Monday, July 21, 2014

A Simple Free Open-source conference presentation timer

Although PEBL is designed for creating and sharing psychological tests, I've used it to make a handful of little graphical utilities for other purposes.  This includes the launcher, and the data combining tool, and other things.  I recently held a conference and needed a way to alert speakers about the time left, along with sort of warnings that they are running out of time.  I created a simple presentation timer in PEBL for this purpose.  I ended up making some tweaks mid-conference to improve usability, but I thought I'd make it available for anyone.  It requires 0.14 because of its use of certain buttons.

Thursday, July 17, 2014

Setting up different parameter sets: Example with forward and backward digit span.

The new parameter setting feature in the PEBL launcher let's you control many aspects about the tasks in the battery without doing any programming. This will typically let you alter aspects of the design, timing, and number of trials of a test to fit your experiment.  For some tests, a parameter lets you decide which version of the test to use.  This includes the digit span and corsi blocks (decide whether to test forward or backward), the tower of london and tower of hanoi (specifying which problem set to use), and many others.

Tuesday, July 8, 2014

Overview of some of the new tests in the PEBL Test Battery 0.14

I have incorporated a bunch of new tests into the latest version of the test battery.  Here is an overview of some of the new additions and major changes to previous tasks.  By my count, we have added more than 20 new tasks since the last revision, bringing the total to around 100.  A semi-complete list is available here.

Note that some of the links below to the PEBL wiki are incomplete.  If you'd like to make help write this documentation, I provide the password to bypass the PEBL nag screen to anyone who will do so.

Thursday, June 26, 2014

A Simple Data File Combiner

As part of PEBL 0.14,we offer a simple tool to help you combine data from multiple files into a single file.

Starting in 0.14, we use a data saving scheme and set of functions that help improve organization and prevent overwriting.  Within each battery folder, a data\ folder is created. Within each data folder, a subject code folder is created, and one or more files saving data are created for each participant in that subfolder.  For some experiments, a master pooled data file will also be created, but not for all.

Tuesday, June 24, 2014

Announcing: PEBL Version 0.14

After a record-setting PEBL 0.13 (with more than 26,000 downloads), I'm excited to release the newest version of PEBL; version 0.14!

 Complete release notes are available at The PEBL Wiki.  This version contains many new improvements, but highlights are listed after the jump.

I'm initially releasing two version for windows. One installation package (which requires administrator access, but PEBL shows up in your menu and creates a battery folder in Documents\pebl-0.14.exp), and another 'standalone' version that could be run off of a usb drive or on a computer which you cannot install software on.

Friday, May 23, 2014

A nonverbal stroop test for children to examine the bilingual advantage

Over the past several years, I have collaborated with Alena Esposito (who was a student at NCSU at the time)  developing some PEBL tests that help measure the impact of executive control and suppression of irrelevant information on bilingual children.  This project already spurred the development of two new stroop tests that are part of PEBL (a standard color stroop and a number stroop), but it also lead to development of a new test, the Bivalent Shape Task (BST), which was published in a paper in Cognitive Development (fulltext), and we just got published as a meta-paper in the Journal of Open Research Software (JORS).

Tuesday, April 1, 2014

A study of executive function in children

Ivan Ropovik just published a study in Intelligence looking at executive function in children. He used a number of PEBL tests, as well as several non-PEBL versions of tests for which PEBL has implementations, to look at the factor structure of executive control in children.  One of their basic covariance (structural equation) model of the data is shown on the left.

Tuesday, March 18, 2014

Running PEBL without installing

Currently, versions of PEBL running on Windows require that you install the software into your c:\Program Files\ directory.  This is inconvenient for some folks, as you must have administrator access. PEBL doesn't really require that you install in order to run, but by doing so you can do things like launching from the menu and letting all users on a computer access PEBL.

If you are having trouble installing, try downloading the stand-alone version here:

This will download a .zip file.  Put it wherever you want (i.e., the desktop), and then right click and select 'Extract All...' to unzip it (there are other ways to do this too, so use whatever you are comfortable with).

Friday, February 21, 2014

Installing PEBL 0.13 on Mac OSX 10.9 (UPDATE)

Since this was posted, I have figured out the problems with PEBL on OSX and uploaded a new fix.  This new fix will work on OSX 10.7 and newer.  Here is a screencast for the new version, the older screencast is still available for users of OSX 10.6, and those who want to install the BST.

Wednesday, January 22, 2014

Paper in Journal of Neuropsychological Methods: PEBL and the PEBL Test Battery

I just published a paper with Brian Piper called  The Psychology Experiment Building Language (PEBL) and PEBL Test Battery (see here for paper)
that provides the most comprehensive description of PEBL to date.  Above I show an (updated) figure from that paper showing the overall growth in PEBL usage over time.  The final tally for 2013 was about 17000 downloads of the pebl installer (22,000 downloads total including other files like manuals), and about 55 published manuscripts, theses, conference papers, etc. that I know of.

Tuesday, November 26, 2013

Recent research on executive function and driving

Conceptual model of individual differences in Executive function. source
I recently came across a series of studies coming out of the University of Toronto Interactive Media Lab studying executive function and driving, lead by Sachi Mizobuchi.  The basic question under investigation is whether the different aspects of executive function, which are known to vary somewhat independently across people, can predict aspects of driving performance.  The three aspects of EF under consideration are shifting, updating, and inhibition.  These each seem like they would be important for driving, especially in the context of operating other devices (shifting) while following directions (updating) and trying to avoid traffic and filter out distracting information (inhibition). This research used the PEBL Bechara (Wisconsin) Card Sorting task to measure shifting.

Sunday, November 24, 2013

That is so random: The PEBL Random Generation Task

Human random number generation has been studied for many years, maybe most famously by Alan Baddeley in his exploration of the central executive, and Akira Miyake in a later study of executive function.  Tasks such as this have been around a lot longer, and Towse and Neil (1998) published a lot of nice metrics of randomness that can be used to assess the quality of randomness of a sequence.

To implement a PEBL version of this, I modeled the version described in Miyake's paper, and implemented many of Towse and Niel's randomness measures to provide an automatic report. 

Sunday, August 25, 2013

Measuring Attention with the Kinect---and PEBL

Darren Stanley just completed his Master's thesis at RIT called "Measuring attention using the Microsoft Kinect"; the degree was in computer science.  The research is actually similar to another recent study by Qiu and Helbig (2012), that used more complicated motion capture setups, and used some PEBL tests for validation.

The study used three of PEBL's attention/vigilance tasks, the TOAV, the pCPT, and the PPVT to measure and induce an attention task set on 20 participants. They simultaneously measured behavioral signatures related to posture and facial gestures, gaze, audio, and some other things.  Then, they used regression analyses to determine which features predicted behavioral aspects of flagging attention (such as RT).

Tuesday, July 16, 2013

PEBL in a browser: 4. The asychronous evaluator.

This is fourth in a series of blog posts describing porting PEBL to the browser using emscripten.

The biggest issue in running anything within a browser is that it has to by 'asynchronous'.  I'm still not completely sure about all the ins and outs of this, but what it essentially means is that anything the script does goes on hidden from the display of the browser, and it only gets updated when control is ceded back to the browser.

Friday, July 12, 2013

PEBL in a browser: 3. File system access

 This is third in a series of post about compiling PEBL into javascript using emscripten.

Like most moderately complex programs, PEBL uses files to store information it reads and enables it to run. For even the simplest programs, PEBL must have access to:
  • A script file which defines the experiment
  • A set of files containing located in pebl-lib containing PEBL-defined functions.
Also, if you want any images, text (which need fonts), or the like, these would also be stored in files.