Study on coding working memory event via independent components energies of multichannel local field potentials / 国际生物医学工程杂志

ABSTRACT

Objective To investigate how the independent components(ICs)energies of multichannel local field potentials(LFPs) code event base on the analysis of ICA of the cortical LFPs of rats. Methods Taking the event point as the zero point, 15-channel LFPs between the span of ±500ms recorded from the prefrontal cortex of rats were decomposed into 15 ICs. The energies of the ICs were computed in a 50-ms window. By sliding the window with step of 25 ms, a dynamic distribution mapping of the 15 ICs' energies was established. ICs with distinctly increased energies during the span of ±200 ms, which indicating that these ICs energies coded event,were selected as the targets. The corresponding channels of these ICs were determined consequently via the inverse transformation of ICA. Results Considering each trail of the repetitious analysis for the same segment of data, the spatial localization of the dominate function region(s) turned out to be relatively stable in spite of the uncertainty of the number and sequence of the target IC(s) due to the ambiguities of the decomposition of ICA.Meanwhile, the analysis results of a series of data segments showed satisfactory correspondence between data segments and dominate function regions. Conclusion The ICs' energies of multichannel LFPs are able to code events in working memories; It is valid for ICA to identify the coding patterns of multichannel LFPs to events; ICA is capable to localize the dominate function regions of event coding with satisfactory robustness.