Joint PSTH

Joint PSTH matrix shows the correlations of the two neurons around the reference events.

Parameters

Parameter	Description
XMin	Time axis minimum in seconds.
XMax	Time axis maximum in seconds
Bin	Bin size in seconds.
Reference	Specifies a reference neuron or event.
Bottom Neuron	The neuron of event shown along the horizontal axis (the vertical axis shows a neuron selected for analysis).
Diag	The width (in seconds) of the area in the scatter matrix around its main diagonal used to calculate the main diagonal histogram.
Normalization	Scatter matrix normalization.
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.
Int. filter type	Specifies if the analysis will use a single or multiple interval filters.
Interval filter	Specifies the interval filter(s) that will be used to preselect data before analysis. See also Data Selection Options.
Create filter on-the-fly	Specifies if a temporary interval filter needs to be created (and used to preselect data).
Create filter around	Specifies an event that will be used to create a temporary filter.
Start offset	Offset (in seconds, relative to the event specified in Create filter around parameter) for the start of interval for the temporary filter.
End offset	Offset (in seconds, relative to the event specified in Create filter around parameter) for the end of interval for the temporary filter.
Fix overlaps	An option to automatically merge the overlapping intervals in the temporary filter.
Smooth	Option to smooth the histograms (not the scatter matrix) after the calculation. See Post-Processing Options for details.
Smooth Filter Width	The width of the smooth filter. See Post-Processing Options for details.
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.
Matrix Scale	An option on how to draw the scatter matrix (color or black and white).
Font size (% matrix)	Font size in percent of scatter matrix height.

Summary of Numerical Results

The following information is available in the Summary of Numerical Results

Column	Description
Variable	Variable name.
YMin	Y axis minimum (added for compatibility with other analyses, always 0).
YMax	Y axis maximum (added for compatibility with other analyses, always 1).
Spikes	The number of spikes of the neuron shown on the vertical axis used in calculation.
Filter Length	The length of all the intervals of the interval filter (if a filter was used) or the length or the recording session (in seconds)
Mean Freq.	Mean firing rate (Spikes/Filter_Length).
Hist. norm.	Normalization factor. Histogram bin counts are divided by this value.
Color scale minimum	Scatter matrix color scale minimum.
Color scale maximum	Scatter matrix color scale maximum.

Algorithm

The main Joint PSTH matrix shows the correlations of the bin counts of two neurons around the reference events. Histograms to the left of and below the matrix are standard perievent histograms for two specified neurons. The first histogram to the right of the matrix shows the correlations of near-coincident spikes around the reference events. The far-right histogram shows correlations of firings of two neurons around reference events.

Reference

See the following paper for details on Joint PSTH analysis:

M. H. J. Aertsen, G. L. Gerstein, M. K. Habib and G. Palm. Dynamics of Neuronal Firing Correlation: Modulation of “Effective Connectivity” J. Neurophysiol., Vol. 61, pp. 900-917, 1989.