Application Kata "n-back"

Develop a program with which a so-called [n-back test] can be carried out.

The subject is presented with a sequence of letters as visual stimuli. For each stimulus, they have to decide whether the current stimulus matches the nth previous stimulus [1].

In the following example, the letters markedwhich should be recognized as repetitions at 3-back:

T L H C H S C C Q L C K L H C Q T R R K C H R

For a new test must be specified:

• Name of the test person
• n (1..9)
• Stimulus duration: How long should each stimulus be presented? (in msec)
• Number of stimuli (10..100)

At the end of the test, the subject is presented with the percentage of correct decisions as a result. The decision is correct if it recognizes a repetitive stimulus, but also if it does not indicate a repetition where there is none.

The respondent is asked to indicate whether a stimulus is repeated by clicking a button or pressing a key (e.g. space bar).

The progress of a test is written to a log file at the end. Example [2]:

Test person=Peter Müller
Stimulus duration=500
N=3 Start=2013-05-16T18:34:23
Stimuli=TLHCHSCCQLCKLH...
Answers=NNNNJNJNNNJNJJ...

A test in progress can be aborted at any time. Even then, a result is shown and a log is written.

If no test is currently running, a new one can be started.