Nov 27 2012

Did You Not Notice or Not Remember?

Quick – think of the location of the nearest fire extinguisher to where you work (your office, desk, station, or whatever). Fire extinguishers are fairly large and usually conspicuously red objects that are deliberately placed in an obvious and accessible location. Their design and placement is meant to make you notice them, so that you know where they are in an emergency.

However, in a recent study, only 13 out of 54 subjects (24%) we able to recall the location of the nearest fire extinguisher to their office. In some cases subjects worked in the same location for years and walked by the fire extinguisher multiple times per day. How could they not notice something so obvious after hundreds of encounters?

Psychologists have identified a number of phenomena related to how people attend to the world around them. By now you have probably seen the famous basketball passing video (if not, take a look before reading further). This is an example of inattentional blindness – we can only attend to a small percentage of all the sensory information that is coming our way. Our brains evolved to sift through this information and pick out the bits that are likely to be important or relevant. Further, we can consciously direct our attention at certain details of the environment, and when we do we become relatively blind to other aspects of our environment to which we are not attending.

We are also subject to change blindness - even major changes that occur right before our eyes can be missed. This appears to be due to attention and visual processing. Change blindness is less for foreground objects than background objects, for approaching objects than for receding objects, and for new objects in our visual field than for existing objects. These all suggest that we are more likely to detect change for  those things in our visual field that also tend to have a stronger grip on our attention.

The new study possibly identifies a third distinct phenomenon known as inattentional amnesia. It is likely that the subjects in the study noticed the fire extinguisher at some point over the years (probably many times) but for some reason they still did not remember it. This implies that memory for such details is not automatic for most people, even through extreme repetition. There has to either be a trigger or a conscious effort to remember the detail.

There are many examples of this from everyday life. Try to recall the details of a common object. lan Castel, an associate professor of psychology at UCLA and lead author of the study, notes:

“If I asked you to draw the front of a dime or the front of a dollar bill from memory, how well could you do that? You might get some elements right. Do you know who the president is? On the dime, is he facing left or right? Does it say ‘In God We Trust’ on the front of the dollar or the back? Do you know what else it says? You’ve seen it so many times, but you probably haven’t paid much attention to it.”

We tend to notice and remember details that are important to us. Chess masters are better at remembering the location of pieces on a chess board. Physicists are better at remembering the details of a physics equation, and noticing small changes. Think of something at which you have a great deal of knowledge, experience, or interest. After I started studying birds I began to notice small details of bird coloring and anatomy to which I was previously blind. Architects likely notice and remember details of buildings that most people could not recall.

This all makes sense from an adaptive point of view – why waste brain power on small details that are not important to us? It is helpful to recognize the role of conscious effort in noticing and remembering details. Remembering even important details, like the location of life-saving equipment, is not likely to happen automatically.

It is worth noting that in a follow up a few months later every one of the 54 subjects in the study were able to remember the location of the fire extinguisher. Once their attention was drawn to its location, with the further reinforcement of being surprised and perhaps embarrassed by not remembering its location, that detail was encoded in their memory. This research, therefore, justifies all those tedious training sessions, fire drills, airplane lectures, and instructional videos that we have been subjected to over the years. You really should practice and study emergency procedures, locate the nearest exit, and make a conscious effort to remember important details.

This study also adds further evidence to the larger concept that our brains are highly flawed instruments. Perhaps the most important aspect of being a good critical thinker is simply recognizing that there are many ways in which we cannot rely upon our brains to be accurate and unbiased observers and recallers of reality. We need to be forever skeptical of what we think we remember, and rely more on objective external sources of information and valid processes of evaluation.

So add inattentional amnesia to your list of the many various ways in which the human brain is fallible, and think of ways to compensate for this weakness.

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21 responses so far

21 Responses to “Did You Not Notice or Not Remember?”

  1. NicoleIntroverton 27 Nov 2012 at 8:53 am

    It’s sad, every time I open the cabinet under the kitchen sink to get trash bags or Windex I think to myself, “Oh! THERE’S the fire extinguisher!”

  2. DevoutCatalyston 27 Nov 2012 at 10:30 am

    Not sure if I did not notice or if you did not remember to tell us that you’re the guest on Point of Inquiry this week,

    http://traffic.libsyn.com/pointofinquiry/POI_2012_11_27_Steven_Novella.mp3

  3. Zhankforon 27 Nov 2012 at 11:01 am

    Coins don’t have a front and a back, they have an obverse and a reverse. /InsufferablePedant

  4. tmac57on 27 Nov 2012 at 12:10 pm

    For many years,I was charged with doing a monthly routine of inspecting the many (22) fire extinguishers in the telephone central office where I worked.
    It annoyed me a bit, to do what seemed like an excessive amount of inspection,especially since they also hired a professional fire inspector to do the same thing,once per year.
    After reading this,I am beginning to suspect that the real reason for the monthly inspections was so that I would know exactly where the nearest extinguisher was (and I certainly did) in case of a fire*.

