Bats run the 3D mapping problem at 1 cm resolution.
CA1 place fields in flying Rousettus aegyptiacus are volumetric, isotropic,and remap across sessions
coexisting with head-direction cells encoding azimuth, pitch and roll.
No surface-bound species exhibits this geometry.
Yartsev & Ulanovsky, Science 340:367 (2013)
Finkelstein et al., Nature 517:159 (2015)
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The field is moving from ground to air.
Wave 1 โ fly: perception circuits.
Wave 2 โ mouse: cortical columns.
Wave 3 โ bat: active sensing +volumetric cognition.
If the next decade of connectomics is airborne, the next decade of AI is too.
Flies gave us the full-brain connectome (FlyWire, 2024).
Mice gave us the cubic millimeter (MICrONS, 2025).
Bats add what both lack: a brain evolved for real-time active sensing in 3D.
The problems bats solve daily are the problems AI still fails โ echo scene analysis at 0.5 ms, volumetric navigation, delay-based ranging.
Modern connectomics has mapped the fly It has mapped the mouse.
It has not yet mapped a brain that flies โ and actively senses its world.
Bats are the missing case: echolocation demands sub-millisecond auditory computation; flight demands volumetric cognitive maps.
That is the ACx project.
0x357fe078c2d95986143de84190f273a742041e1e
Connectomics has spent two decades on the ground.
The fly: mapped. The mouse: mapped. The next model system flies โ and actively senses its world.
Bats are the new frontier for AI and brain science: active sensing,
sub-millisecond timing, volumetric maps.
We are building that atlas now.
Horseshoe bats listen through an acoustic fovea.
Cochlear filters tuned to the CF2 harmonic reach Q โ 400 โ they resolve a few hertz at 61 kHz, among the sharpest in vertebrate hearing.
Flying bats compensate for Doppler shift within ยฑ2 Hz, keeping echoes inside that filter at full speed.
Schnitzler, Nature 219:79 (1968)
Neuweiler, Naturwissenschaften 77:345 (1990)
Modern connectomics has mapped the fly It has mapped the mouse.
It has not yet mapped a brain that flies โ and actively senses its world.
Bats are the missing case: echolocation demands sub-millisecond auditory computation; flight demands volumetric cognitive maps.
That is the ACx project.
0x357fe078c2d95986143de84190f273a742041e1e
Modern connectomics has mapped the fly It has mapped the mouse.
It has not yet mapped a brain that flies โ and actively senses its world.
Bats are the missing case: echolocation demands sub-millisecond auditory computation; flight demands volumetric cognitive maps.
That is the ACx project.
0x357fe078c2d95986143de84190f273a742041e1e
Delay-tuned neurons convert time into space.
In Pteronotus parnellii, FMโFM combination-sensitive cells respond
only when the echo follows the call at a preferred delay โ 0.4 to 18 ms.
Arrayed across the auditory cortex, they tile an axis of distance: a neural ruler.
Suga & O'Neill, Science 203:69 (1979)
Suga, J Exp Biol 146:277 (1984)
#Neuroethology #Echolocation
Modern connectomics has mapped the fly It has mapped the mouse.
It has not yet mapped a brain that flies โ and actively senses its world.
Bats are the missing case: echolocation demands sub-millisecond auditory computation; flight demands volumetric cognitive maps.
That is the ACx project.
#Connectomics #Neuroscience