isi

Make plots of the inter-spike interval (ISI) distribution, and compute statistics from the inter-spike intervals.

CV Coefficient of Variation of the ISI is defined as the mean standard deviation, SD, of the ISI distribution divided by the mean of the distribution.

CV2 Proposed by Holt et al. (1996, J Neurophysiol). This measure should be less sensitive than CV to slow changes in firing rate (slow on the time scale of the average ISIs). For two consecture ISIs, a and b,

          2 * |a-b|
    CV2 = ---------
             a+b

Thus, it is the difference divided by the mean of two consective intervals.

Options

• simple

• isi_integrate - integrate between isi_a and isi_b

• cv_trial

• cv2_trial - Compute one cv2 value for each trial, average together. Output file format:

    [infile_name]  [mean_CV2]  [SD]  [n]
  

• cv_skew_scatter

Parameters

• start - start time for binning (sampling units).
• period - duration of plot (sampling units).
• maxisi - [200] maximum ISI value to consider.
• min_interval_count -
• isi_a -
• isi_b -

Examples are given below.

Example

#  
#  Inter-spike interval
#
isi
group 0
simple

maxisi 200