shown abnormal activity in two regions of the medial prefrontal cortex that connect with the caudate nucleus.
As the authors note, people who are depressed, anxious, and/or have OCD, are much more likely to think about potential negative outcomes of a situation than positive outcomes.
The anxiety and OCD components here are easy to see. It’s commonly pointed out that, in those with anxiety disorders, “life becomes small.”
True – if the animals in the study are passing up on all the rewards because of fear, well, what is life? There are no rewards, only dread.
I’m not exactly sure, though, how depression fits into all of this.
When I’m anxious, this study has the ring of truth. I’ll gladly give up a selfie with a cobra. Or a selfie with a flash on, because — you know — could the bright lights flashing at my eye provoke the onset of macular degeneration?
But when I’m depressed, I’m actually much more likely to take a selfiie with the cobra, because I don’t really care what happens with my life.
So to me, this study has a lot more to say about our anxiety and OCD than our depression.
So the question is — how do we manipulate the caudate nucleus in humans to enrich our lives again?
Your move, Eli Lilly.
[Photo: Pexels]
