Full Idea
Computational psychologists object to the 'ecological' approach to perception (with its externalist, direct realist picture), because it leaves us entirely in the dark as to how our senses 'pick up' information about the environment.
Gist of Idea
Computationalists object that the 'ecological' approach can't tell us how we get the information
Source
E.J. Lowe (Introduction to the Philosophy of Mind [2000], Ch. 6)
Book Reference
Lowe,E.J.: 'Introduction to the Philosophy of Mind' [CUP 2000], p.154
A Reaction
I find myself siding with the computationalists, but then I have always favoured the representational view of perception among philosophers. Lowe comments that both approaches neglect actual experience. We construct models, e.g. of London.