Questions prompted by cable burn-in sound imrovement discussions

Learned hearing:  
I recently read an article concluding that, over time, the brain adds detail to the raw information detected through the ears.  This neural detail may be good (more nuance, more detail, better sound) or quite bad (tinnitus “noise” from damaged hearing receptors).  

Physical changes in cables (speaker or interconnects):  
About twelve years ago I recall seeing some “burn in” data collected on cables and conductors alone (excluding components or speakers) that was rather equivocal as to what, if anything, was actually changing during the burn-in.  
Note: This is not meant to argue about burn-in of components or speakers.  A complex variety of physical changes, which may occur over time of use in tubes, resistors, capacitors, crossovers and especially in sound transducers, would be far more difficult to document.

Q1:  Is anyone aware of any “sounds better” studies isolating new conductors alone, wherein measurable changes in conductance data support a true “burn in” improvement over time?

Q2:  More generally, assuming some amount of learned hearing occurs during the burn-in, what portion of sound improvement is neural vs. attributable to data supporting physical changes in conductors?

Q3:  Finally, what is the likely burn-in priority attributable to conductors versus speakers and components?