Neuropsychology
Network Disconnection Mapper
Five regions, six pathways, four tasks. Break any one thing and see which tasks notice - including the ones that fail while every region is intact.
Simulated — a conceptual diagram, not an anatomical atlas
Learning objective
By the end you should be able to explain how damage to a connection produces a deficit far from the lesion.
About 15 minutes. Nothing you do here is saved or sent anywhere.
This diagram is a toy
Five boxes and six lines. No real brain has five regions, no real pathway carries one thing, and nothing here is positioned anatomically. Treat it as a cartoon of an argument, not as a map.
- Answer the opening question.
- Load a case. The four task outcomes above the controls change with it, and nothing has to be configured first.
- Open Change the network yourself to damage a region or cut a pathway - one at a time to begin with - and watch the same four outcomes.
- Find two different single failures that produce exactly the same profile. There are several.
First, a judgement
A fictional person understands everything said to them and names pictures without difficulty. Asked to repeat a spoken word back, they cannot - and the difficulty is worst for unfamiliar words.
The network
Need a hand?
Nothing here changes the controls for you, and none of it says what you are going to find.
Key terms
- Node and pathway
- The boxes and the lines in the diagram. A box stands for a processing stage rather than a piece of anatomy, and a line for the connection between two stages.
- Disconnection
- A deficit produced by damage to a connection between two stages that are both themselves intact.
- Impaired
- Here, a task that has lost its main route and is getting through on a second one. It is a distinct state from failing.
- Profile
- The pattern across all four tasks read together. One task's outcome on its own is not a profile.
Break something and see who notices
Each task needs a particular route through the network. Break one region or one pathway, then read the four outcomes.
What this state shows
Task by task
| Task | Main route | Second route | Outcome |
|---|
What every box and line stands for
| Element | Type | Stands for | State |
|---|
The names describe jobs the network has to do somewhere. They are not anatomical labels, and no real region, tract or published model is reproduced.
Challenge - how many causes fit?
A fictional person cannot name pictures, cannot repeat spoken words and cannot say what you are describing. They point to the right picture every time you name one.
What this demonstrates
Cutting a pathway between two intact regions produces the same task failures as damaging one of them, which is why a deficit localises a disruption rather than a function. The same profile can arise several ways, and networks usually degrade before they stop. Localisation and network accounts are not rivals: a region still does something, and what it does depends on what it is connected to.
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.