Last week, Kumar Duraivel (6th year PhD candidate) presented Khanna, Muñoz, and Kim et al. ’s new paper on the neuronal mechanisms of speech production using state-of-the-art ultrahigh-density Neuropixel probes. This 🧵 explores our thoughts (🤍 & ❔) www.nature.com/articles/s41...
Neuropixels recordings from the language-dominant prefrontal cortex reveal a structured organization of planned words, an encoding cascade of phonetic representations by prefrontal neurons i...
Thank you to the authors at Mass General Hospital for your work, and we look forward to following its progress!
❔3️⃣: In figure 4a, neuronal activity exhibits a peculiar selectivity for morphemes during planning and production. Can authors explain the symmetric change in selectivity patterns during the transition?
❔2️⃣: The temporal ordering of speech elements during planning were compared against perception and were found to be unique. However, the participants underwent a passive speech perception task in this experimental study. If the participants had to perform...
❔1️⃣: The authors defined the planning epoch as 500 ms before word utterance onset (identified from voice onset time). However, motor articulation starts earlier than audible sound, which in turn could confound articulation with planning mechanisms...
🤍3️⃣: The use of state-space analysis of neuronal dynamics revealed a clear separation of speech planning elements transitioning to the speech utterance.
🤍2️⃣: The authors showed the temporal ordering of these features reflected coding of phonetic elements into syllabic segments. This coding is unique to speech planning/production mechanism and is distinct from speech perception mechanism.
🤍1️⃣: The study uncovered neuronal correlates of phonological coding and syllabification in caudal middle-frontal gyrus, by extracting the selectivity of phonetic, syllabic, and morphological components of upcoming speech.