Wisconsin Card Sort
Crack the hidden sorting rule
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What is the Wisconsin Card Sort?
The Wisconsin Card Sort, or Wisconsin Card Sorting Test (WCST), was developed by David Grant and Esta Berg in 1948. The participant sorts cards that differ in the colour, shape and number of their symbols. Nobody tells them the sorting rule. They only hear whether each choice is right or wrong, and after a run of correct answers the rule changes without warning.
Neuropsychologists use the Wisconsin Card Sort to assess set-shifting and abstract reasoning. A key score is the number of perseverative errors, where a person keeps sorting by a rule that no longer applies. The Neuroptimize version recreates this puzzle on a phone or computer: match each new card to one of four reference cards, work out the hidden rule from the feedback, and notice when it quietly changes.
How to play the Wisconsin Card Sort
- Four reference cards sit along the top: one red triangle, two green stars, three yellow crosses and four blue circles. A new card appears below them.
- Tap the reference card the new card belongs with, or press keys 1 to 4. The hidden rule is colour, shape or number of symbols, and you have to discover which from the "Correct" or "Wrong" feedback.
- After a run of correct matches the rule changes to a different one with no announcement. Your first couple of mistakes while finding the new rule are not counted against your accuracy, as long as you are not repeating the old rule.
- A session is 30 cards or 60 seconds, whichever comes first. The results show how many rules you cracked and how many perseverative errors you made.
- At early levels the rule holds for six correct answers in a row, and hints tell you when it has changed. As the level rises the rule changes sooner, down to three in a row, and the hints disappear from level 6.
- From level 6 some cards also share more than one feature with a single reference card, so a correct answer no longer tells you exactly which rule is active. The feedback also gets quicker from level 10.
Strategies and tips
Test one dimension at a time
When you do not know the rule, pick colour, shape or number and stick with it for a card. If it is wrong, move to one of the other two. This systematic approach finds the rule in at most three tries.
Drop the old rule immediately
A "Wrong" after a streak of correct answers almost always means the rule has changed. Do not try the old rule again, because repeating it counts as a perseverative error and is not forgiven.
Count your streak
The rule changes after a fixed number of correct matches in a row, and that number falls from six towards three as the level rises. Keeping count helps you expect the change instead of being surprised by it.
Use ambiguous cards carefully
From level 6 a card may match one reference card on two features, so a "Correct" on it does not prove which rule you are using. Confirm the rule on a card where the three features point to three different reference cards.
Say the rule to yourself
Keeping a one-word label in mind, such as "shape", makes it easier to apply the rule consistently and to notice when you need a new one.
The science behind the Wisconsin Card Sort
The Wisconsin Card Sorting Test was developed by David Grant and Esta Berg in 1948. Participants sort cards by colour, shape or number without being told the rule, which changes after a run of correct answers. It is used in neuropsychology to assess set-shifting and abstract reasoning, abilities associated with the prefrontal cortex.
Frequently asked questions
What does the Wisconsin Card Sorting Test measure?
It is used to assess set-shifting, the ability to change strategy when the rules change, along with abstract reasoning and use of feedback. It is commonly given in neuropsychological assessment, and performance has been linked to the prefrontal cortex.
What is a perseverative error?
A perseverative error is continuing to sort by a rule that used to be correct but no longer is. It shows difficulty letting go of an old strategy. Neuroptimize counts these separately and shows the total at the end of each session.
How do you know when the rule has changed?
In the classic test you are not told. The only signal is that a choice which would have been correct a moment ago is now marked wrong. The Neuroptimize version gives a hint at the lowest levels, then leaves you to spot it from the feedback alone.
Is the Wisconsin Card Sort game free?
The Wisconsin Card Sort is a Pro game in Neuroptimize, and Pro starts with a 7-day free trial. Free players can also get it as the Pro game of the day in their daily workout.