Instantaneous Cross-Correlation Analysis of Neural Ensembles with High Temporal Resolution

One of the fundamental difficulties in neural assembly studies is the lack of an effective, high-resolution measure of the spatiotemporal structure in spike trains obtained from a single realization. This chapter proposes a systematic approach to estimate the cross-correlation (CC) of spike trains, over time and in only one realization. The solution lies in an alternate defi nition of cross-correlation which suggests that, rather than time averaging as is current practice, ensemble averaging should be used. This observation suggests a natural instantaneous CC (ICC) estimator as required for high temporal resolution and real-time ensemble analysis and decoding. Results are shown in simulated data sets and neural activity of rat motor cortical neurons during a behavioral task.