mixingmemory | July 14, 2007Through Saturday, a bunch of posts containing pictures and little more will be showing up here while I'm traveling on airplanes. They're meant to make a point, but what that point is will be clear only to a few of you. Some of the pictures are kinda cool, but for most of them, I recommend ignoring them entirely.
mixingmemory | July 13, 2007Here is an interesting article by Taylor, Micolich, and Jonas (via Integrated Science) on Jackson Pollock and the physics behind his work's appeal:
This question triggers reservations from both scientists and artists. However, for the abstract paintings produced by Jackson Pollock in the late 1940s, scientific objectivity proves to be an essential tool for determining their fundamental content. Pollock dripped paint from a can on to vast canvases rolled out across the floor of his barn. Although recognised as a crucial advancement in the evolution of modern art, the precise quality and…
mixingmemory | July 12, 2007So the last post was pretty dense, and I haven't used an example since the first post, so I thought I'd throw one out there that you can play with. In what follows, I pretend to use the equations, but I'm actually doing all this in Excel. If you've got Excel, here are some helpful functions. AVERAGE gives you the mean of a range of numbers, VAR gives you the variance, and STDEV gives you the standard deviation. Note that VAR and STDEV give you the variance and standard deviation for a sample (i.e., using n-1 instead of n). If you want population variance and standard deviation, use VARP and…
mixingmemory | July 12, 2007So far we've been talking about different distributions and their parameters. If we're looking at a population with known parameters, then we're going to be dealing with either a normal distribution or a standardized normal distribution (Post I and II). If we're dealing with samples, we're going to use either the sampling distribution of means, if the population parameters are known, or more often, the t-distribution if they're not (post III). Normal and standardized distributions allow us to determine the probability associated with a particular value of a variable in a population, and thus…
mixingmemory | July 8, 2007Before we start in on new stuff, let's recap what we've covered so far. We started with the Central Limit Theorem, which tells us that if a bunch of random variables go into determining the values of yet another variable, then the values of that variable will approximate a normal distribution. The normal distribution is great because the measures of central tendency -- the mean, median, and mode -- converge, and because the measures of spread (variance and standard deviation) can be associated with specific probabilities (derived from the area under the curve in the distribution).
Then we…
mixingmemory | July 4, 2007For the 4th of July I give you America circa 1995, in 4 minutes and 50 seconds, as seen through a Super 8, and with a soundtrack:
mixingmemory | July 4, 2007Long, long ago, during my first summer as a grad student (technically, I wasn't even a student yet), in one of my first meetings with my graduate adviser, he suggested that I think about the problem of representing negation. The problem of representing negation? That seemed like an odd suggestion. I mean, I was looking for potential research projects, and negation, being so common in everyday speaking and thinking, seemed like an issue that would have been researched to death, so that there's little I could have done with it. But as the grad student saying goes, ours' is not to question why,…
mixingmemory | July 2, 2007In case you haven't noticed, ScienceBlogs has a new neuro-blogger, and he's one you probably already know: MC, or Mo, the Neurophilospher. And he's hosting the 26th edition of Encaphalon at his new digs.
mixingmemory | July 2, 2007Apparently so. Recent research has shown that pleasant smells can increase pain tolerance, and a recent paper by Prescott and Wilkie(1) suggests that it is specifically sweet smells that do so. I'll just skip to the experiment, and spare you the background, because the experiment contains all you need to know.
They started with three types of smells: sweet and pleasant (caramel), unsweet and pleasant (after shave), and unpleasant (civet musk, which I hear smells awful). The inclusion of both sweet and unsweet pleasant smells allowed Prescott and Wilkie to distinguish between the analgesic…
mixingmemory | July 1, 2007So in the last post, we talked about the normal distribution, and at the very end, discussed that if you knew the mean and standard deviation of a population for a particular variable, than you can compute the probabilities associated with a particular value of that variable within that population. The problem is, to do so, you have to use a really long equation that involves math and stuff, and if you're reading this, chances are you're not a big fan of math. I know I'm not. What we need, then, is a simpler way to get those probabilities. And it turns out there is just such a way: a…
mixingmemory | June 30, 2007Ah, yes, a real game (kidding, Scrabble people). If you've watched many baseball games or baseball movies, you know that one of the things that makes for a successful hitter is the ability to predict what the next pitch will be. Is it going to be inside or outside? Will it be a fastball or a breaking ball? If you're expecting a fastball and get a slow, breaking curveball, it's unlikely you'll get anywhere near it. So cognitive processing is an important part of being a good hitter. At least, that's what a hitting coach would tell you. And according to a 2002 paper by Rob Gray in Psychological…
mixingmemory | June 29, 2007I know I've said this before, but I'm going to say it again. Anyone who reads the fundamentalist atheist blogs (you know, like the biggest blog on ScienceBlogs) knows that these people have a lot of passion and energy. They use it to write 50 posts a week pummeling creationists and telling us how evil religion is. Can you imagine what they might accomplish if they redirected that energy towards really important progressive issues like, say, health care, or poverty, or reproductive freedom, or AIDS in African American youth, or ending the war, or you know, pretty much anything else?
