Dissociations between speech perception and phonological short-term memory deficits

Abstract

Some patients with phonological short-term memory deficits also show deficits in speech perception. This study investigated the possibility that these patients' short-term memory pattern derives from a general phonological processing deficit. We compared the short-term memory performance of patient EA, who has previously been shown to have a short-term memory deficit and a mild speech perception deficit, to that of other aphasic patients who show similar deficits in speech perception. Only EA showed the short-term memory pattern that has been identified as due to a phonological retention deficit. It is concluded that the retention of phonological information depends on capacities that are separate from those employed in speech perception. A model of speech perception and phonological storage is discussed that can account for mild impairments of speech perception co-existing with normal phonological short-term memory.