Noise affects auditory and linguistic processing differently: an MEG study

We investigated the influence of noise on brain responses to spoken sentenc es in MEG. Sixteen subjects had to listen to acoustically presented sentenc es and judge their syntactic correctness. Sentences were either presented o n a silent background or with noise. Noise had differential effects on earl y auditory and syntactic processes. While noise affected early auditory pro cesses only in the right hemisphere, noise had a general effect on processe s. The evoked responses to syntactic violations compared with correct sente nces, namely an early left anterior negativity, were significantly suppress ed when noise was present. The noise suppression effect, however, was not l ateralized. NeuroReport 11:227-229 (C) 2000 Lippincott Williams & Wilkins.