Getting started with Blackrock data
The specifications of the Blackrock file formats can be found on the company’s website. Blackrock files come in 2 flavors. One file type has the extension
.nev, and contains information about extracellularly recorded spiking activity. The other file type has as extension
.nsX, with X any number between 1 and 9. These files contain continuously sampled data, e.g., local field potentials.
To read Blackrock data, you will need the NPMK toolbox. The latest version is available from https://github.com/BlackrockMicrosystems/NPMK.
Set the path
To get started, you should add the FieldTrip main directory to your path, and execute the ft_defaults function, which sets the defaults and configures up the minimal required path settings. See also this frequently asked question.
addpath <path_to_fieldtrip> ft_defaults
Reading spike data
To read spike data from
.nev files, you would do the following
spike = ft_read_spike('yourfile.nev')
This returns the spike timestamps and waveforms in a format according to ft_datatype_spike.
Reading continuous LFP data
To read continuous LFP data from
.nsX files, you can use the following high-level FieldTrip code
cfg = ; cfg.dataset = 'yourfile.nsX' % you can specify additional preprocessing options, such as filters data = ft_preprocessing(cfg)
This returns the LFP data in a format according to ft_datatype_raw.
You can also use the low-level reading functions like this
hdr = ft_read_header ('yourfile.nsX') dat = ft_read_data ('yourfile.nsX') evt = ft_read_event ('yourfile.nev') % note that the nsX file does not contain trigger events, but the corresponding nev file does
See this FAQ for more details about the high-level and low-level functions.