Autocorrelograms Versus Time

This analysis shows the dynamics of the autocorrelograms over time. It calculates multiple autocorrelograms using a “sliding window” in time. Each autocorrelogram is shown as a vertical stripe with colors representing the bin counts. Horizontal axis represents the position of the sliding window in time.

Parameters

Parameter	Description
XMin AutoCorr	Autocorrelogram time axis minimum in seconds.
XMax AutoCorr	Autocorrelogram time axis maximum in seconds.
Bin AutoCorr	Autocorrelogram bin size in seconds.
Normalization	Histogram units (Counts/Bin, Probability or Spikes/Second). See Algorithm below.
Start	Start of the first sliding window in seconds.
Duration	Duration of the sliding window in seconds.
Shift	How much sliding window is shifted each time.
Number of shifts	The number of sliding windows to be used.
Matrix Scale	Specifies color scale for drawing matrix.
X Axis (Sliding window axis alignment)	Allows to specify what values are shown in the sliding window axis. There are two options: Start of Window and Center of Window. Suppose your data has the strongest correlation at 50 seconds. This means that the window that has 50 seconds as its center will show the highest autocorrelation values. If the window width is 20 seconds, it will be the window [40,60]. If you are using ‘Start of window’ option, you will see the peak at 40 instead of 50 seconds. However, with ‘Center of window’ option, the peak will be at 50 seconds.
Smooth	Option to smooth the histogram after the calculation. See Post-Processing Options for details.
Smooth Filter Width	The width of the smooth filter. See Post-Processing Options for details.
Select Data	If Select Data is From Time Range, only the data from the specified (by Select Data From and Select Data To parameters) time range will be used in analysis. See also Data Selection Options.
Select Data From	Start of the time range in seconds.
Select Data To	End of the time range in seconds.
Interval filter	Specifies the interval filter that will be used to preselect data before analysis. See also Data Selection Options.
Send to Matlab	An option to send the matrix of numerical results to Matlab. See also Matlab Options.
Matrix Name	Specifies the name of the results matrix in Matlab workspace.
Matlab command	Specifies a Matlab command that is executed after the numerical results are sent to Matlab.
Send to Excel	An option to send numerical results or summary of numerical results to Excel. See also Excel Options.
Sheet Name	The name of the worksheet in Excel where to copy the numerical results.
TopLeft	Specifies the Excel cell where the results are copied. Should be in the form CR where C is Excel column name, R is the row number. For example, A1 is the top-left cell in the worksheet.

Summary of Numerical Results

The following information is available in the Summary of Numerical Results

Column	Description
Variable	Variable name.
YMin	Y axis minimum.
YMax	Y axis maximum.
Color Scale Min	Color scale minimum.
Color Scale Max	Color scale maximum.
Spikes	Number of spikes used

Algorithm

NeuroExplorer calculates here multiple autocorrelograms (see Autocorrelograms for more information on how each autocorrelogram is calculated).

Each autocorrelogram is calculated for a different interval (window) in time:

``[window_start[i], window_end[i]], i = 1,...,Number_of_Shifts``

That is, for each autocorrelogram only the timestamps that are within the window are used.

The following rules are used to calculate the windows:

window_start[1] = Start

window_end[1] = Start + Duration

window_start[2] = Start + Shift

window_end[2] = Start + Shift + Duration

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