    *In fact,early on in my telephone company career,I did have to extinguish a fire that was started by a welder in the basement.

  5. davewon 27 Nov 2012 at 1:02 pm

    This is why high-risk professions use checklists. Repetition is as likely to help you remember something as overlook it without noticing. I posted a checklist next to my tablesaw for exactly the same reason.

  6. SARAon 27 Nov 2012 at 1:25 pm

    One of my employees was married to a fireman and she suggested a simple quiz to give my group asking them things like “where’s the extinguisher”. The embarrassment did in fact make everyone aware of that and other emergency procedures.

    I had the impression that this idea was something the fire dept often suggested, but I might not be recalling that correctly.

  7. locutusbrgon 27 Nov 2012 at 1:57 pm

    @ Steve
    “This study also adds further evidence to the larger concept that our brains are highly flawed instruments. Perhaps the most important aspect of being a good critical thinker is simply recognizing that there are many ways in which we cannot rely upon our brains to be accurate and unbiased observers and recallers of reality. We need to be forever skeptical of what we think we remember, and rely more on objective external sources of information and valid processes of evaluation.”

    I am not sure I agree the description of the brain as highly flawed instrument. As a neurologist you have a more intimate knowledge of the workings and I would not presume that I know more. Still I think that highly flawed is based upon point of view, and what you think the brains purpose truly is. As a didactic recording device our brain fails miserably.
    You could make the argument that the ability to forget has a great many advantages, allocation of resources, speed, and efficiency to name a few upsides. As you well know the reason why robots have a great deal of problems with simple tasks is because of their inability to dismiss unimportant input and taxing computing power. Is it desirable to have our brain focus and retain every single sensory input? The clothing on your body, temperature, sound, every small movement with no ability to push important things to the front and dismiss unimportant stimuli. Would we ever be able to talk in crowed room and understand. Would walk into a unfamiliar room and probably be overwhelmed with sensory input. Would we be like giant sloth’s unable to move quickly. We both know that that brain is not using only 10% of its capacity. If we lacked the ability to dismiss would humans even exist?

    I know that you know second part of your statement is the real problem. Not that the brain is flawed or highly flawed, rather that we think that it is not. Still I think that it is presumptive to presume that perfect recall would be better. Would we all be like Dustin Hoffman in rainman?

  8. Joctrelon 27 Nov 2012 at 6:20 pm

    @Steve Yeah, what locutusbrg said. You could call a hammer a lousy screwdriver (or a Birmingham screwdriver, as I learned from QI), or you could call a television a lousy car stand.

  9. Steven Novellaon 27 Nov 2012 at 7:51 pm

    locutus – that’s a valid point, but I am talking about what most people falsely assume about their brain, that they can rely upon their perception and memory.

    You are correct that the limitations are partly a reasonable tradeoff for functionality, they are also partly inherent.

    It is a matter of framing. The brain is very good at what it does, it just doesn’t do what most people think it does.

  10. ccbowerson 27 Nov 2012 at 9:54 pm

    “It is a matter of framing. The brain is very good at what it does, it just doesn’t do what most people think it does.”

    I often have a similar reaction to what locutusbrg was expressing above when I hear or read things that emphasize the limitations of our brain or perception, and I think it does have to do with framing. There are some things that our biological brains do very well (e.g. pattern recognition), and that may result in some “flaws” (e.g. seeing patterns that aren’t there), but often skeptical perspectives emphasize the flaws.

    I understand why – the average person’s intuition of how the brain functions is inaccurate. In fact, I am often surprised at how little insight people have on these topics, because many of the systematic errors or biases have always seemed pretty obvious to me. Talk to the average person, though about a number of topics (memories, multitasking, errors in the workplace, etc) and you’ll see that underscoring the systematic errors we make is important. For those of us who “get” this perspective, it would be nice to advance the conversation to add the necessary layers of complexity to the topic.

  11. Jared Olsenon 28 Nov 2012 at 1:55 am

    Knowledge of the fallibility and inherent biases of our brain is one of the most important in the skeptics’ toolbox, but I’ve found it to be the most difficult to convey to the True Believers. In an argument it just falls DOA…

  12. SimonWon 28 Nov 2012 at 2:31 am

    I believe that the difference between chess amateurs and chess masters is for pieces in a proper game, and that for random piece positioning the differences are much smaller, or non-existent. Which is taken to mean the chess master is “chunking” the position, and this able to remember it better because he is remembering fewer bits of information. Of course this is from memory, so I might well be wrong.

