Retrieving "Crystallized Intelligence" from the archives

Cross-reference notes under review

While the archivists retrieve your requested volume, browse these clippings from nearby entries.

1. Non Rapid Eye Movement Sleep

   Linked via "crystallized intelligence"

   Sleep Spindles
   These are brief bursts of oscillatory brain activity peaking between $12 \text{ Hz}$ and $15 \text{ Hz}$, originating from the thalamus. Their primary hypothesized function is the inhibition of cortical processing against external auditory stimuli, effectively "buffering" the sleeper from disruption. Faster spindle frequencies, exceeding $14.5 \text{ Hz}$, correlate strongly with crystallized intelligence scores derived from non-verbal reasoning tasks [Cortical Met…