Neuropsychology
Executive Function Task Laboratory
Four executive tasks and six underlying capacities. Predict what each task needs, then take a capacity away and see which tasks notice.
Simulated — original task descriptions and a transparent model, not real testing
Learning objective
By the end you should be able to say why no executive task is pure, and why the lowest score does not name the weakest process.
About 30 minutes, in two experiments. Nothing you do here is saved or sent anywhere.
A transparent model, not a measurement
Nobody performs these tasks. Each task is a set of weights on six capacities, and every score you see is a weighted average computed from sliders you set. The weights are an argument about what tasks require, written for teaching. No standardised test, subtest or item is reproduced, and no score means anything about the person reading it.
- Experiment 1. For each task, tick the processes you think it needs, then reveal the model's weights.
- Experiment 2. Reduce one capacity at a time and watch all four task scores.
- Then find two different reductions that make the same task the lowest.
First, a judgement
A fictional person scores well below their control group on a colour-word conflict task, and within range on three other executive tasks.
The laboratory
- 1 What each task needs
- 2 Taking a capacity away
Need a hand?
Nothing here changes the controls for you, and none of it says what you are going to find.
Key terms
- Inhibition, switching, updating
- Three processes this model treats as separate capacities you can turn down. They are the model's inputs, not a settled inventory of what the brain does.
- Processing speed
- How quickly material is dealt with, independently of whichever process a task is named after.
- Task weight
- How heavily one task draws on one process in this model. It is revealed only after you have committed to a guess.
- Strategy
- Where the person sits between working quickly and working accurately. It is set separately from any capacity.
Experiment 1 - what each task needs
What this task needs, once revealed
All four tasks, at these capacities
Reading this
The four tasks
The whole weight matrix
No row contains a single non-zero entry, and no row contains fewer than five. There is no pure executive task, and the weights are an argument about task demands rather than a measurement of them.
Challenge - a report to correct
What this demonstrates
Every one of these tasks loads on several processes at once, so one low score never identifies which capacity is reduced. That is the task-impurity problem, and it is why a battery reports converging patterns across tasks rather than a diagnosis from any single one. Speed and sustained effort are part of the pattern, not nuisance.
For teaching elsewhere: take this activity as one self-contained block of HTML, on the clipboard or as a file. Either way it is styled so that it will not disturb the page you put it into.