Intra-Extra Dimensional Set Shift (IED)
Intra-Extra Dimensional Set Shift is a test of rule acquisition and reversal. It features visual discrimination and attentional set formation maintenance, shifting and flexibility of attention. This test is sensitive to changes in the fronto-striatal areas of the brain and is a computerised analogue of the Wisconsin Card Sorting test.
Two artificial dimensions are used in the test:
- Pink shapes
- White lines
In this task, participants must use feedback to work out a rule that determines which stimulus is correct. After six correct responses, the stimuli and/or rule changes.
Initially the task will involve simple stimuli which are made up of just one of the dimensions e.g. two white lines that differ in shape. Later on in the task, compound stimuli are used: white lines overlaid on the pink shapes.
The shifts in rule are initially intra-dimensional (i.e. the pink shapes remain the only relevant dimension) and then later extra-dimensional (i.e. white lines become the relevant dimension).
Outcome measures assess the number of errors made, the number of trials completed, the number of stages completed and latency.
Please contact us to discuss your normative data requirements. Please note, we do not recommend using normative data in place of a control group.
When to use this test
We would recommend using this test to assess cognitive function in: