Real academic research on DJing exists, and it is recent and explicitly preliminary. A UK research council funded project has produced outputs on beatmatching using EEG, motion capture and audio analysis, alongside work on tracking two isochronous beat patterns simultaneously. A collaborator description indicates roughly 28 DJs were recorded beatmatching in a laboratory setting. These outputs are described in the record as preliminary analysis, not as established findings about task complexity or system counts.

A separate 2022 narrative review by Pombo argues that DJing draws on general brain-processing features with neurobiological roots and discusses evoked potentials and auditory spatial attention. It is a discussion article in a small journal, not an empirical study of DJs, and it does not establish a complexity ranking.

On the musician cognition sub-claim, the literature is real but mixed. Hansen, Wallentin and Vuust found expert musicians significantly outperformed non-musicians on digit span. An fMRI study by Pallesen and colleagues found musicians showed greater activation in frontal, parietal and subcortical attention and working memory networks than non-musicians. However, Gagnon and Nicoladis reported that musicians only rarely outperformed non-musicians across seven working memory tasks. So the direction of the finding is not uniform, and none of this work is about DJs specifically.

On timing precision, the sensorimotor synchronization literature places human timing sensitivity in the tens of milliseconds, not below one millisecond. Published psychophysical data indicate a detection threshold of roughly 2 percent for step changes relative to a 500 millisecond baseline interval, which is about 10 milliseconds. Repp's work found musicians show smaller thresholds than non-musicians, but still within that general order of magnitude. Reviews also note that phase correction ceases to function above roughly 8 to 10 Hz, another indication that this system operates well above the sub-millisecond scale.