Caltech internal speech in human supramarginal gyrus, 2024
Device
No device entry covers this hardware yet. The spec card below lists what the source says.
Lab or organization
Caltech internal speech in human supramarginal gyrus, 2024
A study of whether single neurons in the supramarginal gyrus (SMG) can support an internal speech brain-machine interface. Two participants with tetraplegia performed internal and vocalized speech of eight words, six real words and two pseudowords, while activity was recorded from SMG and primary somatosensory cortex (S1). First author Sarah K. Wandelt; Richard A. Andersen is the last author. Published in Nature Human Behaviour, May 2024.
Participants and hardware
- Participant 1: one 96-electrode multielectrode array in SMG and two 96-electrode arrays in S1.
- Participant 2: one 64-electrode array in SMG and two 64-electrode arrays in S1.
- The array manufacturer and model are not stated in the portions of the paper read for this sheet, so the sheet does not link a device entry.
- Author affiliations in the Europe PMC record of the paper include the California Institute of Technology (Division of Biology and Biological Engineering and the T&C Chen Brain-Machine Interface Center), the Keck School of Medicine of USC and Rancho Los Amigos National Rehabilitation Center.
Results as stated
| Measure | Value |
|---|---|
| Online internal speech BMI | Eight-word vocabulary, closed loop, 79% (participant 1) and 23% (participant 2) average classification accuracy with 16 to 32 training trials |
| Training | Decoder trained on 1.5 s of neural data per repetition, eight repetitions per word, on three separate session days |
| Internal vs vocalized | The discussion reports stronger representation for vocalized (74%) than internal speech (55%) in participant 1, and 24% internal vs 21% vocalized in participant 2 |
Limits
Two participants who were speech-abled, with different array sizes and very different results. The authors note that precise comparison of implant locations is difficult because of anatomical differences between the participants.
Primary sources
- Wandelt SK et al., Representation of internal speech by single neurons in human supramarginal gyrus, Nature Human Behaviour (2024), DOI 10.1038/s41562-024-01867-y.