Speed and quality of unconscious thinking

Consider the situation where you have a technical problem at work. You think about it consciously for a while without making much progress. Later on, maybe as you wake up or while you’re in the shower, a new idea pops into your head. How did that happen? You were solving the problem somehow without being conscious of doing so. What are the factors that determine the speed and quality of such thought?

I have a little habit of multiplying numbers in my head. When I’m feeling awake I can do this relatively quickly and accurately, but when I’m tired it takes me noticeably longer and I lose track more easily. I don’t really believe that my brain is like a motor that spins faster or slower depending on how much energy I have. And the fact that I make mistakes when I’m tired seems to point to something more like interference rather than just raw speed.

Multiplying numbers is a process that I’m mostly conscious of. But for the mental processes that occur unconsciously are there differences in speed and quality of unconscious thought in the same way that there are for conscious thought?

I don’t have much of an answer to this question except some little pointers that there is some analogous difference in quality and that some sorts of tiredness can degrade the quality of unconscious thought similarly to conscious thought.

For a start, we memorise our times tables as children and then that retrieval happens unconsciously while we’re doing mental arithmetic. From my own experience, the speed and accuracy of that retrieval seem to be among the things that go worse when I’m tired.

This musing was prompted by a situation that I found myself in after moving house last year. Moving was a fairly unpleasant process in itself, and meanwhile a work project that I was responsible for was going more slowly than I’d originally estimated. And there were a number of mildly stressful admin tasks that were in flight simultaneously: claiming insurance for items damaged in the move, trying to communicate to the energy company for the old flat that I was no longer living there, dealing with some internet connectivity problems at the new house, and so on.

When I write it out, it’s clear that there was a lot on my mind that was stressing me, and that it’s perfectly understandable that I’d be feeling some strong emotions after moving house (and moving cities, too). And certainly the whole experience was quite mentally draining. But at the time I was unable to explain to myself why I was feeling upset. I had to talk to someone else in order to make sense of it. When things are going well I can trust my unconscious thoughts to make sense of things in some way and put things in order, but in this case I felt like that was failing to happen. It was as if my unconscious mind had got stuck, or perhaps was just operating more slowly than usual.

I associate that stuck unconscious mind sensation with depression. For the periods in my life when I’ve felt depressed, perhaps part of it was that my unconscious mind wasn’t solving problems for me.

Sometimes it seems like I can deal with at most two problems simultaneously: If there’s only one problem then I decide what I want to do about it and then do it. If there are two problems then I decide what I want to do about the first, then I decide what I want to do about the second, and then I do those things. But with three or more problems, I just spin my wheels uselessly. It seems like every time I try to pick one of the problems to work on, the presence of the others is overwhelming and everything just feels too hopeless to attempt.

I said at the beginning that when I’m struggling to do mental arithmetic it seems more like interference rather than slowness. And when I’m juggling multiple problems, there also seems to be interference.

Unconscious thought needs time and space. Shower thoughts, going for a walk, staring out of the window – all are ways of creating space for unconscious thinking. And maybe some of this is better described as semi-conscious: being aware of what’s coming up, but not directing it. Indeed, most creative thought seems to operate something like that.

Presumably there are things that require some sort of processing that we simply never become conscious of. These might look like complex situations that we navigate successfully, potential conflicts that we avoid, good ideas and insights that we have (unaware of everything that fed into them), even physical coordination and grace. It seems reasonable to expect that these things will go worse when we’re tired or stressed.