[ { "id": "authors:h3jmk-tvs77", "collection": "authors", "collection_id": "h3jmk-tvs77", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230323-759541000.3", "type": "monograph", "title": "Compositional coding of individual finger movements in human posterior parietal cortex and motor cortex enables ten-finger decoding", "author": [ { "family_name": "Guan", "given_name": "Charles", "orcid": "0000-0002-8040-8844", "clpid": "Guan-Charles" }, { "family_name": "Aflalo", "given_name": "Tyson", "orcid": "0000-0002-0101-2455", "clpid": "Aflalo-Tyson" }, { "family_name": "Kadlec", "given_name": "Kelly", "orcid": "0000-0002-8765-7253", "clpid": "Kadlec-Kelly" }, { "family_name": "G\u00e1mez de Leon", "given_name": "Jorge", "orcid": "0000-0002-9481-4915", "clpid": "G\u00e1mez-de-Leon-Jorge" }, { "family_name": "Rosario", "given_name": "Emily R.", "orcid": "0000-0002-1540-197X", "clpid": "Rosario-Emily-R" }, { "family_name": "Bari", "given_name": "Ausaf", "orcid": "0000-0002-5279-5023", "clpid": "Bari-Ausaf-A" }, { "family_name": "Pouratian", "given_name": "Nader", "orcid": "0000-0002-0426-3241", "clpid": "Pouratian-Nader" }, { "family_name": "Andersen", "given_name": "Richard A.", "orcid": "0000-0002-7947-0472", "clpid": "Andersen-R-A" } ], "abstract": "Objective. Enable neural control of individual prosthetic fingers for participants with upper-limb paralysis. \n\nApproach. Two tetraplegic participants were each implanted with a 96-channel array in the left posterior parietal cortex (PPC). One of the participants was additionally implanted with a 96-channel array near the hand knob of the left motor cortex (MC). Across tens of sessions, we recorded neural activity while the participants attempted to move individual fingers of the right hand. Offline, we classified finger movements from neural firing rates using linear discriminant analysis (LDA) with cross-validation. The participants then used the neural classifier online to control individual fingers of a brain-machine interface (BMI). Finally, we characterized the neural representational geometry during individual finger movements of both hands. \n\nMain Results. The two participants achieved 86% and 92% online accuracy during BMI control of the contralateral fingers (chance = 17%). Offline, a linear decoder achieved ten-finger decoding accuracies of 70% and 66% using respective PPC recordings and 75% using MC recordings (chance = 10%). A compositional code linked corresponding finger movements of the contralateral and ipsilateral hands. \n\nSignificance. This is the first study to decode both contralateral and ipsilateral finger movements from PPC. Online BMI control of contralateral fingers exceeded that of previous finger BMIs. PPC and MC signals can be used to control individual prosthetic fingers, which may contribute to a hand restoration strategy for people with tetraplegia.", "doi": "10.1101/2022.12.07.22283227", "publication_date": "2022-12-09" }, { "id": "authors:mwd3n-6mp66", "collection": "authors", "collection_id": "mwd3n-6mp66", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230322-367733000.28", "type": "monograph", "title": "Cognition through internal models: Mirror neurons as one manifestation of a broader mechanism", "author": [ { "family_name": "Aflalo", "given_name": "Tyson", "orcid": "0000-0002-0101-2455", "clpid": "Aflalo-Tyson" }, { "family_name": "Chivukula", "given_name": "Srinivas", "orcid": "0000-0002-3570-162X", "clpid": "Chivukula-Srinivas" }, { "family_name": "Zhang", "given_name": "Carey", "orcid": "0000-0001-9867-4510", "clpid": "Zhang-Carey-Y" }, { "family_name": "Rosario", "given_name": "Emily R.", "orcid": "0000-0002-1540-197X", "clpid": "Rosario-Emily-R" }, { "family_name": "Pouratian", "given_name": "Nader", "orcid": "0000-0002-0426-3241", "clpid": "Pouratian-Nader" }, { "family_name": "Andersen", "given_name": "Richard A.", "orcid": "0000-0002-7947-0472", "clpid": "Andersen-R-A" } ], "abstract": "Cognition relies on transforming sensory inputs into a more generalizable understanding. Mirror neurons are proposed to underlie this process, yet they fail to explain many key features of human thinking and learning. Here we hypothesize that mirror-like responses are one limited view into a more general framework by which internal models of the world are built and used. We recorded