This repo contains a function (cleanUtahLFP.m) and associated function dependencies that can be applied in order to identify bad channels and time periods in high-density local field potential recordings from a multielectrode array such as a Utah array.
1. Each channel’s voltage time series is normalized by mapping voltage to zscore.
2. For each channel, the time points at which the voltage exceeds some user-defined absolute z-score (Zhigh, default = 6),
are marked as bad time points for that channel.
3. For each of the bad time points identified, the time point is marked as a bad time point in general if a certain number of
other channels (nChanForBadTime, default = 10) exceed a lower z-score threshold (Zlow, default = 4) within a certain time period
(dtForBadTime, default = 1 second).
4. These general bad time points were then extended to general bad time periods by marking any time point within a user-defined
period (dtReject, default = 1 second) as a bad time point.
5. Time periods bad for individual channels are identified. These are defined similar to the general bad time periods except
using the time points for which the nChanForBadTime criteria was not met.
6. Bad channels are identified as having a large number of non-general time periods (nBadtoRejectChan, default = 10).
Download this repo and add it to your MATLAB path.
See 'demo.m' for example implementation.
For visualization of results, users must download this tight subplot library