Press "Enter" to skip to content

Author: Erik Marsja

PhD Student in Psychology, Umeå University. Main interest is experimental and cognitive psychology. Enjoy programming in Python and R.

How to install PyschoPy on Linux Mint Debian Edition

How to Install PsychoPy on Linux Mint

Installing PsychoPy on Linux Mint was not straight forward.  This is a short guide on how to install PsychoPy on Linux Mint Debian edition. After some searching around on forums and such I found a solution and put it together in one place. PsychoPy is an application written in Python for creating experiments (e.g., for psychology or neuroscience). See my post PsychoPy – Free and Open Source Experiment builder written in Python for my thoughts on the software..

What is the Cross-modal oddball paradigm?

My current research focus on how attention can be captured by deviating stimuli. I will briefly describe the paradigm I have used – the cross-modal oddball task. Before I go into the cross-modal oddball task I will describe the auditory oddball task. In the oddball paradigm the subjects are exposed to a repetitive stream of distracting sounds. Furthermore, they can be either passive (i.e., watching a film) or engaged in a task (i.e., making judgments of durations of the tones). Typically subjects are exposed to two types of  distractors; one standard, presented frequently (i.e., 80 % of trials), and an oddball (‘Novel’ or ‘Deviant’) presented on infrequent trials (i.e., 20 % of the trials).

Cross-modal oddball sound sequence
Example of an oddball sequence. Black tones represent standard sounds and red represents deviant or novel sounds.

There is a plethora of research using the oddball paradigm in examining electrophysiological responses (i.e., ERPs) to deviating sounds (for reviews see; Bendixen, SanMiguel, & Schröger, 2012; Friedman, Cycowicz, & Gaeta, 2001). However, when engaged in a primary task there is also a behavioral cost – the response time to target tone is slowed by the presentation of a deviant (e.g., Berti, 2008).

Python script for trial randomization

In this post you will find a Python script for randomizing conditions with constraints (i.e., never 2 consecutive trials of X). This script will in a later post be implemented in a cross-modal oddball task created in Psychopy.

I recently started to use Psychopy to build experiments. To build my experiments (mainly oddball tasks) I have, up until I found psychopy, used e-prime. In an oddball task one does not usually present several oddball (typically called “novel” or “deviant”) stimuli in succession. Without getting into detail; I was not able to solve this problem with e-primes scripting language “e-basic” so I made a python script instead. With this script I pre-generated .txt-files that I loaded into e-prime and got my constraints fulfilled.