Authors:

Penolazzi, B., HAUK, O. & PULVERMULLER, F.

Reference:

Year of publication:

2005

CBU number:

6171

Abstract:

Psycholinguistic behavioural studies have accumulated evidence for early lexical access and context integration: within the first 200 milliseconds after the presentation of critical stimulus information. This finding is at odds with most of psychophysiological data, which have considered the late N400 evoked component to reflect aspects of word semantic processing and context integration It has been suggested that the absence of early neurophysiological reflections of psycholinguistic processes in many previous studies might be due to large stimulus variance on relevant linguistic parameters, which affect linguistic processing to different levels: pre-lexical (or perceptual), lexical and post-lexical (or contextual). Here, we investigated, for the first time, the contribution of linguistic factors which take their places in each of these levels: the length of a word, the frequency with which it occurs in a language, and the probability with which it occurs in a given semantic sentence context. We found that word frequency and word in-context probability have their neurophysiological reflection remarkably early, around 100 ms after written word onset. However, interactions of word length with both the frequency and probability factors demonstrated that word length has a strong modulating influence on the early neurophysiological effects, which therefore disappear if words of different lengths are being mixed. These results have important theoretical as well as methodological implications for neuropsycholinguistic studies.