Fig. 2: Results of a proof-of-principle experiment performed with 6 fluorescent beads.

From (a) to (d) we have: (a) the ensemble temporal activity (fiber photometry), (b) the superimposed pattern image of 6 fluorescent bead fingerprints when simultaneously excited (imaged detected via sCMOS camera) (see “Methods” and Fig. S1); (c) the short MMF located at a distance of 60 ± 10 µm from the fluorescent beads; (d) a CMOS Basler camera with the ground truth image of the sample (see Fig. S1 for setup scheme details). e The ground truth (GT) fingerprint patterns obtained from each bead when they were individually excited. f The fingerprint patterns obtained via NMF demixing are to be compared with the GT patterns in (e). g The individual temporal activity traces of the sources obtained with NMF (blue) and their corresponding GT traces (gray). The NMF trace (#6) was not recovered well by NMF since bead #6 was localized very close to the fiber core edge, therefore yielding low signal/contrast of its pattern (see GT scattering fingerprint of bead #6 in (e)). h The GT-NMF time trace correlations. The average diagonal value of the first 5 beads was <δ_g,n > = δ_avg = 85.4% with \({\sigma }_{\delta }\) = 3.6%. To better evaluate the off-diagonal elements (time trace cross-talk), we subtract them from their corresponding GT-GT coefficients. Then, we averaged the absolute values of these differences and we obtained the mean absolute error of \({\zeta }_{{avg}}=\) 7.06% with a standard deviation of\(\,{\sigma }_{\zeta }=\) 7.29% for the first 5 beads (see Supplementary Note 2). i The GT-GT temporal trace correlation table. Importantly, the GT-GT correlation coefficients show that although each GT trace was unique over time (singular profile), GTs from different sources were not fully uncorrelated. For example, GT traces of beads #3 and #4 were fairly correlated (γ_3,4 = γ_4,3 = 31.2%, in (i)) and had a very clear spatial overlap (see GT and NMF scattering fingerprints #3 and #4 in (e) and (f)).