I’ve been reading up on memory lately and found an interesting effect that might speak (in a totally non-scientific way) to something that seems to be part of our collective culture. I was listening to research CDs by Diana Deusch (see an earlier post for more background) and a pitch memory experiment caught my attention.
Here’s a quick blurb on “Short Term Memory for Pitch” from her site:
Suppose you play a tone, and this is followed by another tone which is either the same in pitch as the first, or differs by a semitone, most people find it very easy to decide whether the two tones are the same or different. This is true even when the tones are separated by a five second delay.
That’s all very well and good, of course, but when the intervening silence is filled with other tones, the task becomes much more difficult. Nothing strange there, I think we all get that. What gets more interesting, though, is when you fill the space between tones with spoken words (in this case they are spoken numbers). As Deusch says:
Most people find the memory task much easier when spoken numbers rather than tones are played during the interval between the test tones. This contrasts remarkably with the memory loss that occurs when a sequence of tones is played during the interval between the test tones, even though the extra tones can be ignored. So we conclude that the pitch of a tone is held in a specialized memory store, and that interference takes place between pitches inside this store. Other materials – such as spoken numbers – do not enter the store, so they produce much less interference with memory for pitch.
According to the background reading I’ve done in memory, it turns out that short term memory can only juggle a handful of similar items before they are either committed to longer term memory or lost. In fact, George Miller, while at Bell Labs, determined that the number of similar items is about seven, plus/minus two. Research has since shown that the number of “storable items” differs by type and situation (eg. seven for digits, six for letters, and five for words).
What I find interesting is how this might map into popular culture. For example, I’ve always wondered why people tend to remark about recent films being “the best movie ever.” I don’t take those statements literally, but assume them to be infused with exuberant hyperbole to make a point. It’s also relatively well known that in order to capitalize on this effect, movies in contention for Oscars are purposefully released near voting time.
So, if all this is well known, what’s the point of this post? First of all, I think it’s interesting to play with the temporal effect of “liking” something (ie. adding more relative weight to recent interests, degrading them over time). Second, I think it’d be interesting to explore if we’re hardwired to only allow for something like 7 +/- 2 “greatest” movies/songs/etc. in our heads at any given time.
March 26th, 2007 | 
One Gravity Reactions
Those of you who know me already know the reasons for my current fascination with things in space. For those of you outside the loop, check out the Wikipedia entry for my friend Sunita.
For some reason, today I almost fell while walking down the hall thinking about 1G (ie. one gravity) reactions we take for granted. I don’t know what neurons fired in my head, but whatever combinations they were made me consciously think about my next step. While thinking about it, then, I almost missed where to place my next foot. Weird.
The moral of this post, I suppose, is not to take gravity for granted (or otherwise, forget about it totally and move on).