The broad sensitivity of the N400 to both lower and higher level factors that impact meaning processing has spawned a number of accounts that position the N400 at the junction where these processes intersect – namely, at the level of semantic access itself (Kutas & Federmeier 2000; see also Lau et al 2009; van Berkum 2009). However, even this “middle ground” approach cannot explain the full range of N400 data if the assumptions of the traditional processing model are maintained. For example, on the assumption that a word must be recognized before its meaning can be accessed, N400 effects for non-lexically represented stimuli remain inexplicable. Similarly, on the assumption that processing is wholly or largely feed-forward, it becomes difficult to reconcile the immediate and often dominant influences of more global aspects of context on initial semantic access.
