Numerical Results for PeriEvent Rasters Are Available in Version 5

Many NeuroExplorer users asked me why perievent rasters analysis lists only perievent histograms in the numerical results table.

The reason was that listing all the timestamps for each line of the perievent raster can use a lot of RAM and can slow down the program. For example, for a spike train with 10,000 spikes, we may have 10,000 raster lines containing up to 10,000 spikes in each raster line. This adds to 100 million timestamps which would use 800 MB of RAM. Besides, the user can analyze dozens of neurons, so using so much RAM may not work, especially for a 32-bit application that cannot use more than 2 GB of RAM. The situation is somewhat better for a 64-bit program, but the program would still be too slow.

In NeuroExplorer Version 5, I came up with a solution — the program stores some of the results of the perievent raster analysis in memory and calculates all the timestamps for perievent rasters on-the-fly:


PeriEvent Rasters Numerical Results

What I found interesting was that the graphical representation of the perievent raster:


PeriEvent Raster

creates an impression that each line of the raster contains many data points while in reality each line contains only a few points as we can see from numerical results above.

Complete numerical results for PeriEvent Raster analysis and for all the other analyses that did not provide all the results in version 4 (Cumulative Activity Graphs, Instant Frequency, ISI versus Time, Poincare Maps and Synchrony versus Time) are available in NeuroExplorer 5.001 and later.

If you purchased NeuroExplorer Version 5 license, download the latest Version 5 installer.  Otherwise, download NeuroExplorer Version 5 Demo today!

 

What’s New in NeuroExplorer Version 5

Version 5 is a truly significant expansion of functionality over the previous version. Version 5 adds several new analyses (Hilbert transform, head direction analysis and others), multi-taper spectral calculations, statistical tests (t-tests, ANOVA) and immediate data preview. The new version is also faster and can handle multi-gigabyte data files.

Here is the list of the main improvements implemented in version 5 of NeuroExplorer.

When NeuroExplorer version 5 loads a data file, it shows a preview of all data channels:

v5DataPreview

NeuroExplorer version 5 provides vastly improved spectral analyses of spike trains and continuous channels:

  • Single-taper and multi-taper calculations of spectra
  • 6 windowing functions
  • 3 preprocessing options
  • Jackknife confidence
  • Ability to replicate Matlab spectral calculations
  • Up to 10 times faster calculation of spectral results

Several new analyses of continuous data (LFP) are available:

  • Perievent rasters for continuous

perirastercont1

  • Power spectra for continuous
  • Coherence for continuous
  • Single trial spectrum analysis
  • Single trial phase analysis using Hilbert transform
  • There is a new ‘Analyses of Continuous Data’ analysis group that lists all the analyses that can be
    used with continuous channels:

ContVarAnalyses

 

Digital filtering options for continuous data are expanded and now include both IIR and FIR filters.
FIR filters can be used when a band-pass filter with a narrow frequency range is required.

  • 3 new IIR filters
  • 3 new FIR filters
  • Power spectra for continuous
  • Coherence for continuous
  • Single trial spectrum analysis
  • Single trial phase analysis using Hilbert transform

There are also improvements in spike train analyses:

  • Multi-taper options in spike train spectral analyses
  • Firing rate versus head direction analysis

New statistical tests to compare results across conditions can be run directly in NeuroExplorer:

  • Implemented via integration with freely available R-project
  • ANOVA test across multiple conditions
  • T-test test across two conditions
  • Wilcoxon test test across two conditions

ttest3

New version is available as a 64-bit Windows executable. This removes previous memory limitations
(all the available RAM can now be utilized by the program). The new version is also faster: computationally demanding analyses are run in parallel using all CPU cores.

NeuroExplorer Version 5 supports new .nex5 data file format (currently in development) that is more flexible than .nex file format:

  • Allows to save files of more than 2 GB in size
  • Allows to save unlimited metadata for the whole file and for every file variable in JSON format

The new version has the ability to save and restore results:

  • Saves all numerical and graphical results in a series of linked files
  • A user can open results files without recalculation and access both graphical and numerical results
  • A user can recalculate analysis results with a single mouse click

National language support is also implemented in the new version:

  • NeuroExplorer Version 5 correctly displays folder and file names in any language supported by Windows
  • A user can use any language to name files and variables in files
  • A user can also use any language to enter comments in data files and scripts

languages

See also: Waveform analysis in NeuroExplorer, Working with Results Files, Dealing with Noise and Artifacts in Data Viewer, New Phase Analysis, Python Scripting in NeuroExplorer