The universals in models of cognition are typically abstract universals.

The theorist has taken a number of different things and defined something common between them.

It could be different words – “horse”, “bowl”, “spoon” ... – noun is common between them.

It could be speech sounds – their ability to change the meaning of a word is common between them: “bat” is different from “pat”, so /b/ and /p/ are phonemes.

It could be situations (everyday tasks, psychology experiments, problems resulting from a stroke) that all seem to involve attention.

It could be things that eyes do – moving, searching, fixating, taking in only part of the visual world – letting us define an eye.

Such entities end up in models, labelled “noun level”, “phoneme level”, “eye” or “attentional processor”.

But they have only the sense and the meaning that we gave them at the time.