Role of thalamus in human conscious perception revealed by low-intensity focused ultrasound neuromodulation
Hyunwoo Jang, Panagiotis Fotiadis, George A. Mashour, Anthony G. Hudetz, Zirui Huang
Nature Communications 2025 · 10.1038/s41467-025-66832-3
Abstract
The neural basis of consciousness remains incompletely understood. While cortical mechanisms of conscious perception have been extensively investigated in humans, the role of subcortical structures, including the thalamus, remains less explored. Here, we elucidate the causal contributions of different thalamic regions to conscious perception using transcranial low-intensity focused ultrasound (LIFU) neuromodulation. We hypothesize that modulating distinct thalamic regions alters perceptual outcomes derived from Signal Detection Theory. We apply LIFU to healthy human anterior (transmodal-dominant) and posterior (unimodal-dominant) thalamic regions, further subdivided into ventral and dorsal regions, during a near-threshold visual perception task. We show that high duty cycle modulation of the ventroanterior (VA) part of thalamus enhances object recognition sensitivity. Sensitivity enhancement magnitude correlates with the core-matrix cell compositions of the stimulated thalamic region. Connectivity analysis of a large-scale functional magnetic resonance imaging dataset confirms strong transmodal connectivity of VA thalamus with frontoparietal and default-mode networks. We also demonstrate target-invariant effects of high duty cycle LIFU disrupting object categorization accuracy. These findings provide causal insight into the cytoarchitectural and functional organization of the thalamus that shape human visual experience, especially the role of matrix-cell-rich, transmodal-dominant VA thalamus.
Abstract via europepmc.
Exposures
Exposure 1: LIFU to four left thalamic regions (VA, VP, DA, DP) at 70% or 5% duty cycle
Target: thalamus — “four regions of the left thalamus, including the VA, VP, DA, and DP thalamus”
Device: BrainSonix · BrainSonix Corporations · BXPulsar 1002 ✓
| Waveform | pulsed | |
|---|---|---|
| Fundamental frequency (kHz) | 650 | ✓✓✓ |
| Pulse duration (ms) | 70, 5swept | ✓✓✓⚑ |
| Pulse repetition frequency (Hz) | 10 | ✓✓✓ |
| Duty cycle (%) | 70, 5swept | ✓✓✓⚑ |
| Sonication duration (s) | 30 | ✓✓✓ |
| Free-field pressure (kPa) | 197, 710swept | ✓✓✓ |
|---|---|---|
| Free-field Isppa (W/cm²) | not reported | |
| Free-field Ispta (W/cm²) | 1.02 | ✓✓✓ |
| In-situ estimate | deratingsingle value | |
| In-situ pressure (kPa) | 165, 619swept | ✓✓✓⚑ |
| In-situ Isppa (W/cm²) | 1.03, 14.4swept | ✓✓✓ |
| In-situ Ispta (W/cm²) | 0.72 | ✓✓✓ |
Pulse repetition frequency 10 Hz (100 ms period), duty cycle 70% or 5% (pulse width 70 or 5 ms), 30 s sonication alternating with 30 s off, 12 sonications per block; four LIFU-ON blocks, one per thalamic region in pseudorandomised order, one duty cycle per participant.
Flags from extraction
exposures[0].timing.pulse_duration_ms— Text lists 'pulse duration: 100 ms', which matches the 10 Hz period, and separately 'pulse width of 70 and 5 ms'; the pulse width values were recorded as pulse duration (burst rule resolved from the paper's own pulse-width statement).exposures[0].in_situ.pressure_kpa— Derated (FDA method, 0.3 dB/cm/MHz) values recorded as in_situ; the paper also gives simulated in-brain pressure of 72.6 and 258.2 kPa (70% and 5% DC) from BabelBrain, not recorded here. Non-derated incident values placed in unspecified_domain because the paper does not name the medium.n_subjects— 60 enrolled and randomised; 54 analysed (27 per group). Enrolled number recorded.exposures[0].target.terms— Four thalamic subregions (VA, VP, DA, DP) are listed as one exposure; the authors' VA is not the classical VA nucleus.exposures[0].timing.duty_cycle_pct— Two duty cycles given to two separate groups; list order [70,5] matches pressure and intensity lists.auditory_control— Transducer noise awareness was surveyed and used as a covariate; no masking or sham.