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Part of the measured effect may come from the subject simply hearing the pulse.","posed_since":"2008","precise":"Identify the mechanism by which focused ultrasound at $0.2\\ \\text{to}\\ 1.5\\ \\mathrm{MHz}$, spatial-peak pulse-average intensity below about $10^8\\ \\mathrm{erg}/(\\mathrm{s}\\ \\mathrm{cm}^{2})$ and mechanical index below 1, modulates neuronal firing. Candidates: radiation force and membrane strain, intramembrane cavitation, mechanosensitive ion channel activation, local heating of order $0.1\\ \\mathrm{K}$, and indirect auditory activation. An answer is a mechanism predicting the sign and magnitude of the effect versus frequency, pulse length and duty cycle.","problem_ref":null,"references":"","settled_by":"Experiments with auditory confound removed, varying frequency and pulse parameters independently, with simultaneous measurement of displacement, temperature and neural response.","status_note":"Auditory confounding demonstrated in rodents in 2018 forced reinterpretation of earlier results; no consensus mechanism as of 2025.","title":"How focused ultrasound changes neural activity","topic_ref":"8f240ebd4ecd5f8e303bb3f92d02a60c846c51e2ff4c97cf08dac7930e62b3b4"},"content_withheld":"false","files":[],"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"72838bb0075f9ed93fbb7e246fff6c4cd303702b700d2e7cd552e4afbebe1e7f","schema":"pubphys.attested/1"},"id_token":null,"id_token_withheld":"false","envelope":{"attested_hash":"5b146673ea729f0257b02717a42b99a07ec239c91d11f216a5840af5a09126ef","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"VPjP3Q9egNZCFb58JNwwBgim3wYnetgQ_Hc5Qs0NCdwJvJv1InJw5HGX6pVVauPtmZmXlR7lcafrIFd8yJVnCA"},"schema":"pubphys.envelope/1"},"ots":{"attested":["AE9wZW5UaW1lc3RhbXBzAABQcm9vZgC_ieLohOiSlAEIWxRmc-pynwJXsCcXpCuZoH7COckdEfIWpYQK9aCRJu_wIFsmK5mKGiQV4SZG66-yLRRSLi2kf-Syi5Hpc9cT0eWpCPAgy6fCiDZW4MWCCGQXGgc8wnl4JAGzpsgFeXDMUmtPg_4I8CB67-aIRbM2fAxlIYgZAdg_pBlIDhq72DXUjamKc_dnngjxINbL0sXbhBaWaySC4LbvP2B4DBSDcS-4IVr6YE-8TCbtCPEg7OAbElGdCur0S_pqWU-IAC_lgdFywsOB9Mh8_gsO0ZwI8CDFkncYPaRj7AJppFaxX963BJFn6vfBnW-IA5zVcjJfewjxIPKV6XkIVxB6zTNwShcXvtclGhIqSpEaTf5Jioh6nDXPCPEgeXNVzcuD027sru55Y1PcT2z1CuWU2W4A3vqh452xOX0I8SCuet_E6kln8_ZRXavjld8BdUsVBp253AP3BX1K8IYKnwjwIK9SXvHBwgJE5CknXtp2lOqKcbHlJ-ncP9sNjnTHUJsmCPEgytIBB3x7TFDT-XqOV-9vpqw1NKoAu0dhtsCbAMql2L0I8CCtNZgmApuKULvPC9nsMCaM05arV-F3o5FTlnJCnRvdMgjwIBGYo5Vxy-d7U5zKv5vp3Ii7hJPH_BDLCzA13c47p9q7CP_wCHbghVgOFMuNCPAQPZK2lHbTMqcCYUotzOQcmQjwIJ7ruRIs6HnufKxCpmLUgeUl0aUu0ov4_3PqcppS-bddCPEgI530