The Stroop test aims to measure the time taken to
carry out a cognitive task with interference, thus
allowing to measure selective visual attention. On the
two first parts of the test, colours are illustrated (first
part) or written (second part) on two different boards.
The examinee must name the colour or read what is
written as fast as possible, whilst making as few
mistakes as possible. The third test consists in naming,
as fast as possible and without mistakes, the colour of
the ink in which 50 colour words are written (e.g.
word “RED” written in green ink). The time required
to carry out this third test was chosen as the main
indicator of selective attention. The metric qualities of
the Stroop test have been demonstrated many times