In my last post I explored the role of the default mode network in addiction. One conclusion was that addicts’ brains activate the default mode network more than the brains of nonaddicts.
This brought us to a paradox. Actually two paradoxes. (My wife hates it when I pun, but a pair o’ ducks already sounds like two… Ok, ignore that and we’ll proceed.) The default mode network (a set of 6-8 brain regions that often become synchronized) corresponds with daydreaming, nondirected thinking, going with the flow, imagining oneself in the past and/or future, etc.
Paradox 1: Isn’t it good to be in the default mode? Isn’t that the foundation of creativity or at least relaxed self-reflection? (well expressed by Persephone in a comment on the last post)
Paradox 2: Addiction is characterized by craving, which means highly focused attention on a single goal. I want to get some…..now! This focused state corresponds with an entirely different network of brain structures (including the dACC) — those involved in intense, planful activity, or homing in on a problem that needs to be resolved.
So how do we reconcile the “positives” of the default mode network, and the “negatives” of the task-focused network, in order to arrive at a coherent model of addictive behaviour?
And while we consider this, let’s reflect on Shaun’s lovely metaphor, also from comments on the last post:
I have always described addictive behaviour as walking through a field of tall grass. We tread a path and we become “programmed” to walk this path. We return to this path every time we feel “lost”.
My former student, Professor Rebecca Todd, suggested something similar, but in more concrete terms. Falling into an addictive act should be seen as a micro-developmental process. That means it isn’t a single event; it develops, but it develops in micro time — in seconds or minutes. Duh. Why didn’t I think of that? Almost every emotional phenomenon is best seen as a micro-developmental process — a cascade (love that word) that takes a few seconds, minutes, or even hours to unfold. Thank you, Rebecca! (I like to think I taught her to be brilliant, but maybe she just came that way.)
So here’s the beginning of a micro-developmental model that puts these ideas together:
Step 2: Impulse. This is exactly the state from which impulsive behaviour can easily spring. Because it’s…thoughtless. Free-floating fantasies lead to images of drugs, booze, sex, food, or whatever it is that attracts you. And off you go!
Scientists have very good evidence of the link between impulsivity and drug-taking. The following is from an article by Dalley, Everitt, and Robbins, 2011:
Impulsivity is the tendency to act prematurely without foresight…. One form of impulsivity depends on the temporal discounting of reward [which means going after immediate rewards, even at the expense of long-term consequences], another on….response disinhibition [what it sounds like: just do it!]. Impulsivity is commonly associated with addiction to drugs from different pharmacological classes…
Step 3: Focused attention driven by desire. The third step is that tightly focused preoccupation with the soon-to-be (I hope, I wish) reward. Now brain activation patterns have switched over completely, from the nondirected to the directed, from the default mode to the highly-focused, task-oriented mode (which, in the case of addiction, must include hyperactivation of the nucleus accumbens / ventral striatum, spiking on dopamine). Now all your energies are directed at solving the problem: getting it and doing it — plus subsidiary problems like paying for it, lying about, and hiding it.
I believe there is a fourth step, compulsion, which is not the same thing as impulse (though they are related). More about that next post. I also believe there are different strategies for trying to stop the cascade, depending on which step you’re in. I’d love to hear your ideas about that.
Finally, here’s Bhagavan Das, that wise / spiritual / contemplative / meditative dude with a huge beard, talking to us from a recent documentary:
You’ve got to realize one thing: you need to tame your wild and crazy mind. Your mind has a very very bad habit, which we call self-cherishing.
That may be where all the trouble starts: the free-ranging fantasies of the default mode converge on the wish to improve the way you feel.