If you don’t understand the title of this post, you almost certainly will regret reading further. We’re doing an experiment in which one target is presented along with m distracters.

I’ve transitioned to all open-source software for my science. The Python language and its libraries VisionEgg and Psychopy are more than sufficient to code my perception experiments. For data analysis, I’ve gotten pretty far with the SciPy library for Python, which has probability distributions, function minimization, Fourier transforms, etc. The Matplotlib library makes it easy to make plots in a way familiar for old MATLAB users like me.

The Cauchy distribution is a unimodal distribution with fatter tails than a Gaussian. (Fig 1 at right) Janssen & Shadlen (2005), Nature Neuroscience found that monkey LIP neuron activity followed the subjective hazard function of an objective bimodal probability density function, which goes up, down, then up again.