Ca. Seger et al., Neural activity differs between explicit and implicit learning of artificial grammar strings: An fMRI study, PSYCHOBIOLO, 28(3), 2000, pp. 283-292
Functional magnetic resonance imaging was used to investigate the neural ar
eas underlying retrieval of implicit and explicit knowledge about letter st
rings. Participants studied strings formed according to an artificial gramm
ar, then performed implicit-learning-based judgments (judging the grammatic
al status of the string) or explicit-learning-based judgments (recognition)
on novel grammatical strings. In comparison with a baseline task, recognit
ion and grammatical judgments led to different patterns of neural activatio
n: Recognition activated the right frontal cortex, whereas grammatical judg
ment activated the left frontal cortex. Recognition led to higher activity
in the precuneus and medial occipital cortex, whereas grammatical judgments
led to suppression of activity in the precuneus and activation in the late
ral occipital cortex. When the surface structure of the strings was changed
, grammatical judgments led to bilateral frontal activity and bilateral but
left-lateralized activity in the occipital and parietal lobes. These resul
ts provide further evidence for a dissociation between the neural bases of
implicit and explicit learning.