ABX discrimination test

ABX discrimination is a term that is used for three stimuli presented on an ABX trial. The third is the focus. The first two stimuli (A and B) are standard, S1 and S2 in a randomly chosen order, and the subjects' task is to choose which of the two is matched by the final stimulus (X). (Glottopedia)

This package contains the operations necessary to initialize, calculate and analyse the results of an ABX discrimination task.

Check out the full documentation at https://docs.cognitive-ml.fr/ABXpy.

Organisation

It is composed of 3 main modules and other submodules.

• task module is used for creating a new task and preprocessing.
• distances package is used for calculating the distances necessary for the score calculation.
• score module is used for computing the score of a task.
• analyze module is used for analysing the results.

The features can be calculated in numpy via external tools, and made compatible with this package with the h5features module, or directly calculated with one of our tools like shennong.

The pipeline

In	Module	Out
data.item parameters	task	data.abx
data.abx data.features distance	distance	data.distance
data.abx data.distance	score	data.score
data.abx data.score	analyse	data.csv

See Files Format for a description of the files used as input and output.

The task

According to what you want to study, it is important to characterise the ABX triplets. You can characterise your task along 3 axes: on, across and by a certain label.

An example of ABX triplet:

A	B	X
on_1	on_2	on_1
ac_1	ac_1	ac_2
by	by	by

A and X share the same 'on' attribute; A and B share the same 'across' attribute; A,B and X share the same 'by' attribute.

Example of use

See examples/complete_run.sh for a command line run and examples/complete_run.py for a Python utilisation.

Installation

The recommended installation on linux and macos is using conda:

conda install -c coml abx

Alternatively you may want to install it from sources. First clone this repository and go to its root directory. Then

conda env create -n abx -f environment.yml
source activate abx
make install
make test

Build the documentation

To build the documentation in the folder ABXpy/build/doc/html, simply have a:

make doc

Citation

If you use this software in your research, please cite:

ABX-discriminability measures and applications, Schatz T., Université Paris 6 (UPMC), 2016.