HoldsUp

Huberman Lab · 2025-09-29 · Andrew Huberman (host), Poppy Crum

Enhance Your Learning Speed & Health Using Neuroscience Based Protocols | Dr. Poppy Crum

41 research-tied claims examined: 2 contradicted 2 overstated 2 context 33 supported 2 unverified

2 Needs context
0:12:47Poppy Crumneeds contexthigh

The modern standard musical pitch tuning for the note A is 440 Hz, whereas in the Baroque era the standard pitch for A was 415 Hz.

"So like that would be A = 440 Hz, right? But that's a standard that we use in modern time, and what A is has actually changed throughout our lives with aesthetic, with what people liked, with the tools we used to create music. In the Baroque era, A was 415 Hz" (said at 0:12:47)

Modern concert pitch is standardized at A4 = 440 Hz (established internationally by ISO 16). However, during the Baroque era (roughly 1600–1750), there was no single universal pitch standard; tuning varied considerably by region, instrument, and setting (such as Chorton vs. Kammerton, spanning approximately 392 Hz to over 465 Hz). A = 415 Hz (approximately one equal-tempered semitone below A = 440 Hz) is a modern convention widely adopted by historically informed performance ensembles and reproduction instrument builders to represent Baroque pitch, rather than an era-wide fixed historical standard.

2:08:15Poppy Crumneeds contextvery low

Barn owls raised with prism glasses that visually shift their field of view by 15 degrees develop a secondary auditory-visual map in the brain, with auditory neuron dendrites realigning to the shifted visual inputs.

"And then he would rear and raise these owls with prism glasses that effectively shifted their visual system by 15 degrees... And consequently, he saw the cells, the auditory neurons, he saw their dendrites realigned to the now 15-degree visually shifted cells. And it was this realization that they developed a secondary map that was now aligned with the 15-degree shift of the prism glasses" (said at 2:08:15)

The speaker accurately describes Eric Knudsen's landmark research showing that juvenile barn owls raised with prism glasses shift their auditory space map in the midbrain (inferior colliculus and optic tectum) to realign with the optically shifted visual field, forming a coexisting secondary learned circuit. However, the anatomical mechanism involves axonal sprouting and remodeling of projecting axons from the central nucleus of the inferior colliculus (ICC/ICCls) to the external nucleus (ICX) rather than the realignment of auditory neuron dendrites. Because the findings are based entirely on animal experimental neurobiology, the GRADE certainty is very low.

Unverified means no publication matching the claim was located; it does not prove the claim false. Spotted an error? See the corrections policy - disputes from the people quoted are prioritized.