IDED: Internal / External Dimension Shift Task


A test for response reversal and the ability to concept-shifting between an internal and an external dimension.

This task is concerned with response reversal and the ability to concept-shifting, namely between an internal and an external dimension. The task is based on work by, among others, Mitchell et al. (2002).

Participants learn on the basis of feedback (“good” or “wrong”) to choose between 2 stimuli that can consist of 2 dimensions: shape and line pattern. They are presented in 2 of 4 white rectangles (see figure). The task consists of the following 9 stages that are completed in that order:

  • SD:Simple Discrimination;
  • SR: Simple Reversal;
  • CD: Compound Discrimination-separate;
  • CDS: Compound Discrimination Superimposed;
  • CR: Compound Reversal;
  • IDS: Intra Dimensional Shift;
  • IDR: Intra Dimensional Reversal;
  • EDS: Extra Dimensional Shift;
  • EDR: Extra Dimensional Reversal.

At each stage the rule that needs to be learned changes, and only the next stage is reached after reaching the learning criterion in the previous stage. This task criterion can be set in the task, as well as the maximum number of trials before a stage is stopped (in case the learning criterion is not reached). Crucial is the transition from stage IDR to EDS when an element of the external dimension becomes important. According to Mitchell, this task can distinguish between 2 functions of the frontal lobe (response reversal and inter-dimensional shift learning). The most important dependent variable is the percentage of errors at each stage.

An English language version is available.

This task is also part of the package forMinds, which is used at the Pompe Foundation. Order is on condition that agreements are made with the Pompe Foundation about the use of the task.


  • Mitchell,D.G.V., Colledge,E., Leonard,A. & Blair,R.J.R. (2002). Risky decisions and response reversal: is there evidence of orbitofrontal cortex dysfunction in psychopathic individuals? Neuropsychologia, 40, 2013-22.
  • Brand,N., Von Borries,K. & Bulten,E. (2010). Progress with MINDS, a testmanager for psychological assessment, research and education: applications in the forensic psychiatric domain. In: A.J.Spink, F.Grieco, O.E.Krips, L.W.S.Loyens, P.J.J.Noldus & P.H.Zimmerman (Eds), Proceedings of Measuring Behavior 2010 (Eindhoven, the Netherlands), pp. 396-398.