4 Confound Elimination

A naive ensemble in which path roughness, Cs  , and SE  all co-vary together could produce a spuriously high correlation. We eliminate this confound by design:

We additionally report the partial Spearman correlation ρ(Cs,SE  | roughness)  , where roughness is defined as the frequency-weighted amplitude sum:

     K∑max       (          )
R  =     (2k − 1) |Ak|+ |Bk |.
     k=1

This quantity is an explicit proxy for path roughness that is independent of the spectral complexity definition. If the full correlation ρ(Cs,SE )  collapses to near zero after conditioning on R  , the correlation would be a confound artifact. If it survives, the conjecture Cs ∝ SE  is supported beyond the common roughness dependence.