Your brain multitasks like a 1980’s personal computer

Posted: April 19, 2013 in Learning, Mental Reboot
Tags: ,

I am generally very much against trying to draw parallels between how the brain works and how a computer works, but this one struck me as certainly funny and possibly useful.  And it’s been rolling around in my head for a while so it’s time to try to get it out so that I can think about something else 🙂

I have heard over and over again and from many sources that multitasking (trying to do more than one thing at the same time) is basically impossible and what we do when we think we’re multitasking is demonstrably less efficient than doing the same things one at a time.  But having spent many years in endless meetings with other middle managers I have observed that the most successful of my peers seemed to pull off something resembling this – reading and responding to email while still being able to track and participate in the thread of conversation that’s going on in the room.   Or even better, the Kung Fu teachers who could call out counts for exercises for the main class while demonstrating totally different exercises in a different rhythm to the new students – I’ve tried that one, it is really, really hard.

So I’ve been doing a decent amount of reading about how the brain works and my tentative conclusion is that the way this is being accomplished is pretty close to how computers of my youth managed to do a couple of things at the same time.  I’m not talking about computers like the one I’m typing on right now.  Today’s computers have a sh*t ton of stuff built into the processor that enable smooth and efficient switching between multiple tasks.  Simply put, there are a bunch of smarts built into the chips that lets the operating system ask the processor to save its working memory for one process and load up its working memory for another process.  This is called a context switch and allows for smooth transition between processes many, many times a second.  Between that and the fact that modern processors have multiple cores and can actually be computing multiple things at the same time I can absolutely guarantee that my brain doesn’t work like a modern computer in this respect.

So what is going on?  It looks like there are at least two mechanism that help us pull off the appearance of multitasking.  The first one is that you have a small amount of very versatile working memory that you may be able to  split up so that you use one part in one way and the other part in another way – effectively at the same time.  This is probably what the Kung Fu teacher in the above example is doing.  With sufficient practice, you end up chunking the information needed to repeatedly call out exercises in a way that leaves you enough working memory left over to deal with the other task of demonstrating to new students.  On the computers I grew up with something pretty similar was used.  A timer based signal would cause an interrupt to happen to let a small program do something useful.  One of the arts of writing these small programs was to use as few as possible of the registers and other resources in the processor (read working memory) so that it was cheaper/faster to switch back to the main program and make it appear that it was doing two things effectively at the same time.

The second interesting aspect of the brain is that at least two of the senses have built in buffering mechanisms.  For hearing you have something called echoic memory that allows you to access up to the last six seconds of what you heard even if you aren’t consciously paying attention to it.  For seeing, you have a similar thing called iconic memory which gives you about a second’s worth of buffer.   This is pretty similar to how input worked in the computers I grew up with.  Some small I/O controller chip would monitor a port and push information into a buffer, then periodically interrupt the main processor to let it know that it had new information to deal with.  Then a small program would start running on the main processor to decide what to do with the new information.  Like the timer based example above the secret to writing an efficient program of this type is to minimize the use of resources while the decision is being made so that the time spent switching back and forth between this program and the main one isn’t noticeable to the user.

So where does that leave the middle manager sitting in a meeting writing email?  I think the people that do this the best probably have larger buffers and either naturally larger working memory to be able to swap back and forth between the two things their doing or are doing better chunking of the incoming data.

And where does that put someone like me who is demonstrably bad at these kinds of multitasking.  Should I continue to just cite the work that talks about how it’s not efficient and refuse to try?  Or are there exercises for improving echoic/iconic buffer utilization that I haven’t run across yet?  Or is this this yet another case for developing better chunking abilities for every-day life?

P.S. The things I’ve read recently that contributed to this line of thought were, Brain Rules: 12 Principles for Surviving and Thriving at Work, Home, and School, CODE, and Memory and the Human Lifespan

  1. David B. Gray says:

    Can you relate multiprocessing to playing the piano with two hands? When I played drums, keeping the beat with my right foot hitting a pedal to hit the bass drum, tapping the cymbal with my left hand and off and on again using both hands/sticks to pound on the snare drum seemed to be multiprocessing.

    My students read and write on their electronic devices in lectures and now in seminars. I wonder how one could test what they are processing, if anything, during the lecture or discussion.

    One issue I’ve been struggling with is how do humans seem to do similar activities in different environmental settings (contexts) and do this with small or large adjustments over time. Early childhood and post-traumatic injury seem to be periods of required large changes while other periods of life seem more gradual change periods. The early childhood rapid changes may be rooted in our evolution but changes post major injury? Childhood development may be a period of building storage and major switching stations But post injury seems to me to be more new routing of old pathways. Do processing centers that managed walking, balance and routine motor patterns atrophy or are they taken over with new responses to a more selected set of stimuli?

    • ohdwg says:

      I think the drumming with multiple extremities/playing piano with both hands is similar to the kung fu teaching example. Extensive practice lets you chunk the knowledge or in this case skill in a way that lets you make use of it with less of your working memory/processing power and lets you do other things effectively at the same time. I image the classic one-man band is the extreme example of this 🙂

      On students – do you sometimes wish that there were either locked down devices (so that all they could do is take notes on them) or that you as the professor had some way of seeing at a high level what the class is doing on their devices? I know in ‘classes’ at work it was often the case that one of the requirements was for laptops to be closed during the lecture part of the class.

      I imagine that the post-traumatic injury change of context has to be a very profound example of changing how one learns, depending on the trauma either mentally or physically or both. If you haven’t delved into neuroplasticity yet, it’s well worth a look.

  2. GlennN says:

    I think there is something to patterns that allow for faster recall, “multi-tasking” and/or fluency. But, fluency doesn’t always result in the most accurate of responses so beware of the middle manager who seems to be multi-tasking when there are new patterns emerging… Perhaps you’re right, pre-emptive multitasking is what we do but for some things we really do need to pay attention for others until we see the pattern and become more fluent… -g

    • ohdwg says:

      Very good point, even the managers that seem to be best at catching up with email (or even coding) while in meetings sometimes get deep enough in to their secondary task that they need to be pulled out rather forcefully.

      Do you have a particular reference for how you’re using fluency here? It seems like there might be more behind that than I’m aware of (always up for throwing another book in the queue).

      • GlennN says:

        I actually don’t have a single reference; there are many; some of which I don’t remember. The Invisible Gorilla is one that reminded me of the others including, and don’t laugh, some dog training books where patterns (chunks) form expectations and reactions as well as illusions – the result of an incorrect prediction. What I liked about the use of the term fluency is the imagery. Imagine someone fluent in a language and what it takes – word association, feelings, sounds, smells etc. All of which, I think, are tasks happening almost at the same time or perhaps individually like time-slicing…

      • ohdwg says:

        Cool. Thanks. I should go back and re-read the Invisible Gorilla. It’s been a while. I may skip the dog training books, but I can see how that would be relevant (I’m not laughing – Really). Do you have thoughts on the distinction between fluency and flow? I feel like fluency might be a part of flow but I’m not sure if that makes sense.

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