populations of single neurons in the human posterior parietal cortex as a participant felt or observed diverse tactile stimuli. We found that mirror-like responses were fragile and embedded within a richer population response that encoded generalizable and compositional features of the stimuli. We speculate that populations of neurons support versatile understanding, not through mirroring, but instead by encoding representational building blocks of cognition.One-Sentence SummarySimilar neural responses during observed and experienced sensations are mediated by shared compositional building blocks, not mirror neurons.", "doi": "10.1101/2022.09.06.506071", "publication_date": "2022-09-08" }, { "id": "authors:vp3gv-zad89", "collection": "authors", "collection_id": "vp3gv-zad89", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211013-152456288", "type": "monograph", "title": "Preserved motor representations after paralysis", "author": [ { "family_name": "Guan", "given_name": "Charles", "clpid": "Guan-Charles" }, { "family_name": "Aflalo", "given_name": "Tyson", "orcid": "0000-0002-0101-2455", "clpid": "Aflalo-Tyson" }, { "family_name": "Zhang", "given_name": "Carey Y.", "orcid": "0000-0001-9867-4510", "clpid": "Zhang-Carey-Y" }, { "family_name": "Rosario", "given_name": "Emily R.", "clpid": "Rosario-Emily-R" }, { "family_name": "Pouratian", "given_name": "Nader", "orcid": "0000-0002-0426-3241", "clpid": "Pouratian-Nader" }, { "family_name": "Andersen", "given_name": "Richard A.", "orcid": "0000-0002-7947-0472", "clpid": "Andersen-R-A" } ], "abstract": "Neural plasticity allows us to learn skills and incorporate new experiences. What happens when our lived experiences fundamentally change, such as after a severe injury? To address this question, we analyzed intracortical population activity in a tetraplegic adult as she controlled a virtual hand through a brain-computer interface (BCI). By attempting to move her fingers, she could accurately drive the corresponding virtual fingers. Neural activity during finger movements exhibited robust representational structure and dynamics that matched the representational structure, previously identified in able-bodied individuals. The finger representational structure was consistent during extended use, even though the structure contributed to BCI decoding errors. Our results suggest that motor representations are remarkably stable, even after complete paralysis. BCIs re-engage these preserved representations to restore lost motor functions.", "doi": "10.1101/2021.10.07.463105", "publication_date": "2021-10-09" }, { "id": "authors:twz8h-fx526", "collection": "authors", "collection_id": "twz8h-fx526", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200422-071051130", "type": "monograph", "title": "Neural correlates of cognitive motor signals in primary somatosensory cortex", "author": [ { "family_name": "Jaffari", "given_name": "Matiar", "clpid": "Jaffari-M" }, { "family_name": "Aflalo", "given_name": "Tyson", "clpid": "Aflalo-Tyson" }, { "family_name": "Chivukula", "given_name": "Srinivas", "clpid": "Chivukula-S" }, { "family_name": "Kellis", "given_name": "Spencer S.", "orcid": "0000-0002-5158-1058", "clpid": "Kellis-Spencer-S" }, { "family_name": "Armenta Salas", "given_name": "Michelle", "orcid": "0000-0002-0634-2891", "clpid": "Armenta-Salas-M" }, { "family_name": "Norman", "given_name": "Sumner L.", "clpid": "Norman-S-L" }, { "family_name": "Pejsa", "given_name": "Kelsie", "clpid": "Pejsa-K" }, { "family_name": "Liu", "given_name": "Charles Y.", "clpid": "Liu-Charles-Y" }, { "family_name": "Andersen", "given_name": "Richard A.", "orcid": "0000-0002-7947-0472", "clpid": "Andersen-R-A" } ], "abstract": "Classical systems neuroscience positions primary sensory areas as early feed-forward processing stations for refining incoming sensory information. This view may oversimplify their role given extensive bi-directional connectivity with multimodal cortical and subcortical regions. Here we show that single units in human primary somatosensory cortex encode imagined reaches centered on imagined limb positions in a cognitive motor task. This result suggests a broader role of primary somatosensory cortex in cortical function than previously demonstrated.", "doi": "10.1101/2020.04.20.041269", "publication_date": "2020-04-21" } ]