N-Backer

N-backer - Copyright ©2011-2012 School of Computing Science, Newcastle University

Paper: Monk, A. F., Jackson, D., Nielsen, D., Jefferies, E., & Olivier, P. (2011). N-backer: An auditory n-back task with automatic scoring of spoken responses. Behavior research methods, 43, 888-896. https://doi.org/10.3758/s13428-011-0074-z

About

N-back is a secondary task that loads working memory. The numeric n-back task requires the volunteer to listen to a stream of presented digits and to say the digit they heard 'n-steps' back in time. (e.g. in the 2-back sequence 3 1 6 9, one would be asked to say 3 on hearing 6, 1 on hearing 9 and so on).

N-Backer uses speech synthesis and recognition to automate the presentation and scoring of this task. The tool aims to simulate in normal volunteers some of the symptoms observed in, for example, patients in the early stages of dementia when they carry out multi-step tasks.

Quick start

• On a computer running Windows, download the executable file archive from Releases (also available in the repository as bin/nback.zip) and open the .zip archive.

• Copy the executables out of the archive to a folder.

• Run nback-xp.exe or nback-inproc.exe (see Troubleshooting below), and press the Play button.

• Read into the computer's microphone the digit you heard 1-back (e.g. in the sequence 3 1 6 9, say 3 on hearing 1, 1 on hearing 6, and so on).

Troubleshooting

• nback-xp.exe should be run on Windows XP

  • It won't work properly on Windows Vista / 7 / 10 / 11, as the speech recognition will also recognize system commands.
  • nback-inproc.exe is an attempt to use an in-process, non-shared recognizer that will not detect system commands and should work on later versions of Windows -- but this is not well tested.
  • If necessary, you could try running it in a Virtual Machine running an older version of Windows.

• If it doesn't start at all, ensure the Microsoft .NET 3.5 SP1 installed:

  • http://www.microsoft.com/download/en/details.aspx?id=21

• To obtain the synthesized voices that it was designed for, install the Microsoft Speech SDK 5.1:

  • http://www.microsoft.com/download/en/details.aspx?id=10121 (SpeechSDK51.exe also available in the depends folder)

• It is designed for use with head-mounted microphone

  • Check in the Speech Recognition Control Panel that the correct audio input is selected.