FT_SPIKEDENSITY
Note that this reference documentation is identical to the help that is displayed in MATLAB when you type “help ft_spikedensity”.
FT_SPIKEDENSITY computes the spike density function of the spike trains by convolving the data with a window. Use as [sdf] = ft_spike_density(cfg, data) [sdf, sdfdata] = ft_spike_density(cfg, data) If you specify one output argument, only the average and variance of spike density function across trials will be computed and individual trials are not kept. See cfg.winfunc below for more information on the smoothing kernel to use. Inputs: DATA should be organised in a RAW structure with binary spike representations obtained from FT_APPENDSPIKE or FT_CHECKDATA, or a SPIKE structure. Configurations: cfg.timwin = [begin end], time of the smoothing kernel (default = [-0.05 0.05]) If cfg.winfunc = @alphawin, cfg.timwin(1) will be set to 0. Hence, it is possible to use asymmetric kernels. cfg.outputunit = 'rate' (default) or 'spikecount'. This determines the physical unit of our spikedensityfunction, either in firing rate or in spikecount. cfg.winfunc = (a) string or function handle, type of window to convolve with (def = 'gauss'). - 'gauss' (default) - 'alphawin', given by win = x*exp(-x/timeconstant) - For standard window functions in the signal processing toolbox see WINDOW. (b) vector of length nSamples, used directly as window cfg.winfuncopt = options that go with cfg.winfunc For cfg.winfunc = 'alpha': the timeconstant in seconds (default = 0.005s) For cfg.winfunc = 'gauss': the standard deviation in seconds (default = 1/4 of window duration in seconds) For cfg.winfunc = 'wname' with 'wname' any standard window function see window opts in that function and add as cell array If cfg.winfunctopt = [], default opts are taken. cfg.latency = [begin end] in seconds, 'maxperiod' (default), 'minperiod', 'prestim'(t>=0), or 'poststim' (t>=0). cfg.vartriallen = 'yes' (default) or 'no'. 'yes' - accept variable trial lengths and use all available trials and the samples in every trial. Missing values will be ignored in the computation of the average and the variance. 'no' - only select those trials that fully cover the window as specified by cfg.latency. cfg.spikechannel = cell-array ,see FT_CHANNELSELECTION for details cfg.trials = numeric or logical selection of trials (default = 'all') cfg.keeptrials = 'yes' or 'no' (default). If 'yes', we store the trials in a matrix in the output SDF as well cfg.fsample = additional user input that can be used when input is a SPIKE structure, in that case a continuous representation is created using cfg.fsample (default = 1000) The SDF output is a data structure similar to the TIMELOCK structure from FT_TIMELOCKANALYSIS. For subsequent processing you can use for example FT_TIMELOCKSTATISTICS Compute statistics on SDF FT_SPIKE_PLOT_RASTER Plot together with the raster plots FT_SINGLEPLOTER and FT_MULTIPLOTER Plot spike-density alone The SDFDATA output is a data structure similar to DATA type structure from FT_PREPROCESSING. For subsequent processing you can use for example FT_TIMELOCKANALYSIS Compute time-locked average and variance FT_FREQANALYSIS Compute frequency and time-ferquency spectrum.