The role of nondeclarative memory in the skill for language: Evidence from syntactic priming in patients with amnesia

- The memory system underlying syntactic processing is still unclear.
- Amnesia patients show robust syntactic priming effects; matched controls do not.
- Aging may explain why healthy (older) controls don't show priming effects.
- Syntactic processing most likely supported by nondeclarative memory.

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 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 syndrome display deficits in all subdomains of declarative memory, yet their nondeclarative memory remains intact, making them an ideal patient group to determine which memory system supports syntactic priming. In line with the hypothesis that syntactic priming relies on nondeclarative memory, the patient group shows strong priming tendencies (12.6% passive structure repetition). Our healthy control group did not show a priming tendency, presumably due to cognitive interference between declarative and nondeclarative memory. We discuss the results in relation to amnesia, aging, and compensatory mechanisms.