CONTENTS:
Channel selection
Analysis types
Parameter button
Plot window
Channel
The name of the recorded data that is currently selected. A channel
contains a particular type of data, for example spike times or
continuous values. The type of channel determines the types of
analyses that can be applied to the channel. This Viewer currently
supports two channels (0 and 1), where channel 0 is the primary
analysis channel and channel 1 is used for cross-correlation analysis.
Analysis
The type of analysis (or plotting format) to be applied to the
selected channel. The choices may vary depending on the type of data
channel that has been selected. The following are common choices:
- Raster - for spike data, each spike is plotted as a
vertical line segment and the x-axis is Time. Often, time t=0 is
the reference point for the beginning of the trial.
- PSTH - Peri-stimulus time histogram. This represents
the mean instantaneous firing rate around some temporal reference
(usually t=0). A binsize is chosen, and the mean firing rate within
a bin is computed by averaging spikes within that bin across all
trial within each group.
- ISI - Inter-spike interval distributions for spike data.
- Tuning_Curve - A single value is associate with each
group and is plotted against one of the variable parameters along
the x-axis. For a spike channel, the y-value is usually the mean
firing rate averaged across time. For a continuous channel, the
y-value is typically the average of the data over time.
- Var_vs_Mean - Variance of spike count vs. mean spike count.
- Choice_Prob - Choice probability (CP). This analysis
computes the CP for a given spike channel with respect to a decision
variable. The decision variable is specified by the
parameter decision_var, it should take only values of 0 or 1,
and this variable parameter should have the Group by
button unchecked in the variable parameter panel. The CP
value will be printed, along with the number of trials for each
choice, at the top of the plot window, which shows the distributions
of spike counts for Choice 0 and Choice 1.
- Plot - For continous data, this is a simple plot of the
raw data values vs. time.
- CCG - Cross-correlation, and auto-correlation, for spike
data. Channel 0 is the time reference, thus a peak to the
right of zero indicates that Channel 1 follows Channel 0.
- SC_Corr - Spike count correlation, scatter plot and
Pearson's r-value. The plot_type option can be:
- scatter - Regular scatter plots, one for each group.
- zscore - Points from each group are transformed to
z-scores. An addition group, Overall is add that
contains the points from all other groups combined, and
has an overall r-value.
- Tuning_Corr - Tuning curve correlation,
for signal correlation estimation. This analysis computes
the correlation coefficient between two tuning curves. Only the
mean values are used. In the Param menu,
the plot_type option can be:
- tuning - Regular tuning curves
- scatter - Means from tuning curves are plotted against each
other in a scatter plot form
- Pop_Dynamic - Dynamic map of population activity. The
plot shows a map of the response (normalized to the largest value
in the display frame) for the given population in a time window. The time
window is set by the Dynamic time window controls (ti is the
index of the time segment, and dt is the length of the time
segment during which the response is computed). The time window is
relative to t0, which is set via the Param button.
The .nd file must include a set of channels having the format pname_0_0
... pname_M_N, where 'pname' is the population name and 'M'-1 and 'N'-1 are
the numbers of units in the x- and y-dimensions.
Param button
This button opens a dialog window that allows you to adjust parameters
that control the analysis and plotting of data. Each analysis type
may have a different set of parameters. The parameters t0
and tn are remembered across analyses; therefore, if they are
changed for one analysis, their new values will apply to other
analyses.
Plot Window
Within the plot window, the currently selected plot is shown in black
with any others shown in light gray. However, for raster plots, the
current rasters are shown in red, the others in black. The selection
box at the top of the plot window can be used to change the currently
selected plot. You can also click in the main plot panel and then use
the arrow keys to scroll through the plots. Pressing t in the plot
window will open a text window showing data for the current plot.