Analysis of Slow (Theta) Oscillations as a Potential Temporal Reference Frame for Information Coding in Sensory Cortices
Figure 4
Example and population data for visual cortex data.
A) Data from an example neuron showing the spike raster (left) and the average responses for the three codes (right). The spike raster displays the responses to multiple repeats of the video stimulus during ten selected epochs (concatenated for display purposes). Spikes are color coded with the phase of the theta (2–6 Hz) band LFP at the time of spike. The average responses illustrate the trial-averaged responses for each code. Colors indicate the phase bins, gray-scales indicate the time bins. B) Decoding performance across neurons (n = 37, mean and s.e.m.) for the three codes (N = 8 bins, T = 160 ms window, 2–6 Hz LFP). C) Difference between the decoding performance in time- and phase-partitioned codes and the spike count for each neuron. Neurons are sorted according to the difference for the time-partitioned code (red). Parameters as in B). D) Histogram across neurons of the % gain in decoding performance in the dual time- and phase-partitioned code over the better (for each neuron) of the two individual codes. Parameters as in B). E) Population averaged decoding performance for different lengths of the stimulus epoch window T (N = 8 bins) and for different numbers of bins (T = 160 ms). F) Ratio of the information in the phase-partitioned code to the information in the spike count when using different frequency bands (4 Hz width) to derive the oscillation phase. Abscissa values indicate center frequencies for each band.