Why is 'Red Cross' different from 'Yellow cross'? A neuropsychological study of noun-adjective agreement with Italian compounds

This study investigates the performance of two Italian non-fluent aphasic
patients on noun-adjective agreement in compounds and in noun phrases. A
completion, a reading, and a repetition task were administered. Results
show that both patients were able to correctly inflect adjectives within
compounds, but not in noun phrases. Moreover, they were sensitive to
constituent order (noun-adjective vs. adjective-noun) within noun phrases,
but less so within compounds. These results suggest differential
processing for compounds as compared to noun phrases: while the latter
require standard morphosyntactic operations that are often impaired in
aphasic patients, the former can be accessed as whole words at the lexical
level.