Figure 1

Example of an oscillatory episode from middle cortical layers. Upper trace reflects a time series from a single photodetector within the array (extracellular microelectrode recordings follow a nearly identical pattern). Below this trace are sequences of optical frames from the different qualitative regimes (each row has 15 ms interframe interval from images collected at 1 kHz, imaging field 5 mm diameter). Spectral colormap proportional to voltage dye absorbance.Reuse & Permissions

Figure 2

Dynamics from a 7 sec oscillatory episode in Fig. 1. At the left side are shown the eigenvalues corresponding to the first 6 spatial eigenmodes ${\mathit{\nu }}_i$ based upon the photodetector amplitudes. Below the amplitude eigenmodes are shown the corresponding spatial frequency eigenmodes. These 3 sets of eigenmodes correspond to seconds 1, 4, and 7 from the episode. The column of trajectory plots from each of the 7 sec shows the relationship between the first three temporal modes ${\mathit{u}}_i$. Note the simplification of dynamics during seconds 4–6. On the right side are global amplitude and spatial frequency eigenmodes calculated from all 7000 images collected. Gray scale proportional to scaled eigenmode amplitudes.Reuse & Permissions

Figure 3

Data from second 4 from Fig. 2 during a rotational spiral. Top panel shows a single spatial image of raw data, while bottom rows show inner product of spatial image on eigenmodes 1, 2, and 3. A movie showing the temporal sequence of these projections is archived in 10.Reuse & Permissions

Figure 4

(a) Energy fraction plotted for partial sums of modes for example from Figs. 1, 2, 3. (b) Effective instantaneous dimension $d(t{)}_{\mathrm{eff}}$ shown for each resampled data set below and as mean and standard deviation above for amplitude, and for spatial frequency in (c). (d) Box and whisker plot for spatial frequency data shown in (c). Each box bounds the 25% and 75% percentiles, and outliers greater than 1.5 times the interquartile range are shown as $+$ signs.Reuse & Permissions