778 reputation
48
bio website
location Halifax, Canada
age 32
visits member for 2 years, 9 months
seen Dec 9 '13 at 3:06

Cognitive scientist, statistician, programmer, tinkerer


Mar
30
comment How to analyze reaction times and accuracy together?
Looking at the pros/cons to using a binomial mixed effects model of accuracy as a function of RT and other predictors is one of the projects I had planned before this discussion for our summer stats student, though I'm thinking of looking at both linear and generalized additive models of the effect of RT.
Mar
30
comment How to analyze reaction times and accuracy together?
IE has become lamentably standard in some fields partly, I suspect, because it feels somewhat intuitive and is certainly an easy "solution" to the vexing problem of combining speed and accuracy. Admittedly, I don't have data explicitly demonstrating the invalidity of the speed-accuracy scaling assumed by IE (though I now think I'll task a student to generate this data through simulations this summer), but it would seem rather remarkable if the simple IE scaling, which at least rather questionably models accuracy as a proportion (see Dixon, 2008, "Models of accuracy..."), comes out as valid.
Mar
30
comment How to analyze reaction times and accuracy together?
Unfortunately inverse efficiency assumes a particular scaling of RT and error rate that is completely unsupported. Even Dr. John Christie, a colleague of mine that gave IE its name, has since come to completely oppose its use.
Mar
30
comment How to analyze reaction times and accuracy together?
These days I prefer LBA because it's computationally simple/faster to fit and because I haven't seen any demonstrations of cases where diffusion can fit data that LBA can't
Mar
11
comment How can I create computer based psychology experiments using OS X?
@ArtemKaznatcheev I haven't empirically tested things myself, but I've been told by sources I trust that web-based RT collection isn't reliable. However, it's easy enough to take a python script and create a stand-alone app (or exe) using py2app (or py2exe) that your participants can download.
Feb
28
comment How can I create computer based psychology experiments using OS X?
Yet another addendum: the code I linked is very much written in a procedural style rather than an OOP style. This is because I find OOP unnecessary for the simple stuff I tend to do and find it takes a little more effort (both coding and planning) to do fully OOP experiments. Possibly just a personal quirk though.
Feb
28
comment How can I create computer based psychology experiments using OS X?
Oh, and just a heads-up: the timing in that experiment is slightly non-optimal insofar as it uses the time at the beginning of the trial loop to label found responses during that iteration of the loop. Now that I think of it, there should probably be another "now = time.time()" line right above the "pygame.events.pump()" line, just in case there is a delay during stimulus presentation. In the end, though, this will all be obviated when I finish my side-project to update SDL1.2 & pygame to implement SDL1.3/2.0's high precision timer and event timestamping...
Feb
28
comment How can I create computer based psychology experiments using OS X?
Here's a zip of one of my moderately well-commented experiments: filedropper.com/castforweb
Feb
28
comment How can I create computer based psychology experiments using OS X?
I'll link the code from one of my experiments once I add some comments.
Feb
8
comment How can consumers obtain an image and analysis of their own brain?
Also, be sure to ask (ideally ahead of time) for a copy of the raw anatomical data, not simply a print-out of a few slices. Bring a high-capacity USB stick to store it on.
Feb
6
comment What are good examples of applying dynamical systems in cognitive science?
Is Busemeyer's work really anything beyond application of decades-old models of perceptual decision making (diffusion, various accumulator models) to more abstract non-perceptual judgements?
Feb
3
comment What are different ways to determine centroids of fMRI activation, their drawbacks and perks?
@Ruben The reason is that as a discipline, cognitive science is stuck in a "jack of all trades, master of none" approach to training and conduct of research. That is, researchers try to take responsibility for too many roles in research (theoretician, empiricist, statistician, etc) and in doing so cannot provide deep expertise throughout. The superior alternative is to emulate the approach taken in physics and work in teams of specialists, including data analysts with PhDs in statistics who make their career contributing to statistical rigor and innovation.
Jan
23
comment Perception of time as a function of age
There's definitely a finding that, when asked to produce time intervals, older individuals produce systematically longer intervals than younger individuals. I think there was a BBC documentary that "replicated" this live, but I can't remember its name nor the original reference...