Effect of visual input on syllable parsing in a computational model of a neural microcircuit for speech processing
Objective. Seeing a person talking can help us understand them, particularly in a noisy environment.
However, how the brain integrates the visual information with the auditory signal to enhance speech
comprehension remains poorly understood. Approach. Here we address this question in a computational
model of a cortical microcircuit for speech processing. The model consists of an excitatory and an
inhibitory neural population that together create oscillations in the theta frequency range. When
stimulated with speech, the theta rhythm becomes entrained to the onsets of syllables, such that the
onsets can be inferred from the network activity. We investigate how well the obtained syllable
parsing performs when different types of visual stimuli are added. In particular, we consider
currents related to the rate of syllables as well as currents related to the mouth-opening area of
the talking faces. Main results. We find that currents that target the excitatory n...