    Sloutsky did some work on this that suggests your conclusions may be wrong about experts. In particular he concluded recall is related to categorization, and that experts may categorize and thus lose detail, whilst children (and presumably chess amateurs) see and recall the trees and not the wood (to mangle a metaphor). This could be pretty critical sort of error in medical diagnosis, in that experts might well find a likely diagnosis, and then see the symptoms that match whilst not paying attention to those that don’t.

    Either way I’m sure we learn that fire extinguishers aren’t dangerous, and generally aren’t interacted with, so can be safely ignored . I know where my nearest fire extinguisher is at work, but only because it got in the way so I had to interact with it. Couldn’t tell you where the other ones are in the building, but I know there are more.

  13. BillyJoe7on 28 Nov 2012 at 5:55 am

    “think of the location of the nearest fire extinguisher to where you work”

    About five years ago I chanced upon an odd-ball fireman servicing the fire-extinguisher…so I was instantly able to recall where it is located, even though that was probably the last time I actually set eyes on it even though it is not hidden from view. Prior to that I was not even aware that we had one.

  14. tmac57on 28 Nov 2012 at 9:16 am

    Here are some QuickTime demos of change blindness:

    http://www2.psych.ubc.ca/~rensink/flicker/download/index.html

    Some of these are devilishly hard to spot,but once you see the difference,you wonder why you didn’t see it immediately. Very strange!

  15. aabrown1971on 28 Nov 2012 at 11:45 am

    Steve – out of curiosity, regarding the basketball video: what does it mean if I was able to correctly count the passes and definitely *did* notice the gorilla? I like sending these things to my wife, but after viewing this one, I decided not to. I’m not sure if it’s a “bad illusion” or just me.

  16. aabrown1971on 28 Nov 2012 at 11:53 am

    Update: I showed my wife and she had the same results as me. I don’t think we’re uber-men. :) I just think it’s not a very good illusion. Great article, though. I definitely have no idea where the fire extinguisher is at work, and I’m sure I pass by it all the time (and have been through our safety training course).

  17. Steven Novellaon 28 Nov 2012 at 12:23 pm

    aabrown – it’s technically not an illusion. It’s an example of inattentional blindness.

    About 60% of viewers do not see the gorilla. That means that about 40% do. No such effect is 100%.

    The percentage is probably lower for people reading an article about inattentional blindness. That’s just my guess.

    If you are interested there is a lot of follow up research on the factors that affect the percent of people who do or do not notice the gorilla. It’s not clear if there is something different about the 40% that notice the gorilla or if it’s just a quirky effect of that one experience. Does it mean that everyone will notice the gorilla (or equivalent) 40% of the time, or that 40% of the people will notice it 100% of the time? Probably somewhere in between.

  18. aabrown1971on 28 Nov 2012 at 8:20 pm

    Thanks for explaining, Dr. Novella. I will definitely be looking into the follow up research. Very interesting topic.

  19. aabrown1971on 28 Nov 2012 at 8:33 pm

    I bet others reading this will enjoy these as much as I did:

    Daniel Simons’ YouTube page:
    http://www.youtube.com/user/profsimons

    Daniel Simons’ TEDx talk:
    http://www.youtube.com/watch?v=eb4TM19DYDY

    DevoutCatalyst – THANK YOU for the POI reminder! Looking forward to listening.

  20. Jared Olsenon 29 Nov 2012 at 5:19 am

    Thanks to DevoutCatalyst I caught your appearance on POI. Pithy and to-the-point as usual, but I’ve never heard you sound more like Ray Romano before! But then ‘Everybody Loves Steven’!!

  21. mlegoweron 13 Dec 2012 at 10:53 am

    “This research, therefore, justifies all those tedious training sessions, fire drills, airplane lectures, and instructional videos that we have been subjected to over the years. You really should practice and study emergency procedures, locate the nearest exit, and make a conscious effort to remember important details.”

    I’m sorry, but isn’t the reason that fire extinguishers are bright red, exits are clearly labeled, etc. exactly because we shouldn’t bother remembering where they are? I don’t need to store that data because, in the event of a fire, I can quickly scan my surroundings and detect the bright red fire extinguisher. Should we really be exerting effort inculcating the precise locations of things that should be easily detected under cursory examination? Instead we should just be assuring people, “There are fire extinguishers near you at all times. They are bright red. In the event of an emergency look around and you’ll find one. Until such time as that, don’t worry about it.”

    It’s a compression algorithm, right? It’s much easier to remember
    “Fire extinguishers look like this. They are almost everywhere.”
    than it is to remember
    “If I am home, the fire extinguisher is at x. If I am at work, the fire extinguisher is at y. If I am at the gym, the fire extinguisher is at z…”

    This is all assuming that memory is a scarce resource and that memorizing more complex notions is somehow more costly than memorizing simpler notions. Maybe that isn’t true, in which case this would not apply. Maybe I am falling victim to the “your brain is a computer” fallacy and brain data isn’t the same as digital data.

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