Stimulus and cognitive factors in cortical entrainment to speech

Abstract

Understanding speech is a difficult computational problem yet the human brain does it with ease. Entrainment of oscillatory neural activity to acoustic features of speech is an example of dynamic coupling between cortical activity and sensory inputs. The phenomenon may be a bottom-up, sensory-driven neurophysiological mechanism that supports speech processing. However, cognitive top-down factors such as linguistic knowledge and attentional focus affect speech perception, especially in challenging real-world environments. It is unclear how these top-down influences affect cortical entrainment to speech. We used electroencephalography to measure cortical entrainment to speech under conditions of acoustic and cognitive interference. By manipulating the bottom-up, sensory features in the acoustic scene we found evidence of top-down influences of attentional selection and linguistic processing on speech-entrained activity.