Syntactic Priming in Anterograde Amnesia: Evidence for Implicit Learning Victor S. Ferreira, Kathryn Bock, Michael P. Wilson, & Neal J. Cohen Syntactic priming, an effect whereby speakers tend to repeat the syntactic structures of sentences they have recently experienced, has been used to probe how syntax is represented and formulated. One explanation for syntactic priming and its persistence over time is that it is due to implicit learning -- the tuning of the cognitive mechanisms that create sentence structure (Bock & Griffin, 2000; Chang et al., 2000; Ferreira, 2003). We tested this explanation by determining whether people who have brain damage that causes anterograde amnesia exhibit syntactic persistence. Anterograde amnesics show explicit memory for events or actions at near-chance levels, whereas they show implicit memory for events or actions at near-normal levels. If syntactic persistence is attributable to implicit learning, then strikingly, anterograde amnesics should repeat the syntactic structures of sentences they can’t explicitly remember. We assessed syntactic persistence and recognition memory in four anterograde amnesics and four matched controls. Participants heard and repeated dative (double-objects or prepositional datives) and transitive (active or passive) prime sentences, then zero, one, six, or ten intervening neutral sentences, and then they described dative- and transitive-eliciting target pictures. Recognition memory for prime sentences was assessed after targets were described. Syntactic persistence occurred at normal levels for both the amnesics and the controls, with priming effects of 6.4% and 9% respectively. In contrast, explicit recognition memory for the primes was impaired for the amnesics relative to the controls, with a d’ of 0.79 compared to 1.57. Lag did not reduce priming, and it affected recognition memory only in controls. The preservation of syntactic priming and its persistence over lags in amnesic patients support an implicit learning account of syntactic priming.