Archive for the ‘Statistics’ Category

Matlab finite() function warnings

The latest version of Matlab deprecated the finite() function in favor of isfinite(). This is all fine and dandy in terms of improving the scripting language, but this change currently causes a crapalanche of warnings to be thrown as you use SPM. Usually along the lines of: Warning: FINITE is obsolete and will be removed […]

The ‘Voodoo Correlations’ saga continues

Saddle up cowpokes, and prepare yourselves, for yet another episode of Voodoo Correlations. The latest salvo comes in the form of a reply authored by Lieberman, Berkman, and Wager. This is an invited paper that will appear in a future edition of Perspectives on Psychological Science alongside the original Vul, Harris, Winkielman, and Pashler paper. […]

January 31, 2009 • Posted in: CogNeuro, MRI, Statistics • 1 Comment

The “Ten Commandments of SEM”

Structural equation modeling (SEM) is a confirmatory method that allows researchers to test hypothesized relationships between variables and probe the ways that they influence each other. Rightly done it can be a very useful approach to have in your toolbox of methods. Still, true to most complicated techniques there are few ways to do it […]

January 22, 2009 • Posted in: Statistics • No Comments

The ‘Voodoo Correlations’ debate heats up

It hasn’t taken long for the academically-heated exchanges to begin with regard to the recent Vul, Harris, Winkielman, and Pashler paper. You can’t call out such a large group of authors, say their results are practically meaningless, and not have some of them speak up. One group of authors who were red-flagged as having non-independence […]

January 15, 2009 • Posted in: CogNeuro, MRI, Statistics • 1 Comment

Voodoo Correlations in Social Neuroscience

The progress of science is not a continuous, linear process. Instead it moves forward in fits and starts, occasionally under protest. For a young field cognitive neuroscience has made dramatic advances in a relative short amount of time, but there have been some mistakes that we keep making again and again. Sometimes we get so […]

Voodoo Correlations Index

This post serves as an index of the articles that reference the ‘Voodoo Correlations in Social Neuroscience’ debate. The original paper has now been renamed ‘Puzzlingly high correlations in fMRI studies of emotion, personality, and social cognition’. There have been five posts so far, each listed below: [1] Voodoo Correlations in Social Neuroscience: [2] […]

The Presidential Election

Politics on a weblog is like picking up a stick of old, wet dynamite.  You might grab it and absolutely nothing happens, or it might very well explode in your face.  It is for this reason that I try to avoid political discussion on  Every weblog must have a focus, and there are more […]

Quote of the Week – Tukey

“The combination of some data and an aching desire for an answer does not ensure that a reasonable answer can be extracted from a given body of data.” – John W. Tukey, 1986

August 18, 2008 • Posted in: Quotes, Statistics • No Comments

Quote of the Week – Fisher

“Modern statisticians are familiar with the notion that any finite body of data contains only a limited amount of information on any point under examination; that this limit is set by the nature of the data themselves, and cannot be increased by any amount of ingenuity expended in their statistical examination: that the statistician’s task, […]

August 8, 2008 • Posted in: Quotes, Statistics • No Comments

Principal Components of Individual Differences

I have been spending the last few weeks exploring principal components analysis (PCA) of functional imaging data. PCA has been around for over a century, having first been invented by Karl Pearson in 1901. I have always been taught that PCA was a powerful data reduction technique, allowing a handful of components to represent the […]

August 6, 2008 • Posted in: Statistics • No Comments