Effects of acoustic distortion and semantic context on lexical access

This study explored the role of attentional and perceptual factors in lexical access by examining the effects of acoustic distortion on semantic priming of spoken words by a sentence context. The acoustic manipulations included low-pass filtering, which was intended to interfere with the sensory encoding of the acoustic signal by reducing intelligibility, and time compression, which was intended to disrupt central language processing by reducing processing time. These distortions were applied to the sentence context to explore how the contribution of contextual information to lexical access is affected by acoustic degradation. Low-pass filtering significantly reduced semantic facilitation. In contrast, temporal compression significantly reduced semantic inhibition without affecting facilitation. These qualitative differences between two forms of acoustic distortion are discussed in terms of the activation, selection, and integration of lexical-semantic information in models of lexical access. Filtering may have its primary effect on a relatively early, automatic process (reflected in facilitation effects), while compression has its primary effect on a later, more demanding process (reflected in inhibition effects). Practical and theoretical implications for higher-level language processing in hearing-impaired and elderly populations are discussed.