vHzdwz_3o9jYQ3WablSaV64Wfn7Pmby5WLyI-A0I8QRqwKw78AhITF7Tr3a1xACD3-MNLvkMjiwraHR0cHM6Ly9ib2IuYnRjLmNhbGVuZGFyLm9wZW50aW1lc3RhbXBzLm9yZ_AIfrBm5kAMH2cI8BAGKsbR52Yj2ZyRBj8fybyrCPEg15Kg4Ne2LGSKxM-WnEce5gVwiluZijYEWJ8P_lNnKQ4I8QRqwKw68AhHyujKJ6ONvACD3-MNLvkMji4taHR0cHM6Ly9hbGljZS5idGMuY2FsZW5kYXIub3BlbnRpbWVzdGFtcHMub3Jn"],"envelope":["AE9wZW5UaW1lc3RhbXBzAABQcm9vZgC_ieLohOiSlAEIkxDIb1NHKYABvZvs_lKGxG0PK1dRyIh-xXK8MjXJx2rxIJMHU72RIzWiaOicKH_fkOyu1_f0CgqIhidzqEdWWBoPCPEg9CQOP1y9UHrTn0h4LB20bwYw6qm4vYKAla5ihWFMF4cI8SAV2EFc4wFMAGmnbEkaDN76wdiYX2lXS8J-kLvlTbzL7QjwIHfSQYqESSSv-uHQyE1DljuciHRKxHOVRBjmGjbu8NtQCPAgZwt4Fc35re53DNB2gOCAh6KbrneUdp3rE9-3feiEUgsI8SD9mIHe18venKtdnvaos8JZe4kGyurougLNUDaZqjqb4QjxID4GM9LaCJsrZhWbEPtHBfDrOPGQi4CH8Bu_7M-4ow1RCPAgyYYKAjmHpniaTNWfQfwaMNMI3Vm3FjqZ7JUny3t_J48I8SAzYkfrMCtnlPZF7RCs0vhySIZDq30HHv5Q-Y2E93F_lgjwIIhzmnVeFxVHRiBmi7SsQd_gIBRvsrzzZf-fzyEkp8wnCPAgy6DmLQtIuWm-zrDRmaSy95vcFWsjvWyppQO7wIWrfC4I8SAQuuTPkAGyvS_wKMy9BtKvnki2puESdY2vXem8hT1uIQjwIBGYo5Vxy-d7U5zKv5vp3Ii7hJPH_BDLCzA13c47p9q7CP_wCHbghVgOFMuNCPAQPZK2lHbTMqcCYUotzOQcmQjwIJ7ruRIs6HnufKxCpmLUgeUl0aUu0ov4_3PqcppS-bddCPEgI530vHzdwz_3o9jYQ3WablSaV64Wfn7Pmby5WLyI-A0I8QRqwKw78AhITF7Tr3a1xACD3-MNLvkMjiwraHR0cHM6Ly9ib2IuYnRjLmNhbGVuZGFyLm9wZW50aW1lc3RhbXBzLm9yZ_AIfrBm5kAMH2cI8BAGKsbR52Yj2ZyRBj8fybyrCPEg15Kg4Ne2LGSKxM-WnEce5gVwiluZijYEWJ8P_lNnKQ4I8QRqwKw68AhHyujKJ6ONvACD3-MNLvkMji4taHR0cHM6Ly9hbGljZS5idGMuY2FsZW5kYXIub3BlbnRpbWVzdGFtcHMub3Jn"]},"log":{"leaf_index":"1687","tree_size":"2123","proof":["0708c014592fff018155b53adcd66030798eaefed1ea641321477b4bd6ecece8","82bb15a2ebb996cb62b571855632a380b2e1d61cc880ea99f84ca1a5219a37fc","696f52915cab1a511c4b22c079b7542d58af0a659a10dcc383129dc4b115b0dc","a2d3c297643a79dd0fb179786c46462cafa77e3963e86e8ab890d7359cc907a1","caf3aaf7abacffafee13c59454b0b372967486c11b7db4c6692ad4d07c1ecfe9","6b2467aa4edd542218825348a906bda11b49c0d24dd6b86cdea0d312a60fbd07","7bab5cdbf43016d7b2eecb74cc666c93395111858e7ca7229801aedbba4d59ca","f543c359bec9c0ceb251b6f6155b4dd99c4d9e5b57b3a3d45ac1d4386bdb309f","a8cef064ef9c15524538954d820d60e39424932bbb86df562c6b87106df2eda9","35f1d0a5e69da98f9992a5251e4e3df1933c2f26543c7a40b2681ecfa194443a","2b97406e15e4d451a5450b3b53b677749fe0fa759579146dbfa1544c1e61a0ed","addcf2e0ff7974e4aa99af5e30d409f90d9f4311a4d85f5baf3e125eeb45b4c1"],"checkpoint":"pubphys.com/log/v1\n2123\npXVcluz7BF4vgChQs6lShuU0386gCH0RxrC1sxyE3rI=\n\n— pubphys.com/log/v1 JFPwIOLzsUD22XoTVyTfk/FMVj/u3f3DxZk4V/Ws10KVSS+8WQSwhunQ//EAhyS9Td5CyM0E++85GMezmKd8240j9Q8=\n","promise":null},"orcid_key_evidence":[],"attesting":null}