NINFA

Small Matlab Framework for running Custom Neurofeedback Protocols on LSL Streams

Requirements

• Windows 10/11
• Matlab 2020a

Starting

1. Open this folder in Matlab
2. Open and start main.m in Matlab

Configuration

1. Select your device
2. [Optional] Adjust TYPE of LSL input stream
3. Click OPEN to connect with LSL input stream
4. Configure SETTINGS, ID and EPOCHS
5. Click START to run a session

DEVICE

• Select your device type and model from the available options.
• Add a device by creating a .json file for it in subfolder devices
  • Take a look at the existing nirs_nirx_nirsport2.json
  • The most important part is defining the LSL channels sent by the device

LSL STREAM

Setting	Description
TYPE	LSL type of input stream to open. This is device specific.
CHANNELS	Number of channels found in LSL stream
SAMPLE RATE	Measured Samplerate / Reported Samplerate by Device

Important

The measured samplerate should (almost) equal the reported samplerate.
Otherwise this turns from green to red and you're likely suffering
from packet loss (e.g. due to bad or overloaded wifi).

SETTINGS

Setting	Description
PROTOCOL	The Matlab file from folder protocols with algorithm executed on each window.
CHANNELS	Select LSL channels to use in the selected protocol
WINDOW SIZE (S)	Size of the sliding window in seconds. The window always contains last n seconds of samples.
SESSION LENGTH (S)	The session will automatically stop after this time.

ID

Setting	Description
STUDY	Name of Study
SUBJECT	Number of Subject
RUN	Number of Run

The session will be automatically saved in subfolder sessions with name STUDY-SUBJECT-RUN.mat

EPOCHS

An epoch is a configurable timespan within a session.

Setting	Description
START (S)	Start of Epoch (in seconds)
END (S)	End of Epoch (in seconds)
MARKER	Marker Value (1-99) of Epoch (also sent on LSL)
VISIBLE	Visibility of Bar in Feedback Window during Epoch
COLOR	Background Color in Feedback Window during Epoch

• Add epoch by clicking +
• Remove last or selected epoch(s) by clicking -
• Chose background color of selected epoch(s) by clicking COLOR

LSL Output

Trigger

• Sends triggers on LSL with stream type and name set to Trigger
• Sends trigger with value 100 on session start
• Sends trigger with value 101 on session end
• Sends trigger with custom value from column MARKER on each epoch start

Marker

• Sends markers on LSL with stream type and name set to Marker
• Sends markers with same samplerate as LSL input (one marker for each LSL input sample)
• Default value is 0 (if no active epoch)

Protocols

• A protocol calculates a feedback value from an input window
• To add a protocol put the Matlab file in subfolder protocols
• The Gauss.m example requires a NIRS device that sends at least one HbO channel with μmol/L unit
• The RecordOnly.m works with any device type and model and just records data

Drift and Execution Times

• DRIFT shows current offset in playback schedule (where we are vs. where we should be)
• It typically occurs if the average runtime of your protocol is larger than 1s/samplerate
• If your protocol requires more time then skip some windows and repeat the previous feedback for them (see example1.m)

Feedback Window

Shows a centered bar with feedback values <= 0.5 visualized in blue and values > 0.5 visualized in red.