アイテム詳細

要旨

Syntactic priming, the phenomenon in which participants adopt the linguistic behaviour of their partner, is widely used in psycholinguistics to investigate syntactic operations. Although the phenomenon of syntactic priming is well documented, the memory system that supports the retention of this syntactic information long enough to influence future utterances, is not as widely investigated. We aim to shed light on this issue by assessing 17 patients with Korsakoff’s amnesia on an active-passive syntactic priming task and compare their performance to controls matched in age, education and premorbid intelligence. Patients with Korsakoff's amnesia display deficits in all subdomains of declarative memory, yet their implicit learning remains intact, making them an ideal patient group to use in this study. We used the traffic-light design for the syntactic priming task: the actors in the prime trial photos were colour-coded and the participants were instructed to name the 'green' actor before the 'red' actor in the picture. This way we can control which syntactic structure the participant uses to describe the photo. For target trials, the photos were grey-scale so there was no bias towards one structure over another. This set-up allows us to ensure the primes are properly encoded. In addition to the priming task, we also measured declarative memory, implicit learning ability, and verbal IQ from all participants. Memory tests supported the claim that our 17 patients did have a severely impaired declarative memory system, yet a functional implicit/procedural one. The control group showed no deficit in any of the control measurements. In line with the hypothesis that syntactic priming relies on procedural memory, the patient group showed strong priming tendencies (12.6% passive structure repetition). Unexpectedly, our healthy control group did not show a priming tendency. In order to verify the absence of a syntactic priming effect in the healthy controls, we ran an independent group of 54 participants with the exact same paradigm. The results replicated the earlier findings such that there was no priming effect compared to baseline. This lack of priming ability in the healthy older population could be due to cognitive interference between declarative and non-declarative memory systems, which increases as we get older (mean age of the control group is 62 years).