Sometimes…
mixingmemory | June 29, 2007So here's the first post on statistics. If you know the basics, and I suspect most of you do, then you can just ignore these posts (unless you want to check to make sure I'm getting it right). If you don't know the basics, then hopefully you will when I'm done. Even for those of you who've never taken a stats class, much of this will probably be familiar, but I'm going to start from the assumption that I'm writing for someone who has no knowledge of statistics whatsoever, so bear with me. Alright, let's begin.
The Normal Distribution
In cognitive psychology, two related types of statistics…
mixingmemory | June 28, 2007I kid you not:
Halpern, D.F., & Wai, J. (2007). The world of competitive Scrabble: Novice and expert differences in visuospatial and verbal vbilities. Journal of Experimental Psychology: Applied, 13(2), 79-94.
Competitive Scrabble players spend a mean of 4.5 hr a week memorizing words from the official Scrabble dictionary. When asked if they learn word meanings when studying word lists, only 6.4% replied "always," with the rest split between "sometimes" and "rarely or never." Number of years of play correlated positively with expertise ratings, suggesting that expertise develops with…
mixingmemory | June 27, 2007So the other day, I was talking to someone about one of the studies I was planning on posting about. I mentioned one of the results, and he said he'd really like to see the means and standard deviations. I thought to myself, "Alright, I'll put those in the post," but when I actually started writing the post, I began to fear that including standard deviations might just be confusing to people who don't have any background in statistics. So I left them out. But I didn't feel very good about leaving them out. So I decided to take action, and write a series of posts on the basics of the sorts of…
mixingmemory | June 26, 2007It's now clear that by age 3, children have a pretty sophisticated theory of mind, which includes an understanding of the limits of the causal powers of thought. They know that thoughts cause behaviors and other thoughts, but they're also aware that simply thinking about something can't affect it. Except, according to a recent paper by Woolley, Browne, and Boerger(1), when it comes to wishing. They cite results from a study by Vikan and Clausen(2) in which 96% of 4 to 6-year old children believed that their wishes could affect others. Which raises an interesting question: when do children…
mixingmemory | June 25, 2007Picture in your head one person throwing a ball to another. How were the two people oriented spatially? Was one on the left, and the other on the right? If so, which one was on the left, and which on the right? Chances are, the thrower was on the left, and the catcher was on the right. For some reason, that seems to be our default way of representing actions: with the actor on the right, the patient on the left, and the actions occurring from left to right(1), as in this beautifully drawn figure:
Why is that? Good question, but before we answer it, let's look at some research.
The most…
mixingmemory | June 24, 2007Jonathan Rowe, over at Positive Liberty, posted a link to Ophelia from The Last Waltz. Because I've been a fan of The Band since I was a little kid, I'm upping the ante, with "Carivan" with Van, the Man, who just tosses the mic and walks off stage at the end:
and "Mannish Boy," with you know who and Paul Butterfield (and by the way, I'm pretty sure 5 minutes ain't a man):
and "Evangeline," with Emmylou Harris:
All this justified as me telling you a bit about myself, but really they're here so I can find them later. Just be glad I didn't give you "The Night They Drove Old Dixie Down" and "…
mixingmemory | June 22, 2007All of you are probably familiar with color opponency, but just in case, I'll give you a quick refresher. I'll even start with the history. In the 19th century, there were two competing theories of color vision. The first was the Young-Helmholtz theory (sometimes called the trichromatic theory), which argued that there were three types of photoreceptors: one for red, one for green, and one for blue. The second was Ewald Hering's color opponency theory, which argued that there were three color pairs: black-white, red-green, and blue-yellow. Each color in the pair canceled out, or inhibited the…