Brain Capacity and 7+/- 2 Information Bits?

One of the things I sometimes hear people talk about is the idea that brain can only manage 7+2 information bits at a time. On some occasions, people are referring to our memory capacity (we can only remember 7 + 2 bits); on others, people have stretched this to mean our brains can handle only 7 + 2 bits of information at any one time.

I need to challenge this as a brain myth worth losing.

I want you to think about the brain instead as an amazing system of billions of possible connections all networked together and all doing what they do in unbelievably short time periods.

Here are some "bits" of information I'd like you to consider:

  • The 7+ 2 is a measure of working memory – how much can we consciously hold and use in some way in any few seconds. Nothing more than that.
  • “Holding” 7 “clusters” in working memory is a more realistic description – the 7 things can be individual letters, but the word “letters” is just one cluster (if one can read English).
  • I’ve used "clusters" or “things”, because “bits” can be used to refer to separate elements of some kind OR as used in information theory meaning “information bits” = the smallest unit of information that lets us distinguish a difference. It can get confusing about which sense we are using it in -- giving rise to the Brain Myth above.
  • What was likely really measured in the original 1956 study that gave rise to this 7+ 2 number is the time to deliver the information presented -- not the pure number of clusters themselves. This is a bit tricky to get across clearly. It means that delivering 7 digits takes x seconds and we can actually hold "information" (here: 7 digits) across that number of seconds (here: about 7 seconds). It does NOT mean that we can only remember “7 things”. So in looking at later research, we discover different limits across different kinds of information based on how long they take to deliver: 7 as the maximum for digits, 6 as our maximum for letters, 5 max for words, even fewer for longer words, etc.
  • Also, this research is measuring what we can communicate as recall rather than what we are able to absorb (what “got in”) as information. Do you see the difference? Because it takes us longer to share the information we are "holding", that means we can hold less -- because it's taking more time. When we don't have to communicate it, when we are just using that information in real time, we can do much much more.
  • We are able to handle much larger amounts of information in real life than in studies measuring working memory recall (e.g., non-experts in an area can recall about 4 to 8 things – that’s about 2.8 bits in the strict information-theory sense, depending on the way they are presented). But when we are reading, writing, playing tennis, etc., we are processing much much more – think about this:

 o   Sharing our conscious experience of any moment: about 16 bits per second

o   Conscious experience (not just recall or communication, but awareness): something less than 100 bits per second

o   Brain processing of sensory and internal stimuli: more like 100,000,000 bits per second

  •  Even though these numbers differ depending on whose research we look at, there is still generally a one million to 1 ratio between what is sensed by the brain and what we consciously perceive.

 I’ll throw in one more tidbit in case it’s not totally off-topic -- which is that our conscious awareness of making decisions, recognizing something etc. lags behind our non-conscious activity by about 0.5 seconds. .... So that decision or choice you think you just made, you actually made about half a second earlier. ;-)

I think all this has implications for what and how much we try to do consciously vs using other strategies that let us maximize the bigger processing power of what’s going on “under the hood” (or “under the bonnet”) like environmental cues, intuition, etc. Also, that it’s likely not our brain getting overloaded (unless there’s injury or dysfunction), it’s our conscious awareness trying to deal with too many things.

 What can we do to let the power of our brain do what it does without trying to drive a 100 million bits using the power of 100 bits?

What if the "problem" of getting overwhelmed isn't our brain, but our need to be aware of and "in control" of everything? Those attempts to multi-task and be on top of everything actually divides the available resources and makes us less capable.

What if moving more things to "automatic" could actually improve our preformance?  That's the power of productive habits, using tools in smart ways, and setting up our environments to kee pus pointed in the right direction.

What other ideas do you have for letting the 100 million drive more often? ;-)