Synchrony_BrainMaster_Revised.pdf

Disclaimer: The content below was generated with the assistance of AI and then reviewed and edited by BrainMaster Technologies, Inc. It is provided for educational and informational purposes only and does not constitute medical advice.

Overview of EEG Synchrony Training #

Synchrony training is a neurofeedback approach focused on increasing or decreasing the degree to which EEG signals from two or more channels operate in a coordinated manner. This BrainMaster technical guide outlines practical methods for implementing synchrony training using BrainMaster EEG systems, emphasizing hardware configurations, protocol options, and clinical use scenarios.

Synchrony training requires a minimum of two EEG channels and cannot be performed using a single-channel or bipolar hookup. Instead, channels are recorded in a monopolar configuration with neutral references (e.g., ears or linked ears).

Core Concepts of Synchrony Training #

Required Hardware and Channel Configurations #

• Minimum of two EEG channels is required

• Supports 2-channel and 4-channel synchrony training

• Compatible with BrainMaster systems including 2E, 2EW, Atlantis modules, and Atlantis 4×4

• Supports advanced configurations using the Open Focus Synchrony Trainer (OFST)

Synchrony training may be conducted:

• Within a single individual

• Between two individuals

• Simultaneously within and between two individuals (using 4-channel setups)

EEG Frequency Bands Used in Synchrony Training #

Synchrony protocols can be applied to most EEG frequency bands, with specific clinical considerations:

• Alpha (8–12 Hz): Most commonly trained; associated with relaxation and mental clarity

• Gamma (35–45 Hz): May be trained; associated with higher cognitive processing

• Theta and Delta: Not recommended due to associations with drowsiness and distraction

• Beta: Less commonly trained due to localization and associations with tension

Alpha and gamma synchrony may also be trained together as an emerging technique.

Synchrony Metrics and Training Methods #

Built-In Synchrony Metrics #

BrainMaster systems support multiple synchrony metrics, including:

• Coherence (pure and training coherence)

• Similarity

• Spectral Correlation Coefficient (SCC)

• Comodulation

• Phase relationships

These metrics reward increasing similarity between EEG channels using auditory or visual feedback.

Sum-Channel Mode for Synchrony Training #

What Is Sum-Channel Mode? #

Sum-channel mode is a key method described in this guide. When enabled:

• Channel 1 becomes the sum of channels (1 + 2)

• Channel 2 becomes the difference between channels (1 − 2)

This approach:

• Uptrains the summed signal

• Downtrains the difference signal

• Rewards synchronization in phase, frequency, and amplitude

Sum-channel mode can be applied in both 2-channel and 4-channel configurations.

One-Person Synchrony Training #

Two-Channel Training #

• Common electrode pairs: C3/C4, P3/P4, O1/O2

• Frontal placements (F3/F4) are generally not recommended

• Uses standard BrainMaster synchrony or “peak” protocols

• Thresholds are manually adjusted (autothresholding not recommended)

Four-Channel Training #

Four-channel training allows both:

• Interhemispheric synchrony

• Intrahemispheric synchrony

Two sum-channel modes are available:

• Split Mode: Separates left and right hemisphere synchrony

• Combine Mode: Maximizes overall synchrony across all channels

Two-Person Synchrony Training #

Two-Channel Interpersonal Training #

• Each person contributes one EEG channel

• Focuses on synchrony between individuals, not within

• Can be enhanced using coherence or comodulation metrics

• Grounding is shared via jumper leads or physical contact

Four-Channel Interpersonal Training #

• Each participant uses two EEG channels

• Enables training of:

  • Individual brain synchrony

  • Combined interpersonal synchrony

• Implemented using the Atlantis 4×4 EEG system

• Internal grounding within the device eliminates the need for shared ground leads

Open Focus Synchrony Trainer (OFST) #

The OFST is an external hardware device that:

• Combines up to five EEG channels into a single analog output

• Can be used for one-person or two-person synchrony training

• Produces a summed EEG signal that is then trained using standard BrainMaster protocols (e.g., alpha “relax” protocols)

OFST enables combined synchrony training across multiple cortical sites and participants using simplified EEG inputs.