Neuroethology in the service of neurophonetics

Single-neuron recording methods, as commonly used in neuroethology studies, provide the needed spatial and temporal resolution capacities to generate explicit hypotheses addressing the ‘how’ of language processing. The goal of this article is to describe two well documented neural processing mechanisms that can provide insights into (1) the auditory decoding of speech sounds, and (2) disambiguation of context-induced variability in stop place perception. The neural unit underlying speech sound processing is the combination-sensitive neuron, and the neural entity best suited to resolve context-induced variability in the speech signal is the neural column. The ‘absorption’ of stimulus variability via signal-specific columnar encoding is contrasted to exemplar-based treatments of stimulus variability in neural systems.

► Neuroethology studies provide ideal spatial/temporal resolutions to study speech.
► Auditory combination-neurons can provide the neural mechanism underlying the acoustic decoding of speech.
► Specialized neural columnar architectures can absorb lawful variability and thus normalize input signals.
► Locus equations illustrate a lawful orderliness in contrasting stop place categories.
► Hypothesized neural columns encoding F2onsets ∼ F2offsets can resolve the non-invariance dilemma in stop place perception.