This is a 7-column tab-separated list containing:

1. ID for word/picture group;
2. Word presented;
3. Picture displayed at top-left;
4. Picture displayed at top-right;
5. Picture displayed at bottom-left;
6. Picture displayed at bottom-right;
7. Difficulty level.

It is important to note that the difficulty levels were obtained from a test given in the USA, for which participants were able to listen to each word as well as being displayed visually upon the screen.

This resource can be downloaded or viewed using the link: picvoc_test.txt

If you have wget available (typically on linux systems), then you can also obtain a copy using the command

 wget  -nd  biobank.ndph.ox.ac.uk/ukb/ukb/docs/picvoc_test.txt